Abstracts & Materials
Access the comprehensive collection of research abstracts and conference materials from SustainX 2026. Organized by thematic pillars, this repository showcases the innovative contributions of the global scholarly community at IIT Madras.
Total Abstracts
100
Presentation Slot Details
Please refer to the Programme Schedule for presentation time slots, session chairs, and venue information.
Machine Learning Framework for Forecasting N2O Emissions in Industrial Wastewater Treatment Systems
S. Hemalatha and S. R. Ambati · IIPE Visakhapatnam
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The rising contribution of nitrous oxide (N2O) emissions from industrial wastewater treatment systems (WWTS) has further heightened the demand for more sophisticated predictive and monitoring tools to account for such emissions in global greenhouse gas (GHG) inventories. In this study, the framework of a soft sensor is proposed to predict the N2O emission based on the operational and process data generated by the industry-wide model of the wastewater plant and the GHG plant. Machine learning (ML) soft sensors were designed based on process variables of dissolved oxygen, ammonium, nitrate, nitrite, airflow rate, influent COD, temperature and reactor loading conditions. The results show that the proposed soft sensors based on ML can effectively capture the nonlinear relationships between the operational disturbances and the N2O emissions with high predictive accuracy and better computational efficiency than the conventional soft sensors based on mechanistic information.
Physics-Informed Neural Networks for Turbulent Wake Reconstruction of a Marine Current Turbine
T. Vijaya Lakshmi, S. Rajendran and A. Samad · IIT Madras
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Characterizing the turbulent wake of marine current turbines is essential for optimizing array layouts, yet obtaining dense full-field velocity measurements remains prohibitively expensive. This study presents a physics-informed neural network (PINN) framework for reconstructing the three-dimensional unsteady turbulent wake of a marine current turbine from sparse velocity observations. The framework achieves R2 ≈ 0.89 and Pearson correlation r ≈ 0.94 for the streamwise velocity, accurately reconstructing the wake deficit and temporal dynamics from only 10% of available snapshots. These findings demonstrate that PINNs offer a viable path toward full-field turbulent wake characterization from sparse measurements.
Comparative Evaluation of RL-based Single & Dual Agent Architectures against DE-Tuned PI Benchmark Controllers on Activated Sludge WWTPs
S. Tenneti and S. R. Ambati · IIPE Visakhapatnam
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Aeration dominates the operational energy demand of municipal wastewater treatment plants, reportedly reaching 45–70% in activated-sludge systems. This study investigates whether deep reinforcement learning (RL) can identify and suppress inter-propagating disturbances on the Benchmark Simulation Model No. 2 (BSM2), through single- and dual-agent architectures benchmarked against a PI controller optimized via differential evolution. Among PPO, DDPG, TD3, SAC, and A3C, PPO delivered the most stable training and the lowest tracking error; in dual-agent deployment, PPO reduced mean-squared tracking error by ~26% on the DO loop and ~12% on the nitrate loop relative to the DE-tuned PI baseline.
TransChem: A Hybrid Transformer-Cheminformatics Framework for Predicting Li-Ion Conductivity in Polymer Electrolytes
V. Parambil, U. Tripathi, H. Goyal and R. Batra · IIT Madras
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Lithium-ion batteries have gained significant attention in applications ranging from portable electronics to electric vehicles and grid-scale energy storage. However, conventional liquid electrolytes pose safety risks and environmental concerns due to flammability and leakage. Solid polymer electrolytes (SPEs) offer a safer, more sustainable alternative with improved mechanical stability and recyclability. Over the past decade, machine learning (ML) approaches have accelerated the discovery of new SPE materials, reducing the experimental cost and waste associated with traditional trial-and-error methods. Among various ML models, transformer-based architectures such as TransPolymer have demonstrated superior performance over classical approaches by capturing complex contextual information embedded in polymer sequences. However, such deep learning models often operate as “black boxes,” limiting their interpretability and, consequently, their utility for advancing chemical understanding. In contrast, classical ML models based on cheminformatics-derived features offer greater interpretability but suffer from lower predictive accuracy and limited scalability across large chemical spaces. In this work, we introduce TransChem, a hybrid ML framework that integrates transformer architectures with cheminformatics-based descriptors to achieve state-of-the-art performance in predicting Li-ion conductivity of polymers. Our analysis demonstrates that incorporating cheminformatics features provides complementary, chemically meaningful information to the transformer-based model, enhancing both its predictive accuracy and interpretability. Furthermore, feature analysis on trained TransChem models identifies key chemical factors governing Li-ion conductivity in polymers, underscoring the interpretability of the framework. TransChem thus offers a promising hybrid approach for data-driven polymer design, with potential for extension to the broader field of molecular and materials informatics.
Cooperative Game-Theoretic Framework for Circular EV Energy Ecosystem Planning: A Case Study of Mangaluru Taluk, Dakshina Kannada, Karnataka, India
Amartaya R. Nair, Aditya V. Padwalkar and Anupam Sharma · Chanakya University
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The electrification of transportation stands out as a practical step toward creating circular energy systems, though real progress hinges on where and how charging stations are established. This paper presents a cooperative game theory approach for planning EV charging stations across Mangaluru Taluk, Dakshina Kannada district, Karnataka, India, involving four stakeholders: MESCOM (the electricity utility), charging station operators, municipal land authorities, and EV fleet aggregators. The Shapley value is applied to ensure fair distribution of benefits, and the framework treats EVs as potential Virtual Power Plants. When stakeholders cooperate, station placements improve, the grid becomes more robust, and per-user charging costs decline compared to uncoordinated deployment.
Techno-Economic Optimization of Solar-Driven Green Hydrogen Systems for Circular Energy Transition, Carbon Resource Valorization, and Industrial Decarbonization
V Durga Praveena and Seshagiri Rao Ambati, PhD · IIPE
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Green hydrogen (gH2), produced using renewable energy sources, is a vital component of the transition to industrial decarbonization due to its carbon-free generation and potential to replace fossil fuels in hard-to-abate sectors. This study presents a simulation-based techno-economic evaluation of an integrated solar photovoltaic (PV) and alkaline electrolyzer system for green hydrogen production, comparing direct coupling, MPPT-DC converter integration, and battery-assisted electrolysis configurations. The minimum Levelized Cost of Hydrogen (LCOH) achieved was Rs 376/kg (3.66 €/kg), demonstrating that strategically optimized renewable hydrogen systems can strengthen sustainable energy transitions while offsetting future carbon compliance costs.
Why India’s EV Battery Boom Is a Future Waste Crisis Waiting to Happen: A Multi-Stakeholder Analysis of Circularity Gaps
Aman Srivastava, Krishna Malakar and Rahul Muralidharan · IIT Madras
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India’s electric vehicle transition is predicated on a rapid shift to LFP (Lithium Iron Phosphate) chemistry (86% market share), yet the economic viability of LFP battery recycling remains critically underexamined within the policy architecture of the Battery Waste Management Rules, 2022. This study addresses the research gap between ambitious Extended Producer Responsibility (EPR) targets and the operational realities of domestic refining capacity. Employing a multi-stakeholder mixed-methods framework, we assessed circular design maturity, traceability readiness, and EPR compliance across OEMs (Original Equipment Manufacturers), battery producers, and formal recyclers. Results reveal a unanimous consensus (100% of stakeholders) that LFP recycling is presently unprofitable – a market failure wherein the dominant chemistry of the future constitutes a latent waste liability. Further findings expose a “closed-loop impossibility”: recyclers achieve 99.5% battery-grade material purity but lack domestic cell manufacturing offtakers, rendering the value chain linear (import–use–export). Additionally, while OEMs assert minimal leakage, recyclers report 60–90% feedstock sourcing from an informal sector disproportionately burdened by an 18% GST (Goods and Services Tax) rate on recycled scrap. We also identify a temporal misalignment wherein EPR collection targets are set for an 8-year horizon against a 15-year LFP lifespan. To reconcile policy intent with industrial viability, there is a need for a phased mandate for battery passports, chemistry-specific performance-based EPR targets, state-facilitated aggregation to formalize the informal sector, and targeted subsidies for LFP hydrometallurgical refining. We conclude that absent these structural interventions, India’s circular economy framework will remain a notional construct rather than a functional, closed-loop system.
Multi-Objective Life Cycle Optimization of Biomass-to-Value-Added Products Conversion Networks
Kaushik Kundu, Avan Kumar, Hariprasad Kodamana and Kamal K. Pant · IIT Delhi
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Biomass gasification is imperative to sustainable chemical production in the global transition to a circular bioeconomy, which demands optimizing multi-product distribution on an industrial scale. This work tackles the challenge of upscaling laboratory results to a 1000 kg/hr pilot-scale refinery using an integrated surrogate model-based multi-objective optimization. Results indicate a stable globally optimal syngas distribution ratio for methanol, hydrogen, ammonia, and power generation using coconut shell as feedstock, with life cycle assessment confirming that upcycling biochar into Carbon Black can achieve a 40% reduction in global warming potential.
Sustainable Recovery of Neodymium from E-Waste Using Citric Acid Leaching: Advancing Circularity in Critical Mineral Supply Chains
Thamilselvi J and Vaani N · VIT Vellore
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The accelerating demand for rare earth elements (REEs) has been driven by their critical role in low-carbon technologies, creating pressure on primary resources. This research focuses on the recovery of neodymium from e-waste using citric acid as a biodegradable and environmentally benign leaching agent, evaluating the influence of leaching time, temperature, and acid concentration on metal recovery efficiency. Maximum recovery was observed at higher acid concentration (1 M), demonstrating the potential of organic acid-based hydrometallurgical processes as a sustainable alternative to conventional mineral acid leaching.
A Scenario-Based Framework for District-Scale EV Battery End-of-Life Flows and Reverse Logistics Burden in India
JL Sriniketh, Suprava Mishra and Agnivesh Pani · IIT (BHU) Varanasi
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The rapid expansion of electric mobility in India is poised to generate substantial volumes of end-of-life (EOL) battery waste, placing growing pressure on reverse logistics networks. This study develops a district-scale, scenario-based forecasting framework coupling EV stock projection with reverse-logistics burden estimation, evaluating Base Case, High EV Penetration, OEM-led LFP Dominance, and Extended-Life Circular Economy scenarios. National EOL battery volumes rise sharply from ~14–15 GWh in 2030 to ~135–136 GWh by 2050, with the Extended-Life pathway materially deferring peak reverse-logistics burden in high-adoption districts.
Spatiotemporal Foresight of EV Battery End-of-Life Flows in India: District-Scale Hotspots for Critical Mineral Recovery
Suprava Mishra, JL Sriniketh and Agnivesh Pani · IIT (BHU) Varanasi
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India's rapid transition to electric mobility is most often assessed through adoption growth, while the downstream challenge of battery end-of-life (EOL) management remains insufficiently quantified. This study develops a district-scale spatiotemporal foresight framework linking future EV battery EOL flows to critical-mineral recovery potential. By 2050, retired EV batteries in India could contain approximately 9,660 tonnes of lithium, 17,455 tonnes of nickel, and 3,320 tonnes of cobalt, with 39 districts identified as immediate priorities for early recycling capacity, collection networks, and second-life value chains.
Feasibility and Environmental Impact Analysis of Critical Metals under Sustainable EV Frameworks
Nidhi Pandey and Pankaj Pathak · SRM University-AP
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The rapid expansion of electric vehicles (EVs) has increased the demand for critical metals such as lithium, nickel, and cobalt, raising concerns regarding resource depletion. This study evaluates the environmental and energy performance of recycling nickel–manganese–cobalt (NMC) cathodes from spent lithium-ion batteries compared with primary extraction, using a life cycle assessment (LCA) approach. Recycling 1 kg of spent NMC batteries resulted in a global warming potential of 5.97 kg CO2-eq, versus 109.9 kg CO2-eq for primary extraction, highlighting the importance of battery recycling in promoting a circular economy for sustainable EV development.
Integrating Circular Economy into Infrastructure Projects: A Site-Level C3E Framework for Construction Execution
Paidi Maneesha, Santhosh Loganathan and Mouli Durai · NIT Tiruchirappalli
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The transition from linear to circular economy-based construction practices remains largely conceptual, with limited practical application at the project site level. This study develops the C3E (Control–Compliance–Circularity in Execution) Framework, embedding circular principles directly into construction workflows through control mechanisms, compliance systems using indicators such as the Waste Generation Index (WGI), and circularity strategies including structured on-site reuse and supplier-linked take-back mechanisms, enabling a transition from reactive waste handling to proactive material management.
Exploring Pathways to Industrial Water Circularity: A Configurational Analysis of Corporate Water Management Practices
Shweta Dasgupta, Amit Banerji and Varsha Rokade · MANIT Bhopal
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Increasing water stress and regulatory pressures are driving industries to transition toward more sustainable and circular water management practices, though the pathways to higher water circularity remain heterogeneous. This study explores these pathways using a configurational approach based on fuzzy-set Qualitative Comparative Analysis of firm-level cases across sectors. The findings highlight that multiple pathways exist: technologically advanced firms under regulatory and water stress pressures tend to achieve high circularity, while strong sustainability orientation combined with supportive infrastructure can also enable similar outcomes.
Processing of Printed Circuit Board Waste for Selective Recovery of Valuable Metals: A Sustainable Urban Mining Approach
Rajesh Cheduri and Pankaj Pathak · SRM University-AP
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Waste printed circuit boards (PCBs) represent a high-value fraction of electronic waste due to their complex multi-metallic composition. This study investigates a hydrometallurgical route for selective recovery of valuable metals from discarded PCB waste through integrated pre-treatment, leaching, and separation processes, including mechanical comminution, alkaline treatment, and acidic leaching under varying operational parameters. Efficient recovery of valuable metallic constituents from PCB waste reduces environmental risks while promoting resource circularity and sustainable urban mining practices.
Pyrolysis-Based Circular Recycling of Waste Printed Circuit Boards for Resource Recovery and Emission Reduction
Anjana E I, Venkatesan J, Prathish K. P. and Jayasankar K · CSIR-NIIST
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Rapid industrialization has accelerated the generation of electronic waste, making waste printed circuit boards (WPCBs) a critical secondary resource for material recovery. This study presents a sustainable approach through controlled pyrolysis coupled with environmentally responsible processing, achieving ≈98% purity copper recovery and ≈93% gold recovery efficiency via a modified fire-assay method, alongside deep eutectic solvent (DES)-based extraction as a green alternative to toxic cyanide-based leaching, with controlled pyrolysis significantly reducing dioxin and PCB emissions compared to open burning.
Molecular Dynamics Investigation of Structure–Property Relationships in PBSA/PHBH Biopolymer Blends for Circular Packaging
Vaishnu Suresh Kumar, Pritam K. Jana, Mehran Ghasemlou, Benu Adhikari, Sarbani Ghosh, Banasri Roy, Fugen Daver and Mohit Garg · BITS Pilani
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The increasing demand for environmentally benign packaging materials has popularized biodegradable polymer blends that can support a circular plastics economy. In this work, molecular dynamics (MD) simulations are used to understand how the structure and composition of PBSA and PHBH biopolymer blends influence their mechanical performance and morphology. MD simulations show that PBSA and PHBH are immiscible and form distinct droplet–matrix microstructures, with increased interfacial contact facilitating more efficient stress transfer and increasing Young's modulus with increasing PHBH content, highlighting how computational modelling can help design biodegradable polymer blends for sustainable packaging.
Designing Circularity: Reversible Polymers as a Pathway to a Sustainable Plastic Economy in India
Pondharshini Ponnusamy · Bharathidasan University
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As India moves towards rapid urbanisation and consumerism, large volumes of plastic are generated annually, and existing recycling systems primarily rely on mechanical recycling, which degrades polymer quality and leads to downcycling. This paper proposes a conceptual model that shifts from a recycling-centric approach to a material-design-based approach using reversible polymers characterised by dynamic covalent bonds that enable disassembly and reassembly without loss of quality. By adopting redesignable plastics as a recoverable resource at the molecular level, India can strategically position itself as a global leader in next-generation polymer systems.
Transitioning to a Circular Plastics Economy: The Role of Natural Bio-Binders in Sustainable Biocomposites
Rutuja Sandeep Prabhudessai and Sampatrao D. Manjare · BITS Pilani, Goa Campus
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The widespread usage of petroleum-based plastics has led to serious environmental issues, driving increased research on sustainable substitutes, especially bio-composites using natural binders. This review examines the structural makeup, functional mechanisms, extraction approaches, and applications of natural bio-binders – cutin, chitosan, lignin, and soy protein isolate (SPI) – as replacements for synthetic binders, each exhibiting distinct characteristics such as thermal stability, hydrophobicity, antibacterial activity, or improved intermolecular bonding, underscoring the importance of transitioning toward bio-based binding systems for a circular plastics economy.
Valorization of Invasive Prosopis juliflora Branch Wood through Pulp Extraction and Handmade Paper Production
Trilokesh C · Thiagarajar College, Madurai
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Prosopis juliflora is an invasive species that poses serious ecological threats by depleting groundwater and suppressing native vegetation. This work produces handmade paper from P. juliflora branch wood pulp obtained via a simple alkaline extraction method, characterized using SEM, FTIR, XRD, and TGA-DSC-DTA analyses. The resulting handmade paper exhibited a thickness of 2.65 mm, burst strength of 2.74 kg/cm2, and grammage of 255 g/m2, marking the first attempt at producing handmade paper from P. juliflora branch wood and transforming an invasive species into a sustainable resource for the paper industry.
IoT-Based Device Coupled with Nano-Enhanced Multilayer Filter for Detection, Monitoring, and Remediation of Microplastic Pollution in Urban River Systems
T. Mehendale, S. Joshi, S. Pednekar, S. Joshi, S. Pitkar and Dr. M. R. Mulay · COEP Technological University
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Microplastics are one of the major contaminants of freshwater ecosystems across the globe. This project designs a microplastic interceptor system equipped with IoT-based sensors to monitor blockage and membrane integrity, consisting of a nano-enhanced V-boom interceptor with a microfilter layer followed by a nano-filter layer of CNT and graphene oxide to filter finer impurities. Integration of sensors at various stages provides real-time updates and alerts, ensuring the proper use of technology to implement sustainable solutions for environmental conservation.
Assessing the Suitability of Utilizing Atmospheric Water for Solar Photovoltaic Module Cooling for Enhancing Energy Generation
Abdul Raziq K. V., Dhinesh Thanganadar and Sharon Hilarydoss · Kannur University / IIPE
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Conversion efficiency of PV modules drops by about 0.21 to 0.50% for every 1.0°C rise in operating temperature, and conventional water cooling methods require large fresh water supply. This work proposes a new concept of PV module cooling using atmospheric water, coating a silica gel layer over the module's rear surface to adsorb and desorb atmospheric water. The optimum silica gel layer thickness was found to be 3.5 cm, with peak module temperature dropping by 10°C and daily energy generation enhancement of about 1.0 to 3.0%, making the system truly closed-loop and sustainable.
Continuous Greywater Treatment Using Date Seed Biochar: Fixed-Bed Column Performance and Breakthrough Curve Analysis
Anusha Kalaiselvan and Prasanna K · SRM Institute of Science and Technology
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This study explores the use of Date Seed Biochar (DSB) as an eco-friendly adsorbent for continuous greywater treatment using a fixed-bed column system, examining breakthrough behaviour under dynamic flow conditions. Both the Thomas and Yoon–Nelson models effectively described the column's performance, showing that agricultural waste-derived Date Seed Biochar can be effectively used in a continuous greywater treatment system, offering valuable insights for decentralized water reuse and sustainable resource management aligned with circular economy principles.
Resource Recovery from Sewage Using an Integrated Permeate Channel Ultrafiltration Membrane System Coupled with Anaerobic Digestion
Arvind Kumar Shakya and Purnendu Bose · IISER Mohali / IIT Kanpur
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Membrane filtration offers a promising pathway for resource recovery from sewage by concentrating organic matter for subsequent bioenergy production. In this study, an integrated permeate channel (IPC) ultrafiltration (UF) membrane system was evaluated for sewage filtration and anaerobic digestion of the resulting concentrate, using primary treated sewage from the Jajmau STP, Kanpur. The anaerobic digester achieved an average methane production of 6 L/day over 300 days of operation, demonstrating the potential of IPC-UF membrane systems for sewage resource recovery and sustainable bioenergy generation.
Hydrometallurgy Based Recovery of Transition Metals from Spent Lithium-Ion Batteries and Catalyst Synthesis
Asish Abhishek, Upare Vishal Baburao and Anjana P. Anantharaman · NIT Warangal
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Metal comprises around two-thirds of all chemical elements naturally occurring on Earth, and recyclability is an important parameter for metal sustainability. This work recovers active metals from spent lithium-ion batteries via hydrometallurgy – alkali leaching followed by multi-step directional precipitation – and reuses the extracted metals as a catalyst for the phenol degradation reaction. The phenol degradation reaction confirms above 98% degradation across samples, demonstrating the dual benefit of valorizing end-of-life battery materials and effectively treating organic pollutants.
Evaluation of Recycling Routes for Mixed Batteries: A Life Cycle Approach
Usman Ali, Ivan Korolev, Manivannan Sethurajan and Sami Virolainen · LUT University
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Lithium, an important component in lithium-ion batteries, has been placed on the European Union's critical raw material list, making recycling of end-of-life lithium-ion batteries crucial to preserving natural resources. This work evaluates the environmental performance of pyrometallurgical versus hydrometallurgical recycling routes when the incoming waste is a mixed stream of cells with varying chemistry rather than a single well-defined chemistry, taking nationwide Finnish industrial parameters and EU regulatory standards as applied parameters.
Bio-Derived Vanillin–PEI Fluorescent Sensor for Cu2+ Detection
Berly Robert, Mohanraj Jagannathan, Moon Il Kim and Sreeram K. Kalpathy · IIT Madras
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Monitoring trace heavy metal ions in water is essential for environmental sustainability and public health, and copper (Cu2+) becomes toxic at elevated concentrations. This work reports a sustainable, water-soluble fluorescence sensor for Cu2+ detection prepared through an in situ Schiff base reaction between polyethylenimine (PEI) and bio-derived vanillin, exhibiting bright fluorescence that is progressively quenched upon Cu2+ addition with a visible colour change enabling naked-eye detection. The sensor achieves a detection limit of approximately 290 nM with high selectivity over ten competing metal ions.
Recovery of Metals from the Co-Rich NMC Black Mass Using CAG Solvent
Dr. Indumathi Ilango, Rishab Verma and Dr. Nitin Muralidharan · IIT Madras
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Lithium-ion batteries (LIBs) are widely utilized in electric vehicles and electronic gadgets, and their active cathode materials contain critical metals whose reserves are in short supply. This work addresses metal extraction via solvometallurgy, using a novel green solvent synthesized from Choline Chloride:Acetic Acid:Ethylene Glycol to selectively extract metals from the Black Mass (BM) of spent batteries. Almost 75–80% of all the metals were extracted using this solvent (CAG) at 60°C, offering a sustainable and eco-friendly alternative to conventional hydrometallurgical processing.
Application of Alternating Current Fields in Mitigating Membrane Fouling: A Sustainable Approach
Dr. Saikat Bhattacharjee · BITS Pilani
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Membrane fouling is a critical challenge in water treatment and separation technologies, significantly impairing operational efficiency and longevity of filtration membranes. This study explores the utilization of alternating current (AC) electric fields as a viable, sustainable method for addressing membrane fouling in filtration processes. Through comprehensive analysis, this work elucidates the mechanisms by which AC fields interact with foulants and promote membrane cleaning, contributing to more effective and environmentally friendly filtration systems.
Waste to Frameworks: PET Derived UiO-66 for PFAS Remediation
Deborah Salomi D, Khushi Jain · Dayananda Sagar College of Engineering (DSCE), Bengaluru
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The simultaneous rise of polyethylene terephthalate (PET) waste and persistent per- and polyfluoroalkyl substance (PFAS) contamination necessitates sustainable material strategies capable of addressing both environmental challenges through integrated resource recovery and remediation. This study presents a green, aqueous, and DMF-free synthesis pathway for the conversion of post-consumer PET waste into the zirconium-based metal–organic framework UiO-66 for potential PFAS adsorption applications. PET flakes were subjected to alkaline depolymerization under reflux conditions to recover terephthalic acid (1,4-benzenedicarboxylic acid, BDC) linker material, which was subsequently coordinated with zirconium oxychloride in the presence of acetic acid as a coordination modulator under controlled thermal conditions (90–95°C). The synthesized UiO-66 was obtained as a stable white porous material with an overall practical yield of approximately 64.8% from PET-derived precursor feedstock. Fourier Transform Infrared Spectroscopy (FTIR) analysis confirmed the presence of characteristic coordinated carboxylate vibrations and zirconium–terephthalate framework interactions, indicating successful progression toward UiO-66 formation. Comparative precursor ratio optimization studies were additionally performed to evaluate the influence of linker concentration on framework development and material quality. Advanced characterization through X-ray diffraction (XRD) and scanning electron microscopy (SEM) is currently ongoing to further validate crystallinity and morphology. By integrating PET waste valorization with advanced porous material engineering, this work establishes a scalable and environmentally benign pathway toward next-generation adsorbent platforms for emerging water contaminant remediation.
Machine Learning-Guided CO2 Adsorption Prediction in MOFs to Support Downstream Carbon Capture Technologies
Tanishka Pal, Xavier Mulet and Sarbani Ghosh · BITS Pilani / RMIT University, Melbourne
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Metal–organic frameworks (MOFs) are promising candidates for carbon capture owing to their highly tunable structural and chemical properties, which enable enhanced CO2 selectivity and lower regeneration energy requirements compared to conventional separation materials. However, the rational design and optimization of MOFs for carbon capture applications require a fundamental understanding of CO2 adsorption. Conventional experimental approaches for evaluating adsorption performance are often time-intensive, costly, and dependent on sophisticated instrumentation, while molecular simulation techniques demand significant computational resources. To address these challenges, this work presents an AI-driven machine learning framework for predicting and understanding CO2 adsorption behavior in MOFs. A comprehensive dataset containing diverse physical, structural, and chemical descriptors of MOFs was used to train predictive models that capture complex adsorption patterns across varying operating conditions. The performance of the developed models was systematically benchmarked using multiple statistical evaluation metrics to ensure predictive reliability and robustness. The proposed framework successfully reconstructed CO2 adsorption isotherms over a broad pressure range, showing strong agreement with simulated and experimental observations. Beyond predictive capability, SHAP (SHapley Additive exPlanations) analysis was applied to identify the dominant factors governing CO2 adsorption behavior. The analysis revealed a hierarchy of influential structural features and highlighted the significant roles of chemical properties, along with thermodynamic operating conditions and physical descriptors, in determining adsorption performance. Overall, this study demonstrates the potential of AI-driven predictive intelligence to accelerate the discovery, rational design, and capacity of advanced MOFs for sustainable carbon capture applications and smarter material selection strategies.
Utilization of Agricultural Waste Biomass for Furfural Production
Subhajit Patra · MANIT Bhopal
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Agricultural wastes such as rice straw and sugarcane bagasse are lignocellulosic biomass with huge potential applications in the circular economy. This study emphasizes the acid hydrolysis process of agricultural waste with high hemicellulose content for xylose production, followed by furfural production and separation via simulation using different routes. The role of reaction parameters and sequencing strategies is explored, including a techno-economic assessment, to detect their impact on product purity and separation efficiency.
Towards Circular Fashion: Smart Recycling Strategies for Polyester–Cotton Blended Fabrics
Shriya Saravanan, Tarun S, Bino T K · Amrita Vishwa Vidyapeetham
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The rise of fast fashion has driven a sharp increase in textile waste worldwide, with polyester–cotton blends posing a particular recycling challenge since the two materials behave very differently in most recycling processes. This work examines greener, more cost-effective ways to process these blended fabrics, reviewing current recycling technologies and exploring emerging approaches such as automated sorting and improved fiber-recovery methods, considering waste management across the full lifecycle of a garment and outlining pathways for cycling used textiles back into the supply chain.
Valorization of Pistachio Shell Lignocellulose for Starch-Based Bioplastic Films
Subramee Sarkar, Thaarani S., Ethayaraja Mani and Sreeram K. Kalpathy · IIT Madras
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Agricultural biomass residues represent an abundant and renewable feedstock for biodegradable alternatives to petroleum-derived plastic films, yet many lignocellulosic wastes remain underutilized. In this work, pistachio shell biomass was valorized through selective lignin extraction using alkali, organosolv, and deep eutectic solvent fractionation routes, with the cellulose-rich fraction incorporated into starch-based films and lignin explored as a functional additive. The resulting starch-based cellulose–lignin composite films highlight the potential of agricultural waste-derived biopolymers for circular packaging applications.
Sustainable Recovery of Critical Metals from Spent NMC Black Mass via Binary and Ternary Deep Eutectic Solvents
S. Sharma and N. Muralidharan · IIT Madras
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Deep eutectic solvents (DESs) have emerged as promising green solvents for recycling of spent lithium-ion batteries. In this study, a binary DES (Choline Chloride:Ethylene Glycol) and a ternary DES (Choline Chloride:Ethylene Glycol:Citric Acid) were designed and optimized for efficient metal leaching. The optimized binary DES exhibited high lithium selectivity (50±2% Li leaching while minimizing co-leaching of other metals), while the ternary DES achieved leaching efficiencies of 99±2% for Li, 98±4% for Ni, and 99±2% for Mn, demonstrating significant potential for sustainable metal recovery from spent LIBs.
Upcycling Multilayer Packaging (MLP) Waste into Circular, Industrial Materials
Harsh Jadia, PhD and Deepali Jadia, PhD · Independent Researcher
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India generates 3.8 million tons of multilayer packaging (MLP) waste every year, conventionally considered unrecyclable because separation is energy-intensive and mixed polymers have poor compatibility. This innovation utilises a proprietary biochemical process to efficiently separate these materials using bio-based formulations that weaken interfacial bonding between aluminium and polymer layers within a 24-hour timeframe at greater than 90% efficiency, transforming discarded packaging into high-quality industrial plastic pellets similar to compounds used for footwear sole manufacturing, with further applications being explored in electrical components and automobile parts.
Feedstock-Conditioned Process Design for Sustainable Carbon Resource Valorization: Coal-to-GO/rGO Manufacturing as a Demonstration Case
R. Shankar and T. Thomas · IIT Madras
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Heterogeneous carbonaceous resources offer scalable pathways to advanced carbon materials, but their conversion is constrained by variations in composition, mineral matter, and feedstock-preparation burden. Here, coal-to-GO/rGO conversion is used to demonstrate a feedstock-conditioned process design framework integrating coal-rank routing, ash and mineralogical triggers, and early-stage sustainability screening, demonstrated through a lignite-to-GO case study. The framework introduces the Feedstock Conditioning Penalty, with feedstock conditioning contributing approximately 72% of greenhouse-gas emissions in the case study, identifying upstream upgrading as the dominant sustainability hotspot.
SynoProtein Approach to Syngas to Circular Fish Feed: Optimization of Hydrogen- and Methane-Oxidizing Bacterial Coculture for Multi-Component Syngas Valorization
Anju Pilakka Veedu and Yifeng Zhang · Technical University of Denmark
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Industrial biogenic gas streams contain complex mixtures of hydrogen, carbon dioxide, and methane, but conventional single-strain gas fermentation underutilizes mixed syngas. This work develops a coculture system comprising Hydrogen-Oxidizing Bacteria (HOB) and Methane-Oxidizing Bacteria (MOB) to simultaneously valorize mixed gaseous residues into a high-value Single-Cell Protein (SCP) for fish feed, optimizing cultivation kinetics and scaling the system ≈5-fold to a 1000 mL bioreactor, yielding a maximum biomass productivity of 4.8–6.0 g/L/day and establishing a scalable baseline for closed-loop, sustainable industrial bio-ecosystems.
Smart Decentralized Biomedical Waste Treatment for Sustainable Healthcare and Circular Economy
Atly Pauly, Dr. Joshy Varkey and Sreejith Shankar · Bio Vastum Solutions Pvt Ltd
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The increasing generation of biomedical waste poses significant challenges to healthcare systems due to environmental concerns, high treatment costs, and stringent regulatory requirements. Bio Vastum Solutions Pvt. Ltd., in collaboration with CSIR–NIIST, has developed an innovative decentralized biomedical waste treatment technology based on rapid disinfection and solidification principles, achieving more than 99.9% pathogen reduction and eliminating the need for incineration. A prototype has been successfully installed and demonstrated at AIIMS New Delhi, supporting SDG 3, 6, 9, and 12.
A Sustainable Zero-Discharge Process for Debromination and Resource Recovery from End-of-Life Printed Circuit Boards
K. Shivaraj Kumar, Sruthika Kore, Ganga K. Vijayan, R. Ratheesh, Tiju Thomas and Sreeram K. Kalpathy · IIT Madras
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The rapid growth of electronic waste has intensified the need for sustainable technologies enabling resource recovery while minimizing environmental impact. This work develops a low-temperature (<200°C), atmospheric-pressure solvothermal debromination process achieving approximately 98% removal of brominated compounds from waste PCBs (TRL 4), with the processed solvent regenerated via vacuum distillation to establish a zero-liquid-discharge system. The technology is being scaled to a pilot plant processing 200 kg of PCBs per day, alongside proof-of-concept green-solvent-based gold recovery from waste RAM modules.
Lead Removal from Aqueous Medium Using Thiol-Rich Novel Fe/TGA Nanocrystals
R. V. Mohan Malavya and Sirshendu De · Department of Chemical Engineering, Indian Institute of Technology, Kharagpur
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Novel thiol functionalized iron-based nanocrystalline particles (denoted as Fe/TGA) was synthesized using a facile precipitation strategy. The physico-chemical characteristics of Fe/TGA were explored using different analytical techniques (XRD, FTIR, FESEM, EDX and Zeta potential). The material exhibited significant lead (Pb) adsorption capacity which was analyzed using detailed batch mode experimentation to elucidate the influence of different operating parameters, such as, pH, dose, feed concentration, time and temperature. Langmuir isotherm fitted better with the adsorption profile and a maximum adsorption capacity of nearly 600 mg/g was evidenced. Pb adsorption was endothermic in nature and followed pseudo-second order kinetics. The material showed appreciable Pb selectivity with different ionic groups. The regeneration studies revealed good efficacy of the material after 4 cycles of operation. The strong Pb binding capacity of thiol groups through effective chelation was determined to be the uptake mechanism confirming chemisorption. The negative surface charge of Fe/TGA also facilitated the sorption of Pb moieties through strong electrostatic forces. Overall, the simple synthesis process and superior Pb removal capacity of the nanoparticles offer credible promise and scope for application in field of water treatment.
Poster Display Instructions
Kindly report by 8:30 AM for registration and proceed to Hall 4, IC&SR to put up your posters.
24 July
Poster Registration Nos. 1–30
25 July
Poster Registration No. 31 onwards
- Presenters displaying their posters on 24 July are requested to remove their posters at the end of the day (EOD).
- Detailed instructions regarding poster pin-up and display will be provided at the Registration Desk.
- For any queries related to your poster presentation, please contact the Registration Desk for assistance.
Role of Artificial Intelligence in Advancing Sustainable Development, Circular Economy, and Economic Growth in India’s Chemical Industry under Union Budget 2026–27
Pranav Mishra, Utkarsha Zarbade and Satyajit Bhattacharjee · Department of Chemical Engineering, Guru Ghasidas Vishwavidyalaya, Bilaspur, Chhattisgarh 495009, India
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The integration of Artificial Intelligence (AI) in the chemical industry is transforming the sector toward sustainable development, circular economy practices, and economic growth in India. AI-driven technologies such as predictive analytics, smart manufacturing, process automation, and waste optimization are improving production efficiency, reducing energy consumption, and minimizing environmental impact. In the framework of a circular economy, AI supports resource recovery, recycling, waste management, and the reuse of industrial by-products, thereby promoting efficient utilization of raw materials and reducing industrial pollution. These advancements directly contribute to the goals of sustainable development by encouraging green chemistry, lowering carbon emissions, conserving natural resources, and supporting environmentally responsible industrialization. The Government of India through the Union Budget 2026–27 is expected to strengthen the adoption of AI and digital technologies in chemical manufacturing by increasing investments in innovation, research and development, renewable energy, and industrial infrastructure. Budget initiatives focusing on “Make in India,” green hydrogen, clean energy transition, and smart industrial ecosystems can accelerate the modernization of India’s chemical sector while generating employment and enhancing global competitiveness. Furthermore, the combination of AI, circular economy principles, and sustainability strategies can help Indian chemical industries achieve long-term economic resilience and environmental balance. Thus, AI acts as a bridge connecting technological advancement, sustainable industrial practices, and national economic policies, paving the way for a greener and more efficient future for the Indian chemical industry.
GreenScore AI: A Circular Economy-Based Sustainability Scoring and Resource Optimization Framework for Smart Farming
Ashmitha S · Department of Agricultural Engineering, Agricultural Engineering College and Research Institute, Tamil Nadu Agricultural University, Coimbatore 641003, India
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Sustainable agriculture is challenged by the need to balance productivity with efficient resource use and environmental conservation. This research presents GreenScore AI, an artificial-intelligence-driven framework designed to assess and enhance sustainability in smart farming through circular economy principles. The proposed system evaluates key agricultural parameters such as water consumption, energy usage, waste generation, and crop productivity to generate a comprehensive sustainability score. GreenScore AI not only quantifies farm performance but also provides intelligent, data-driven recommendations to optimize resource utilization and minimize waste. By promoting practices such as water reuse, efficient energy management, and recycling of agricultural residues, the system supports the transition from linear to circular farming models. The integration of real-time data and machine learning techniques enables adaptive decision-making tailored to specific farm conditions, and a user-friendly interface ensures that farmers can easily interpret the results and implement suggested improvements. Designed with scalability and affordability in mind, GreenScore AI is particularly relevant for small and marginal farmers; the proposed approach not only bridges the gap between advanced digital technologies and field-level practices but also contributes to building climate-resilient and sustainable agricultural systems.
Netara: A Decentralized AI Inference Framework for Circular Compute via Idle Edge Devices
Velayutham S · Independent Researcher, Chennai, India
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The rapid expansion of artificial intelligence (AI) workloads has intensified reliance on centralized data centers, resulting in significant energy consumption and infrastructure constraints. Concurrently, billions of edge devices, including smartphones, laptops, and IoT systems, operate at low average utilization, representing a vast pool of underutilized computational capacity. This study presents Netara, a decentralized AI inference framework that applies circular economy principles by transforming idle edge devices into a distributed computing network without requiring additional physical infrastructure. The proposed system consists of a lightweight device agent that activates during idle periods, a task orchestration engine that decomposes workloads into micro-tasks, a consensus-based verification mechanism that ensures reliability across heterogeneous nodes, and a REST-based interface for seamless integration. By extending the lifecycle utilization of existing hardware, the framework reduces dependence on energy-intensive data centers and minimizes the need for new infrastructure. Preliminary evaluation of a controlled prototype network demonstrates the feasibility of parallel task execution and fault-tolerant inference, with projected cost reductions of 60–80% relative to comparable centralized inference systems, alongside corresponding decreases in energy demand. The proposed approach contributes to sustainable AI infrastructure by establishing decentralized, edge-based inference as a scalable model aligned with circular economy principles, particularly for improving access to affordable AI in resource-constrained regions and the Global South.
An Integrated Life-Cycle, System-Dynamics, Artificial-Intelligence, Multi-Criteria, and Reinforcement-Learning Framework for Sustainable Municipal Solid Waste Management in India
A. Kundu · Vinod Gupta School of Management, IIT Kharagpur
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Municipal solid waste management in India is a complex socio-technical challenge shaped by rapid urbanization, changing consumption patterns, heterogeneous waste composition, infrastructure deficits, informal recycling networks, environmental externalities, and evolving policy mandates. This paper presents an integrated decision-support methodology for evaluating and optimizing urban waste-management systems in the Indian context. The proposed framework combines five complementary analytical layers: life-cycle assessment for environmental quantification, system dynamics for long-term, feedback-rich simulation, artificial-intelligence-based forecasting for waste-generation prediction, fuzzy TOPSIS for technology ranking under uncertainty, and reinforcement learning for adaptive policy sequencing. The framework is designed around Indian municipal realities, including high organic fractions, variable collection efficiency, monsoon effects, festival-linked waste spikes, legacy dumpsites, dependence on the informal sector, and limited municipal finance. Recent policy and empirical research are incorporated to continue the expansion of the Swachh Bharat Mission–Urban 2.0, to address India’s approximately 150,000 tonnes per day of urban waste generation, and to address global projections that municipal solid waste may increase substantially by 2050. The methodology supports comparative assessment of sanitary landfilling, composting, anaerobic digestion, material recovery, waste-to-energy, refuse-derived fuel systems, and biomining of legacy waste. By coupling environmental, economic, technical, social, and policy variables, the framework provides a reproducible, transparent, and adaptive basis for sustainable waste-management planning in Indian cities.
Digital Twin-Integrated Circular Water Management for Sustainable Hydrosphere Governance
Cyril Justin S and Nanthan S · Agricultural Engineering College & Research Institute (AEC&RI), Tamil Nadu Agricultural University (TNAU), Coimbatore, India
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The unsustainable nature of linear water management models, which create freshwater waste and consume excess treatment energy and lack hydrosphere visibility during climate change and urbanization periods, has become evident through global water scarcity and rising hydrological disasters. The project introduces a Digital Twin–Circular Nexus framework which combines Digital Twin (DT) technology and Circular Water Technologies (CWT) to create a comprehensive water management system. Digital Twin systems establish exact virtual models of infrastructure systems, covering treatment plants and river basins, by utilizing Internet of Things sensors, artificial intelligence analytical tools, and satellite information to monitor systems in real time and make predictive models. The Circular Water Technologies process, which includes Membrane Bioreactors and Granular Sludge systems, enables wastewater to undergo advanced treatment for recycling purposes while closing material loops to recover valuable resources and reduce freshwater consumption. The system operates through three architectural levels: micro systems for plant optimization, meso systems for urban leak reduction and demand management, and macro systems for basin-scale forecasting and transboundary equity. This system delivers transformative operational efficiencies, substantially reducing freshwater usage and significantly abating maintenance costs, while enhanced resilience against floods and droughts is enabled by advanced probabilistic modeling. The development of Digital Twin Earth Hydrology depends on cloud-based artificial intelligence systems which provide solutions for data interoperability and cybersecurity obstacles. The data-driven concept directs water systems toward circular operations while achieving efficient outcomes which can be implemented worldwide to create a sustainable future for hydrosphere management.
Valorization of Invasive Parthenium hysterophorus into Engineered Biochar for Simultaneous Removal of Heavy Metals and Pharmaceutical Pollutants from Industrial Wastewater: A Sustainable Circular Economy Approach
Sanskrithi K. S. and Keerthana S. · Department of Chemical Engineering, Rajalakshmi Engineering College, Chennai, India
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The uncontrolled proliferation of Parthenium hysterophorus, an aggressive invasive weed widespread across India, poses severe ecological, agricultural, and public health challenges. Concurrently, the discharge of heavy metal ions like chromium (Cr), lead (Pb), and cadmium (Cd), alongside pharmaceutical pollutants from industrial effluents, has emerged as a critical environmental concern, threatening aquatic ecosystems and human health. This study proposes the valorization of Parthenium hysterophorus biomass into engineered biochar as a low-cost, sustainable adsorbent for the simultaneous removal of heavy metals and pharmaceutical contaminants from industrial wastewater, addressing both invasive weed management and water pollution within a circular economy framework. The proposed methodology involves pyrolytic synthesis of biochar from Parthenium hysterophorus under optimized temperature and residence time conditions, followed by chemical activation to enhance surface area, porosity, and functional group density. Characterization of the synthesized biochar will be conducted using BET surface area analysis, FTIR spectroscopy, SEM-EDX, XRD, and TGA to establish structure–property correlations. Batch adsorption experiments will investigate the effect of pH, contact time, adsorbent dosage, and initial pollutant concentration on removal efficiency in both single and multi-pollutant systems. Adsorption kinetics, equilibrium isotherm modeling, and thermodynamic studies will be performed to elucidate the underlying adsorption mechanisms. This study aims to demonstrate that Parthenium-derived biochar serves as a high-performance adsorbent in complex multi-pollutant systems, offering a scalable and economically viable solution for industrial wastewater treatment. The dual-benefit approach of invasive weed valorization and pollutant remediation positions this work as a meaningful contribution toward sustainable water management.
Natural Lotus Wax-Modified Commercial Sponges for Efficient Oil Absorption
Santhra Krishnan P., Sriharitha Rowthu and Sreeram K. Kalpathy · Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600036, India · Department of Materials Engineering, Indian Institute of Technology Gandhinagar, Gandhinagar, Gujarat 382055, India
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Oil-contaminated water streams continue to pose significant environmental and resource recovery challenges, necessitating the development of sustainable, cost-effective treatment technologies. Commercial cleaning sponges are inexpensive, widely available, and possess highly interconnected porous networks, making them attractive candidates for absorbent-based water remediation. However, their intrinsic amphiphilicity and large pore sizes often permit the rapid penetration of both water and oil, limiting separation selectivity. In this work, a simple, material-efficient surface modification strategy based on the deposition of natural lotus wax is proposed to regulate capillary-driven liquid transport in commercially available sponges. Pristine and wax-modified sponges will be evaluated in terms of pore morphology, pore size distribution, wettability, absorption performance, and liquid infiltration behavior. Static and dynamic contact angle measurements and time-dependent uptake experiments will be employed to investigate wetting transitions and transport kinetics. Pore characteristics will be quantified through image analysis, while the infiltration behavior of water and oil will be interpreted using capillary pressure and Washburn infiltration concepts to establish relationships between pore architecture, surface energy, and liquid transport dynamics. The study aims to elucidate how natural wax deposition alters pore geometry and surface wettability, thereby affecting liquid invasion in highly interconnected porous networks. It is anticipated that even low wax loadings will significantly retard water penetration while preserving rapid oil uptake, thereby improving oil–water selectivity without extensive modification of the underlying sponge structure. By combining an inexpensive commercial substrate with a bio-derived surface treatment, the proposed approach is expected to provide a scalable and environmentally benign route for selective oil removal from contaminated water streams, further contributing to a mechanistic understanding of capillary transport in porous absorbents and supporting the development of materials for circular water management and resource recovery applications.
A Sustainable Solution for Textile Wastewater Management in India: Pilot-Scale Implementation of Electrochemical Ozone Oxidation Process for Dye Wastewater
Anju Anna John, Kannan A and Indumathi M. Nambi · Environmental Division, Department of Civil Engineering, Indian Institute of Technology Madras, Chennai 600036, India · Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai 600036, India · School of Sustainability, Indian Institute of Technology Madras, Chennai 600036, India
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The textile industry is one of the largest consumers of freshwater, with nearly 90% of the utilized water discharged as wastewater containing persistent organic pollutants (POPs), synthetic dyes, heavy metals, acids, alkalis, and surfactants. Among these, synthetic dyes are particularly recalcitrant and resist degradation by conventional treatment processes. Chlorination, widely employed for color removal, results in the formation of toxic and carcinogenic disinfection byproducts (DBPs), posing significant environmental and public health risks. Furthermore, Zero Liquid Discharge (ZLD) systems, though effective in water recovery, are associated with challenges such as excessive sludge generation, salt accumulation, membrane fouling, and high operational costs. In this study, we present an electrochemical ozone oxidation process (ECOOP) based on the synergistic integration of ozonation and electrolysis for the efficient treatment of textile wastewater. The system operates without chemical additives and generates multiple reactive oxygen species (ROS), including hydroxyl radicals, sulfate radicals, and superoxide radicals, enabling non-selective and complete mineralization of organic contaminants. High-strength dye bath effluents are treated using ECOOP for enhanced color and organic removal, while low-TDS wash streams are directed to conventional biological treatment, thereby optimizing system performance and reducing overall load. Pilot-scale implementation in a major textile cluster demonstrated promising results, with dye bath effluent achieving approximately 54% COD reduction at lower current density, indicating energy-efficient operation and scalability potential. The treated effluent can be integrated with selective salt management approaches to enable in-plant water reuse for dyeing applications, reducing freshwater dependency and improving techno-economic feasibility. The approach directly supports SDG 6 (Clean Water and Sanitation), SDG 12 (Responsible Consumption and Production), and SDG 14 (Life Below Water), advancing sustainable hydrosphere management within the textile value chain.
Closing the Loop in Sludge Treatment: Reusable Fe-Loaded Biochar for Enhanced Electrocoagulation Dewatering
Vaibhav Kabdwal, Mohanakrishnan Logan and Indumathi Nambi · Department of Civil Engineering, Indian Institute of Technology Madras, Chennai, India
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Electrocoagulation (EC) has emerged as an effective technique for sewage sludge dewatering; however, its practical application is often limited by high energy consumption and operational costs. In this study, EC with iron electrodes was optimized for sludge dewatering by systematically varying key operational parameters, including applied voltage, electrode spacing, and reaction time. The dewatering performance was evaluated using specific resistance to filtration (SRF) and moisture content reduction. To enhance process efficiency and promote resource recovery, the EC-treated sludge was further converted into iron-loaded biochar (Fe–BC) via thermochemical treatment. The synthesized Fe–BC was reutilized as an additive in subsequent EC cycles to improve floc formation, electrical conductivity, and overall dewatering efficiency. The impact of Fe–BC addition on energy consumption, treatment time, and dewatering performance was systematically investigated. Furthermore, the reusability of Fe–BC was assessed over multiple cycles to determine its performance stability and functional lifespan. Changes in physicochemical properties of Fe–BC after repeated use were analyzed to understand the mechanisms governing its effectiveness. The results demonstrate that Fe–BC significantly enhances EC performance while reducing energy requirements, with a gradual decline observed beyond a certain number of reuse cycles.
Reactive Transport Modelling in Porous Media using COMSOL-MATLAB-PHREEQC
C. Bersha Angelin Christal and Swapna Singha Rabha · Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai 600036, India
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The interaction between pore structure, permeability, pressure gradients, and transport mechanisms such as advection, diffusion, and mechanical dispersion governs fluid flow in porous media. In reactive transport systems, dissolved chemical species undergo geochemical phenomena such as mineral dissolution, precipitation, ion exchange, and aqueous speciation while moving across interconnected pore spaces. Understanding subsurface processes is made easier by Reactive Transport Modelling (RTM) in porous media. In practice, RTM uses one of the Operator Splitting (OS) approaches, known as the Sequential Non-Iterative approach, which solves the equations of transport and reactions separately rather than simultaneously. This study presents a coupled framework integrating COMSOL Multiphysics, MATLAB, and PHREEQC to solve RTM problems. The coupling approach uses COMSOL’s transport-solving capabilities with PHREEQC’s geochemical equilibrium and kinetic calculations, with MATLAB serving as a data exchanger and OS interface. The benchmark problem used is a 2D axisymmetric problem: pesticide transport and reaction in soil. The effective saturation plotted along with the velocity field helps us understand the rate and direction at which the pesticides move through the soil. After pesticide infiltration, the concentration of aldicarb reaches a steady state as the plume gets concentrated around the source, while aldicarb sulfoxide affects a larger soil volume, exhibiting a distinct ring-band pattern after 10 days. The benchmark study reveals that the coupled framework can accurately capture the evolution of contaminated plumes in soil. The developed methodology can be further extended towards applications in geological CO2 sequestration; understanding these coupled processes is critical for predicting long-term storage stability, mineral trapping mechanisms, porosity evolution, and environmental consequences of carbon capture and storage (CCS) technologies.
A Scalable PEDOT:PSS-Based FTIR Sensor Platform for Quantitative Heavy Metal Detection in Aqueous Media
Suvitha S. Kumar, Sreeram K. Kalpathy and Tiju Thomas · Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600036, India · Centre for Resource Efficiency, Recyclability, and Circularity in Energy Transition, School of Sustainability, Indian Institute of Technology Madras, Chennai 600036, India
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A critical component of water quality management is ensuring that concentrations of heavy metal ions remain below their permissible thresholds. Although specific heavy metals (HMs) at low concentrations are beneficial as essential minerals for human health and micronutrients for plants, their excessive presence poses risks of cumulative toxicity across the biosphere. Therefore, the development of dependable and sensitive tools for quantitative heavy metal detection over a broad concentration range is important. To address this need, a simple and scalable sensor platform based on polymer test strips was developed. We report the development of a sensor for Cu, Pb, Ni, Hg, and Zn in aqueous environments, capable of operating across concentrations from 1 nM to 10 mM while maintaining an error margin of 10% or less. Test strips were fabricated by drop-casting poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate) (PEDOT:PSS) onto glass substrates, followed by dip-coating in aqueous heavy metal ion solutions. The resulting polymer–metal systems were analyzed using Fourier transform infrared (FTIR) spectroscopy, and calibration curves were constructed from spectral region areas. Interactions between polymer groups and metal ions are interpreted through Pearson’s Hard and Soft Acids and Bases (HSAB) theory, revealing selective binding mechanisms. This approach uses FTIR spectral shifts to indicate structural and electronic changes within the polymer matrix. The method is scalable, cost-effective, and compatible with handheld FTIR devices, offering a practical alternative to ICP-OES for portable and on-site monitoring of heavy metals, yielding substantial advantages from both societal and commercial viewpoints.
Light-Propelled Bio-Based Micro-Motors for Active Photocatalytic Removal of Polycyclic Aromatic Hydrocarbons (PAHs) from Coal Mine Wastewater
A. Hariharan, Chinthalapudi Naga Lakshmi and Swathi Sudhakar · Department of Applied Mechanics and Biomedical Engineering, Indian Institute of Technology Madras, Chennai 600036, India
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Polycyclic aromatic hydrocarbons (PAHs) are persistent and highly toxic organic pollutants frequently detected in coal mine wastewater, posing severe risks to aquatic ecosystems and human health due to their carcinogenicity, bioaccumulation, and environmental persistence. Conventional remediation strategies, including adsorption, biological treatment, and advanced oxidation processes, are often constrained by high operational costs, slow degradation kinetics, and limited removal efficiencies. In this work, we propose the development of bio-derived photocatalytic micromotors based on renewable pectin for the active degradation of PAHs under visible-light irradiation. Pectin, a naturally abundant and biodegradable polysaccharide, was employed as the structural matrix for synthesizing microparticles via a hydrothermal approach, followed by asymmetric deposition of titanium dioxide (TiO2) to impart photocatalytic functionality. The synthesized particles were characterized to evaluate their morphology, surface chemistry, and structural integrity, confirming the successful fabrication of TiO2-functionalized pectin microparticles suitable for photocatalytic applications. Ongoing studies are focused on investigating the degradation of representative PAHs under blue-light irradiation in the presence of hydrogen peroxide, where TiO2 is expected to generate reactive oxygen species capable of oxidizing PAHs into less harmful products. The active photocatalytic platform enhanced catalyst–pollutant interactions, leading to efficient degradation of representative PAHs. At an initial concentration of 10 ppm, TiO2-functionalized pectin micromotors achieved ≈100% degradation of anthracene and ≈70% degradation of naphthalene after 24 h of blue-light irradiation. These findings demonstrate the effectiveness of bio-based photocatalytic micromotors for degrading persistent organic pollutants and highlight their potential as sustainable and environmentally friendly materials for coal mine wastewater remediation.
ZnFe2O4/TiO2/rGO Nanocomposites for the Efficient Photocatalytic Degradation of Polycyclic Aromatic Hydrocarbons
Chinthalapudi Naga Lakshmi, A. Hariharan and Swathi Sudhakar · Department of Applied Mechanics and Biomedical Engineering, Indian Institute of Technology Madras, Chennai 600036, India
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There is growing global interest in advancing wastewater treatment methods to effectively remove polycyclic aromatic hydrocarbons, which are persistent, toxic, and carcinogenic contaminants. Conventional techniques are ineffective at removing these compounds. Photocatalysis is one of the best oxidation techniques utilising solar energy, degrading these persistent compounds into non-harmful products; however, heterogeneous photocatalytic degradation of water pollutants presents a considerable challenge due to its complex nature. In this work, we synthesized ZnFe2O4/TiO2/rGO nanocomposites for the photocatalytic degradation of naphthalene under visible light irradiation. XRD analysis confirmed the formation of cubic-phase zinc ferrite and tetragonal-phase titanium dioxide in the composite. Morphological analysis revealed the successful integration of the ZnFe2O4/TiO2 nanocomposite with rGO nanosheets, resulting in a well-defined heterojunction. This heterojunction facilitates efficient exciton separation and transport, suppresses charge carrier recombination, and enhances the generation of reactive oxygen species, thereby playing a crucial role in the photocatalytic degradation of naphthalene. The ZnFe2O4/TiO2/rGO nanocomposites showed improved photocatalytic performance compared to bare ZnFe2O4 and TiO2 nanoparticles. The increased efficiency resulted from their narrow bandgap, improved visible-light absorption, and enhanced charge-carrier separation and transport.
Co3O4 Nanostructures for Supercapacitors: Toward Circular Electrode Design
Chrisma Rose Babu, E. I. Anila, Sreeram K. Kalpathy and Tiju Thomas · Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600036, India · Centre for Resource Efficiency, Recyclability and Circularity in Energy Transition (CRRET), School of Sustainability, Indian Institute of Technology Madras, Chennai 600036, India · Department of Physics and Electronics, CHRIST (Deemed to be University), Bangalore 560029, India
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Cobalt is a critical metal widely used in energy storage technologies, and its recovery from various electronic waste streams, especially batteries, offers a promising route toward circular resource utilization. In the present work, we have used a commercially available cobalt precursor to synthesize Co3O4 nanostructures for supercapacitor applications, while the broader motivation of the study is to establish a foundation for future use of recovered cobalt-based feedstocks. Transition metal oxides are widely explored for high-performance supercapacitor electrodes, and cobalt oxide is especially attractive because of its mixed-valence redox activity, structural stability, and pseudocapacitive behaviour. In this work, Co3O4 nanoparticles were synthesized by a hydrothermal route. The material showed a cubic spinel structure and mesoporous morphology, which enhanced ion diffusion and charge-transfer kinetics. The as-synthesized Co3O4 delivered the highest specific capacitance of 1195.05 F g−1 at 1.5 A g−1 in the three-electrode configuration. A symmetric supercapacitor device fabricated using Co3O4 demonstrated a specific capacitance of 870.6 F g−1 at 5 A g−1, along with an energy density of 77.3 W h kg−1 and a power density of 1997.7 W kg−1. Thus, the work provides a strong foundation for future studies on recovered cobalt-based electrodes and eco-friendly current collectors for sustainable energy storage.
Multi-Stimuli-Assisted Catalytic Degradation of Rhodamine B using Bismuth Ferrite Nanoparticles
Kokkiligadda Jhansi and Parasuraman Swaminathan · Electronic Materials and Thin Films Lab, Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600036, India
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Multifunctional materials can be used to develop highly responsive catalysts for degradation of harmful chemicals by leveraging multiple energy sources simultaneously; these can surpass traditional environmental clean-up techniques, typically based on photocatalysis, and minimize inefficiencies while addressing the challenge of intensive energy consumption. In this study, we demonstrate the efficacy of this multi-stimuli approach by using bismuth ferrite (BFO), a multiferroic material capable of being activated by a combination of light (photocatalysis) and ultrasound (piezo-catalysis), to facilitate the breakdown of organic dyes. This unique combination of multiferroic BFO with multi-stimuli inputs demonstrates an innovative approach to pollutant degradation compared to conventional approaches that rely on photocatalysis alone. Our work focuses on examining the multi-stimuli catalytic efficiency of BFO nanoparticles for the degradation of Rhodamine B (RhB) at a concentration of 20 mg L−1, significantly exceeding the concentrations (5–10 mg L−1) documented in prior photo- and piezo-catalysis investigations. The simultaneous utilization of these energy sources results in markedly faster reaction rates compared to using a single energy source, paving the way for the development of adaptable and versatile technologies based on multiferroic materials, designed to perform efficiently under diverse and evolving conditions, for effectively cleaning real-world wastewater and environmental remediation.
Magnetite Graphene Oxide (MGO) Incorporated Hollow Fiber Membrane for Pharmaceutical Wastewater Treatment
Harshita Dihora, Mrinmoy Mondal and Puyam S. Singh · Membrane Science and Separation Technology Division, CSIR-CSMCRI, Bhavnagar 364021, India
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Pharmaceutical wastewater containing micro-pollutants is an important environmental problem because these pollutants tend to persist in the environment. Membrane-based separation processes are regarded as a convenient and compact means of treating wastewater. The main aim of this research study was to separate the pharmaceutical active compound nystatin by applying the membrane technique. To achieve this, graphene oxide (GO) and magnetite graphene oxide (MGO) were synthesized, and MGO was then incorporated onto a polysulfone-based hollow fiber membrane to improve its separation performance. Membranes of varying MGO loadings were analyzed using FT-IR, Raman spectroscopy, XRD, XPS, FE-SEM, HR-TEM, EPR, DSC, and TGA techniques. Among all the membranes used, M-4, which contained 0.03% MGO, displayed the highest effectiveness, with a permeability of ≈71.34 L/m2h·bar at 1 bar pressure, nystatin rejection of 98%, and a MWCO of ≈1531 Da. The improved membrane performance was mainly attributed to enhanced membrane morphology and hydrophilicity, which contributed to high permeation flux and improved separation efficiency.
Water Recovery from Saline Water using Hydrophobic Polyvinylidene Fluoride (PVDF) Hollow Fiber Membrane Based Direct Contact Membrane Distillation (DCMD)
Vishal B. Gohil, Mrinmoy Mondal and Puyam S. Singh · Membrane Science and Separation Technology Division, CSIR-CSMCRI, Bhavnagar 364021, India
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Direct contact membrane distillation (DCMD) is a thermally driven desalination technique that has gained increasing attention for high-salinity water treatment due to its ability to operate at low temperatures while delivering high separation efficiency and effectively utilizing low-grade heat sources. In this study, a PVDF hollow fiber membrane engineered with a sandwich tri-layer porous morphology was employed to enhance vapor transport and reduce mass-transfer resistance. The membrane exhibited a hydrophobic surface with a water contact angle of 115°, ensuring stable operation without pore wetting. DCMD performance was evaluated using a 3.5 wt% NaCl feed solution, achieving an average permeation flux of 7.5 L/m2h and a salt rejection exceeding 99.7% with a hot saline water stream at 80°C and a cold distillate stream at 18°C. The system demonstrated stable long-term operation over a continuous 10-hour run, confirming the suitability of the PVDF hollow fiber structure for energy-efficient and reliable desalination applications.
Enhanced Primary Treatment and Hybrid Wastewater Treatment Systems for Domestic Sewage
Md Sarfraz Ahmad and Dr. Maithili Mohanty · Department of Civil Engineering, National Institute of Technology Rourkela, Sundargarh, Odisha 769008, India
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One of the most recent advancements in the enhancement of pollutant removal in municipal wastewater treatment is Chemically Enhanced Primary Treatment (CEPT). By treating the primary stage of wastewater treatment with coagulants and flocculants, there is an increase in the removal of suspended solids and particulate organic matter, along with an overall improvement in treatment efficiency and organic load reduction provided to subsequent downstream biological treatment processes. CEPT does, however, increase the rate of chemical consumption and sludge generation, as well as operational costs and the hazards of chemical handling and disposal. At the same time, hybrid decentralized wastewater treatment systems have been gaining popularity, presenting an even more viable option as they focus on treating domestic wastewater in the absence of centralized treatment systems; these systems combine one or more treatment processes such as septic tanks, Up-flow Anaerobic Sludge Blanket (UASB) reactors, and constructed wetlands to promote organic matter removal without high energy or operational costs, and have been proven through numerous studies to remove high and low levels of Chemical Oxygen Demand (COD), Biological Oxygen Demand (BOD), and Total Suspended Solids (TSS) from domestic wastewater. In this regard, improving the hydrolysis and solubilization of complex organic matter during the initial stages of treatment has been identified as crucial for augmenting subsequent biological processes. The present study examines current treatment methods and hybrid configurations to gain insights into their mechanisms, treatment efficacy, benefits, and shortcomings, and elucidates major technological deficiencies while indicating possible avenues for the creation of novel, sustainable methods to enhance the primary stages of wastewater treatment while minimizing chemical use and lowering operational costs.
Glucoside-Assisted Enhancement of CO2 Hydrate Formation Kinetics: Molecular Dynamics Investigation
Ramkhelavan Kanaujiyaa, Tarak K. Patra and Atanu K. Metya · Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai 600036, India · Department of Chemical and Biochemical Engineering, IIT Patna, Patna 801106, India
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Gas hydrates, or clathrate hydrates, are crystalline compounds in which water molecules form hydrogen-bonded cages that encapsulate guest gases such as CO2 and CH4 under high-pressure, low-temperature conditions. Naturally occurring in deep-sea sediments and permafrost, these hydrates also hold promise for technological applications, including gas storage, separation, transportation, greenhouse gas sequestration, wastewater treatment, desalination, and flow assurance in oil and gas pipelines. However, their inherently slow formation kinetics remain a major limitation for large-scale carbon capture and storage. In this work, molecular dynamics (MD) simulations are employed to examine the impact of glucoside-based additives – caprylyl glucoside, decyl glucoside, lauryl glucoside, and their sulphonated derivatives – on CO2 hydrate nucleation and growth. The influence of pressure, temperature, and additive concentration is systematically investigated to provide molecular-level insights into glucosides as kinetic hydrate promoters. Our results demonstrate that glucoside-based promoters significantly enhance hydrate formation and growth, advancing the understanding of hydrate–promoter interactions and underscoring their potential for efficient, sustainable CO2 capture and storage strategies.
A Novel Wave Powered Maritime Surveillance System
Suman Kumar and Abdus Samad · Department of Ocean Engineering, Indian Institute of Technology Madras, Chennai, India
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Unmanned coastal surveillance systems (UCSSs) powered by ocean wave energy can be deployed along coasts where close observation is needed to prevent infiltration or detection of unknown objects that could threaten a country’s security. Existing systems generally use solar power, which requires a large battery. A wave energy converter (WEC) extracts energy from ocean surface waves and reduces the battery requirements of a UCSS. This study describes a WEC, Sindhuja-I, that supplied power to a UCSS. The Sindhuja-I is portable and can be deployed at 10 m to any water depth in the sea. The UCSS was designed and tested in the wave basin facility at IIT Madras, and system performance was recorded under different wave conditions. A few objects were detected and identified using an image-processing strategy. The WEC produced varying power, reaching up to 20 W, while the camera consumed around 2 W under different laboratory test conditions.
Energy System Transition as Carbon Valorisation: Grid Expansion, Fossil Displacement, and Decentralised Renewable Persistence in Rural India
Srikant Shaw and Santosh Kumar Sahu · Department of Humanities and Social Sciences, Indian Institute of Technology Madras · School of Sustainability, IIT Madras
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Transitioning rural energy systems away from fossil-dependent technologies toward cleaner alternatives is central to circular energy strategies in developing economies. However, the pathway through which centralised grid expansion interacts with decentralised energy systems, and whether it reinforces or undermines carbon valorisation at the household level, remains empirically underexplored. This paper examines how large-scale rural electrification reshapes the household energy portfolio through technology displacement, fossil fuel dependence, and clean energy capital accumulation, using nationally representative panel data from the CEEW ACCESS survey covering rural households across six Indian states in 2015 and 2018. Exploiting district-level variation in grid connection growth under India’s Saubhagya and DDUGJY programmes, we employ a difference-in-differences design validated across fixed effects, standard first-difference, and augmented first-difference estimators. The results identify three mechanisms through which grid expansion contributes to and partially constrains circular energy system transitions. First, grid expansion displaces fossil-intensive decentralised nodes: diesel-powered microgrids, which constituted 91 per cent of the baseline decentralised supply sample, decline significantly in treated districts, closing a linear fossil extraction-combustion loop at the community level. Second, kerosene lighting declines by 30 percentage points in treated households, representing a substantial reduction in carbon-intensive household energy flows and a shift toward lower-emission grid electricity. Third, and critically, solar home systems are statistically unaffected by grid expansion, indicating that clean decentralised technologies retain their role in the energy portfolio even as fossil-dependent alternatives exit, a finding consistent with circular energy system logic where complementary rather than substitutable technologies coexist. Downstream, treated households accumulate grid-complementary energy capital, including inverters and electrical appliances, deepening system integration and extending the productive utilisation of energy infrastructure. The aggregate transition from diesel and kerosene toward grid electricity and persistent solar represents a partial carbon valorisation pathway: reducing the carbon intensity of energy services delivered while preserving decentralised renewable capacity. However, substituting diesel microgrids for a coal-heavy grid implies that the net emissions benefit depends critically on the carbon intensity of grid supply, underscoring the importance of concurrent grid decarbonisation as a condition for realising the full circular energy potential of rural electrification programs.
CFD Modelling of Reactive CO2 Absorption in Structured Packings
Matam Sandeep Chandra, Praveen Kumar and Swapna Singha Rabha · Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai, India
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CO2 is one of the major greenhouse gases causing global warming, and carbon capture, utilization, and storage (CCUS) is one of the novel technologies addressing the issue of CO2 emissions. Among various CO2 capture methods, amine-based CO2 absorption remains a widely used technology in industry, with efficiency depending on factors such as operating conditions, the type of amine used, and the effectiveness of gas–liquid contact. Structured packings offer excellent mass transfer efficiency, low pressure drop, good wettability, and high capacity compared to random packings for effective gas–liquid contact, but are also more sensitive to maldistribution, which reduces gas–liquid mass transfer, making it important to improve mass transfer in structured packing. This work focuses on developing a multiphase Eulerian CFD model to predict the hydrodynamics, mass transfer, and CO2 absorption in monoethanolamine (MEA) for an in-house structured packed column. The computational domain consists of a packed column of 28 cm height and 5 cm diameter, equipped with structured packing of 4.979 cm diameter to enhance gas–liquid contact; the liquid phase consists of aqueous MEA solution filled to a height of 28 cm, with a binary gas mixture of 28.2 wt% CO2 and 71.8 wt% N2 introduced from the bottom at 0.021 m/s. The governing momentum, energy, and species transport equations are solved using OpenFOAM v8.0, beginning with an investigation of hydrodynamics followed by detailed modelling of CO2 absorption in MEA, where CO2 reacts with MEA to form carbamate (CO2 + H2O + 2 MEA ⇌ MEACOO− + MEAH+). Mass transfer between gas and liquid phases is incorporated through a Sherwood number correlation, Sh = f(Re, Sc), and the predicted CO2 loading and capture efficiency at different gas velocities are validated against in-house experimental data; the effective interfacial area across the column is estimated from the gradient of the liquid volume fraction. Unlike the porous media approach commonly used in the literature, which fails to capture the realistic flow distribution across packings that strongly influences mass transfer, the present work employs in-house realistic structured packing geometry, allowing the flow behaviour within the packing elements to be observed, and the resulting CFD predictions of product formation are compared with those obtained using the porous media approach.
Sustainable MEA-Based CO2 Capture: Mass Transfer and Solvent Stability Analysis
Praveen Kumaar R and Swapna Singha Rabha · Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai, India
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Post-combustion CO2 capture using aqueous monoethanolamine (MEA) is one of the most mature technologies for reducing industrial carbon emissions. However, long-term operation is often limited by solvent degradation and corrosion, leading to reduced process efficiency, increased solvent consumption, and higher operational waste generation. From a circular energy perspective, improving solvent stability and extending solvent lifetime are essential for enhancing the sustainability of carbon capture systems. In this study, CO2 absorption experiments were conducted in both semi-batch and continuous modes to investigate capture performance, mass transfer behaviour, solvent degradation, and corrosion in MEA-based systems under realistic operating conditions. Experiments were carried out in a stainless-steel packed column (5 cm diameter, 1 m height) using 10–30 wt% MEA solutions over a range of temperatures and inlet CO2 concentrations. Initial CO2 absorption efficiencies of 80–90% and CO2 loadings of 0.45–0.50 mol CO2 mol−1 MEA were achieved; with prolonged operation, capture capacity declined by 25–35% due to solvent aging and degradation. Mass transfer analysis revealed absorption fluxes on the order of 10−4 mol m−2 s−1, while liquid-side mass transfer coefficients and enhancement factors decreased significantly with continued operation, indicating deterioration in reaction and transport performance. Solvent degradation and corrosion were characterized using HPLC-RID, FTIR, NMR, TGA, and ICP-OES; results showed 20–30% MEA loss, reduced thermal stability, and progressive iron accumulation due to corrosion. Additional studies under N2/CO2 and Air/CO2 environments confirmed that oxygen substantially induces degradation and metal leaching. Overall, this work highlights the importance of solvent preservation and corrosion reduction for developing more sustainable and resource-efficient amine-based CO2 capture systems aligned with circular energy principles.
Experimental and Computational Investigation of Solute Transport in Porous Media
Vishnu Priyan J, Paridhi Goel and Swapna Singha Rabha · Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai 600036, India
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Pore-scale modeling has limitations for large-scale transport studies because it is restricted to small domains and may not fully capture reservoir heterogeneity. In this study, porosity data were extracted from a real cylindrical core sample (24 cm length and 5 cm ID) using MATLAB-based image-processing techniques; the workflow integrated MATLAB for data processing and geometry generation, while COMSOL Multiphysics was used for transport simulations. Rock permeability was estimated using the Pape et al. (1998) correlation based on pore-structure characteristics, and the resulting datasets were mapped onto a cylindrical geometry for numerical simulations. The influence of diffusion coefficient, dispersivity, and permeability distributions on tracer transport was analyzed, with both spatial and temporal tracer distributions quantified using residence time distribution (RTD) and dilution index analyses; the dilution index was determined using image-processing-based methods described by Kitanidis et al. (1994) to evaluate mixing and spreading behavior. Variations in permeability and porosity were found to influence flow velocity and RTD, while fractures created preferential flow pathways that accelerated transport and reduced mixing. Further, experiments were conducted in homogeneous and heterogeneous synthetic media to generate controlled data; the movement of the tracer plume at the outlet was analyzed to measure RTD at various flow rates, and images were captured with a high-speed camera to evaluate the dilution index. At lower flow rates, the RTD curves showed a broader distribution with a long tail, while as flow rate increased, tracer breakthrough occurred earlier and the extent of tailing decreased. The qualitative visualization results were consistent with the RTD analysis, thereby linking pore-scale heterogeneity to overall transport behavior. The developed model will be further applied to understand CO2 transport and flow behavior in sub-surface flow.
Energy-Based Screening of Advanced Solid Adsorbents for Sustainable CO2 Capture Applications
Paridhi Goel, Praveen Kumaar R. and Swapna Singha Rabha · Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai 600036, India
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Adsorption-based carbon capture has emerged as a promising alternative to conventional amine absorption, offering several advantages. In conventional temperature-swing adsorption (TSA) processes, regeneration is typically performed at a constant heating temperature, which often results in excessive thermal driving forces, irreversible heat transfer, and poor energy utilization; the large regeneration energy requirement during the desorption step remains a major challenge limiting the large-scale deployment of adsorption systems. The present work proposes a simplified thermodynamic framework for analyzing regeneration energy requirements in adsorption-based CO2 capture systems, introducing the concept of pinch-based thermal management to define optimized desorption conditions during the regeneration of solid adsorbents. The model is employed to analyze different heating strategies, with the baseline constant-temperature case first validated against reported literature results; the validated model is then employed to evaluate various heating strategies and their influence on regeneration energy demand, desorption duration, and thermodynamic efficiency. The model framework is further extended to compare the regeneration behavior of various solid adsorbents such as metal-organic frameworks (MOFs), covalent organic frameworks (COFs), zeolitic imidazolate frameworks (ZIFs), and amine-functionalized silica adsorbents. The expected outcome of this work is the identification of adsorbent materials and regeneration strategies that offer lower specific energy consumption and improved thermodynamic performance, providing a simple yet effective platform for screening emerging adsorbents from an energy perspective and enabling a more performance-oriented evaluation rather than one based solely on adsorption capacity.
Multiscale Modeling Framework for Electrically Heated Steam Methane Reforming Reactor
T. Bhumana, S. De, A. P. van Bavel, A. N. R. Bos and H. Goyal · Indian Institute of Technology Madras, India · Shell India Markets Private Limited, Bangalore, India · Shell Global Solutions International B.V., Amsterdam, Netherlands
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The increasing availability of affordable renewable electricity offers a significant opportunity to decarbonize energy-intensive chemical processes. Among various electricity-to-heat technologies, including microwave and induction heating, Joule heating has emerged as a promising option owing to its high thermal efficiency, rapid thermal response, and scalability. While experimental studies have demonstrated the feasibility of electrically heated catalytic reactors, the development of computational design frameworks for reactor optimization and scale-up remains limited. In this work, a two-dimensional axisymmetric computational fluid dynamics (CFD) model is developed to investigate the coupled electro-thermal-species transport behavior in a Joule-heated steam methane reforming (SMR) reactor, incorporating the heterogeneous reaction kinetics proposed by Xu and Froment. The CFD predictions are validated against the experimental temperature profiles reported by Wismann et al., demonstrating good agreement with the measured data. The model further provides detailed insights into the interplay between heat transfer, mass transfer, and reaction kinetics through analyses of Nusselt and Sherwood numbers along with characteristic time scales. In addition, the influence of axial power distribution on reactor performance is systematically examined while maintaining the same average power input; three power profiles – constant, linearly increasing, and linearly decreasing – are evaluated for their impact on temperature distribution, methane conversion, hydrogen yield, and reactor length reduction. The simulations reveal that a linearly decreasing power profile produces a more uniform temperature distribution, resulting in enhanced methane conversion and hydrogen yield, and that comparable reactor performance can be achieved at significantly reduced reactor lengths, highlighting the potential of power tailoring as a strategy for process intensification in electrically heated catalytic reactors.
Mass Transfer Analysis in the Catalyst Layer for Electrochemical Reduction of CO2
Vedha Vaishnavi R and Himanshu Goyal · Indian Institute of Technology Madras, Chennai, India
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Electrochemical utilization of CO2 has significant potential to convert CO2 into valuable chemicals such as CO, and recent advances in gas diffusion electrodes (GDEs) have improved CO2 electrolyzer performance. However, the catalyst layer (CL) is multiscale, multiphase, and multiphysics, making accurate modelling a challenge; various 1D models report transitions from a kinetic to a mass-transfer-controlled regime as applied potential increases, but the physical representation of CO2 gas–electrolyte liquid distribution and wettability underlying the mass transport limitations remains simplified. In this study, a validated 1D model is combined with pore-scale Volume of Fluid (VOF) simulations to examine how gas–liquid distribution and wettability influence mass transfer limitations in the CL. A 1D model of a microfluidic CO2 electrolyzer with an Ag GDE is developed and validated against experiments; simulations are performed at 1 atm and 0.5 M KHCO3 electrolyte, with reduction potential varying from −0.5 V to −2 V (vs. RHE). The 1D model is implemented in COMSOL Multiphysics, and the gas–liquid distribution is investigated using the VOF method in ANSYS Fluent. The developed 1D model is analyzed for two wettability conditions in the CL – wetted (thin electrolyte film) and flooded (electrolyte-filled pores) – and the mass transfer analysis identifies the gas–liquid mass transfer coefficient as the sensitive parameter, which is commonly overestimated in the literature using diffusivity–film-thickness relations. From VOF simulations, under hydrophilic conditions the CL remains flooded irrespective of increasing contact angle at 1 atm, showing that flooding-dominant transport provides a more realistic description of gas–liquid distribution in the CL than thin-film transport assumptions.
Scalable Azo-Dye Based Carbon Quantum Dot for Optical Management
Ayush George and Abhay Vijay Kotkondawar · Department of Chemistry, Institute of Chemical Technology–Indian Oil Odisha Campus, Bhubaneswar, India
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Azo dyes are a versatile class of organic compounds widely recognized for their intense coloration, photophysical properties, and broad applications in industrial and biomedical fields. The current investigation explores their potential as carbon dot precursors through a facile solvothermal synthesis approach, transforming the azo dye precursor under solvothermal conditions to facilitate carbonization and the formation of organic solvent-soluble carbon quantum dots (green-yellow CQDs). The developed method produced CQDs with a reaction yield of approximately 68% and exhibited strong fluorescence emission in the visible region. The physicochemical properties of the synthesized CQDs were comprehensively characterized using FT-NMR, HR-TEM, XPS, UV-DRS, and photoluminescence (PL) spectroscopy. Low-resolution TEM images revealed the formation of colloidal assemblies with average sizes ranging from 50 to 70 nm, while HR-TEM analysis indicated that the individual CQDs distributed within these assemblies possessed average particle sizes below 1.5 nm. The synthesized CQDs displayed pronounced fluorescence emission around 483 nm along with a high fluorescence quantum yield in DMF solution. Furthermore, a CQD-based luminescent film was fabricated using a poly(methyl methacrylate) (PMMA) matrix and successfully integrated onto a blue LED chip to construct a down-conversion light-emitting device; the Commission Internationale de l’Éclairage (CIE) chromaticity coordinates of the fabricated LED were determined to be approximately (0.27, 0.32). The excellent optical properties, solvent processability, and tunable fluorescence characteristics of azo-dye-derived CQDs highlight their potential applications in optical management, light-emitting devices, sensing, and advanced photonic technologies.
Assessing the Impact of Particle Size and Constituent Ratios of Mixed Household Waste on Syngas Production: A Hybrid Analysis
Srijan Sanjeev Shahane, Rohan Dutta and Vikranth Volli · School for Climate Action, Anant National University, Ahmedabad, Gujarat 382115, India
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India has complex waste management challenges due to its mixed waste streams. Thermochemical conversion pathways are effective for extracting value from this waste as gaseous or liquid fuels, with efficiency and product formation determined by process temperature and feedstock composition. In this ongoing study, the characteristics of a mixed feedstock and their impact on syngas production and quality in a high-temperature gasification system are explored. The feedstock consisted of mixed sawdust, low-density polyethylene (LDPE) garbage bags, and kraft paper bags, shredded and mixed in different ratios. For sawdust mixtures, moisture and volatile matter were 7.2–7.36% and 85–86.9%, respectively, with ash content between 1.4–2.1%; for kraft paper, these parameters were 4.478%, 89.1%, and 6.86%, respectively; and for the garbage bag sample, they were 0.395%, 87.96%, and 9.36%, respectively, with ash content attributable to fillers and additives. The results of the proximate analysis show that both particle size and feedstock composition influence output and reaction kinetics; moisture and volatile matter, along with particle size and mixture ratios, play a role in determining the quality of syngas produced. These findings will aid in identifying ideal feedstock pre-treatment conditions for chemical recycling.
Synergistic Stability Enhancement of Magnesium-Doped MAPbI3 Perovskite Solar Cells via Vacuum Thermal Annealing
Nalini V, Aneela Perumulla, Nithin Xavier, Mukundan R. Pillai, Soumya Dutta, Mousumi Upadhyay Kahaly, Sreeram K. Kalpathy, Tiju Thomas and Sumangala T. P. · Department of Physics, School of Advanced Sciences, Vellore Institute of Technology, Vellore, Tamil Nadu 632014, India · Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600036, India · Department of Electrical Engineering, Indian Institute of Technology Madras, Chennai 600036, India · ELI ALPS, ELI-HU Non-Profit Ltd., Szeged H-6728, Hungary · Institute of Physics, University of Szeged, Szeged H-6720, Hungary · Centre for Resource Efficiency, Recyclability and Circularity in Energy Transition, School of Sustainability, Indian Institute of Technology Madras, Chennai 600036, India
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Perovskite solar cells (PSCs) have recently achieved power conversion efficiencies (PCEs) comparable to conventional silicon photovoltaics. Despite this progress, commercialization remains limited by poor long-term stability and the need for fabrication in inert atmospheres, typically in glove boxes. To address the stability concerns, magnesium (Mg), an earth-abundant, non-toxic element, was explored as a partial substitute for lead in MAPbI3 perovskites; Mg incorporation was designed to block iodine vacancy sites, thereby reducing oxygen diffusion and mitigating degradation pathways. To overcome current challenges, precursor synthesis (MAI: methylammonium iodide and PbI2: lead iodide), ink preparation, and doping procedures were performed under cost-effective, open-air laboratory conditions (temperature: 30±2°C; relative humidity: 35±4%) within a fume hood, eliminating the need for sophisticated inert-atmosphere processing. Mg-doped perovskites were subjected to different annealing conditions, including conventional annealing and vacuum annealing (VA), to evaluate the impact of thermal treatment. Comparative analysis revealed that Mg doping alone increased the average grain size to ≈350 nm, while the combination of Mg doping with VA produced significantly larger grains (≈850 nm), as confirmed by SEM analysis. Mg-doped perovskite films subjected to vacuum annealing exhibited significantly improved moisture resistance, confirmed through climatic test studies at 35°C and 80–85% relative humidity, conditions known to accelerate material degradation. In addition to improved durability, the films exhibited a twofold enhancement in power conversion efficiency (PCE) under low-humidity conditions. Collectively, these results highlight the synergistic effect of Mg incorporation and vacuum thermal annealing in mitigating moisture-induced degradation pathways while simultaneously boosting device performance, highlighting the potential of compositional engineering with Mg and process optimization via vacuum annealing as complementary strategies to improve both the stability and efficiency of perovskite solar cells, paving the way for environmentally benign and commercially viable perovskite photovoltaics.
Valorization of Waste Biomass to Hard Carbon Anodes for Sodium-Ion Batteries
Nithyasree Manohar and Nitin Muralidharan · EMERGE Research Group, Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai 600036, India · Centre for Resource Efficiency, Recyclability, and Circularity in Energy Transition, Indian Institute of Technology Madras, India · School of Sustainability, Indian Institute of Technology Madras, Chennai, India
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The rising demand for cost-effective and sustainable energy storage solutions has necessitated the exploration of alternative battery technologies beyond traditional lithium-ion batteries. Sodium-ion batteries (SIBs) have emerged as a viable alternative for large-scale energy storage systems due to the natural abundance, extensive geographical distribution, and low cost of sodium resources. Among the numerous anode candidates, hard carbon has attracted considerable interest due to its high reversible capacity, suitable working potential, and compatibility with sodium-ion storage mechanisms. In this study, banana peduncle, an abundant agricultural waste biomass, is used as a sustainable precursor for the synthesis of hard-carbon anode materials. The biomass is initially subjected to acid hydrolysis to remove impurities and partially decompose lignocellulosic components, followed by potassium hydroxide (KOH) activation to develop a porous structure and increase the availability of active sites; the activated precursor is subsequently carbonized under an inert atmosphere to obtain hard carbon with a disordered microstructure favorable for sodium-ion storage. Structural and morphological characteristics of the synthesized materials are investigated using X-ray diffraction (XRD), Raman spectroscopy, and scanning electron microscopy (SEM). The combined acid hydrolysis, chemical activation, and thermal carbonization processes are expected to produce hard carbon with enlarged interlayer spacing, abundant defect sites, and hierarchical porosity, facilitating sodium-ion diffusion and storage. This work presents a cost-effective, environmentally sustainable approach to valorize banana peduncle waste into high-value hard carbon materials and highlights its potential as an anode material for next-generation sodium-ion batteries.
DFT Study on Conversion of Lignin-Derived Compounds in Supercritical Water, Methanol, and Ethanol Environments
Praveen Kumar Reddy Annapureddy and Nanda Kishore · Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India
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The transformation of lignin-derived compounds into high-value chemicals is a crucial step in the development of sustainable biomass-based energy systems and circular bioeconomies. The thermodynamic feasibility of two representative lignin-derived conversion pathways – conversion of ferulic acid to cinnamic acid and guaiacol to cyclohexanone – was investigated in supercritical methanol and supercritical ethanol. Thermodynamic parameters such as the change in Gibbs free energy (ΔG) and change in enthalpy (ΔH) were determined at different temperature and pressure conditions mimicking supercritical processing. The calculated Gibbs free energy values for both reactions were negative under all investigated conditions, indicating thermodynamically favourable reaction behaviour regardless of the solvent environment; however, the values for supercritical methanol and ethanol were relatively more negative than for supercritical water, implying increased thermodynamic favourability and improved stabilisation of reactants and products in alcohol-based supercritical media. The Gibbs free energy for the conversion of guaiacol to cyclohexanone was more negative at higher temperatures, indicating that the required thermodynamic driving force is lower at higher temperatures. The calculated enthalpy values were positive for both reactions in all solvent systems, confirming the endothermic nature of the reactions and emphasising the importance of thermal energy input during conversion. These findings highlight the significance of solvent effects in determining the thermodynamics of biomass conversion reactions of lignin-derived materials, offering valuable insights for the development of sustainable thermochemical conversion processes and circular energy systems using supercritical alcohols as efficient reaction media for biomass upgrading.
Electrification of CO2 Sorbent Regeneration using Microwave Heating
Devangshi Debraj, Niket S. Kaisare and Himanshu Goyal · Indian Institute of Technology Madras, India
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The rise in CO2 emissions underscores the need for efficient carbon capture and low-energy sorbent regeneration. Conventional desorption methods based on a purge gas are either slow or energy-intensive, as they rely on indirect heat transfer mechanisms inherently limited by gas–solid contact efficiency; electrified heating using renewable energy presents a promising pathway to decarbonise energy-intensive processes in the chemical industry. Electrified approaches such as microwave swing adsorption (MSA) enable rapid and selective volumetric heating of the solid phase, significantly reducing desorption time and energy consumption. MSA has demonstrated improved efficiency across fluidised, packed, and structured bed configurations, each with distinct multiphase flow and heat transfer characteristics; however, there is a lack of mechanistic understanding of microwave–material interactions coupled with desorption kinetics. In an in-house reactor system, adsorption capacity, desorption efficiency, and the influence of varied flowrates and desorption temperatures on gas–solid interaction and regeneration performance are analysed for CO2 capture using Zeolite 13X. Microwave heating desorption cycles were subsequently conducted to assess the viability of microwave irradiation as a selective heating mode in a packed bed environment, and the evolution of temperature profiles within the bed provides insight into the energy deposition characteristics of microwave heating and its implications for bed-scale heat and mass transfer. A key focus of this work is to provide a rigorous basis for isolating the contributions of flow dynamics and heat transfer, since understanding these multiphase interactions is central to translating laboratory-scale performance into scalable, industrially relevant systems.
Performance Evaluation of a Pilot-Scale Two-Column VPSA System for Post-Combustion CO2 Capture Using Zeolite 13X Beads
R. Harish Ragavendran, Parthiban V, Satyanarayanan Seshadri and Swapna Singha Rabha · The Energy Consortium, Indian Institute of Technology Madras, Chennai, India · Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai, India · School of Sustainability, Indian Institute of Technology Madras, Chennai, India · Department of Applied Mechanics & Biomedical Engineering, Indian Institute of Technology Madras, Chennai, India
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Post-combustion carbon capture is considered one of the promising approaches for reducing industrial CO2 emissions and supporting sustainable energy transition strategies. In the present study, a pilot-scale Vacuum Pressure Swing Adsorption (VPSA) system integrated within a mobile containerized unit was experimentally investigated for cyclic CO2 capture using zeolite 13X beads as the adsorbent material. The zeolite bead size ranged from 1.5–2.5 mm, and the adsorption columns possessed an internal diameter of 0.45 m with a total height of 1.5 m and a packed bed height of 0.70 m. The VPSA system consisted of two adsorption columns operated alternately under adsorption and vacuum desorption conditions to ensure continuous cyclic operation. A simulated flue gas mixture containing air and CO2 in an 80:20 ratio was supplied from the bottom of the packed bed at a total flow rate of 125 SLPM using a compressor. During adsorption, selective adsorption of CO2 occurred within the zeolite 13X packed bed, while regeneration was achieved using a vacuum pump under desorption conditions; the adsorption process exhibited exothermic characteristics, with bed temperatures reaching nearly 110°C during cyclic operation. System performance was evaluated over five consecutive adsorption–desorption cycles through breakthrough analysis, adsorption capacity, CO2 production rate, pressure drop characteristics, and cyclic stability studies. The experimental investigation demonstrated stable VPSA operation with effective CO2 separation under industrially relevant operating conditions, highlighting the potential of zeolite 13X-based packed bed systems for post-combustion carbon capture applications.
Production of Biofuel from Algal Biomass by Aqueous Phase Reforming
Taanisha Mukhopadhyay and Dr. Gourisankar Roymahapatra · Department of Chemical Engineering, IIEST Shibpur, Howrah, India · Department of Metallurgy and Materials Science Engineering, IIEST Shibpur, Howrah, India · Department of Applied Science and Humanities, Haldia Institute of Technology (Autonomous), Haldia 721657, West Bengal, India
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With the growth of the human population, the need for sustainable energy resources has increased substantially; large-scale utilisation of fossil fuels would leave few viable energy resources for future generations, making renewable and clean sources of energy – Green Energy Resources – essential. Biological hydrogen (H2) production (BHP) enhancement through the use of nanoparticle (NP) supplements in the growth media has recently emerged as a promising approach; nanoparticles, including metal and metal oxide NPs, have shown significant improvement in BHP. Suitable bacteria such as C. butyricum, used as inoculum together with gold nanoparticles (AuNPs), provided an effective approach for H2 production from sucrose, while Kappaphycus alvarezii and sludge were also processed for bio-hydrogen production. Aqueous phase reforming with 7.5 wt% Au was found to give a 62.3% higher yield from synthetic wastewater containing sucrose as feed under anaerobic culture, compared to a control applying the minimum amount of AuNPs; overall, the catalyst achieved 61.25% bio-hydrogen production. The maximum bio-hydrogen yield was 36.1% for a 2:1 (sludge:algae) ratio at 360°C. The high ratio of acetate to butyrate and low ethanol production observed in the presence of AuNPs is associated with a significant increase in H2 production. With the aim of expanding applications of bio-nanotechnology for hydrogen production, AuNPs were also biosynthesized via aqueous-phase reforming of a synthetic compound (brewery wastewater) supported on activated carbon; these AuNPs demonstrated strong catalytic performance for the degradation of industrial pollutants, making the environment cleaner and more sustainable. Overall, hydrothermal gasification (aqueous phase reforming) yielded syngas, biochar, and enhanced H2 production via liquid-phase formation, while anaerobic digestion of cyanobacterial biomass broke down complex organic and inorganic compounds in industrial wastewater, facilitating an efficient reforming process.
Machine Learning-Based Battery Second-Life Classification for Sustainable Electric Vehicle Ecosystems
Amartya R. Nair, Aditya V. Padwalkar and Anupam Sharma · School of Engineering, Chanakya University, Bengaluru, Karnataka, India
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The rapid growth of electric vehicles (EVs) has led to a significant increase in lithium-ion batteries, posing both environmental challenges and resource wastage concerns. Many batteries are removed from EV applications when their State of Health falls below 70%, yet they still have sufficient usable capacity for secondary applications such as stationary energy storage. This paper proposes an AI-driven Smart Battery Second-Life Decision System that enables classification of used EV batteries into reuse, repurpose, or recycle pathways. The system senses key battery parameters, including voltage, current, temperature, and internal resistance, using an embedded hardware platform; these inputs are processed through a machine learning model trained to estimate battery health metrics such as State of Health (SoH) and Remaining Useful Life (RUL). Based on predictive analytics, the system performs automated decision-making to determine optimal second-life utilization: batteries with higher health are redirected for reuse in EV or mobility applications, moderately degraded batteries are repurposed for stationary storage such as solar energy systems, and critically degraded batteries are sent for recycling. The proposed solution contributes to circularity in the battery industry by extending battery lifecycle, reducing waste, and improving resource efficiency, while enabling scalable and cost-effective decision intelligence for sustainable battery management in emerging EV ecosystems.
Deep Eutectic Solvent Electrolytes for Sustainable Lithium–Sulphur Batteries
Dipshikha Jana, Bibhas Kumar Nayak and Kshetramohan Sahoo · Department of Chemical Engineering, National Institute of Technology, Rourkela-769008
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The rapid shift to green and renewable energy demands efficient storage solutions which must also be sustainable. Lithium–sulphur (Li–S) batteries are attractive options due to their high theoretical energy density, low cost, and sulphur abundance. However, conventional electrolytes suffer from polysulfide shuttle, instability, and environmental concerns. This work explores deep eutectic solvent (DES)-based electrolytes as greener alternatives, offering low volatility, non-toxicity, and improved solvation behaviour. We focus on designing and optimizing DES formulations to mitigate electrolyte–electrode interaction challenges, aiming to enhance cycle life, stability, and efficiency. The study aims to advance Li–S batteries as a sustainable option for large-scale renewable energy storage.
Extraction of Critical Metals from Spent LiFePO4 (LFP) Batteries using Polyol-Based Metallurgical Method
Franklin Darlingboy Tellewoyan and Dr. Nitin Muralidharan · EMERGE Research Group, Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai, India · Centre for Resource Efficiency, Recyclability and Circularity in Energy Transition, Indian Institute of Technology Madras, Chennai, India
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Due to the massive increase in the use of lithium-ion batteries in electronic devices and electric vehicles, there has been a drastic increase in battery demand along with economic and environmental concerns. Conventional approaches, including pyrometallurgy, hydrometallurgy, and direct recycling methods, are widely used for recovering critical metals such as Li, Ni, Co, and Mn from spent or dead Li-ion batteries; however, conventional hydrometallurgical methods use toxic acids and bases, while pyrometallurgy uses very high temperatures. Here, we demonstrate a green polyol-based metallurgical approach using citric acid in ethylene glycol (CAEG), which serves dual functions – leaching and forming a complex precipitate – during the extraction of lithium from LiFePO4 (LFP) black mass. LFP black mass was pyrolyzed at elevated temperatures to remove volatile impurities, and the pyrolyzed black mass was characterized using techniques such as XRD, FTIR, ICP-MS, and TGA to understand its chemical composition. Leaching was performed using the CAEG solution, and the duration of precipitation was optimized; the leachate and residue were also characterized to evaluate leaching efficiency. It was found that >90% of the Li can be selectively extracted using the CAEG method, demonstrating that a polyol-based metallurgical approach can be a viable green method to extract Li from LFP black mass.
Solvent-Based Lithium Extraction: A Combined Molecular Dynamics and Experimental Study
Shamanth Y. U., Jitendra Carpenter, Subrahmanya Bhat K., Srikanth Divi and Anoop Kishore Vatti · Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal 576104, India
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Lithium-ion batteries (LIBs) are central energy-storage technologies for modern electrification, particularly in electric vehicles, and are increasingly being deployed in stationary grid energy-storage applications. Recycling lithium from spent batteries allows valuable resources to be reintegrated into the supply chain, thereby supporting the development of a circular economy and advancing sustainable development. Liquid–liquid extraction is considered an efficient and cost-effective approach for lithium recovery. In this study, molecular dynamics simulations were carried out to examine the selective separation of lithium using deep eutectic solvents and ionic liquids, followed by experimental validation. The work provides an in-depth discussion of the extraction mechanism, solvation behavior, atomic-level interactions, extraction efficiency, and various structural and dynamical properties.
Recovery of Active Cathode Material from Spent Mobile Lithium-ion Batteries using a Custom-made Ternary Deep Eutectic Solvent
Appurva K, Rajesha P M, P Hemanth, V M Aravind, Raju K Gupta and Sudhir H Ranganath · Bio-INvENT Lab, Department of Chemical Engineering, Siddaganga Institute of Technology, Tumakuru, Karnataka, India · Department of Chemical Engineering, Indian Institute of Technology Kanpur, U.P., India · Department of Sustainable Energy Engineering, Indian Institute of Technology Kanpur, U.P., India · Chandrakanta Kesavan Centre for Energy Policy and Climate Solutions, Indian Institute of Technology Kanpur, U.P., India · Tvastra InnoTech Solutions Pvt. Ltd., Tumakuru, Karnataka, India
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Lithium-ion batteries (LiBs) are integral to modern technology, powering a broad array of devices, including mobile phones, laptops, electric vehicles, and systems for renewable energy. However, their widespread utilisation presents considerable environmental and social challenges, notably due to the reliance on scarce and hazardous materials that necessitate energy-intensive extraction and processing methods. Recycling of LiBs emerges as a viable strategy to address these issues, offering a method to reclaim valuable metals and reduce the demand for the extraction of fresh raw materials. Furthermore, recycling initiatives have the potential to generate economic opportunities and foster innovation within the battery sector. Conventional recycling methods, including pyrometallurgical and hydrometallurgical processes, are energy-intensive and hazardous. To address this, we developed a novel Ternary Deep Eutectic Solvent (TDES), which is green and composed of Hydrogen Bond Donors and Acceptors in a specific molar ratio. This solvent offers several advantages, such as low freezing points, high thermal stability, low volatility, and tunability. Spent mobile phone batteries were dismantled under water to safely recover active cathode material (ACM), which contained Li, Co, Ni, and Mn. The TDES achieved rapid leaching of the ACM at 90 °C within 30 minutes and at a significantly lower operating temperature (90 °C) than traditional methods (700 °C). High extraction efficiencies of ~99% were achieved for Li⁺, Co²⁺, Ni²⁺, and Mn²⁺. Subsequent stage-wise selective precipitation allowed recovery of high-purity metal oxides of Nickel, Manganese and Cobalt and Lithium is selectively precipitated as Lithium carbonate. Kinetic analysis indicated that leaching was controlled by both liquid-film diffusion and product-layer diffusion for Li and Co. The same TDES was applied to LiNi₀.₈₅Co₀.₁Al₀.₀₅O₂ (NCA), yielding extraction efficiencies of ~68% Ni, ~64% Co, ~92% Al, and ~70% Li, aligning with elemental analysis. Further optimisation of metal recovery from NCA systems is under current investigation. Overall, the developed TDES demonstrates strong potential as a sustainable and efficient medium for LIB recycling.
Direct Electrochemical Extraction of Lithium Metal from Black Mass Leach Liquor
Lakshmi Narayana Manickavasagam, Abraham Samuel Thangadurai and Nitin Muralidharan · EMERGE Research Group, Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai, India · Centre for Resource Efficiency, Recyclability & Circularity in Energy Transitions, Indian Institute of Technology Madras, Chennai, India
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Electrification of transport and grid-scale energy storage has resulted in the manufacturing and utilization of billions of Li-ion batteries. With increasing electrification to meet net-zero demands, the number of batteries required is also increasing exponentially year by year, and at this rate, millions of tonnes of spent or dead lithium batteries and thousands of tonnes of production scrap would be generated in the next few years. To ensure sustainable use of renewable technologies integrated with battery energy storage systems, recycling of critical materials from spent Li-ion batteries is crucial. LiNi1-x-yMnxCoyO2 (NMC) and LiFePO4 (LFP) are the most predominant battery chemistries in use; in NMC batteries, Ni, Mn, Co, and Li are the most valuable metals, whereas in LFP, Li is the most valuable metal. Conventionally, critical materials are recovered using hydrometallurgical and pyrometallurgical techniques; however, in these methods, Li is generally recovered at the final step owing to its small atomic radius, generally in salt form with a low recovery efficiency (40–60%). Here, we demonstrate a novel electrochemical technique, utilizing a Li-ion-conducting membrane, to selectively recover Li in its metallic form from black mass leach liquor, which can potentially be integrated with conventional hydrometallurgical techniques to recover Li at the very first step, significantly reducing Li loss.
TBP Encapsulated in Pickering Emulsion for the Selective Recovery of Lithium from Salt Brines
Guguloth Naresh, Etheyaraja Mani, Sulalit Bandyopadhyay and Sreeram K. Kalpathy · Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, India · Department of Chemical Engineering, Indian Institute of Technology Madras, India · Department of Chemical Engineering, NTNU, Norway
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Lithium has already occupied an unshakable position in the field of energy transformation, due to its near-irreplaceability in the production of high-energy-density batteries for electric vehicles. The world is moving towards zero-emission mobility, which requires the electrification and decarbonization of the transport sector. The new energy market has been expanding rapidly, with a dramatic increase in lithium demand worldwide, estimated at 1,607,000 tons in 2050; meanwhile, the gap between demand and supply is becoming increasingly severe, and a sustainable supply of lithium is essential to the healthy development of the lithium battery market. Therefore, it is imperative to develop new technologies and expand various channels for highly efficient lithium recovery. Currently, several common technologies, such as adsorption, ion exchange, solvent extraction, and membranes, have been developed for lithium recovery from salt lake brine. Among these technologies, solvent extraction using tributyl phosphate (TBP) and FeCl3 as coextractants offers unique advantages, including excellent lithium selectivity in brines with high Mg/Li ratios, stable cycling performance, and simple operation; however, the conventional TBP technique has several limitations, including poor mass transfer, unstable interfaces, extractant loss, and high energy intensity. Therefore, we propose a new technique in which TBP is encapsulated within Pickering emulsions for efficient extraction of Li from salt brine.
Sustainable Benign Route to Utilize Spent Lead-Acid Batteries for Producing PbCl2 Electrodes for Next-Generation Li-Ion Batteries
Andrews Cyril A, K. K. Sahu and Srijan Sengupta · Centre for Circularity, School of Sustainability, Indian Institute of Technology Madras, India · CSIR–National Metallurgical Laboratory, Jamshedpur, India · Department of Materials, Rishabh Centre for Research and Innovation in Clean Energy, IIT Jodhpur, India
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In response to the rising demand for energy storage, researchers are prioritizing improving lithium-ion batteries’ specific energy and volumetric energy capacity. Lead (Pb) stands out as a promising anode option due to its high gravimetric capacity of 569 mAh/g and volumetric capacity of 6452 mAh/g, offering significant potential to enhance the performance of these batteries. Upgrading from discarded lead-acid batteries (LABs) to more contemporary lithium-ion batteries will be an alternative approach to meeting growing demand; LABs have a high lead content, resulting in the highest recovery rate during extraction. Pyrometallurgical processes remain the primary method for lead recycling; however, they pose several drawbacks, including harmful environmental impacts, such as the emission of lead dust and sulfur dioxide (SO2), and high energy consumption. A few recently developed environmentally friendly hydrometallurgical processes operating at near-ambient temperatures have shown great potential for recovering lead from spent lead-acid batteries; direct dissolution of lead through brine leaching offers a promising, clean recovery pathway for recovering lead chloride from lead-acid batteries. In this work, LAB paste material was separated and dissolved in brine solution to produce PbCl2 through crystallization, a green recycling technique that transforms waste into resources for active anode material in lithium-ion batteries. A novel strategy is explored to use recovered lead halide (PbCl2) with two-stage lithiation, offering superior electrochemical performance as a replacement for pristine Pb in the negative electrode.
Efficient Xtraction and Treatment for Recovery of Advanced Critical-Materials and Technologies (EXTRACT)
Abraham Samuel Thangadurai and Nitin Muralidharan · EMERGE Research Group, Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai 600036, India
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The global scramble to secure tech metals, battery minerals, and rare earths is encountering a significant bottleneck, and current extraction routes – large, environmentally destructive mines or reliance on risky overseas supply chains – are no longer sufficient. This challenge is addressed by the EXTRACT (Efficient Xtraction and Treatment for Recovery of Advanced Critical-materials and Technologies) programme, through the development of integrated hydrometallurgical methodologies for the efficient extraction, purification, and valorization of critical materials from complex feedstocks, primarily end-of-life lithium-ion batteries and spent electronic assemblies. The approach uses smart chemical recycling, green solvents, and cleaner processes to recover high-purity critical materials from commonly overlooked sources such as low-grade ores, old electronics, and industrial waste, substantially reducing the energy and toxic waste normally associated with metal refining. Beyond recycling, the recovered elements are refined back into high-grade materials ready for use in next-generation batteries; lithium, cobalt, nickel, manganese, copper, aluminum, and graphite are the critical materials that underpin rechargeable battery technologies essential to modern energy storage and electronics. The processing line includes optimized leaching, solvent extraction, and electrowinning-based purification steps that selectively recover these materials at battery-grade purity, enabling direct re-integration into the manufacture of recycled battery cells and high-purity metal products, with real-time process monitoring and closed-loop reagent management minimizing chemical consumption and secondary waste generation throughout. EXTRACT provides a scalable, low-impact hydrometallurgical platform to support critical-material supply chains and accelerate the shift towards a circular battery economy.
Fabrication of Dry-Processed Flexible NASICON-Type Solid Electrolyte for Solid-State Sodium-Ion Batteries
Kowsika Murugesan and Nitin Muralidharan · Department of Chemical Engineering, Indian Institute of Technology Madras, India
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Solid-state electrolytes offer both safety and enhanced energy density, making them highly desirable for future batteries; however, the challenge with solid-state electrolytes remains in finding scalable, cost-effective processing techniques. In this work, a dry fabrication technique using polytetrafluoroethylene (PTFE) as a binder for the NASICON-type (Na3Zr2Si2PO12–NZSP) electrolyte is investigated, an approach that eliminates the use of toxic and flammable organic solvents in the electrolyte. The ionic conductivity of the flexible NZSP–3% PTFE electrolyte film is found to be 1.12 × 10−4 S cm−1; the ceramic NZSP electrolyte contributes to the ionic conductivity, while the uniformly distributed PTFE fibrils offer flexibility. Morphological investigation of this electrolyte film reveals that the fibrillated PTFE holds the NZSP powder together through its 3D fibrous structure. Symmetric cell studies demonstrate good interfacial stability against sodium metal, eliminating dendrite formation up to 100 cycles at 0.1 mA cm−2. In addition, this approach utilizes abundant sodium metal as the anode, highlighting the capability of dry-processed electrolytes as a scalable pathway towards next-generation solid-state sodium-ion batteries.
Carbon Alchemy: Lignite Transformed into High-Performance Graphite Anode
Venkatesan Natesan, Santhoshini Murugan, Mysore Sridhar Santos, Karthic Natarajan and Kothandaraman Ramanujam · Clean Energy Laboratory, Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, Tamil Nadu, India · The Energy Consortium, Indian Institute of Technology Madras, Chennai 600036, Tamil Nadu, India · CIL Centre for Sustainable Energy, Indian Institute of Technology Madras, Chennai 600036, Tamil Nadu, India · CSIR-Central Institute of Mining and Fuel Research, Digwadih Campus, Dhanbad, Jharkhand 828108, India
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An earth-abundant and low-cost lignite coal was employed as a carbon precursor for the synthesis of highly pure synthetic graphite through carbonization, followed by high-temperature graphitization treatment at 2800 °C (SG-2800) and 3000 °C (SG-3000). The results reveal that the microstructures of SG-2800 and SG-3000 are strongly dependent on the graphitization temperature. The SG graphitized at 3000 °C has a perfectly ordered layered structure with a high degree of graphitization, as found from the XRD and Raman studies. SG-3000 is explored as an anode material for a lithium-ion battery (LIB) application. The maximum reversible capacity of 305 mAh g−1 at a current rate of 0.1C was obtained along with 94% capacity retention even after 100 cycles. These findings highlight the potential of lignite coal as an inexpensive and scalable precursor for producing high-performance synthetic graphite suitable for advanced LIB applications.
Hierarchical Flower-like Nanosheet-Stacked Ni-based Bimetallic Metal–Organic Framework Electrode for High-Energy Hybrid Supercapacitors
Kajal Samdhyan, Shiwani Khokhar, Prakash Chand and Hardeep Anand · Department of Chemistry, Kurukshetra University, Kurukshetra, Haryana 136119, India · Department of Physics, National Institute of Technology, Kurukshetra, Haryana 136119, India
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Bimetallic MOFs stand out as the most promising approach since they combine the synergistic effect of two metals. Doping nickel (Ni) with a dopant is a common practice to modify the electrical and chemical properties of the resulting Ni-MOF. For doping, the size of the dopant should be comparable to nickel, which minimizes the lattice distortion and maintains the structural integrity of the MOF material. The ionic radii of Co2+ and Ni2+ are very similar, with Co2+ having an ionic radius of ≈79 pm and Ni2+ ≈83 pm. The incorporation of cobalt into the nickel framework improves both the electrochemical activity and structural properties of the material, making it more suitable for applications such as supercapacitors and batteries. The outstanding electrochemical performance of these hybrid materials can be attributed to (i) the synergistic effect between the metals, which enhances electrical conductivity; (ii) the presence of mesopores, which facilitates the easy diffusion of electrolyte; and (iii) a large surface area and pore volume, which provide significantly more electroactive sites. The flower-like morphology provides a larger surface area compared to the pristine Ni-BDC, facilitating more active sites for electrochemical reactions. Flower-like structures composed of nanosheets can be synthesized by incorporating 0.05 M cobalt solution into synthesized Ni-BDC. The optimized Co@Ni-BDC demonstrated remarkable electrochemical performance, delivering impressive specific capacitances of 2753.3 F/g at a current density of 3 A/g. The retention remained impressively high for Co@Ni-BDC, with 84% capacity retention even after 5000 cycles.
Thermal Stability and Fire Performance of PBS/Bagasse Sustainable Composites – Effect of Diammonium Phosphate Treatment
Shanthini Devi A, Keerthika N. B. and R. Gnanamoorthy · Architected and Sustainable Materials Design Research Centre, Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036, India
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Traditional plastic production remains heavily reliant on fossil fuels, perpetuating a linear “take–make–dispose” economy that accelerates resource depletion and environmental degradation. To overcome this issue, natural material–reinforced composites offer a viable approach to creating a circular industrial ecosystem by utilizing bio-based matrices and agricultural waste residues. Sugarcane bagasse, an abundant agricultural by-product, was utilized as a reinforcing filler in PBS composites; unlike cultivated natural fibers that compete for arable land and water resources, sugarcane bagasse valorizes industrial by-products without expanding the agricultural footprint. The flammability characteristics of new polymer systems are critical to ensuring safety, reliability, and regulatory compliance across diverse engineering applications. The effect of surface treatment with diammonium phosphate (DAP), a halogen-free, inorganic salt flame retardant that encourages char formation through phosphorus–nitrogen synergy, is examined in the current study. The effectiveness of the flame-retardant treatment was evaluated using a comprehensive range of thermal and flammability characterization techniques. Cone calorimetry analysis showed that DAP treatment significantly reduced the peak heat release rate (PHRR), mass loss rate (MLR), and toxic gas emissions of bagasse, thereby enhancing its fire resistance. UL 94 vertical burn tests on PBS/bagasse composites demonstrated robust self-extinguishing properties, a major upgrade from the volatile burning observed in untreated control samples.
Sustainable Approach for Integrated Microwave Pretreatment and Photocatalytic Upcycling of Sugarcane (Saccharum officinarum) Leaf Biomass to Lactic Acid
Alice Jasmine and Tamilarasan Krishnamurthi · Department of Biotechnology, SRM Institute of Science and Technology, Chennai 603203, India · Department of Chemical Engineering, SRM Institute of Science and Technology, Chennai 603203, India
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The depletion of fossil fuels and rising greenhouse gas emissions has intensified the exploration of sustainable energy resources. Sugarcane leaf (SCL) biomass is a promising renewable feedstock for biofuel and biochemical production, and while the application of photocatalysis to biorefinery is of great significance for sustainable development, limited success has been achieved to date. This study aimed to develop an effective delignification strategy for SCL biomass and its subsequent photocatalytic conversion into lactic acid (LA). The initial research focused on developing efficient pretreatment strategies for SCL biomass via microwave-assisted sodium carbonate (SCL-MSC) pretreatment for effective deconstruction of the biomass. Optimization using central composite design identified the ideal pretreatment conditions (508 W, 4 min, 7.87 wt% biomass, 0.87 MSC) that resulted in maximum saccharification yield (RSY of 601 mg g−1 and GY of 231 mg g−1). The optimized cellulose-rich SCL biomass was further converted to LA using a g-C3N4-O 50% photocatalyst, which increased the LA yield to 345.39 mg g−1 while reducing the formic acid yield to 30.45 mg g−1. Furthermore, techno-economic analysis (TEA) revealed that the estimated net production cost of LA was $3.32 kg−1, with an ROI of 14.43% and a payback period of 6.93 years; sensitivity analysis revealed that raw material costs and LA market price significantly influenced the economic viability. Overall, this work demonstrates a sustainable and economically feasible strategy for producing lactic acid from sugarcane leaf biomass through integrated microwave pretreatment and photocatalysis.
Towards Agricultural Circularity: Biomass-Derived Biodegradable Mulch Sheets with Potential for Photocatalytic Soil Remediation
R. Janani and Vidya K. Shetty · Department of Chemical Engineering, National Institute of Technology Karnataka, Surathkal, Mangaluru, India
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Agricultural mulching sheets are widely adopted for enhancing crop productivity, offering benefits such as weed control and moisture retention in soil. However, commercial mulching sheets made from synthetic polymers such as low-density polyethylene, polybutylene adipate terephthalate, and polybutylene succinate contribute to secondary pollution in the form of micro/nano plastics in the soil after use. The present work focuses on the development of biodegradable cellulose-based mulching sheets made from agricultural residues such as sugarcane bagasse, corn husk, rice straw, and banana peduncle as environmentally sustainable alternatives, with the additional objective of in-situ photocatalytic soil remediation. The biomass-derived fibers are subjected to alkaline treatment, bleaching, and homogenization to produce micro-cellulose-rich pulp (MCP); the fiber morphology and hydrodynamics of the MCP are further optimized by the inclusion of biopolymer binders such as polyvinyl alcohol and sodium alginate, which enhance dispersion, consistency, and mechanical integrity during sheet formation. Among the tested precursors, corn husk and sugarcane bagasse show improved homogeneity and processability. The key innovation of the present work is the integration of MCP with a metal-free, soil-friendly photocatalyst, which endows the sheets with soil remediation functionality by photocatalytically degrading pesticide residues present on the soil surface. In summary, this work establishes a sustainable material framework for the development of photocatalyst-integrated cellulose-based mulches with enhanced environmental functionality, advancing both agricultural practice and environmental preservation.
PDMS-Based Nanocomposite Films as Encapsulations to Improve Photovoltaic Reliability and Longevity
Aneela Perumalla, Reitesh K. V. Raman, Tiju Thomas and Sreeram K. Kalpathy · Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600036, India · Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA · Centre for Resource Efficiency, Recyclability and Circularity in Energy Transition, School of Sustainability, Indian Institute of Technology Madras, Chennai 600036, India
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The long-term sustainability of photovoltaic (PV) systems depends on improving their durability, thereby minimizing maintenance costs and material replacement. We developed polymer nanocomposite (PNC) films as multifunctional encapsulants that provide a one-stop solution to heat- and moisture-induced degradation in silicon solar cells, thereby improving PV reliability and longevity. The PNC films were fabricated by dispersing ≈0.45 wt% zinc oxide (ZnO) or titanium dioxide (TiO2) nanoparticles in a dilute solution of polyethylene glycol (PEG) in chloroform, followed by incorporation into polydimethylsiloxane (PDMS) and curing at 80°C for 20 min; the resulting films (≈450 µm thick) were subsequently employed as front encapsulants for commercially available mini silicon solar cells. Thermal aging studies reveal that PNC-encapsulated cells retained >80% of their power conversion efficiency (PCE), whereas unencapsulated cells retained only ≈50% of their initial PCE. Additionally, at 60°C and 90°C, the surface temperature of PNC-encapsulated cells was reduced by ≈5–8°C compared to unencapsulated cells, indicating effective thermal management. Further, when subjected to damp-heat conditions for one week, the PNC-encapsulated cells retained >50% of their initial PCE, whereas the unencapsulated cells retained only ≈17%. Thus, module service life has been extended by simultaneously reducing thermal- and moisture-driven degradation, thereby lowering replacement frequency, minimizing waste generation, and enhancing the lifecycle sustainability of solar energy infrastructure. These attributes position the proposed encapsulation strategy as a promising pathway toward more sustainable industrial ecosystems and resilient green energy supply chains.
Enhancement in Tensile Strength and Moisture Resistance of Surface Functionalized Jute Fibres
Amrutha H, Sirish Namilae and Sreeram K. Kalpathy · Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600036, India · Department of Aerospace Engineering, Embry-Riddle Aeronautical University, Daytona Beach, Florida, USA · Centre for Resource Efficiency, Recyclability and Circularity in Energy Transition, School of Sustainability, Indian Institute of Technology Madras, Chennai 600036, India
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Natural fibres offer desirable characteristics including biodegradability, biocompatibility, low cost, and high specific mechanical properties; however, their variability, low tensile strength, and hydrophilic nature pose significant challenges in composite applications. Surface functionalization of natural fibres has proven to be an effective approach for enhancing their strength, stiffness, and interfacial bonding characteristics while retaining their inherent biodegradability. In this study, surface modification of single jute fibres was performed using hydroxyapatite (HAP), a natural calcium mineral commonly used in bone tissue repair surgeries; earlier reports have shown that HAP has excellent biocompatibility and mechanical performance, and could therefore act as an eco-friendly interface modifier for natural fibres. Surface modification using stearic acid in jute fibre was also carried out to impart moisture resistance and enhance interfacial properties; stearic acid is a biocompatible saturated fatty acid whose incorporation in several matrices has shown an improvement in hydrophobic character. The presence of HAP and stearic acid on the surface of jute fibres was confirmed by FTIR analysis and SEM images, and studies on both HAP- and stearic-acid-coated jute fibres have shown a significant enhancement in tensile strength and thermal properties. Overall, HAP and stearic acid surface modification will help improve the interfacial fibre–matrix bond, thereby broadening the scope of application of natural fibres in composite systems.
Vortex-Induced Vibration Response of a Buoyancy-Assisted Deep-Water Marine Riser Subjected to Varying Currents
Anu Sugathan and K. G. Vijay · Department of Ocean Engineering, Indian Institute of Technology Madras, Chennai, India
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This study investigates the sensitivity of vortex-induced vibration (VIV) response in a buoyancy-assisted deep-water drilling riser subjected to sheared currents. The riser is modelled as a tensioned Euler–Bernoulli beam with coupled cross-flow (CF) and in-line (IL) responses, while hydrodynamic forcing is represented using a wake oscillator model validated against the experimental results of Trim et al. A 1200 m riser fitted with buoyancy modules over the upper 300 m is analysed alongside a bare-riser configuration for various shear parameters. The results indicate that increasing shear reduces the global coherence and amplitude of the CF response, with an overall reduction of approximately 57% between the lowest and highest shear cases; in contrast, the IL response exhibits a non-monotonic trend, increasing at intermediate shear before decreasing at high shear levels, with enhanced multi-frequency behaviour also observed with increasing shear. Compared with the CF response, the IL response shows greater sensitivity to shear in terms of both vibration amplitude and the location of peak response. The effectiveness of buoyancy modules in suppressing VIV is found to depend strongly on the shear profile, being most effective under low-shear conditions and less effective at higher shear levels. These findings highlight that riser designs based on a single representative current profile may not provide conservative predictions across varying operating conditions; therefore, shear-aware VIV assessment using a representative range of current profiles is recommended for buoyancy-assisted deep-water drilling risers.
Experimental Characterization of Bio-Based Roofing Composites with Natural Binder Matrix
Sriram G. and Dr. V. Sathish Kumar · Department of Civil Engineering, Sri Krishna College of Technology, Coimbatore 641042, India
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The increasing demand for sustainable construction materials has driven research toward the development of eco-friendly composites derived from renewable resources. This study focuses on the experimental characterization of bio-based roofing composites reinforced with agricultural fibers and bonded using a natural binder matrix comprising lime and starch, with the objective of developing a lightweight, durable, and thermally efficient roofing material as an alternative to conventional systems. The composite is fabricated by integrating treated agro-fibers with the binder matrix and supplementary materials, followed by molding into corrugated sheet forms, compaction, and controlled curing; fibers enhance tensile strength and insulation properties, while lime contributes to durability and water resistance, and starch improves interfacial bonding. Experimental evaluation includes assessment of physico-mechanical and thermal properties such as density, compressive strength, water absorption, and thermal conductivity. Results indicate that the developed composite exhibits adequate structural performance and improved thermal insulation compared to conventional roofing materials, demonstrating the potential of bio-based composites as sustainable roofing solutions that promote resource efficiency, reduced environmental impact, and applicability in low-cost housing and rural infrastructure development.
Circular Economy Transitions in the Fashion Industry: Toward Sustainable Production Systems and Resource Efficiency
Anzala Suhail Independent Researcher ·
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The fashion industry is one of the most resource-intensive sectors globally, contributing significantly to environmental degradation through excessive water consumption, greenhouse gas emissions, and large-scale textile waste generation. The prevailing linear “take–make–dispose” model has intensified sustainability challenges, necessitating systemic interventions for resource efficiency and waste reduction. In this scenario, the circular economy offers a regenerative framework aimed at extending product life cycles, improving material recovery, and minimizing environmental impacts across production and consumption systems. This poster presents a conceptual and analytical exploration of circular economy integration within the fashion industry, focusing on its role in enabling sustainable production systems. Key circular strategies, including textile recycling, upcycling, eco-design, and the adoption of sustainable and bio-based materials, are examined in relation to their potential to reduce environmental burdens and enhance resource circularity within supply chains. The study further investigates critical barriers limiting large-scale implementation, such as technological constraints, fragmented supply chain structures, economic feasibility, and limited consumer awareness regarding sustainable fashion practices. Additionally, the analysis emphasizes the importance of multi-stakeholder collaboration involving industry actors, policymakers, and consumers in facilitating effective circular transitions. The need for context-specific, scalable, and economically viable strategies is highlighted to ensure long-term sustainability outcomes. This work contributes to the growing discourse on sustainable industrial ecosystems and aligns with global sustainability agendas, particularly Sustainable Development Goals related to responsible consumption and production.
Coal-Incorporated Polymer Composites as Circular Economy Alternatives to Wood-Plastic Composites
Shubham Jaiswal and Ethayaraja Mani · Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai 600036, India · Centre of Excellence in Biodegradable Packaging, Indian Institute of Technology Madras, Chennai, Tamil Nadu, India · School of Sustainability, Indian Institute of Technology Madras, Chennai 600036, Tamil Nadu, India
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The global wood-plastic composite market, valued at approximately USD 10 billion and growing rapidly, faces persistent challenges due to its reliance on wood flour as a primary filler. This material is inherently flammable, prone to biological decay, and degrades under high heat. Meanwhile, large-scale coal preparation plants generate millions of tonnes of coal fines and reject material annually, which are typically treated as low-value waste with limited use. This study introduces coal-incorporated polymer composites as a circular-economy solution that addresses the performance gaps of conventional wood-plastic composites and valorizes an abundant domestic industrial by-product. Following detailed characterization, we will modify the coal to improve its compatibility with plastics. These tailored fillers will then be blended at varying loadings using standard molding techniques. The resulting composites will be evaluated for structural strength, thermal resilience, and fire resistance. Leveraging coal’s carbon-rich structure, we anticipate improved flame retardancy and heat tolerance, reducing dependence on expensive chemical additives. Additionally, this waste-derived filler offers clear economic benefits through its low cost and local availability. Ultimately, this research aims to convert industrial coal refuse into valuable structural materials, lowering disposal burdens, fostering sustainable manufacturing, and supporting national resource efficiency objectives.
From Recycling to Second-Life: Assessing Challenges and Policy Gaps in the Electric Vehicle Battery Reverse Supply Chain
Bindhu A. and Arshinder Kaur · Centre for Circularity, Indian Institute of Technology Madras, Chennai, India · Department of Management Studies (DoMS), Indian Institute of Technology Madras, Chennai, India
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This paper presents a review of reverse supply chains (RSCs) for used electric vehicle batteries. It integrates existing knowledge across battery recycling, battery reuse, second-life applications, material recovery, and policy frameworks. The review highlights multi-dimensional uncertainties in return quality, quantity, costs, and regulation that determine an efficient RSC or used electric vehicle batteries. While recycling shows strong technical feasibility, its industrial scalability remains limited, and the logistics costs dominate the economics. Second-life deployment at 70–80% residual capacity, although it is established, in reality is constrained by liability, standardised state-of-health assessment, and pricing. Policy analysis shows insufficiently regulated global regulations. The paper concludes by identifying research gaps in integrating scalable supply chain logistics, adopting regulation, and viable second-life business models.
Valorization of Clitoria ternatea Biomass for Domestic Wastewater Treatment and Sustainable Concrete Production: A Circular Water-Energy Nexus Approach
Karthika Saramariraj and V. R. Prasath Kumar · Department of Civil Engineering, Faculty of Engineering and Technology, SRM Institute of Science and Technology, Kattankulathur, Chengalpattu Dt., Tamil Nadu 603203, India
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The increasing demand for sustainable and decentralized wastewater treatment has driven advances in biomass-based adsorbents to enhance water quality. This research explores the use of biochar derived from Clitoria ternatea biomass (CT-BC) as an environmentally friendly adsorbent for treating domestic wastewater. Biochar was produced via pyrolysis and tested under various operating conditions to improve pollutant removal efficiency. The adsorption process was analysed using equilibrium and kinetic models to better understand the mechanisms involved in treatment. Advanced characterization methods, including XRD, FTIR, and SEM–EDS, were used to analyse the physicochemical properties of CT-BC. The findings showed a porous, heterogeneous surface with oxygen-rich functional groups, which are ideal for contaminant adsorption. Isotherm and kinetic tests demonstrated that the adsorption was driven by heterogeneous surface interactions and chemisorption. Statistical results confirmed that CT-BC effectively and consistently enhanced wastewater quality at various sampling sites. The results show that biochar made from Clitoria ternatea is an effective, affordable, and eco-friendly option for treating domestic wastewater. Turning biomass waste into a valuable water-purification tool promotes circular resource use and supports sustainable water management. This research supports circular economy principles and helps achieve the UN Sustainable Development Goals on clean water, sanitation, and responsible resource use.
From Residue Burning to Resource Recovery: Crop-Residue Roof Insulation for Sustainable Livestock Shelters in India
S. Rahul Bharath, Srinivasan Periaswamy and Srikant Routroy · Department of Mechanical Engineering, Birla Institute of Technology and Science, Pilani, Rajasthan 333031, India
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Agricultural residues are often treated as waste, despite their potential for productive reuse in rural infrastructure. This study explores a circular application of pearl millet and paddy straw as roof-insulation materials for naturally ventilated dairy shelters in India, with the aim of reducing heat stress while creating value from locally available biomass. A validated EnergyPlus model was used to assess shelter performance across representative Indian climates. The analysis considered roof heat transfer, indoor thermal conditions, Temperature–Humidity Index (THI), and the influence of key design parameters such as insulation thickness, sidewall height, shelter capacity, and cattle heat load. The thermal results were further connected to productivity-related economic benefits and greenhouse-gas mitigation. Crop-residue insulation substantially reduced roof-mediated heat gain and improved indoor thermal conditions, with annual THI reduction varying from 730 to 5826 THI·h across climates. Maximum reductions of 5.62 °C in indoor temperature and 4.18 THI units were observed. Pearl millet straw showed consistently better performance than paddy straw, while shelter geometry and insulation thickness were identified as important design factors. Beyond thermal performance, the intervention showed considerable potential for economic benefit, lower milk-related emission intensity, and avoided emissions from residue burning. The results highlight crop-residue insulation as a practical pathway linking resource recovery, passive cooling, climate resilience, and sustainable dairy production.
SustainX 2026 Conference Companion
The full 148-page conference companion — schedule, speaker biographies, and abstracts — designed as a scholarly research artifact. Read it as an interactive Web Flipbook, or download the Colour E-Book or Monochrome Print PDF editions.
Session Materials
Supplementary materials from the conference — keynote slides and workshop resources — are being collected and will be added to this archive as they are released by the presenters.