Research Projects

Geological carbon dioxide (CO₂) sequestration plays a crucial role in achieving a low-carbon transition model aimed at meeting Net-Zero targets. In this context, hydrate-based CO₂ sequestration has attracted significant interest as a sustainable decarbonization approach, offering high storage capacity and long-term stability. However, several technical and economic challenges (primarily mass transfer limitations owing to poor kinetics) limit its feasibility for large-scale implementation. In this regard, the commercial surfactants used for enhancing its kinetics are associated with reduced effectiveness in mixed sediment lithology, toxicity, non-biodegradability, and thermal degradation. In this regard, this project proposal aims to develop zwitterionic biosurfactants as an excellent alternative to commercial anionic and cationic surfactants from identified natural renewable sources. These surfactants are very little explored for use in hydrate-based technological applications but hold great promise to act as a good CO2 hydrate promoter because of their excellent interfacial tension reduction-enhanced hydrate formation growth mechanism coupled with smoothening of the hydrate morphology. Zwitterionic biosurfactants also have excellent viscoelastic properties, enhanced biodegradability, and enhanced foam stability. Our proposed research aims to develop biodegradable zwitterionic surfactants that not only outperform existing surfactants but are also more cost-effective. We have identified several eco-friendly natural sources as starting materials for their synthesis. The process will involve hydrolyzing triglycerides from oils through methods like saponification to yield fatty acids and glycerol, which will serve as key building blocks for zwitterionic biosurfactants. The synthesis will employ various techniques, including alkylation, amidation, esterification, mannich reaction, and quaternization. To identify the most stable surfactants, we will evaluate parameters such as interfacial tension, contact angle, and salinity stability. To assess the effectiveness of a synthesized zwitterionic surfactant in enhancing CO2 hydrate kinetics, experiments will be conducted using a high-pressure porous bed reactor. This reactor will mimic the subsea hydrate stability zone, incorporating sandy-clayey sediments. Key CO2 hydrate formation parameters, including induction time, gas uptake, water-to-hydrate, and gas-to-hydrate conversion efficiencies, as well as the average rate of hydrate formation, will be analysed to identify the most effective zwitterionic surfactants under simulated in-situ conditions. Considering the fact that research works towards the development of zwitterionic biosurfactants have been limited, this study holds great importance to benefit both the industry and the environment.