Enhancing Methane Storage in Clathrate Hydrates Using Leaf Extract Catalysts: Advancing Sustainable Energy Storage

Abstract

Gas hydrates have garnered attention for their potential to capture and store large gas volumes in their petite latticelike water structure. This study explores the feasibility of enhancing methane hydrate conversion by hastening hydrate process kinetics, maximizing methane uptake, and storage using benign additives sourced from dried leaves of Calotropis procera (CTP) (milkweed) and Nyctanthes arbor-tristis (NA) (night-flowering jasmine). These bioadditives were compared with the well-known methane hydrate former sodium dodecyl sulfate (SDS) and pure water as a baseline. Methane hydrate formation occurred at approximately 271.7 ± 0.78 K with bioadditives, whereas SDS exhibited formation at around 278.15 ± 1.37 K under stirred and nonstirred conditions. Bioadditives required twice the subcooling of the SDS system, and the methane uptake kinetics were faster in nonstirred conditions and doubled under stirring. Overall methane captured with the selected additives was similar to that of SDS, with slightly higher uptake under stirring. These bioextracts displayed favorable methane hydrate affinity, attributed to mixed constituents including alkaloids, flavonoids, cardenolides, carotenoids, and phenolic compounds. These additives, which are biodegradable and less toxic, stand as eco-friendly alternatives to organic agents like SDS. Offering nonfoaming properties for smoother operations and reusability, bioadditives hold promise for sustainable applications.