(367e) Sustainable Methane Storage Using Gas Hydrates with Superabsorbent Polymers (SAPs) and Tetrahydrofuran (THF) Under a Quiescent System

For developing sustainable hydrate-based gas storage system without energy-intensive mechanical agitation, superabsorbent polymers (SAPs) and tetrahydrofuran (THF) were introduced for the methane hydrate formation. With THF solution-absorbed SAPs, methane hydrates were formed immediately without induction time in the absence of stirring. These nucleation characteristics were maintained over 20 cycles of formation-dissociation, indicating that THF solution-absorbed SAPs can be a proper candidate for the sustainable hydrate formation in a non-stirred system. Also, from simulating real enclathration/regeneration situation by adding ventilation/recharging step of methane gas in formation-dissociation cycles,¹ the storage capacity of methane hydrates was slightly declined from the loss of volatile THF during ventilation step. However, due to ‘tuning phenomena’ of THF, the capacity of methane hydrates eventually maintained a constant value. From Raman and power X-ray diffraction (PXRD) spectroscopy, it was revealed that methane molecules were partially occupied 5¹²6⁴ cages, resulting in a constant storage capacity. This work can provide insights into designing a sustainable hydrate-based gas storage system without energy-intensive mechanical agitation.