Influence of chitosan quaternary ammonium salts on the kinetics of methane hydrate formation in multi-complex system

Abstract

Biopolymers are widely used in several fields due to their good biocompatibility and environmental friendliness. Therefore, this study focuses on the experimental study of biopolymer chitosan quaternary ammonium salt for methane hydrate growth in multi-complex systems. The synergistic effect was achieved by adding low concentrations of NaCl and L-leucine. The results showed that both effectively promoted the growth of hydrate with increasing concentration in the separate C system. In the CL system, the addition of a small amount of hydrophobic leucine methane uptake was enhanced by up to 179.9% and the induction time was shortened by up to 76.2%; the addition of small amounts of NaCl increases the gas storage capacity by up to 55.1%, and the addition of high concentrations of NaCl limits the final gas storage capacity due to thermodynamic inhibition. It is noteworthy that the addition of NaCl is all effective in facilitating the nucleation for a short period of time (shortening the induction time by 7.9%–59.8%); the addition of a small amount of leucine to the CN system increased the gas storage density by 19.7% (CNL system) The induction times were not significantly different. These findings provide a theoretical basis for hydrate promoters of biomass and a possible pathway for integrating the development and utilization of natural gas hydrates as a future energy source with sustainable development goals.