Corn's dextrin, a novel environmentally friendly promoter of methane hydrate formation

Gas hydrate has the potential to be used as a high capacity storage of natural gas. Methane is the primary component of natural gas in nature. Therefore, it is of interest to evaluate the thermodynamic and kinetic behavior of methane hydrate for industrialization of natural gas storage through hydrate formation. In this study, the main kinetic parameters of methane hydrate formation in the presence of Corn's dextrin were measured and its performance as a promoter was compared to sodium dodecyl sulfate (SDS). The experiments were conducted in a laboratory-reactor at an initial temperature of 275.15 K, and an initial pressure of 7.5 MPa. The kinetic results showed that the use of Corn's dextrin, SDS, and their mixture significantly reduced the induction time and semicompletion time, and also increased the gas consumption and the rate of gas uptake during hydrate formation, and the apparent rate constant of hydrate growth compared to that of pure water. Corn's dextrin with a concentration of 1 wt% had the best performance to promote the kinetics of methane hydrate formation. Dextrin (1 wt%) declines the induction time from 1256 down to 18 min. The utilization of dextrin also enhanced the final storage capacity of methane hydrate by up to 12.5%. The storage capacity of methane hydrate after 60 min of hydrate crystallization showed the values of 121.6 and 124.5 V/V for 1 and 7 wt% dextrin, respectively, which is greater than that of pure water (32.3 V/V). The average apparent constant of hydrate growth (k(app)) of 7 wt% dextrin until 2 min after the beginning of growth stage was reported approximately 28 times larger than pure water. By comparison of the kinetic results of dextrin with SDS, it was concluded that dextrin could compete against SDS in promoting methane hydrate formation at a specific concentration. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The study evaluated the performance of Corn's dextrin and SDS as promoters in methane hydrate formation. Results showed that 1 wt% Corn's dextrin had the best kinetic enhancement effect, significantly reducing induction time and semicompletion time, increasing gas consumption and uptake rate, and enhancing hydrate growth rate and final storage capacity.