P. Rangsunvigit, K. Inkong, S. Kulprathipanja
Chulalongkorn University,
Thailand
Keywords: biogas, storage, hydrate
Summary:
This work explores the possibility of using gas hydrate technology for biogas storage. It is well known that gas hydrate technology has emerged as a strong contestant for gas storage. However, the technology has its own limitation including slow hydrate formation, which could hinder the gas-storing rate. Potential promoters were tested to alleviate the limitation. The promoters investigated in this work involve both thermodynamic and kinetic types. They include activated carbon (AC), tetrahydrofuran (THF), and sodium dodecyl sulphate (SDS). Experiments in this work followed Singasai et al. [1]. A specially designed crystallizer and control system were used to observe methane and carbon dioxide hydrate formation and dissociation. Temperature and pressure were varied according to the amount of AC, THF, or SDS used in each experiment. The results show that the three promoters, AC, THF, and SDS, contributed to the accelerated methane hydrate formation. Synergistic effects can also be observed with the combination of promoters. However, for carbon dioxide, the promoters can promote the hydrate formation but at a lesser extent than methane. Note that at the same experimental conditions for methane and carbon dioxide, without any promoter, no hydrate formation can be observed for at least 48 hours. For the investigated experimental conditions, the results show that storing biogas via hydrate formation is promising with the added benefit of methane purification.