Methane Hydrate Formation Behavior in the Presence of Selected Amino Acids

Abstract

Industrial-scale capture, storage, and transport of gases and gas mixtures, such as natural gas, CH4, and CO2 in the form of gas hydrate, is an attractive and feasible solution. However, low formation rate and low water-to-hydrate conversion make it challenging to adopt at commercial scale. Selection of an appropriate chemical as hydrate promoter is crucial to the success of such technologies. Amino acids are seen as potential chemicals to use in such applications due to their environmentally benign nature. However, there are uncertainties around their behavior and classification, since their thermodynamic and kinetic effects on gas hydrates are not well established. In this study, we have identified the kinetics of select amino acids (L-valine, L-methionine, L-histidine, and L-arginine) in methane hydrate formation. Results indicate that hydrophobicity of amino acids plays an important role in methane hydrate kinetics. L-methionine and L-valine show maximum normalized gas uptake and lowest induction time compared to L-histidine and L-arginine.