Examination of amino acid inhibitor effect in methane hydrate dissociation via molecular dynamics simulation

Abstract

Amino acids as a new kind of hydrate kinetic inhibitor can effectively prevent the hydrate formation. In this work, molecular dynamic (MD) simulation is carried out to investigate the effect of amino acids on the methane hydrate dissociation, where different kinds of amino acids including glycine, serine and valine are compared. The interaction between amino acids and methane hydrates is further evaluated. The results reveal that the adsorption energy of serine is higher compared to those of glycine and valine. The adsorption energy has a nonlinear increase with the amount of amino acids. Furthermore, the methane hydrate dissociation process with amino acids is discussed. The radial distribution functions under different inhibitors are compared. It is found that the serine has a better inhibition effect on hydrate compared to glycine as well as valine under the combined effect of electrostatic interaction caused by side chains and hydrogen bonds.