Design of methane hydrate inhibitor molecule using Density Functional Theory

Abstract

A strategy for designing methane hydrate inhibitor molecule has been established depending upon geometrical parameters, interaction energy, highest occupied molecular orbital (HOMO) - lowest unoccupied molecular orbital (LUMO) structures and energies, natural bond orbital (NBO) analysis, potential energy curve, Mullikan charge, IR intensity and red shift. One methane hydrate inhibitor molecule namely 2, 2’-oxydipropane-1, 3-diol has been designed based on the established design strategy. Theoretical study of effectiveness of the designed inhibitor molecule has been performed for methane hydrate pentagonal dodecahedron cage (1CH4@512) using WB97XD/6-31++G(d,p). Calculated geometrical parameters, interaction energies and HOMO LUMO study indicate that reduction of the strength of hydrogen bonded network of 1CH4@512 cage is more by designed inhibitor 2,2'-oxydipropane-1,3-diol compared to conventional thermodynamic inhibitor (methanol) and consequently 2,2'-oxydipropane-1,3-diol can be more effective methane hydrate inhibitor than methanol. Keywords: