The study of the adsorption behavior of silica in removing water vapor using computational chemistry methods provides better views on understanding the de- hydration process. In pure adsorption and diffusion, the smaller kinetic diameter of water is the most important factor in decreasing the adsorption and increas- ing the diffusion of water vapor in silica pores. Moreover, in the mixed-use guest molecules, the hydrogen bond of the water vapor molecule and siloxane and the in- teraction between methane and water are effective factors in separating water vapor from methane in the process of dehydration of natural gas. Computational stud- ies using Monte Carlo and molecular dynamics simulation showed that the highest amounts of adsorption calculated in pure and binary mixture adsorption are related to methane and water vapor, respectively. Furthermore, water vapor in a pure diffu- sion is more than methane, and in binary mixture diffusion, methane vapor shows a higher diffusion coefficient.

Keywords