Nickel effects on carbon dioxide and methane adsorptions on porous glass: experimental and monte carlo simulation studies

Abstract

A Grand Canonical Monte Carlo simulation (GCMC) method is used to study the adsorption of methane and carbon dioxide on porous silica glass in the presence and absence of nickel. Nickel atoms are randomly allocated on pore walls, accounting for approximately 1–5% by weight. Experimental data is collected for various nickel concentrations ranging from 0 to 10%. The preparation of porous glass in the presence of Ni is done both with and without calcination in the furnace. The simulation investigates the adsorption of methane and carbon dioxide at temperatures of 273 K and 298 K for different pore widths. The adsorption of methane increases with higher nickel concentration due to the stronger interaction between methane and nickel. However, the opposite behavior is observed in the case of carbon dioxide. Physical adsorption reveals that fluid adsorption on porous glass surfaces decreases as temperature increases. The adsorption of methane begins at the nickel molecule and then progresses further inside the pore. However, in the experimental work, a similar behavior is found for nickel concentrations less than 5% with calcination, after which the adsorption decreases with increasing Ni concentration. This may be attributed to the blocking of Ni molecules at the pore entrance, resulting in difficulty for methane diffusion through the pore. Regarding the effect of Ni allocation on glass surfaces, it is observed that the isotherm obtained for randomly placed nickels is greater than that for nickels placed at the pore edge. This can also be attributed to the pore-blocking effect. The allocation of Ni does not significantly affect the adsorption of carbon dioxide. The finding of this study are supported by similarity to the results reported by others, for example in the study of methane adsorption on activated carbon in the presence of Ni. It can be concluded that nickel on solid surfaces can enhance the adsorption of methane for energy storage.