The effects of potential model of CO2 on its bulk phase properties and adsorption on surfaces and in pores

Adsorption of CO2 using carbonaceous materials is one of the common approaches for carbon capture and storage. To improve this technology, it necessitates the understanding of the underlying mechanisms, for which molecular simulation has been recognised as a useful tool and compensation of experimental study. However, to ensure the reliability of the simulation results, the selection of the reliable potential model is vital. A systematic Monte Carlo simulation was conducted to evaluate the performance of two commonly used potential models of CO2, i.e. the simple 1C-LJ and the TraPPE 3C-LJ + 3Q models, in different scenarios including bulk phase, adsorption on graphite surface and in carbonaceous pores. In addition, a special investigation on the occurrence of step-wised hysteresis in wedge-shaped pore that has been observed with other simple gases. It reveals the consideration of shape and quadrupole of CO2 play an important role in the description on the phase equilibria and adsorption behaviour, especially at temperatures below the triple point.