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

ABSTRACT

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.

KEYWORDS:

• Carbon dioxide
• adsorption
• Monte Carlo simulation
• potential model

Acknowledgement

Authors X. Liu and A.H.H Sim contributed equally to this work. This work was supported by resources provided by the Pawsey Supercomputing Centre with funding from the Australian Government and the Government of Western Australia.

Disclosure statement

No potential conflict of interest was reported by the author(s).