Phase equilibrium properties of CO2/CH4 mixed gas hydroquinone clathrates: Experimental data and model predictions

Hydroquinone (HQ) clathrates seem to be promising inclusion compounds for selective CO2 capture from gas mixtures. However, to date no phase equilibrium data are known in literature for mixed-gas HQ clathrates. This study presents experimental equilibrium pressures obtained within a range of 298343 K for different CO2/CH4 gas mixtures. The clathrate composition is given for each equilibrium point. The capture selectivity is calculated from the molar composition of the CO2/CH4 gas mixture in the clathrate and in the gas phase. The results obtained reveal that CH4 molecules in the CO2/CH4 mixtures are preferentially captured at equilibrium conditions. Our experimental data are compared against numerical predictions obtained from thermodynamic modeling using the Conde's model. Very good agreement is found between the calculated and experimental data in terms of clathrate phase equilibria. (C) 2017 Elsevier Ltd.