Experimental solubility of CO2 and CH4 in imidazolium based ionic liquid; C6mimBF4 at high pressures

摘要

The solubility*of carbon dioxide (CO2) in fresh and recycled ionic liquid (IL); 1-hexyl-3-methyl imidazolium tetrafluoroborate [C6mim][BF4] was experimentally measured at three different temperatures i.e., 303.15 K, 318.15 K, 333.15 K and pressures up to 60 bar. The solubility of CO2 and Methane (CH4) in fresh IL; [C6mim][BF4] was also measured using binary mixtures of CO2 and CH4 i.e., 60/40 (B64) and 40/60 (B46) volume percent at temperatures (303.15 K, 318.15 K, 333.15 K) and pressures up to 60 bar. The solubility measurements for both gases were performed in a specifically designed high pressure miniature gas solubility cell. The solubility of CO2 and CH4 in the studied IL increased almost linearly with an increase in pressure and decreased with an increase in temperature and no significant difference was observed for the amount of CO2 absorbed in fresh and recycled IL at the studied range of operating conditions. It was observed that the presence of CH4 significantly reduced the solubility of CO2 in the studied IL.