Carbon dioxide solubility in some ionic liquids at moderate pressures

Here we presented new solubility data for carbon dioxide in three ionic liquids namely: 1-butyl-3-methylimidazolium trifluoromethanesulfonate, 1-ethyl-3-methylimidazolium ethylsulfate, and 1-ethyl-3-methylimidazolium dicyanamide for temperatures ranging from (303.2 to 343.2)K and moderate pressures up to 6.5 MPa using a thermogravimetric microbalance. From equilibrium (absorption saturation) data, the gas solubility was determined at each fixed temperature and pressure. The buoyancy effect was accounted in the evaluation of the gas solubility. Highly accurate equations of states for carbon dioxide and for ionic liquids were employed to determine the effect of buoyancy on carbon dioxide solubilities. The present solubility measurements are presented as a function of temperature and pressure. An extended Henry's law equation was used to correlate the present experimental solubility data and the result was satisfactory. (C) 2008 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.