Solubility of the Single Gases Carbon Dioxide and Hydrogen in the Ionic Liquid [bmpy][Tf2N

Abstract

Experimental data for the solubility of the two single gases carbon dioxide and hydrogen in the ionic liquid 1-n-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide ([bmpy][Tf 2 N]) are reported for temperatures between (293.1 and 413.2) K. The maximum pressure (the maximum gas molality in the solvent) was 10.8 MPa (4.43 mol·kg -1 ) for carbon dioxide and 8.9 MPa (0.14 mol·kg -1 ) for hydrogen. The experiments were performed using a high-pressure view-cell technique operating on the synthetic method. The solubility of carbon dioxide in [bmpy][Tf 2 N] is more than 1 order of magnitude higher than the solubility of hydrogen. Carbon dioxide becomes less soluble in [bmpy][Tf 2 N] with increasing temperature, whereas hydrogen shows the opposite effect. An extension of Henry's law is employed to correlate the solubility pressures. The final results for the Henry's constant (at zero pressure) of carbon dioxide and hydrogen in [bmpy][Tf 2 N] (on the molality scale) are represented within the experimental uncertainty (about 0.8 % for carbon dioxide and 1.3 % for hydrogen) by In(k (0) H,CO2 /MPa) = 8.5128 - 2057/(T/K) - 0.004274·(T/K) and In(k (0) H, H2 /MPa) = 3.5746 + 343/(T/K) - 0.0008·(T/K), respectively.