Solubility of the single gases H2 and CO in the ionic liquid [bmim][CH3SO4]

The solubility of the single gases hydrogen and carbon monoxide in the ionic liquid 1-n-butyl-3-methylimidazolium methyl sulfate ([bmim][CH3SO4]) was measured with a high-pressure view-cell technique based on the synthetic method. The temperature ranged from ∼293 to ∼413 K, and the pressure reached up to ∼9.3 MPa. The gas molality amounted up to ∼0.1 mol per kilogram of [bmim][CH3SO4]. Carbon monoxide showed a slightly better solubility than hydrogen. The (extended) Henry's law was successfully applied to correlate the solubility pressures. The final results for the Henry's constant (at zero pressure) of hydrogen and carbon monoxide in [bmim][CH3SO4] (on the molality scale) are correlated within the estimated uncertainty (±1%) by ln (kH,H2(0)/MPa)=3.074+602/(T/K) and ln (kH,CO(0)/MPa)=5.3377−66.85/(T/K)−0.0019517(T/K), respectively.