Impact of water on the [C(4)C(1)im][Ac] ability for the CO2/CH4 separation

authors	Navarro, P; Garcia, J; Rodriguez, F; Carvalho, PJ; Coutinho, JAP
nationality	International
journal	JOURNAL OF CO2 UTILIZATION
author keywords	Carbon dioxide; Methane; Gas sweetening; Ionic liquids; Water
keywords	PRESSURE PHASE-BEHAVIOR; CARBON-DIOXIDE CAPTURE; MIXED MATRIX MEMBRANES; IONIC LIQUIDS; CO2 CAPTURE; 1-BUTYL-3-METHYLIMIDAZOLIUM ACETATE; SOLUBILITY; PLUS; EQUILIBRIUM; TEMPERATURES
abstract	The water impact on the CO2 and CH4 solubilities and their selectivity in [C(4)C(1)im][Ac] was evaluated for [C(4)C(1)im][Ac]:H2O molar ratios of 5:1, 2:1, 1:1, and 1:2, for temperatures ranging from (293 to 363) K and pressures up to 70 MPa. In addition, density and excess molar volumes of [C(4)C(1)im][Ac] + water binary systems were measured aiming at understanding the impact of the solvent structure on the gas solubilities. Water is shown to improve the IL capability to solubilize CO2, with equimolar molar ratios leading to enhanced solubilities for pressures up to 5 MPa, whereas [C(4)C(1)im][Ac]:H2O molar ratios of 5:1 and 2:1 present higher CO2 solubility at higher pressures. The impact of water on the solubility of methane, on the other hand, is small, with only a slight enhancement of methane solubility at high pressures observed. The favorable impact of water, on the carbon dioxide solubility, lead to enhanced CO2/CH4 ideal selectivity.
publisher	ELSEVIER SCI LTD
issn	2212-9820
isbn	2212-9839
year published	2019
volume	31
beginning page	115
ending page	123
digital object identifier (doi)	10.1016/j.jcou.2019.02.021
web of science category	Chemistry, Multidisciplinary; Engineering, Chemical
subject category	Chemistry; Engineering
unique article identifier	WOS:000464979200012