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.
keywords
PRESSURE PHASE-BEHAVIOR; CARBON-DIOXIDE CAPTURE; MIXED MATRIX MEMBRANES; IONIC LIQUIDS; CO2 CAPTURE; 1-BUTYL-3-METHYLIMIDAZOLIUM ACETATE; SOLUBILITY; PLUS; EQUILIBRIUM; TEMPERATURES
subject category
Chemistry; Engineering
authors
Navarro, P; Garcia, J; Rodriguez, F; Carvalho, PJ; Coutinho, JAP
our authors
Pablo Navarro Tejedor
Post-Doc Fellowship
Pedro J. Carvalho
Assistant ProfessorProjects
CICECO - Aveiro Institute of Materials (UID/CTM/50011/2013)
Projeto de Investigação Exploratória: Pedro Carvalho (IF/00758/2015)
acknowledgements
This work was developed in the scope of the project CICECO - Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (Ref. FCT UID/CTM/50011/2013), financed by national funds through the FCT/MEC and co-financed by FEDER under the PT2020 Partnership Agreement. P. J. Carvalho also acknowledges FCT for a contract under the Investigador FCT 2015, contract number IF/00758/2015. Additional support from the Comunidad de Madrid Government (project S2013/MAE-2800) and the Spanish Government (projects CTQ2017-85340-R) is also acknowledged. P. Navarro also thanks Spanish Government for his FPI and mobility grants (BES-2012-052312 and EEBB-I-16-10597) and FCT for the postdoctoral grant (SFRH/BPD/117084/2016).