UNIFAC model for ionic liquid‐CO (H₂) systems: An experimental and modeling study on gas solubility

Abstract

in Wiley Online Library (wileyonlinelibrary.com)The universal quasichemical functional-group activity coefficients (UNIFAC) model for ionic liquids (ILs) has become notably popular because of its simplicity and availability via modern process simulation softwares. In this work, new group binary interaction parameters (a mn and a nm ) between CO (H 2 ) and IL groups were obtained by correlating the solubility data in pure ILs at high temperatures (above 273.2 K) collected from the literature. the solubility of CO in [BMIM] 1 [BF 4 ] 2 , [OMIM] 1 [BF 4 ] 2 , [OMIM] 1 [Tf 2 N] 2 , and their mixtures, as well as that of H 2 in [EMIM] 1 [BF 4 ] 2 , [BMIM] 1 [BF 4 ] 2 , [OMIM] 1 [Tf 2 N] 2 , and their mixtures, at temperatures from 243.2 to 333.2 K and pressures up to 6.0 MPa were measured. The UNIFAC model was observed to well predict the solubility in pure and mixed ILs at both high (above 273.2 K) and low (below 273.2 K) temperatures. Moreover, the selectivity of CO (or H 2 ) to CO 2 in ILs increases with decreasing temperature, indicating that low temperatures favor for gas separation.

Gas solubility in long‐chain imidazolium‐based ionic liquids

“…The temperature of the still was controlled by electric heating elements with an uncertainty of ± 0.1 K, and the system pressure was measured by a pressure gauge with a range of 0–20.00 MPa and an uncertainty of ± 0.01 MPa. The details of apparatus and procedure have been described in our previous publications …”

“…The details of apparatus and procedure have been described in our previous publications. 22,23 Computational Details…”

“…The term represents the energetic interaction between groups, and is a function of the group interaction parameters ( α mn and α nm ). In this work, the parameters used in the UNIFAC model were obtained from our published works, and the detailed values are listed in Supporting Information Table S2.…”

Separation of benzene and thiophene with a mixture of N -methyl-2-pyrrolidinone (NMP) and ionic liquid as the entrainer

“…In this work, the IL was decomposed into several functional groups in a similar way as proposed by Lei et al [31][32][33][34], Kim et al [35,36], Breure et al [37]. Meanwhile, the benzene molecule was decomposed as six ACH groups, whereas thiophene and NMP were each treated as one separate group.…”

Process design of carbon dioxide and ethane separation using ionic liquid by extractive distillation

“…The UNIFAC model 32,33 and COSMO-RS model 34 are the models that are most widely used to describe phase equilibria in systems containing ionic liquids, and they are often applied to systems that lack phase equilibrium data. Lei et al 35,36 predicted the solubility of CO 2 and CO(H 2 ) in ILs using the UNIFAC model, and they obtained the interaction parameters for CO 2 , CO (H 2 ) and IL groups by correlating the model data with experimental data. Zhang et al 37 reported the predicted selectivity of CO 2 /CH 4…”