Study on the Phase Behaviors, Viscosities, and Thermodynamic Properties of CO2/[C4mim][PF6]/Methanol System at Elevated Pressures

Chemistry - A European Journal - Tập 9 Số 16 - Trang 3897-3903 - 2003
Zhimin Liu1, Weize Wu1, Buxing Han1, Zexuan Dong1, Guoying Zhao1, Jiaqiu Wang1, Tao Jiang1, Jing Wang1
1Center for Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences Beijing 100080, China, Fax: (+86) 10-62559373

Tóm tắt

AbstractAn apparatus to determine the vapor–liquid equilibria of CO2/ionic liquid (IL)/organic solvent multisystems and the viscosity of the liquid phase at elevated pressures has been constructed. The solubility of CO2 in 3‐butyl‐1‐methyl‐imidazolium hexafluorophosphate ([C4mim][PF6]) and the viscosity of CO2‐saturated [C4mim][PF6] have been studied at 313.15, 323.15, and 333.15 K and at pressures up to 12.5 MPa. The phase behavior of CO2/[C4mim][PF6]/methanol ternary mixture and the viscosity of the liquid phases at equilibrium condition have also been determined at 313.15 K and at 7.15 and 10.00 MPa. The partition coefficients of the components in the ternary system are calculated. Peng–Robinson equation of state and some thermodynamic functions are combined to calculate the fugacity coefficients of the components in the system. It demonstrates that the viscosity of the IL‐rich phase decreases significantly with increasing pressure of CO2, and the effect of temperature on the viscosity of CO2/IL mixture is not noticeable at high pressure, although the viscosity of the CO2‐free IL decreases dramatically with increasing temperature. Compressed CO2 may become an attractive reagent for reducing the viscosity of ILs in many applications. The mole fraction of methanol in the CO2‐rich phase is much lower than that in the IL‐rich phase; this indicates that the interaction between the IL and methanol is stronger than that between CO2 and methanol. The fugacity coefficient of CO2 in IL‐rich phase is larger than unity, while that of methanol is much small than unity, which further suggests that methanol–IL interaction is much stronger than CO2–IL interaction. However, the CO2–IL interaction is stronger than the CO2–methanol interaction.

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Tài liệu tham khảo

 

10.1016/S0040-4039(00)01974-2

10.1021/ol006732d

10.1021/ol0068849

10.1021/ol9907771

10.1016/S0040-4020(01)00373-8

10.1016/S0040-4020(01)00316-7

10.1021/om990956m

10.1039/a903661j

10.1016/S1381-1169(99)00114-4

10.1016/S0040-4039(99)00249-X

10.1016/S0040-4039(00)01592-6

10.1016/S0926-860X(01)00531-2

10.1021/cr980032t

10.1002/1521-3757(20001103)112:21<3926::AID-ANGE3926>3.0.CO;2-U

10.1002/1521-3773(20001103)39:21<3772::AID-ANIE3772>3.0.CO;2-5

10.1016/S0379-6779(97)80758-8

10.1039/b107270f

10.1002/3527600701

 

McHugh A., 1994, Supercritical Fluid Extraction

10.1038/383313a0

10.1021/ja005718t

10.1002/1521-3765(20000602)6:11<2011::AID-CHEM2011>3.0.CO;2-L

10.1002/1521-3765(20021115)8:22<5107::AID-CHEM5107>3.0.CO;2-0

10.1002/1521-3765(20021216)8:24<5593::AID-CHEM5593>3.0.CO;2-B

10.1039/a704371f

10.1126/science.271.5249.624

10.1021/cr970035q

10.1021/cr970090z

10.1021/cr970037a

10.1021/cr970036i

10.1021/cr9700336

10.1021/cr9700989

 

10.1038/19887

10.1021/jp003309d

10.1021/jp020631a

 

10.1039/b009701m

10.1021/ja005718t

10.1039/b101046h

10.1021/ie000710d

 

10.1002/1521-3757(20010716)113:14<2769::AID-ANGE2769>3.0.CO;2-M

10.1002/1521-3773(20010716)40:14<2697::AID-ANIE2697>3.0.CO;2-W

10.1039/b201997c

10.1021/ja0268682

10.1021/jp0103528

10.1351/pac200072122275

10.1039/b005514j

10.1016/S0378-3812(96)03208-6

10.1021/i160057a011

10.1039/A803999B