Effect of Pressure on the Selectivity for the Esterification of Ethylene Glycol with Propionic Acid in Supercritical CO2
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- 作者：Jicheng Zhang ; Tao Jiang ; Buxing Han ; Anlian Zhu ; Xiumin Ma ; Yinxi Zhou ; Liang Bai ; Hongwei Xiang ; Yongwang Li
- 刊名：Journal of Physical Chemistry B
- 出版年：2007
- 出版时间：May 17, 2007
- 年：2007
- 卷：111
- 期：19
- 页码：5322 - 5325
- 全文大小：83K
- 年卷期：v.111,no.19(May 17, 2007)
- ISSN：1520-5207
文摘
The esterification of ethylene glycol with propionic acid was investigated in supercritical CO2 at 50.0 
C.The effect of pressure on equilibrium conversion and selectivity of ethylene glycol monopropionate (monoester)and ethylene glycol dipropinonate (diester) was studied systematically. It was shown that the equilibriumconversion and selectivity was nearly independent of pressure as pressure was lower than 9 MPa. At higherpressure, however, the yield and selectivity of the diester increased considerably, while those of the monoesterdecreased with increasing pressure. The main reason was that reactants and products distributed between thevapor phase and liquid phase at higher pressures. The solvent power of CO2 for the diester is stronger thanthat for the monoester. More diester molecules in the liquid phase were extracted into the vapor at higherpressures, which shifted equilibrium of the consecutive reversible reactions.
C.The effect of pressure on equilibrium conversion and selectivity of ethylene glycol monopropionate (monoester)and ethylene glycol dipropinonate (diester) was studied systematically. It was shown that the equilibriumconversion and selectivity was nearly independent of pressure as pressure was lower than 9 MPa. At higherpressure, however, the yield and selectivity of the diester increased considerably, while those of the monoesterdecreased with increasing pressure. The main reason was that reactants and products distributed between thevapor phase and liquid phase at higher pressures. The solvent power of CO2 for the diester is stronger thanthat for the monoester. More diester molecules in the liquid phase were extracted into the vapor at higherpressures, which shifted equilibrium of the consecutive reversible reactions.