title: Effect of pressure on the selectivity for the esterification of ethylene glycol with propionic acid in supercritical CO2.
abstract: The esterification of ethylene glycol with propionic acid was investigated in supercritical CO2 at 50.0 degrees 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 equilibrium conversion and selectivity was nearly independent of pressure as pressure was lower than 9 MPa. At higher pressure, however, the yield and selectivity of the diester increased considerably, while those of the monoester decreased with increasing pressure. The main reason was that reactants and products distributed between the vapor phase and liquid phase at higher pressures. The solvent power of CO2 for the diester is stronger than that for the monoester. More diester molecules in the liquid phase were extracted into the vapor at higher pressures, which shifted equilibrium of the consecutive reversible reactions.
authors: Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China.
authors: Jicheng
authors: J
authors: Zhang
authors: Tao
authors: T
authors: Jiang
authors: Buxing
authors: B
authors: Han
authors: Anlian
authors: A
authors: Zhu
authors: Xiumin
authors: X
authors: Ma
authors: Yinxi
authors: Y
authors: Zhou
authors: Liang
authors: L
authors: Bai
authors: Hongwei
authors: H
authors: Xiang
authors: Yongwang
authors: Y
authors: Li