甘油经由烯烃醚化和醇脱水制叔丁基甘油醚的非均相热力学对比

Heterogeneous thermodynamic comparison of the tert-butyl glycerol ether synthesis from glycerol via olefin etherification or alcohol dehydration

  • 摘要: 基于吉布斯自由能最小化原则,采用遗传算法对甘油与异丁烯醚化、甘油与叔丁醇脱水制叔丁基甘油醚过程进行了非均相热力学对比研究。在100 mol甘油 + 600 mol异丁烯、100 mol 甘油 + 600 mol叔丁醇的进料条件,40−300 ℃、0.1−0.7 MPa范围内,考察了温度和压力对两种体系的平衡转化率、产物选择性及气液相平衡组成的影响。计算结果表明,甘油和异丁烯醚化过程,低温有利于三叔丁基甘油醚生成,高温有利于二叔丁基甘油醚和单叔丁基甘油醚的生成;提升压力促进了三叔丁基甘油醚的生成,而抑制了二叔丁基甘油醚和单叔丁基甘油醚的产生。甘油和叔丁醇脱水过程中甘油的平衡转化率接近100%,其产物中三叔丁基甘油醚的选择性超过90%,二叔丁基甘油醚选择性小于10%,单叔丁基甘油醚得到有效转化。热力学计算表明,提升压力使得非均相温度区间向右移动,可以利用压力来调节液相中的产物组成。

     

    Abstract: On the basis of the principle of Gibbs free energy minimization, a genetic algorithm was used to carry out a comparative study on the heterogeneous thermodynamics of the glycerol etherification with isobutanol, and the glycerol dehydration with tert-butanol to butyl glycerol ethers. Under the conditions in the temperature range of 40−300 ℃, the pressure range of 0.1−0.7 MPa, the feed of 100 mol of glycerol + 600 mol of other reactant, the effects of temperature and pressure on the equilibrium conversions, product selectivities and gas-liquid equilibrium composition were investigated. The results show that for the etherification process, low temperature is conducive to the generation of tri-tert-butyl glycerol ether, while high temperature is conducive to the generation of di-tert-butyl glycerol ether and mono-tert-butyl glycerol ether. The elevated pressures promote the formation of tri-tert-butyl glycerol, while inhibit the production of di-tert-butyl glycerol ether and mono-tert-butyl glycerol ether. For the dehydration process, the equilibrium conversion of glycerol is close to 100%, the selectivity of tri-tert-butyl glycerol ether is more than 90%, the selectivity of di-tert-butyl glycerol ether is less than 10%, and mono-tert-butyl glycerol ether is efficiently converted. The results also show that for the dehydration process, increasing the pressure moves the heterogeneous temperature range to the right, and the liquid phase composition can be adjusted by changing the pressure.

     

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