不同路线合成乙醇的热力学分析(英文)

Thermodynamic analysis of differentroutes of ethanol synthesis

运用吉布斯自由能最小法对3种不同路线(合成气直接合成、甲醇同系化、醋酸加氢)合成乙醇热力学进行了分析,在温度373 K～873 K,压力0.1 MPa～10 MPa的范围内获得了各路线原料转化率与产物平衡组成随温度与压力变化的关系。对于合成气直接合成乙醇,低温对CO平衡转化率有利,在压力为2 MPa时,温度从373 K升高到873 K,CO平衡转化率从100%降到1.56%:在甲醇同系化合成乙醇工艺中,甲醇的转化率在所研究的温度压力范围内都几乎为100%,低温时(T<473 K)甲醇经同系化反应接近完全转化为乙醇,高温时(7>673 K)甲醇几乎全部分解为CO与H_2;醋酸加氢制乙醇工艺中醋酸的转化率均大于70.79%。对于这3种路线,乙醇的平衡组成在10MPa、373K时达到最大,分别为50%,50%与25%。

Thermodynamic analysis of ethanol （EtOH） synthesis using the Gibbs free energy minimization method for three routes（namely, direct synthesis from syngas, methanol homologation and hydrogenation of acetic acid （HAC）） have been performed in the range of （373- 873） K and （0.1-10） MPa in this study. The conversion of key feedstock and product equilibrium composition are obtained as a function of temperature and pressure. For direct synthesis of ethanol, low temperature favors the CO equilibrium conversion. CO conversion would changes from 100% to 1.56% with increasing temperature from 373 K to 873 K at 2 MPa. For the process from methanol homologation, nearly 100% methanol conversion could be gained at all temperatures and pressures. Methanol would be nearly converted into ethanol via homologation reaction at lower temperature （T〈473 K） and almost decomposed into CO and H2 at higher temperature（T〉673 K）. HAC conversion can reach higher value （〉70.79%） under the conditions studied for HAC hydrogenation. The maximum ethanol equilibrium content was 50 %, 50 % and 20 % respectively for the above three routes at T=373 K, P=10 MPa.