负载型磷化镍催化剂上乙酸加氢制乙醇反应宏观动力学

Apparent Kinetics of Hydrogenation of Acetic Acid to Ethanol Over Supported Nickel Phosphide Catalyst

通过等体积浸渍和N2流中热处理过程制备了Ni2P/SiO_2催化剂,采用固定床反应装置进行乙酸加氢反应,取得不同条件下的乙酸转化率、乙醇等产物产率实验结果,进行了乙酸加氢制乙醇反应动力学研究。在确定乙酸加氢反应流体为气体、分析反应气体变化的基础上,经过推导,确定了乙酸转化及乙醇等产物生成动力学模型方程。利用反应实验数据,确定了各反应的速率常数和表观活化能。统计检验结果显示,乙酸加氢和乙醇生成反应动力学模型均具有较高的模拟计算精度。模型预测分析结果表明,随着反应温度升高、反应压力提高、质量空速减小、氢/酸摩尔比减小,乙酸转化率和乙醇产率均持续增大,在反应温度375℃、反应压力2.5 MPa、质量空速1.0h-1、氢/酸摩尔比10的反应条件下,乙酸转化率和乙醇产率分别达到99.92%和94.79%。

Ni_2P/SiO_2 catalyst was prepared by equal volume impregnation and heat treatment in N2 flow.Through hydrogenation reactions of acetic acid in a fixed bed reactor,the experimental results were obtained,which included acetic acid conversion and the yields of ethanol and other products for different reaction conditions.The reaction kinetics of acetic acid hydrogenation was investigated.On the basis of the determination of the reaction fluid for acetic acid hydrogenation as the gas and the analysis of the change of the reaction gas,the kinetic model equations for the conversion of acetic acid and the formations of ethanol and other products were determined.The reaction rate constants and apparent activation energies of each reaction were estimated by the experimental data.The results of statistical tests showed that the kinetic models of hydrogenation reaction of acetic acid and ethanol formation had higher simulation precision.The model prediction results indicated that the conversion of acetic acid and ethanol yield were increasing with the increases of the reaction temperature and pressure,the decreases of MHSV,and the decreases of the molar ratio of hydrogen to acetic acid.The conversion of acetic acid and ethanol yield were respectively 99.92%and 94.79%under the reaction conditions of reaction temperature of 375℃,reaction pressure of 2.5 MPa,MHSV of 1.0 h-1 and the molar ratio of hydrogen to acetic acid of 10.