正己烷在Pt/HBeta催化剂上的异构化反应动力学模型

Kinetics Model of the Hexane Isomerization on a Pt/HBeta Catalyst

采用等体积浸渍法制备了Pt/HBeta催化剂,并在10 mL固定床反应装置上评价了反应温度和质量空速对Pt/HBeta催化正己烷临氢异构化反应的影响,在此基础上建立正己烷异构化反应动力学模型。结果表明:在 240~ 260 ℃内正己烷临氢异构化反应可以用拟一级动力学模型来描述,反应的活化能 E a=139.06 kJ/mol,指前因子 A = 7.3814×10 13 h -1;建立了连串反应动力学模型,第一步反应活化能 E a1 =167.80 kJ/mol, A 1=7.2130×10 16 h -1 ,第二步反应活化能 E a2 =118.34 kJ/mol, A 2=1.3053×10 11 h -1;当反应温度大于260 ℃,拟一级动力学模型不再适合,修正后270 ℃时的反应级数为1.3,280 ℃时的反应级数为1.7。

The Pt/HBeta catalyst was prepared by the equivalent volume impregnation method and the hydroisomerization reaction of n -hexane was carried out in a 10 mL fixed-bed reactor. The effects of MHSV on the isomerization of n -hexane were investigated at different reaction temperatures. Based on these results, the kinetic model of the isomerization reaction was established. The results show that the hydroisomerization reaction of n -hexane at 240-260 ℃ can be described by a pseudo first-order kinetic model, in which the activation energy is E a=139.06 kJ/mol, and the pre-factor is A =7.3814×10 13 h -1 . Further, we proposed a kinetic model for the sequential reaction, where at the first step, E a1 =118.34 kJ/mol, A 1=7.2130×10 16 h -1 , and at the second step, E a2 =118.34 kJ/mol, A 2=1.3053×10 11 h -1 . We found that pseudo first-order kinetic model is not applicable when temperature is higher than 260 ℃. After corrections, the reaction order at 270 ℃ is 1.3 and the reaction order at 280 ℃ is 1.7.