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用循环流动法研究了压力下在镍路催化剂上气相苯加氢反应动力学。反应条件是:压力5-30气压,温度97-260℃,氢苯克分子比3-50。催化剂粒度为4×4毫米和0.25—0.5毫米。在动力学控制区导出反应动力学方程式:w=kp_(σ6H6)~m,m——苯的反应级数是温度的直线函数,随温度上升由零逐渐增加到一。活化能为12仟卡/克分子,在内扩散控制区导出反应动力学方程式,活化能为7仟卡/克分子。同时,还发现:催化剂内表面利用率与苯分压的次方成正比,并随氢化率增加而减小。这一结果不同於一般宏观动力学的观点。认为苯加氢反应按表面机构进行,控制段为表面反应本身。反应的最适温度是氢苯比和压力的函数,并随後两者的增加而下降。作者从理论上推导了最适温度与氢苯此及压力的关系式,并分析了变化规律,提出了存在最适氢苯比及最适压力的可能性。该研究结果可以用来强化反应过程。
The kinetics of hydrogenation of gaseous benzene over nickel catalyst under pressure was studied by the cyclic flow method. The reaction conditions are: pressure 5-30 atmospheric pressure, temperature 97-260 ° C, molar ratio of hydrogen to benzene 3-50. The catalyst particle size is 4x4 mm and 0.25-0.5 mm. The reaction kinetic equation is derived in the kinetic control zone: w = kp_ (σ6H6) ~ m, m - The reaction order of benzene is a linear function of temperature and increases gradually from zero to one as the temperature rises. The activation energy is 12 kcal / mol and the reaction kinetics equation is derived in the diffusion control zone with an activation energy of 7 kcal / mol. At the same time, it is also found that the utilization of the internal surface of the catalyst is proportional to the second power of benzene partial pressure and decreases with the increase of hydrogenation rate. This result is different from the general macro-kinetic point of view. Benzene hydrogenation reaction that the surface mechanism, the control section for the surface reaction itself. The optimum temperature for the reaction is a function of hydrogen to benzene ratio and pressure, and then both of them decrease. The author deduces theoretically the relationship between the optimum temperature and the pressure of hydrogen and benzene, and analyzes the changing rules, and proposes the possibility of the optimum hydrogen and benzene ratio and the optimum pressure. The results of this study can be used to enhance the reaction process.