Kinetic Model Of Heavy Paraffin Dehydrogenation To Mono-olefins

Alkyl benzene is the main raw material of synthetic detergent, and the biodegradability of linear alkyl benzene is good. Due to the requirements of environmental protection, the demand for biodegradable detergent promoted the growth of output of linear alkyl benzene. Heavy paraffin dehydrogenation to mono-olefins is the key step in the process of synthesis of alkyl benzene. Study on kinetics of heavy paraffin dehydrogenation to mono-olefins is an important basis for simulation of industrial dehydrogenation reactor and optimization of operating conditions.In this paper, based on the experimental data of heavy paraffin dehydrogenation to mono-olefins from catalyst evaluation device of LAB Plant of Jinling Petrochemical Corporation of Sinopec, apparent reaction kinetic model and catalyst deactivation model of heavy paraffin dehydrogenation to mono-olefins were established under industrial reaction conditions. Kinetic model parameters and the catalyst deactivation rate constants under different reaction conditions were calculated by multivariate function Powell method. To the average relative deviation of calculated values and experimental values, the results showed that the overall average relative deviation of heavy paraffin was 0.62%, and the maximum average relative deviation of a single set of experimental data of heavy paraffin was 1.04%; the overall average relative deviation of mono-olefins was 3.37%, and the maximum average relative deviation of a single set of experimental data of mono-olefins was 5.94%. The fitting effect of experimental values and calculated values is good. The established model well reflects the catalytic dehydrogenation process of heavy paraffin.In order to predict the deactivation rate constants under different reaction conditions, deactivation rate constant correlation model was established with different temperature, volume space velocity and hydrogen/hydrocarbon ratio when pressure was fixed. The prediction effect of correlation model is good. Kinetic model of heavy paraffin dehydrogenation to mono-olefins and deactivation model of catalyst were verified with experiment results that were different from those for the estimation of kinetic parameters. The results showed that the overall average relative deviation of heavy paraffin was 0.92%, and the maximum average relative deviation of a single set of experimental data of heavy paraffin was 1.13%; the overall average relative deviation of mono-olefins was 4.46%, and the maximum average relative deviation of a single set of experimental data of mono-olefins was 6.22%.The established models were reliable. The results of this study can provide certain theoretical support for reactor simulation and operating condition optimization of industrial heavy paraffin catalytic dehydrogenation.