Kinetic Model And Simulation Of The Industrial Heavy Paraffins Dehydrogenation

Dehydrogenation of long chain paraffins to mono-olefins is an important process in the production of detergent, then mono-olefin reacts with benzene to generate alkyl benzene which is a common kind of active component in the synthetic of detergent. The conversion of dehydrogenation process is low which was about 12%. Temperature, pressure, hydrogen hydrocarbon ratio and liquid hourly space velocity are all influence factors of the conversion and catalyst deactivation. Futhermore, the percentage of paraffins with different carbon number of the raw material also has a certain influence in determining the quality of the products. Therefore the research of long chain paraffins dehydrogenation on industrial degree has certain practical significance.In this paper, based on the dehydrogenation experimental data of long chain paraffins with different carbon number offered by LAB Plant of Jinling Petrochemical Corporation of Sinopec, apparent kinetics equations of C10～C13 long chain paraffins and catalyst deactivation equation were established according to the reaction mechanism. The parameter estimation results showed that the assumption about reverse reaction presented first order to hydrogen concentration was feasible and deactivation order of catalyst was 2.25. The average relative deviation of experimental value and calculated value of components under different reaction condition was 3.27%, the average relative deviation of target product was 5.19%. The inspection of kinetic models showed it was in good accordance with experimental data, so the model had preferably applicability.The industrial catalyst deactivation model was obtained by combining flow model of the reactor. Unlike laboratory, catalyst in industry showed a linear relationship with using time. The simulation showed that the average relative deviation between calculated value and industrial value of all the components in the first period was 4.17%, and the average relative deviation in the second period was 3.43%. Combined with apparent kinetics model molar percentage of paraffins and mono-olefins with different carbon number out from the total outlet, the inner ring, and the outer ring was predicted. And this could provide certain theoretical basis for the optimization of reactor.