Research Of Reaction Process And Intrinsic Kinetics On Low Temperature Crude Benzol Hydrogenation

The crude benzol is the byproduct of coking industry, by the purification of which chemical foundation raw materials such as benzene, toluene and xylene can be obtained. At present, with the improvement of environmental protection and the increased demands to the high grade triphenyl product, our country's refining crude benzol industry is transformed from the traditional Liquid phase acid pickling law to hydrogenation catalysis gas phase law. The low temperature hydrogenation craft is thought to be a quite ideal hydrogen refining method .It is both possible to obtain the high quality products of benzene series and to solve the environmental pollution problem. It also has many merits such as the simplicity of production and operation condition, the low requests of equipment material, the good economic efficiency and so on. The effective usage of coking crude benzene can largely improve the economic benefits of coking products. Therefore, it has been a recognized and important topic for discussion at home and aboard to research on the use of coking crude benzene which is more important for our country which is the major country of world coke production, expecially for Shanxi where is the base of coal and heavy chemical industry.In this paper, the coking crude benzene hydrogenation process, reaction mechanism and intrinsic kinetics were studied through the self-made integral reactor,self-made Ti-modified Co-Mo/Al2O3 and Ni-Mo/Al2O3 as a catalyst, a non-aromatic content and thiophene content as the evaluation index.1. Low-temperature coking crude benzene hydrogenation process was investigated by using Ti modified Co-Mo/Al2O3 and Ni-Mo/Al2O3 catalysts. The aromatics content and thiophene content of crude benzene were discussed mainly from the T, H2/Oil, VLSP and P, respectively .The results show that:(1)With the increase of reaction temperature,the content of non-aromatic was rised slowly and the trend of thiophene content was first rising then falling.When the temperature between 270 ~ 340℃,the trend of non-aromatic content and thiophene content were both stable.Thiophene content can be reduced to below 1.62ppm;(2)With the increasing of reaction pressure, the non-aromatic was content increased and the content of thiophene was decreased. when the main reactor reaction pressure rose to 2.9Mpa, the thiophene concentration reduced to1.85ppm. (3)With the increasing of liquid space velocity, the non-aromatics content thiophene content were both decreased.When the space velocity between 0.25 to 1h-1, the thiophene content of hydrogenation product was reduced to below 1.43ppm;(4) With the increasing of the ratio of hydrogen volume and oil volume, the non-aromatic content was increased and thiophene content was decreased.When the the ratio of hydrogen volume and oil volume between 600 to 800, the non-aromatic content and thiophene content were relatively stable,especially thiophene content of less than 2.42ppm ;Based on single factor in the above study, the optimum conditions of low-temperature coking crude benzene hydrogenation were obtained by orthogonal experiment: reaction temperature is 290℃, reaction pressure of 2.3MPa hydrogen oil volume ratio of 650, the liquid space velocity of 0.6h-1. Thiophene content can be reduced to 1.35ppm in this condition.2. Based on the research of reaction mechanism,The reaction kinetics of coking crude benzene hydrogenation of thiophene removal was studied at low-temperature. Using 4-order Runge-Kutta method and the modified simplex method for kinetic parameter estimation equations, intrinsic kinetics equation was obtained by orthogonal experimental points. The reaction kinetics equation was as follow:...