Research Of Kinetic Model Of Residue Hydrotreating-Catalytic Cracking Combined Process

According to the sustained growth of national economy, the processing technic of sour crude developed fast with the increasing of import volume of crude oil to our country. The first independent intellectual property of residue hydrotreating unit which founded in later 1999 in Maoming Petroleum Company and combined with 3# fluid catalytic cracking unit to transform sour residue to high quality light oil has became the typical represent in our country. The thesis researched the combined technic and founded its reaction kinetic model to guide the optimization.Because the reactions contained in the residue hydrotreating-catalytic cracking combined process are very complex, the research used the method of fractional steps to found model for the combined process based on the profound analysis of the reaction mechanism. This method which had great innovation simplified the founding process of the model and met different application necessary.1. The process of residue hydrotreating contains two main reactions, hydrofining and hydrocracking. First the research built the kinetic model for the hydrofining based on the forecast objects of the removing rate of nickel, vanadium, sulfur, nitrogen, and carbon residue. The model considered both the five removing rates and the time-varying devitalized factors of catalyst, and the results showed that the total average relative error of the five removing rates is only 5.55%.2. On the base of the measured data of industrial unit, the research built the six-lumping reaction kinetic model for residue hydrocracking to predict the four components of hydrotreated residue and their yields. The results showed that the model had good fitting and provided a fine ground to build model for combined technic.3. Lumped kinetic model of catalytic cracking for hydrotreated residue:â‘ Considering the analysis condition of industrial unit and the process of hydrotreating, the research built lumped model on the base of the analysis of the four components of hydrotreated residue.â‘¡The kinetic model could predict not only the distribution of products, but also the quality of the main products. The research built 14-lumping reaction kinetic model of catalytic cracking for hydrotreated residue, which can predict the distribution of diesel oil, gasoline, LPG, gas and coke, but can predict the quality of the main products: paraffin, cyclanes, olefin and aromatics of diesel oil and gasoline, paraffin and olefin of LPG. The results showed that the average relative error of products predicted distribution was less than 3.0% and the average relative error of main products predicted quality was less than 2.0%.â‘¢The method of fractional steps which was proved reliable and rational solved the problem to calculate 134 kinetic parameters. â‘£The 7-lumping reaction kinetic model of catalytic cracking to predict only the distribution of products, two kinds of 10-lumping reaction kinetic model to predict the distribution of products and the group compositions of diesel and gasoline and the 8-lumping reaction kinetic model to predict distribution of products and olefin and paraffin of LPG were built with the 14-lumping reaction kinetic model. The predict precisions of these models which can be combined or separated to meet different application necessary were correspondent to the predict precisions of the 14-lumping reaction kinetic model.4. These reaction kinetic models of residue hydrofining, hydrocracking and catalytic cracking were combined to build kinetic model for the residue hydrotreating-catalytic cracking combined process. After calculating the model parameters, the model certificated the products distribution and the quality of main products of the combined process. The results of comparison between the combined process model and each individual model built before showed that the predict precisions fixed very well. It also proved the accuracy of the model which had good predict ability.The industrial measured data of the research came from the industrial unit of the residue hydrotreating-catalytic cracking combined process in Maoming Petroleum Company. The research which had high academic and applied value had great instructive significance to the optimization of combined model and provided good referrence to the research of combined technic kinetics.