Study On The Mathematical Model Of MIP-CGP Reaction Process

Catalytic cracking process is one of the main technologies of heavy oil processing, especially in our country. In this century, in order to meet the increasing requirements in response to the social environmental and lack of resource in oil fuel,our oil refining technology workers have developed a series of new catalytic cracking technologies and new processes, so that strides our FCC technology a new step. MIP (Maximizing Iso-Paraffin) is one of the new technologies developed by Sinopec Beijing Research Institute of Petroleum.On this basis, in order to meet the market demand for light olefins such as propylene, MIP-CGP(A MIP process for Clean Gasoline and Propylene) process is developed which not only could reduce gasoline olefins but also could produce more propylene.In order to make this new technology to play its role well in practical applications and to become more comprehensive and realize sustainable development, this paper carried out the research on the mathematical model of MIP-CGP reaction process.In this paper, a newly built MIP-CGP device in Jilin Petrochemical Industry Corporation is the main reseach object.During the reseach of establishing mathematical model for MTP-OGP reaction process, main work was done as below:The research work was started from the literature survey, the investigation and research not only could deepen the understanding of the catalytic cracking process but also could understand the relationship between the MIP technology concept from the reaction mechanism further and the relationship among FCC, MIP and MIP-CGP.The field investigation was the main feature in this literature survey.Through field investigating the newly built MIP-CGP device in Jilin Petrochemical Industry Corporation,we not only obtained a more profound knowledge but aslo collected a lot of the information and the processing measured data which had laid a good foundation for this research. On the basis of the above-mentioned results, this paper carrird out the research for MIP-CGP reaction process mathematical model on the basis of industrial measured data in Jilin Petrochemical Industry Corporation MIP-CGP device and the lumped reaction kinetic model as the reaction kinetic model.Through analyzing the reaction mechanism of MIP-CGP Process and considering the factors such as the actual plant conditions and the feasibility of data sources and meeting the requirements of applications, the reactants of MIP-CGP preocess could be divided as follows: raw oil (saturated hydrocarbons, aromatic hydrocarbons, glial+asphaltenes), gasoline (saturated hydrocarbons, olefins, aromatics), diesel, liquefied petroleum, gas, coke separately as lumped component,(a total of four lumped),there was a total of ten lumped.A ten lumped reaction network was constructed according to the MIP-CGP reaction mechanism.Considering the catalyst inactivation of heavy aromatics adsorption of alkali nitrogen poisoning and other influencing factors, the MIP-CGP ten lumped reaction kinetic model was established.MIP-CGP ten lumped reaction kinetic model contains84kinetic parameters.During calculating the kinetic parameters, in order to avoid the disadvantages of the commen used mono-step method which is easy to lead multi-solution because of too much more estimation parameters and multi-layer determination which increases the work load, this research used a step-by-step estimation method.At the same time, a new intelligent optimization algorithms-genetic Algorithms was used during the parameter estimation process, which could overcome the disadvantages of the high initial value dependence and the slow convergenceprocess of the traditional optimization algorithm and could find out an optimization result within a given parameters quickly and accurately. The combination of the two methods has completed successfulthe estimation of kinetic parameters of the MIP-CGP ten lumped kinetic model.We should consider another component-transfer model, after the reaction kinetic model has been solved. Due to the lack of a cold model test conditions, this study attempts to innovation:on the basis of the in-depth qualitative analysis of fluid flow conditions and the different flow characteristics in the two reaction zone in the MIP-CGP riser reactor, we considered that the two reaction zone must be modeled separately,and then we assumed three possible flow models.After adopting measured data (9-group data) in Jilin Petrochemical Industry Corporation on MIP-CGP device,the three models were assumed to calculate to investigate the fitting situations for the three possible flow model s,and then according to the size of the fitting error to determine the pros and cons of the models. The calculation results and the possible causes of the error size have been discussed and analysed, and finally the fluid flow model in MIP-CGP riser reactor has been determined as non-isothermal plug-flow in the first reaction aera+non-isothermal plug-flow in the second reaction aera. The eatablishment of mathematical model of MIP-CGP reaction process has been completed.Then, a series of verification calculation, prediction calculation and optimization calculation were carried out for the mathematical model of MIP-CGP reaction process. On the one hand, they were carried out to evalute the reliability, extrapolation and application of the model. On the other hand, they could make the model play its role in practice.The verification calculation was carried out for Jilin Petrochemical Industry Corporation MIP-CGP device and for Anqing Petrochemical Industry Corporation MIP-CGP device. The results showed that, the error for the former verification calculation is very small, indicating a good extrapolation for the same device, while, the error for the latter verification calculation is worse than the former’s, indicating that the error mainly comes from the transfer factor. Therefore, the device factor must be considered when the mathematical model of MIP-CGP reaction process is extrapolated to the other similar devices.The prediction calculation consists of two parts. Firstly, the prediction calculation was carried out for the different operating conditions (reaction temperature in the first reaction aera, reaction temperature in the second reaction area, catalyst to oil ratio) of Jilin Petrochemical Industry Corporation MIP-CGP unit and the chart was made with the calculating result. The results showed that the influences of these operating conditions on the product distributions are in line with the reaction law, and meantime, the operating conditions can be found out to meet the requirements for the product distributions from the diagram. Secondly, taking the riser reactor in the MIP-CGP device for object, the calculation was carried out for the expanding diameter position of riser reactor on MIP-CGP technology core, plotting the calculation results. The results can show not only the product distributions and the olefin contents in gasoline vary with the change of the expanding diameter position of riser reactor, but also could analyse and judge the reasonableness of the expanding diameter position of riser reactor.Finally, the optimization calculation was carried out using the built mathematical models for a given operational condition of Jilin Petrochemical Industry Corporation MIP-CGP device. The calculation results show that by an appropriately increasing the catalyst to oil ratio and catalyst inventory in the second reaction area, the gasoline yield enhanced up to40%, which were1.86%higher than that of before, and the olefin content in gasoline decreased to29.4%, which were0.9%lower than that of before. Thus, it can meet the specification requirements for the MIP-CGP device by the company (gasoline yield>40%; olefin content<30%).From the above research, we can see that the research in this paper was carried out taking a newly built MIP-CGP device in Jilin Petrochemical Industry Corporation as the main reseach object on the basis of the industrial measured data results. This study has a series of advantages such as high pertinency, clear purpose, innovative and practical research methods and strong applied value. The above conclusion can not only provide the direct guidances for the optimization of MIP-CGP device in Jilin Petrochemical Industry Corporation, but also have important reference values and references on the other MIP-CGP devices.