System Simulation And Operation Optimization For The Reaction Process Of β-pinene Thermal Cracking

Myrcene is an important chemical raw materials and intermediates in perfume industry, which is mainly producted by β-pinene thermal cracking in industry. In the production operation, the mass concentration of qualified products of myrcene production via β-pinene thermal cracking is more than 78%. The mechanism model of full scale plant of the reaction process was developed arounding the core device β-pinene thermal cracking reactor and the system simulation and operation optimization were carried out based on this model. In which the results could provide guidance for industrial production operation of myrcene. The main research contents are as follows:(1) The advances of kinetic and mechanistic aspects of myrcene production via β-pinene thermal cracking were studied systematically, along with the progress of chemical process modeling. Then, the relationship among the components in the thermal cracking reaction was analysed comprehensively, the reaction network and dynamic model put forward by A.stolle were chosed as the foundation of modeling.(2) Based on domestic industrial process of β-pinene thermal cracking, the main equipments were modeled including preheater, falling-film evaporator, pyrolysis reactor, primary cooler and secondary cooler, then the physical property parameters were calculated and the kinetic parameters were estimated by using gPROMS to construct the model for reaction process of β-pinene thermal cracking. In which, the kinetic paramers of reactor model were fine-tuned by using six groups steady-state data under different working conditions, and other five groups data were used for model validation. Verification results showed that the model had a better prediction performance for concentration of myrcene.(3) System simulation and operation optimization were carried out based on the mechanism model of full scale plant. Firstly, three important process indices were defined, which are the conversion rate of β-pinene, the outlet concentration of myrcene and the unit energy consumption. Secondly, the influence of several key operating parameters on process indices was analyzed, such as the feed flow rate, the reaction pressure, the reaction temperature, and so on. And then, a better operating condiction was chosed as the initial value of the next parameter optimization. Finally, considing the problem of energy saving, the operating parameters were optimized by using NLPSQP under the certain constraints and the minimum of unit energy consumption was set as objective function. Optimization results provided a valuable reference for the operation of myrcene industry.