Modelling of Propylene Polymerization in a Loop Reactor on the Titanium–Magnesium Catalyst Taking into Account the Transformation of Active Centers

The volume of consumed and produced polymers is increasing in the market every day. This is due to the indispensability and convenience of polymers in all industries. The article presents the distinctive features of the use of titanium–magnesium catalysts in the process of propylene polymerization. A mathematical model of the polypropylene polymerization is presented. This model is the basis of creating an expert control complex of the propylene–ethylene block copolymer (PEBC) synthesis process and allowing a quantitative connection to be made between technological parameters of reactors, which allows control of the technological mode with the acceptable accuracy. The experiment catalytic system is microspheric titanium trichloride (MS-TiCl3) and co-catalyst-diethylaluminum chloride. Dependences of different parameters on others are illustrated. The result of the research is as follows: according to the calculations, when increasing the number of blocks in the chain, the average values of molecular weights increase and the polydispersity index decreases; changing the values of the transformation rate coefficients of active centers by the donor k 12 and k 21 allows research into the effect of the donor type.

Multi-objective optimization of an industrial slurry phase ethylene polymerization reactor

Slurry polymerization processes using Zeigler–Natta catalysts are most widely used for the production of polyethylene due to their several advantages over other processes. Optimal operating conditions are required to obtain the maximum productivity of the polymer at minimal cost while ensuring operational safety in the slurry phase ethylene polymerization reactors. The main focus of this multi-objective optimization study is to obtain the optimal operating conditions corresponding to the maximization of productivity and yield at a minimal operating cost. The tuned reactor model has been optimized. The single objective optimization (SOO) and multi-objective optimization (MOO) problems are solved using non-dominating sorting genetic algorithm-II (NSGA-II). A complete range of Pareto optimal solutions are obtained to obtain the maximum productivity and polymer yield at different input costs.

Slurry-phase ethylene polymerization processes: a review on multiscale modeling and simulations

Slurry polymerization processes using Zeigler–Natta catalysts, are most widely used for the production of polyethylene due to their several advantages over other processes. Significant advancements have been made in the modeling of these processes to obtain high-quality final products. The modeling work in this field has a very wide scope due to the great diversity of the catalyst types, polymerization processes, polymerization conditions, product qualities and microstructures that exist at the commercial scale. In this article, we have reviewed and discussed the slurry polymerization processes for the production of polyethylene and the multiscale modeling and simulation framework in slurry reactors. The multiscale modeling framework mainly comprises of the kinetic model, single-particle diffusion models, multiphase hydrodynamics, phase equilibria, reactor residence time distribution and the overall mass and heat balances. Guidelines to implement the multiscale mathematical modeling and simulation in slurry-phase olefin polymerization processes are proposed. Special focus is given on the need to reduce the computational effort for the simulation of industrial reactors so that the models can be used as an effective tool-kit for optimization studies using state-of-art algorithms.

Modeling the Industrial Propylene–Ethylene Copolymerization FBR at Emergency Accidents

In order to quantitatively describe the pressure change during the copolymerization in industrial fluidized bed reactors, a dynamic reactor model was developed according to the mass and energy balances as well as real gas state-equation and copolymerization kinetics. Furthermore, in order to inspect the performance of pressure relief devices in response to the accident conditions, a set of pressure relief equations were also incorporated into the dynamic reactor model. Therefore, the extended reactor model is able to calculate the relief pressure besides other variables in the reactors such as temperature, slurry density and solid hold-up, which provides an important guidance for selecting pressure relief device and safe production. Dynamic data from certain industrial reactor were used to verify the above model. Finally, the application of the extended model was demonstrated by simulating several typical emergency accidents.