Modeling And Analysis Of Fixed Bed Reactor For Vinyl Chloride Synthesized From Acetylene Method

Vinyl chloride (VCM) is a monomer of synthesis polyvinylchloride (PVC) resin,and PVC is one of five general-purpose resins, which is superior performance, widerange of uses. This paper focuses on the process of VCM synthesized from acetyleneand hydrogen chloride in a fixed bed reactor, which is commonly used by the domesticPVC production enterprises, and combined with the actual production data of thefactory to mathematical modeling and optimization analysis, in order to guide theproduction practice of the factory.This paper established respectively one-dimensional mathematical model ofhomogeneous for a fixed bed reactor of the reaction based on two reaction kinetics(denoted as reaction kinetics I and reaction kinetics II) of VCM synthesized fromacetylene and hydrogen chloride. And then, the models have been compared by usingthe actual reactor device parameters and operating parameters of the factory. Theresults show that the reaction kinetics II is more in line with the actual value ofindustrial production, so the reaction kinetics equation of the model has beendetermined. On this basis, two-dimensional mathematical model of pseudohomogeneous has been established for fixed bed reactor, and the distribution of tubetemperature average value and central axis value along the length at two dimensionalmodel have been compared with the distribution of tube temperature along the lengthat one dimensional model. The result indicates the distribution of central axis valuealong the length at two dimensional model and the distribution of tube temperaturealong the length at one dimensional model is very consistent. One dimension modelhas been compiled by Fortran and solved by Runge-Kutta algorithm, and twodimensional model has been compiled by Matlab and solved by Crank-Nicolsonalgorithm. In this paper, one dimensional model has been used to study for the reactionrules of VCM synthesized from acetylene and hydrogen chloride, and then thesimulation results have been compared with the actual temperature data of a certainperiod of time of the former reactor at a factory. The results show that the simulation results in line with the actual data, and the model has a certain accuracy and reliability.The established model has been used to study the various factors affecting VCMproduction in this paper. Acetylene space velocity (u) and catalyst activity (a) wereanalyzed a large effect on the reaction and there was a certain correlation, and gives thecorrelation of both; the best circulation of hot water temperature was85-93℃inindustrial production, and the feed temperature should be not less than80℃, and thebest feed ratio should be around1.05.The established model has been improved and optimized, so the integral dynamicmodel of fixed bed reactor for VCM synthesized from acetylene method has beenestablished, which combined with the coefficient of heat transfer calculation equationand catalyst inactivation equation in this paper. This model has been used to calculatethe changes of the reactor temperature and acetylene conversion rate and total heattransfer coefficient and the catalyst activity along the tube length with time.Meanwhile, optimize control of a single set reactor have been done in paper. It wasconcluded that conforms to the actual operation process. So, the research results showthat the model can be used to guide industrial production of VCM synthesis.