Dynamic Simulation Of A Two-Dimensional Model Of Multistage Gas Phase Fixed Bed Reactor

This paper devotes major efforts to the simulation of temperature field in a tubular reactor which was used to prepare epoxyethane through ethylene epoxidation and this work was proposed by Yanshan institute, which is a branch of Sinopec BRICI. A single reaction tube which belongs to a shell and tube reactor was modeled by C++and subsequently being dynamic simulated, the shell and tube reactor was used to prepare epoxyethane through ethylene epoxidation.Ethylene epoxidation for producing epoxyethane is a strong exothermic reaction, there exists a great concentration and temperature gradient in both axial and radial direction, so the Eulerian method was applied to separate the reaction tube inner space and build a two-dimensional model. The catalyst burn-out process was caused by temperature runaway and the process is unsteady, a model dynamic simulation was carried out for mechanism of the temperature runaway process.Gas-solid phase tubular fixed bed reactor dynamic simulation is the core of this paper and it is suitable for a variety of industrial prodution and testing experimental environments. The simulation program is not only suitable for ethylene epoxidation reactor, so the final objective of this research is to publish a simple and efficient dynamic simulation software which can be applied to gas-solid phase tubular fixed bed reactors. Currently, only chemical equations need to add C++code manually, application programs will be obtained after compiled. The main work in this project is embodied as follows:1. Integrating the one-dimensional and two-dimensional traditional models of fixed bed reactors and subsequently building a block discrete method. Accuracies could be set according to different areas simulation requirements and the computing powder will be assigned reasonable. 2. Calculation method for dynamic simulation equations was optimized. Calculations related to heat transfer, mass transfer and chemical reactions were handled respectively and the calculation parallelization of heat transfer and reaction will be realized, the rest can be calculated faster by multithreading.3. Compared with data of ethanol dehydration to prepare ethylene which was metioned by reference and ethylene epoxidation to prepare epoxyethane which was handled by Yanshan Petrochemical Company Ltd, both of the one-dimensional steady-state simulation result and two-dimensional steady-state simulation result fit the actual data quite well.