The Research Of Dynamic Model In The Simulated Moving Bed Separation Process

Adsorption separation technology is widely used in the field of separated areas. As new types of adsorbents were developed, and adsorption and separation technology has become mature, which have greatly promoted the adsorption and separation technology. In recent years, the use of adsorption separation technology industries bed in adsorption and separation technology has formed a complete technical system. From the fixed bed, circulating moving bed countercurrent to the present development of simulated moving bed, its industrial applications increased gradually.This article focuses on for studying the dynamic model. The devices of simulated moving bed were used of separating of the P-xylene from the mixed xylene process which is known as patented process-Parex process. Since the industrial output of mixed xylene is high, and its components are important chemical raw materials. Therefore, mixed xylene separation technology has become a research focus in the industrial separation. Among these researches, the P-xylene adsorption separation technology is prominent. Parex process which is the core of simulated moving bed unit has formed a complete technical system on the P-xylene production rate, purity rising as technology development.This article summarized the predecessors of the simulated moving-bed model based on the most basic model methodology. The whole process is divided into subsystems and process control strategy subsystem to control the independent process model and the model, avoiding as mixing two different models resulting model form complex and computing machine occupied long and so on. In the establishment of process model, we focus on the simulated moving bed differential unit based on the Euler method. The continuity equation and the motion equations were used to fully describe the concentration and flow rate variation with time. Thereby, the concentration change of full tower was calculated and external access to the logistics affected on the operation of simulated moving-bed.For the model needs to solve partial differential equations of the problem, this article combining many years of practical experience in the process of the model solution adopted a new discrete computing system based on the theory. That is the partial differential equations were used as ordinary differential equations discrete. To ensure calculation accuracy, the calculation the calculation efficiency has been greatly improved, which lays a good foundation for the model industrial applications.