Simulation And Optimization For Delayed Coking Main Fractionator And Absorption-Stabilization System

Delayed coking technology is an important process in secondary processing in oil refining industry which has drawn more and more attention recently owing to low equipment investment, simple process, and mature technology. In a delayed coking unit, the main fractionator and the absorption-stabilization system are the most important part for the products separating which are faced with several problems, such as improving product quality, saving energy and other issues, to optimize and reform has great practical significance.In this paper, using a domestic petrochemical enterprises delayed coking unit as an engineering example, outlines the delayed coking process, current situation and development trend. Process simulation software Aspen Plus is adopted to establish the main fractionator and the absorption-stabilization system accurate model after the analysis of delayed coking process and select a appropriate thermodynamic method and algorithm to solve the above problems. According to the analysis of the simulation results, the device model results have approched to the actual production data, reflected the basic principles of delayed coking process which can be applied to simulate the process of delayed coking. Some operation and control problems are studied by simulation analysis. We find the bottleneck of the process and give the optimization program to illustrate the simulation technology using in the specific application.An improved absorption-stabilization process is proposed In this paper. A pre-absorption tank between the gasoline and the poor absorbed gas is adopted to enhance the absorption effect. The process is analysed by a process simulation software Aspen Plus. By comparing with the original process, it is found that more than 6vΣC3 is absorbed at the absorption section and the3 feed to the re-absorption column is reduced. Thus, it reduced the amount of diesel absorbent in the re-absorption column and the EC3 content in dry gas, which may increase the profit.