Application Of The Method Of System Integration In Several Typical Processes

With the increasing depletion of petroleum resources, the efficient use of fossil resources is of strategic importance. In order to effectively improve the efficiency in the use of petroleum resources, the paper studies two typical processes of the petrochemical industry:atmospheric and vacuum distillation process of crude oil, coal and coke oven gas to synthetic natural gas. Process has been optimized through modeling and simulation, and the efficiency of the process has been improved, energy consumption has been reduced, which provides a reference for the industrial application. The circular economy technologies of the petrochemical industry have been confirmed through survey and expert review, and the basic steps of the integration and optimization of the technologies have been confirmed by case analysis. The main research contents and results are as follows:(1)Based on process simulations of prefractionator, atmospheric distillation unit (CDU), and vacuum distillation unit (VDU) for crude oil using ASPEN Plus software, some key parameters including temperature and flow rate of each distillation unit, and distillation range of the side products of VDU were obtained, and the results calculated from ASPEN Plus were in consistent with the data collected from the factory. Flow rate profiles of vapor and liquid and temperature profiles of three distillation units were analyzed, and related parameters were optimized using sensitivity analysis tools in ASPEN Plus. The diesel yield of CDU was increased by0.22%and duty of CDU reduced6.3%, and the light oil yield of VDU increased by0.18%and duty of VDU reduced11.2%after optimization.(2)The new technology for producing synthetic natural gas from coal and coke oven gas has been simulated with ASPEN Plus software, on the basis of simulating and analyzing the key modules in the technology, the gasification reactor has been simulated and analyzed accurately with kinetics model, the parameters of gasification process has been optimized, the simulation results of the composition of raw gas are consistent with practical values. Methanation reaction has been simulated with kinetics model, the composition of the product gas measures up to the synthesis gas composition standards.At the same time, the elements flow and energy consumption in the process were analyzed. The carbon flow balance results reveal that the carbon is mainly from the raw coal and coke oven gas, carbon conversion efficiency is about97.20%in the coal gasifier, hydrogen is mainly divided into two shares, about64.3%is converted to the product and the rest is loses in the waste water. The calculations show that the energy efficiency of the new process is higher than the existing processes, and the new technology will have great application prospects.(3)The circular economy technologies of the petrochemical industry have been collected by survey, and the encouraging the development technologies have been confirmed by expert review. And the basic steps of the integration and optimization of the technologies have been confirmed by case analysis.