Separation Process Simulation And Optimization Of Olefins Produced By Light Oil Catalytic Cracking Technology

The objective of this research work is going to find an optimizing process scheme after deeply researching the operating plant of the world first 400KTA light oil catalytic cracking industrial demonstration plant.The topic of research work is to optimize the process and energy in the deep chilling separation section based on the material and product composition from real running plant,taking the high energy consumption separation unit as a focus point,adopting the measures of multi-stage distillation,heat pump,ethylene&propylene refrigeration,pinch heat exchange,etc.First,selecting vapor-liquid phase PR state thermodynamic equations of non-polar system through the study of thermodynamic properties of the key components.Building an accurate mathematical model of distillation separation by using Aspen Plus commercial simulation software,and then going to investigate the influence factors of distillation by theoretical stage,the operating pressure and temperature of column and reflux ratio.The process simulation is consistent with the operating plant by comparing key temperature The difference temperature between simulation and real plant is within ±5?,so the accuracy of the mathematical model is verified.According to simulation results and real plant data,the yield of polymer grade ethylene is 30.00%,propylene is 23.30%,and total is 53.30%,higher than steam cracking yields that is about 45%?48%.Secondly,the energy consumption of plant will be optimized by bottleneck analysis.The accurate model has been built through simulation calculation based on the proper thermodynamic and actual plant data.Then the research work is going to establish a comparative model to optimize the olefins separation flow sheet to reduce energy consumption after the analysis of simulation data and compare the heat exchanger network.Each distillation system will be optimized from qualitative to quantitative,to determine the best feed stage and reflux ratio.Using pinch technology and Aspen Energy Analyzer to analysis the process bottleneck,optimizing heat exchanger by the gradual utilizing energy,reducing energy consumption after compare with difference process scheme.At last the total cold duty can be reduce about 10.55%after optimized comparing with basic case.It is reaching a good optimization after simulation and analysis.Therefore,the research content of this paper can provide some science support of olefins separation for the industrial application of light oil catalytic cracking.