Thermal Energy Comprehensive Analysis And Utilization For Carbon Dioxide Capture Process

With the rapid development of economy,the demand of mankind for fossil fuels is gradually increasing,leading to increased CO₂ emissions year by year,causing more and more serious problem of the greenhouse effect.Coal-fired power plants are the concentration of CO₂ emission source,CO₂ capture in the flue gas is very important to alleviate global climate change.Chemical absorption methods have been widely used because of its simple and relatively mature technology,among these methods,MEA absorption has been widely researched and applied in recent decades due to its advantages,such as fast absorption rate and high absorption efficiency.Though it is developing rapidly this method requires large energy consumption and high operation cost.Therefore,research on CO₂ capture process flow of the energy conservation to reduce capture cost has high engineering significance.This article is based on the 100 tons/day of CO₂ capture project of Shengli power plant.It analyzes the CO₂ capture process system,which includes the conventional technology and energy-saving technology,choice of physical method and unit operation module of the CO₂ capture system.The article mainly analyzes the rate-based model selection by using the Aspen Plus software to simulate CO₂ capture conventional process and the energy saving technology.Firstly,the conventional process model of CO₂ capture is established,by using this model,the article studies the absorption and regeneration system features,which includes the effect of some parameters on the system running,such as absorption temperature,absorption liquid concentration and flow,regenerator pressure,reboiler heat load and so on.The distribution of the abosorber and stripper are also analyzed.Then the optimal parameters of conventional process are determined through the analysis of the regeneration energy consumption and its influencing factors.The lowest regeneration energy consumption is 3.93 GJ/t in this case.In terms of the optimal parameters of the conventional process,the distributed heat exchange process,regenerator interstage heating process and MVR?Mechanical Vapor Recompression?heat pump technology are added to improve the energy consumption.The optimal parameters are decided by simulating the model.Finally,this three energy-saving technology are combined to build the overall process model.By simulating this model under the condition of the optimal parameters,it is figured out that the minimum regeneration energy consumption is 2.835 GJ/t,27.86% lower than the optimal working condition of conventional technology.