Research On Optimization And System Integration Of CO₂Capture Via Chemical Absorption In Coal-fired Power Plant

In recent years, the large amount of carbon dioxide (CO2) emission causes greenhouse which is one of the most severe environment problems all over the word to human being. The combustion of fossil fuels, especially from electrical industry, is the main contributor to CO2emissions. In hence, it is extremely significant for electrical industry to achieve the target of inducing CO2emission in the future in our country.Recently, CO2capture and storge (CCS) has been considered as the main force to induce CO2emission. Post-combustion CO2capture technology is widely recognized as a practical method in coal-fired power plants. However, CCS technology in our country is still in research and demonstration phase and it is far to achieve large-scale commercial applications. Commercial application of CCS technology is limited by its extremely high energy consumption which is extracted from steam turbines. So it is necessary to take effective measures to reduce energy consumption of CO2capture so that commercial application of CCS technology can come ture.Based on Aspen Plus microsoft, this paper simulated CO2capture system, analyzed that the main operating parameters influenced thermal consumption and work consumption of CO2capture system and cleared the relationship of different parameters and energy consumption of system. Focused on the main parameters that deeply affect the energy consumption of CO2capture system, two plans of CO2capture system is proposed by system energy integratioa The first plan is that Organic Rankine Cycle recovers the waste heat and the second plan is that the rich absorbent is divided into two regenerators to recover CO2.It is indicated that compared with traditional CO2capture process, the energy consumption of plan one induces9.28%and the energy consumption of plan two induces19.77%.Based on the new chemical obsorption CO2capture system(the second plan) and with a typical600MW coal-fired power plant in China as the research object, CO2capture system and coal-fired power plant are integrated. The impact of the operation of coal-fired power plant with CO2capture system is analyzed. The efficiency penalties of coal-fired power plants with general CO2capture system and new CO2capture system are10%and8.87%.The technology economy analysis of the CO2capture system with a coal-fired power plant is carried out. The generating cost and CO2emission reduction cost are used as two technical economical indexes. The properties of technology economy of600MW supercritical unit with the base CO2capture system (case2)and the novel CO2capture system (case3)are compared so that it is helpful to promote the commercial application of CO2capture technology. The generating cost of case2and case3are0.56yuan/KWh and O.55yuan/KWh and CO2emission reduction cost of case2and case3are283.88yuan/t CO2and269.98yuan/t CO2.