Application Of Mixed Electron And Carbonate-ion Conductor Membrane To CO₂ Capture At Coal-fired Power Plants

More and more attentions have been paid to the greenhouse effects and their impacts on global climate and eco-environment changes The CO2 emission from utilization of coal accounts for about 80%of anthropogenic sources,which plays a key role in enhancing the greenhouse effects.Coal takes the dominant position in the primary energy consumption in China and coal-fired power plants is the dominate consumer.Therefore,the major objectives of this study is to investigate the effect of mixed electron and carbonate ion conductor(MECC)membrane on the CO2 emission from coal-fired power plants.Mixed electron and carbonate ion conductor(MECC)membrane is a typical two-phase composite membrane,which could promote the flow of electrons and carbonate ions.The MECC membrane can be used to capture CO2 from coal-fired power plants due to advantages,such as low energy consumption,simple operation,flexibility,good selectivity,high permeability,and compatibility with the process of high temperature.Thus,Aspen Plus was adopted to establish the model of CO2 capture by MECC membrane,and then this model was applied to simulate and calculate the process of CO2 by the MECC membrane.This study also analyses and compares performance of a 600MW coal-fired power plant,in which MECC membrane or MEA was adopted to capture CO2.Conclusions are as follows:(1)In steam-CH4 reforming system,the operating temperature of the reformer increases with an increase of input of CH4 and there is no clear relationship with operating temperature of the combustion reactor.(2)It is the best operation conditions of steam-CH4 reforming system whenever the following conditions are satisfied:950 ℃,latm in the furnace,and 990 ℃,20.4atm in the reformer;the mole ratio of input of CH4 in the furnace and reformer is 0.6:1.(3)In this CO2 capture system,when It CO2 is captured,149kg CH4 is consumed,and 1529.5MJ energy is generated.(4)Coal consumption rate and net power of 600MW coal-fired power plant reduces by 21.2%and increases by 95.3%,while the efficiency of the power plant increases by 7.2 percentage points,when CO2 is captured by MECC membrane.