Abstract: A model of CO₂ discharge control aiming at minimizing generating cost is established for thermal power plants in consideration of the total thermal power generation process from coal purchase, coal washing, electricity generation to pollutant disposal. According to the monthly production data, the energy consumption of pollutant treatment and CO₂ emission reduction control of a thermal power plant, the CO₂ emissions in different stages of the generation process are calculated with this model. The scenario analysis approach is adopted to analyze the impacts of different carbon capture technologies on the generating cost and CO₂ emissions. The result shows that the CO₂ emissions of coal-fired generation account for 96.00% of the total CO₂ emissions of the power plant, those of coal washing only account for 0.38% and the CO₂ amount discharged by direct and indirect pollutant disposal account for 3.62% of the total emissions. When the CO₂ capture is performed by using the extraction absorption, membrane process or physical adsorption methods respectively, the CO₂ emissions can be reduced by 71.60%, 76.47% and 86.06% accordingly, but the generation cost will increase by 31.16%, 41.52% and 79.44%.

Key words: thermal power generation, CO2 emission, scenario analysis, coal washing process, carbon capture technology