Abstract:

Coal-fired power stations have become the largest CO₂ emission source in China. To achieve carbon neutrality before 2060, we must reduce CO₂ emission in coal-fired power plants. Compared with other carbon capture technologies, Potassium based solid absorbent has the advantages of high capture efficiency and low reaction energy consumption. But its high energy consumption in regeneration greatly affects the performance of coal-fired power plants. The temperature kept by the solar collectors of trough solar collectors can meet the requirements of the regeneration reaction of potassium based solid absorbent. Therefore, a carbon capture system coupled parabolic trough solar collector was set up to coordinated control the CO₂ discharged from coal-fired power generating units. The effects of key parameters such as the solar concentrators' temperature and the working fluid' flow rate on the comprehensive performance of the system can be obtained based on the model for heat concentration and CO₂ capture. Compared with the single coal-fired carbon capture system, the carbon capture system coupling parabolic trough solar collectors with coal-fired power generating units is more effective,whose steam turbine output increases by 29.85 MW increase and comprehensive power generation efficiency increases by 10.3% under the design condition. Adopted the optimized operation scheme, the carbon capture capacity of the system on a typical day has increased to 312.96 t and its daily mean energy utilization rate has increased by 15.84%.

Key words: carbon neutrality, carbon capture, potassium based solid absorbent, solar energy, trough solar collector, coal-fired power plant, power generation efficiency