Solvent Screening and Feasible Study of Retrofitting CO2 Capture System for Natural Gas Combined Cycle Power Plant

The feasible study for retrofitting CCS to the natural gas combined cycle (NGCC) was carried out by Toshiba and China Huadian Engineering Co. (CHEC). The 390MW Banshan NGCC power plant owned by China Huadian Corporation (CHD) in Hangzhou China was selected as a model plant. The CO2 concentration in the flue gas is about 4 vol. %, which is lower than that of coal fired power plant. Amine solvents for the NGCC were selected after investigating a vapor liquid equilibrium (VLE) in laboratory. CO2 recovery energy for capturing CO2 for amine solvents were investigated using Toshiba's Mikawa CO2 capture pilot plant located in Fukuoka Japan, which has the ability to control the concentration of CO2 in live flue gas from coal fired power plant before feeding the flue gas into the absorber tower. The recovery energy under 4 vol. % CO2, 3.0GJ/t-CO2 with 70% capture efficiency was determined for calculation the influence of the steam extraction on the overall steam cycle in power plant. In addition, the estimation of construction and operation cost were executed. It was found that total cost of CO2 capture for full capture is 570 RMB /t-CO2 and that of partially capture case is 879 RMB/t-CO2.