Exergy analysis of IGCC with CO2 pre-combustion capture system
The high energy penalty for CO2 capture is one of the largest barriers for implementing IGCC technology with CCS.Based on the first IGCC plant-Tianjin GREENGEN project in China,this paper is to analyze the constitutions and inner causes of the energy penalty for CO2 capture in IGCC through exergy analysis and to investigate the energy penalty decrease potential through energy level analysis.Results show that the energy penalty for CO2 capture is around 8.1 percentage points when the capture rate is 90%.Direct energy penalty which is caused by separation and compression of CO2 takes about 35~40%of the total and indirect energy penalty including the steam consumption and the exergy losses of fuel caused by syngas shift reaction takes the rest.By optimization of the separation process and system heat integration,we can reduce the energy penalty for CO2 capture to about 4.0~4.5 percentage points under 90%capture rate.Besides,as the CO2 capture rate goes up,the direct energy penalty decreases with the increasing CO2 purity before separation but the indirect energy penalty increases with the greater exergy losses of syngas and steam consumption for shift reaction.Thus,there is an optimal CO2 capture rate that makes the energy penalty for unit CO2 capture minimum.
IGCC CCS energy penalty exergy and energy level analysis optimal capture rate
Xiaozhou Ji Sheng Li Lin Gao Hongguang Jin
Institute of Engineering Thermophysics,Chinese Academy of Sciences(IET,CAS),Beijing,China;University Institute of Engineering Thermophysics,Chinese Academy of Sciences(IET,CAS),Beijing,China
国际会议
桂林
英文
1-8
2013-07-16（万方平台首次上网日期，不代表论文的发表时间）