CO2 capture of IGCC pre-combustion using amyl formate absorption process

摘要

Integrated coal gasification combined power cycle(IGCC)is a clean coal technology,and the concentration of the rich CO2 stream at medium-pressure in the pre-combustion system is high to 0.43(40℃,3MPa).From practical point of view,i.e.large scale,high efficiency,low energy consumption and low cost,the pre-combustion CO2 capture is considered as one of the most promising option.In this study,amyl formate was selected as CO2 physical absorbent,the vapor-liquid equilibrium model of CO2+amyl formate system was established on the basis of the experimental data,and then the process simulation for the CO2 capture of IGCC pre-combustion using amyl formate absorption was completed.A set of appropriate operating conditions was proposed based on impact analysis of CO2 capture performance and energy consumption for of operating conditions,i.e.absorbent circulating rate,absorption temperature and desorption temperature etc..The results show that when carbon capture rate is 87.92％,the CO2 concentration in the output gas stream is up to 96.07％,in which CO and H2 are 29.36％and 65.92％,respectively.It meets the technical requirements for subsequent power process.Owing to what we found in our previous experimental work,amyl formate had an excellent absorption performance for CO2 compared with methanol(Rectisol absorbent)under the same temperature and pressure conditions,in addition the chilled load for CO2 separation is does not need,bring a large decrease in the energy consumption of the absorption unit.Though the desorption temperature increases as well,the overall energy consumption of the system decreases 7％compared with Rectisol process.