Abstract: Oxy-fuel combustion is one of the most potential CO_2 capture and storage technologies for large-scale promotion and commercial application,and the flue gas compression purification and CO_2 purification is the core unit in the whole oxy-fuel combustion system. However,the current studies focused on the process verification of flue gas compression purification after oxygen enriched combustion,and the operating characteristics of flue gas compression unit,especially the migration and transformation of impurities in the process of flue gas compression and its relationship between the operating parameters and the removal efficiencies of impurities,were still unclear. Besides,little attentions have been paid to the purification and production of CO_2 liquid with high purities,which can significantly affect the economic efficiency of the whole oxy-fuel combustion system. Therefore,in order to meet the needs of oxygen enriched combustion flue gas purification and CO_2 purification,the fundamental operating characteristics of the SO_2 and NO_x absorption removal as well as the purification of CO_2 in the compression and purification process of oxy-fuel combustion were systematically studied in the present work,in which the removal of SO_2/NO_x were achieved by pressurized acid adsorption and the purification of CO_2 was achieved by cryogenic distillation.The results indicate that the removal of SO_2 and NO by flue gas purification can reach 100% and 99% respectively. Meanwhile,the purity of food grade liquid CO_2 can reach 99.99%. In the process of flue gas cleaning,the gaseous reaction is dominant,and the residence time for the adsorption of both SO_2 and NO can be shortened by the increase of reaction pressures. As the operating pressures of the SO_2 adsorption column increase to more than 0.8 MPa,the removal efficiency of SO_2 can be 100%,and when the operating pressure of NO adsorption column is more than 3.0 MPa,the emission of NO can meet the demands for the state ultra-low emission. The purity of liquid CO_2 decreases with the increase of operating pressure in the column of CO_2 purification. Furthermore,the energy consumption of CO_2 recovery can be as low as 0.37 MJ/kg CO_2,when the operating pressures for SO_2 removal,NO_x removal,and CO_2 purification are 1.6 MPa,3.0 MPa,and 3.8 MPa.