CO2 capture is imperative currently

cryogenic separation is one of the important methods of CCS(carbon dioxide capture and storage). The accuracy of CO2-N2 phase equilibrium property is related to the liquefied CO2 recovery and recycling purity in cryogenic method

and it will affect the choice of the system and energy consumption analysis further. N2-CO2 phase equilibria calculation based on several state equation models were made in this article. The calculation results show that the PR state equation combined with Vdw mixing rules is most suitable for N2-CO2 phase equilibrium calculation

the maximum deviation is 7.37%

the average deviation is about 3%. Then the CO2 bubble point

dew point and the temperature of sublimation at the condition of 2 MPa with the PR equation model were calculated. An energy consumption analysis about cryogenic system was made

the results show that the method combined liquefaction and sublimation achieved higher recovery and recycling purity

and compared with sublimation separation method

the former method reduce energy consumption by more than 9%. At last

an analysis about the impact of O2 on the CO2-N2 phase equilibrium property was made.