For the purpose of mitigating carbon dioxide (CO2) emissions, reducing cost for CO2 separation and liquefaction is significant in order to develop carbon sequestration technologies for both geological and oceanic. This paper aims at the technological/economical analysis and feasibility study of CO2 membrane separation and liquefaction system by proposing new CO2 separation process using cardo polymer membrane. System optimization for pressure ratio and distillation temperature, top tray CO2 concentration has done for the purpose of reducing CO2 separation and liquefaction cost, comparing with conventional CO2 separation process. Furthermore, economic effect by applying proposed CO2 separation process into different type of CO2 emission source is evaluated by developing CO2 membrane separation analysis program and combined it with general-purpose process simulator PRO¶/Provision. The CO2 separation and liquefaction cost of proposed CO2 separation process is estimated to be lower than those of conventional CO2 separation process, therefore the CO2 separation process using cardo polymer membrane can be assumed to be feasible in near future for carbon mitigation..