In this work, a comprehensive lab-scale carbon capture installation was established to study the separation performances of CO2/N2 systems for the postcombustion technology. Four kinds of mono-/two-stage carbon capture methods containing membrane separation and chemical absorption processes were investigated. The result shows that the CO2 capture performance of the one-stage membrane separation method (Memb) exhibits a profitable CO2 removal efficiency but defective CO2 concentration, while the one-stage chemical absorption method (Chem) indicates both CO2 removal efficiency and CO2 purity of more than 95.0% but suffers a regeneration heat of at least 2.7 MJ/t CO2. The CO2 purity of the two-stage membrane separation method (Memb–Memb) is 46.2% higher than the Memb method because of the additional membrane pretreatment. Two-stage methods have a superior gas recovery efficiency of over 99.0%, which is dramatically higher than the homogeneous Memb method. In addition, the investigation on the hybrid chemical absorption–membrane separation method (Memb–Chem) provides an alternative approach to reduce the mass transfer and solve the problems caused by an unequal mass flow distribution.