The CO_2 capture process using ionic liquids(ILs) in the coal-fired power plant is simulated

in which the physical properties of ILs and ILs-CO_2 phase equilibria are modelled based on experimental data. Analysis shows that the increase of packed height and absorption pressure is beneficial for CO_2 absorption

while the inlet temperature has the dual effect as it influences both the ILs viscosity and CO_2 solubility. The optimum condition is determined with 20 m packed height

4 MPa absorption pressure and 50 ℃ inlet temperature. The regeneration process is more energy efficient with pressure swing method

in which the pressure of ILs-CO_2 stream is reduced to 0.1 MPa with almost no ILs loss. Energy consumption and cost analysis shows that the multistage compressor is the most energy-intensive unit

and the absorption pressure has the largest effect on the system with 4 MPa the optimum parameter. With the optimum condition

the energy consumption of the process is 2.21 GJ/t

which is more energy-efficient than the conventional carbon capture system using monoethanolamine.