Post-combustion carbon capture is the underpinning technology and necessary choice for low-carbon power generation

yet its integration into natural gas combined cycle(NGCC) power plants will significantly reduce the plants' power generation efficiency. In order to reduce the efficiency penalty of the power plants integrated with decarbonization system and improve the energy utilization efficiency of the integrated system

a novel post-combustion carbon capture process that comprehensively recovers the waste heat and liquefied natural gas cold energy is innovatively proposed. Firstly

the key operating parameters of the conventional carbon capture process

including stripper pressure and lean solvent loading

are optimized with sensitivity analysis. On this basis

design and evaluation of novel process is performed. In the novel process

a back-pressure turbine is utilized to recover the pressure energy of the extracted low-pressure steam and assist the lean vapor compression as well as recover the inter-cooling heat of CO_2 compression to heat the reflux condensate of the stripper

which reduces the minimum regeneration energy consumption by 17.3%(to 3.35 GJ) at the flash pressure drop of 90 k Pa.Furthermore

the extracted low-pressure steam is reduced from 68.40 kg/s to 48.95 kg/s by recovering the superheat of steam extraction. Aiming at solving the problems of high energy consumption of the conventional CO_2 compression process and the waste of cold energy in the liquefied natural gas regasification process

a novel CO_2 two-stage compression and intermediate liquefication process is proposed

reducing compression work by 34.5%

and the cooling load and the number of equipment were significantly decreased. Exergy analysis results show that the exergy efficiencies of the novel carbon capture process and CO_2 compression process increase from 23.12% and 62.19% to 29.48% and 65.96%

respectively. The simulation results show that

the net power output of the plant integrated with the novel carbon capture process increases from 341.93 MW to 358.75 MW

resulting in a significant energy saving by increasing the net power output efficiency from 48.85% to 51.25% and decreasing the efficiency penalty from 13.77% to 9.53%.