Abstract: Based on the problems of excessive CO₂ emission, two new processes that liquefied natural gas (LNG) cold energy is utilized for Rankine cycle power generation and CO₂ liquefaction are proposed. Process 1 adds a reheat cycle and a regenerative cycle to the conventional Rankine cycle. Ensuring the cold energy required for pre-cooling and liquefying CO₂ to maintain constant, the process 2 integrates the nitrogen liquefaction system based on the process 1 to reduce the grade difference of the hot and cold streams in the evaporator and improve the exergy efficiency of the evaporator. The effects of exhaust gas temperature, circulating refrigerant pressure and flow rate on process specific work and exergy efficiency were analyzed. The simulation results show that the exergy efficiency of process 1 and 2 is 49.70% and 49.80% respectively, the specific work is 237.70 kJ/kg LNG and 235.20 kJ/kg LNG, and the same liquefaction rate of CO₂ is 0.60 kg/kg LNG. The calculation with a specific example proves that the new processes have good economic and environmental benefits.