The combined cycle gas turbine power plants (CCGTs) are a combined cycle consisting of a gas turbine and steam turbine to generate electricity. After the gas fuel combustion in the gas turbine combustion chamber, the flue gases are passed through the Heat Recovery Steam Generator (HRSG) to extract heat and generate steam further sent to the steam turbine. The CCGT technology is recognized for its highest efficiency in electricity production among the power production technology. A highly efficient CCGT produces even 2.5 times less CO2 than a modern coal power plant. The CO2 emission can be reduced further when the post-combustion CO2 capture methods are applied. The CO2 mass fraction in flue gas is the crucial parameter for the operation of the Post-combustion Carbon Capture (PCC) technology. The PCC technology uses solvents, which react with flue gas and absorbs the CO2, which is treated and separated later. The paper presents the results of the thermodynamic analysis of a combined cycle gas power plant integrated with a post-combustion CO2 capture system. Two different gas fuels such as methane and syngas were considered in the study. Syngas composition was determined from the sewage sludge gasification process and can be treated as zero-emission CO2 gas fuel. Presented results of mass and energy balance analysis of CCGT integrated with PCC CO2 capture can help in the evaluation of CCGT with PCC performances. With the outcomes, the possibilities of CO2 capture from the flue gas using solvents like Monoethanolamine (MEA) and 2-amino-2-methyl-1-propanol (AMP) – Piperazine (PZ) mixture in PCC is also analyzed.