The idea of climate neutrality which refers to a balance between anthropogenic greenhouse gas emissions and their removals by sinks belongs to one of the crucial challenges in the global and European climate change policy. Achieving this goal will not be possible without reducing fossil fuel reliance, renewable energy sources development as well as implementation of Carbon Capture, Utilisation and Storage (CCUS) technologies on a broad scale. International Energy Agency predicts that installed carbon capture and storage capacity needs to be expanded from today’s 40 Mtpa CO2 to over 5600 Mtpa CO2 by 2050 in order to limit global warming to 2°C. CCUS technologies development involves activities relating to: (i) CO2 capture (not only from energy sector but also from the industry), (ii) transport infrastructure development, (iii) use of carbon dioxide to produce valuable products and (iv) permanent storage in geological formations. The objective of this study was to investigate two CO2 capture technologies. First one, amine absorption process, is already mature and characterized as commercial technology, whereas second one is a promising method, using chemical calcium looping and is still under pilot studies. These CO2 separation systems make up separate process units and can be integrated with already existing facilities without having significant influence on their operation. What is more, they can be added to power plants as well as to industrial sources of CO2 emissions such as cement plants and blast furnaces. Energy required to capture process yields efficiency penalty in electricity generation and other processes, which was also pointed out by the results obtained in the research via process analysis of two CO2 capture technologies for natural gas combined cycle (NGCC) power plant. The analysis was conducted using process modelling of energy systems and it constitutes the basis for estimating the CO2 separation installation impact on the performance of the whole plant. Carbon dioxide capture is one of the key elements of ongoing energy transition and its integration with NGCC power units could be determined as essential for maintaining energy security with zero carbon dioxide emission power generation.