CO2 capture analysis in different combustion methods for CO2 utilisation and storage

The high energy consumption of CO2 capture is the main issue of the application of CO2 capture, utilisation and storage, new CO2 capture methods based on oxy-fuel combustion and chemical looping combustion are receiving considerable attention. However, the energy consumption performance of these methods is rarely compared when they are used as the CO2 source for CO2 utilisation and storage. This work analysed both the new developing and traditional methods of CO2 capture process to obtain their energy consumption performances. The CO2 capture processes of the oxy-fuel combustion and chemical looping combustion were respectively built and simulated under pressure varied from 0.1 MPa to 8.0 MPa. The captured CO2 product of each process was set to the same level of parameters for transportation, and a calculation method was developed to convert all types of energy consumption to equivalent power consumption. The results show that both the new CO2 capture methods have notable potential of low energy consumption, especially under higher combustion pressures. If the air separation process is considered, the oxy-fuel combustion CO2 capture requires further technical development to defeat the post-combustion CO2 capture, although it has the advantage of high CO2 concentration. The impacts of pressures of inlet gas and process sequence are analysed to be the key reasons for energy performance. [Received: May 23, 2019; Accepted: January 10, 2021]