Techno-Economic Analysis of CO2 Capture Technologies for Small-Scale Dispatchable Gas Turbines

In order to achieve Net-Zero, small-scale dispatchable OCGTs need CCS. Within the literature, sources routinely overlook these small-scale generators, majority of which fall within the Medium Combustion Plant Directive (MCPD). Currently, these plants are not required to be carbon capture ready, but future energy system restraints will require CO2 abatement on these types of generators. Therefore, this study looks at evaluating CO2 capture for modern gas turbines, specifically looking at OCGTs under <50 MWe. This techno-economic analysis focusses on two CO2 capture technologies
• Chemical Absorption using 30 wt.% Monoethanolamine (MEA).
This is considered the benchmark CO2 capture technology for power generation sources, and it is currently the only technology deployed globally on a large scale power plant.
• Vacuum-Pressure Swing Adsorption (VPSA) using Zeolite 13X.
This technology and sorbent material is close to commercialisation. A large quantity of research already exists in the literature, with several pilot-scale studies.
Within this study, process and economic models are developed and used to analyse the performance of each of the OCGT+CCS plants. Both capture plants work from identical CO2 sources, and to ensure an accurate comparison both CO2 streams are conditioned ready for pipeline transportation.
This study has highlighted an important bottleneck in reaching Net-Zero by 2050. Dispatchable power is crucial for ensuring security of electricity supply; however, the current dispatchable technologies will become too costly if we attach CCS. Therefore, future work needs to investigate different capture and utilisation technologies in order to drive the levelised cost of electricity for OCGT+CCUS down. Moreover, OCGT+CCS needs to be compared against alternative dispatchable power sources such as hydrogen combustion and energy storage, to discover the most effective option for ensuring security of electricity supply.