Co-tutelle UMONS-ULB

ABSTRACT
Recently, the growing share of wind and solar power in the total energy mix has caused severe problems in balancing electrical power generation. Consequently, in the future, all fossil fuel-based electricity generation will need to be run on a completely flexible basis. In this context, micro Gas Turbine cycles constitute a promising and mature Combined Heat and Powertechnology which can offer such flexibility. However, even though their gas emissions are already very low, stringent carbon reduction targets will require them to be completely carbon neutral: this constraint implies the adoption of post-combustion Carbon Capture also on small-scale energy systems. Unfortunately, micro Gas Turbines have not been conceived to be coupled with such units: their low CO2 concentration in the exhaust gas is a severe drawback that makes post-combustion capture very expensive, if not prohibitive. Therefore, a more detailed thermodynamic study is necessary to understand what plant modifications, energy integration and operational strategy must be adopted and thus assess the real potential of this advanced turbine cycle. With this aim in mind, the investigations carried out in this PhD thesis tackled three important aspects:carbon clean operation, energy efficiency and system reliability of mGT systems with Exhaust Gas Recirculation and Carbon Capture unit. As an overall conclusion, this PhD thesis proves — thanks to a thorough thermodynamic analysis, robust optimization and experimental validation — that low-carbon heat and power production from mGTs is feasible and it does not entail major modifications of the base cycle.