Humidified Micro Gas Turbine for Carbon Capture Applications: Preliminary Experimental Results With CO2 Injection

The large adoption of renewable energies is crucial to achieve a low-carbon economy, however, in the transition period, a flexible and clean production from fossil fuels is still necessary. With the current shift towards decentralized power production, micro Gas Turbines (mGTs) appear as a promising technology for small-scale generation. The target of a carbon-clean power production calls for the implementation of Carbon Capture Use and Storage (CCUS) technologies. Compared to coal fired power production, the low CO2 concentration in the exhaust gas of a mGT makes Carbon Capture (CC) much more expensive. However, the CO2 concentration can be increased by performing Exhaust Gas Recirculation (EGR), therefore reducing the CC energy penalty. Additionally, cycle humidification can also help to increase the electrical efficiency of the turbine plant. Nevertheless, the higher CO2 content in the inlet air, in combination with the high humidity level, will affect the operation of the mGT. This paper presents a numerical study of this innovative cycle combined with preliminary experimental validation of CO2 injection. To the authors’ best knowledge, experimental analysis of EGR together with humidification applied to a mGT has never been carried out. Experimental results showed a stable turbo-machinery operation under a moderate CO2 injection. The results of this paper are a first step towards a more severe dilution conditions, with the aim of a full implementation of EGR on a micro Humid Air Turbine (mHAT).