Micro gas turbine operation experience with 100% hydrogen

Kurzfassung

The Institute of Combustion Technology of the German Aerospace Center (DLR) and Power Service Consulting GmbH presented a jet-stabilized combustion chamber system for small gas turbines specially developed for synthesis gases and hydrogen at the VGBe symposium in June 2024. Without modifications to the combustion chamber system, this technology enables also a variable mixture of fuels during operation and therefore offers a high level of fuel flexibility for the respective plant user. The presented combustion chamber technology was integrated into a retrofit package that was developed for the AE-T100 microturbines from the manufacturer Ansaldo Green Tech S.p.A.. This retrofit package includes the installation of the new combustion chamber system and the implementation of a flexible control, regulation and mixing system. To ensure operational safety, the turbine's existing safety precautions were reviewed and supplemented with hydrogen-compatible gas warning sensors. This ensures the safe handling of hydrogen as a fuel. The operation of the converted micro gas turbines with up to 100% hydrogen was successfully tested. The starting processes with pure hydrogen were also investigated. The presentation summarizes the operating experience gained, particularly with regard to operation with hydrogen and hydrogen-natural gas mixture. It is particularly noteworthy that emissions of less than 15 ppm NOx (normalized to 15 vol% residual oxygen) were achieved during hydrogen operation without the need for additional exhaust gas aftertreatment. This result represents remarkable progress, as NOx emissions tend to be higher when running on hydrogen compared to conventional natural gas. Thanks to the emission values achieved, it was possible to fall well below the TA Luft 2021 specification for natural gas, which underlines the efficiency and environmental friendliness of this technology. The converted micro gas turbines including fuel mixing equipment are now available on the market and enable the reliable provision of climate-neutral process heat for medium-sized industrial companies using hydrogen from locally generated wind and PV electricity or from synthesis gases generated in local production or industrial processes by means of gas turbine-based CHP plants.