Bulk hydrogen production and the impact on turbomachinery lifing

Abstract

The EU has made the commitment to reduce pollutant gases emissions by 2030 and achieve climate neutrality by 2050. To achieve these targets the power generation sector must engage. Gas turbines will play a part through the use of alternative fuels such as H2. However the adoption of H2 as a fuel presents multiple engineering challenges, from flame stability, to NOx emissions, to materials’ degradation. The latter is inherently linked to the technologies used to produce hydrogen in the bulk quantities required. Different technologies will generate H2 with differing quantities and types of contaminants (i.e., Cl-based for seawater electrolysis, S-based from steam methane reforming). This is important as, upon combustion, these contaminants can form harmful species in the exhaust stream, linked to mechanisms causing materials degradation. It is therefore crucial to understand the types of contaminants that are present in bulk H2 and so in the combusted gases. This work links together fuel and ingested air chemistry in the gas turbines to the chemical composition of the combusted gases, to the degradation mechanism that might arise in blading materials, and finally their impact on the gas turbine life. Exhaust gas composition has been predicted via thermodynamic modelling, and the condensation of harmful species that will ultimately dictate the corrosion mechanisms (e.g., alkali vapour) calculated.