This report reviews the performance and costs of existing commercial gas turbines and the capability of gas turbines to operate using hydrogen-containing fuel gases. The report was commissioned by ETI to provide background information for a project they will undertake on salt caverns for storage of hydrogen for use in gas turbine power plants.
A wide range of gas turbines are reported by manufacturers to be suitable for fuel gases that contain hydrogen. There is significant experience of using gases that contain mixtures of mainly hydrogen,methane and other hydrocarbon gases, especially refinery off-gases and coke oven gas, which typically contains 50-60%vol H2. Gases with H2 concentrations of up to 95% are reported to be used. There is also experience of using syngas from gasification which typically contains 25-50%vol H2 but the other main constituent is CO, which has substantially different properties to methane.
Use of fuel gas containing H2 presents some significant technical challenges for gas turbines but also some potential benefits.
The biggest technical challenge is reported to be the high flame speed of H2, which can result in flashback, although it reduces the risk of blowout. The properties of hydrogen-methane mixtures in gas turbines combustors vary non-linearly with concentration. It is reported that only when hydrogen becomes the main constituent is there a large variation in the laminar flame speed.
Development aspects and assessments of Gas Turbines (fired by methane and/or H2) are provided, including contemporary OCGT GTs from GE. Additionally, potentially synergistic capture technologies are described