The Deutsche Zentrum für Luft und Raumfahrt (German Aerospace Center, or DLR) and Power Service Consulting (PSC) have successfully proven a commercial gas micro-turbine that can allow it to run on both hydrogen and natural gas.
Green hydrogen has been suggested as a possible climate-friendly alternative to burning natural gas when thinking about decarbonizing energy production. However, there is still no green hydrogen economy to support such things and it may take years to do. Even if it happens, building brand-new power plants is a very expensive undertaking.
According to Peter Kutne, Head of the Gas Turbines Department at the DLR Institute of Combustion Technology, building a new 15-megawatt gas turbine power plant can take up to six years and cost around 30 million euros (US$31 million) while retrofitting an existing plant takes only one and a half years and costs around a tenth of that.
The Retrofit H2 project used micro-turbines with an output of about 100 KW because of their better power-to-weight ratio. In addition, these micro-turbines are also widely used for not only producing power in remote areas, but also applications like backup power for hospitals, as well as heating for hotels, swimming pools, and hotels.
Furthermore, micro-turbines of this output capacity can also power places such as breweries or waste treatment plants that can use their waste methane for fuel.
The problem is hydrogen burns much hotter than natural gas and has a much lower flash point. Therefore, it can easily wreck the combustion chamber of a micro-turbine with its heat and shockwave.
To solve this, engineers created a jet-stabilized burner optimized for hydrogen. The air and fuel injectors are set in a ring to create a backflow in the chamber that pushes the exhaust gases back to mix with the new air/fuel mixture, helping to lower the temperature, reduce nitrogen emissions, and stabilize the flame.
Furthermore, this new arrangement also allows the micro-turbine to burn hydrogen, natural gas, or a mixture of the two by a new adjustable control system and safety technology. The system has been currently run in a pilot plant in Lampoldshausen on pure hydrogen for about 100 hours.