US-based Mainspring Energy has announced successful testing of pure ammonia fuel in its Linear Generator technology system. Thanks to the lower operating temperature of the system, NOx emissions are near-zero. The design features advanced electronics that precisely control the temperature & pressure of the reaction inside the combustion chamber, also allowing the system to adapt automatically to the composition of the incoming fuel. The Linear Generator can thus run on any number of gaseous fuels, including natural gas, biogas, hydrogen, anhydrous ammonia.
Testing of pure hydrogen & ammonia fuel was conducted and compared to conventional fuel (natural gas or biogas). Running on pure hydrogen, the Linear Generator was 2% less efficient than running on gas or biogas, but produced zero NOx emissions. Running on pure (anhydrous) ammonia, the system efficiency was actually 1% higher than gas or biogas, and Mainspring indicates that “off-the-shelf” technology available for current gas turbine models can yield NOx emissions that “meet any permitting standard”.
Historically, the use of ammonia for power generation has been associated with co-firing: using coal, diesel, or hydrogen in order to overcome ammonia’s high ignition temperature and slow chemical kinetics. This of course comes at a price: carbon emissions, added costs for blending, and significant drops in power output. Mainspring’s Linear Generator technology is uniquely positioned to run on pure ammonia without any reductions in power or efficiency, including being able to start on pure ammonia.
We designed the fuel-flexible Linear Generator so that as clean fuels become increasingly available and cost-effective, organizations of all kinds can capitalize on them to run their operations, generate zero-carbon power, and meet their climate goals.Mainspring CEO Shannon Miller in his organisation’s official press release, 22 June 2022
Displacing diesel backups
The scalability of the Mainspring product allows for use behind and in front of the meter in large grids, microgrids, data centers, and similar operations that require constant access to backup power.
Particularly urgent is the need to displace diesel-powered backup generators in applications such as these. In Mainspring’s home state of California, 12 GW of diesel backup generators are currently installed, with obvious pollution, health and fuel cost implications.