University of Minnesota: pioneering demo plants to ammonia energy start-ups
By on January 13, 2026
In our December episode of Project Features, we explored ammonia energy R&D, pioneering demonstration plants, and start-up companies originating from the University of Minnesota, USA. Michael Reese (Director of Operations, University of Minnesota West Central Research & Outreach Center or WCROC), Sameer Parvathikar (Director, RTI International), Matt Palys (Principal Consultant & CEO, Power-to-X Analytics), and Seamus Kane (Co-Founder & CEO, Aza Power) were joined in conversation by AEA Technology Manager Kevin Rouwenhorst. The recording is available on our website, and you can also download the speaker presentations.
WCROC: Demonstration the potential for renewable ammonia for agriculture
Currently, Minnesota does not have any ammonia production capacity, and imports its nitrogen fertilizers from outside the state, primarily urea and anhydrous ammonia.
But, Minnesota is uniquely positioned for producing renewable ammonia and urea locally. Southern Minnesota has some of the best wind potential in the United States, and the state already has significant food processing and bio-fuel production. The bio-ethanol plants use corn as a feedstock, and these produce CO2 as a byproduct, which may be used in combination with renewable ammonia as feedstock for urea production.
Click to enlarge. Renewable ammonia production potential in Minnesota, from Michael Reese, Green Hydrogen and Ammonia: Opportunities for Minnesota and Beyond (Dec 2025).
Current fossil nitrogen fertilizers contribute around 36% of the greenhouse gas (GHG) emissions for corn production, while drying and field work represent around 42% and 14%, respectively. Next to its use as a fertilizer, renewable ammonia as a zero-carbon heating fuel can also decarbonize drying, and ammonia can be used as a fuel for propulsion in the tractors. As the renewable hydrogen infrastructure matures, other products can be manufactured, such as green steel (Minnesota represents around 86% of the iron ore export in the United States), sustainable aviation fuels, renewable methanol, as well as decarbonizing construction.
The University of Minnesota has long-standing research lines regarding renewable ammonia production and application as a zero-carbon fuel. Back in 2013, the University of Minnesota West Central Research & Outreach Center (WCROC) began operating a 100 kilograms per day wind to ammonia pilot in Morris, Minnesota, which was the first flexible ammonia demonstration globally.
RTI International: Up-scaling the Morris demonstrator
Click to enlarge. Installation of the 1 ton per day pilot plant., from Sameer Parvathikar, Next-Generation Ammonia Technology Integration Platform (Dec 2025).
In August this year, a new, scaled-up version of the off-grid renewable ammonia pilot was inaugurated in Morris, with the capacity to produce 1 ton of ammonia per day. Operations are planned to begin in February 2026, targeting at least 6 months of operations. The project consortium has been led since 2021 by RTI International, and was made possible by US$10 million in funding from the US Department of Energy’s Advanced Research Project Agency Energy (ARPA-E). The variable wind electricity is addressed via a combination of alkaline electrolysis and PEM electrolysis, hydrogen storage, and especially flexible Haber-Bosch technology. The pilot plant will be able to validate process control philosophies and technical targets. Learning from the previous demonstrator, unit sizes were optimized, operation scheduling based on real power profiles is possible.
RTI International itself is a US-based non-profit R&D institute located in North Carolina, working on applied R&D with universities, start-ups and other companies. RTI International works with companies and Universities along the ammonia value chain, including ammonia production, ammonia cracking, and ammonia transportation.
RTI International has also developed a low-temperature and low-pressure catalyst in collaboration with Casale, which it claims to have a ten times higher activity than iron-based catalysts and a four times higher activity than Ruthenium-based catalysts on a turnover frequency (TOF) basis. RTI International collaborates with Casale on the novel catalysts in a bench-scale 15 kilograms per day demonstration, which showcases 90% turndown with a ramp rate of >100% per hour.
Power-to-X Analytics: Reducing levelized cost via flexible ammonia production
In the meantime, various ammonia-related companies have spun out of the University of Minnesota. Among these, Power-to-X Analytics performs techno-economic analyses (TEAs) and life cycle assessments (LCAs) for Power-to-X projects based on variable renewable electricity inputs, allowing for optimal technology selection, sizing, and operational scheduling. Power-to-X Analytics also performs services for facility siting and supply chain optimization for clean fertilizers and fuels.
As discussed above, variable renewables will have an impact on operations of renewable ammonia plants, in an off-grid situation (availability) or in power markets with high renewables penetration (price variation). Energy storage buffers such as batteries and hydrogen storage, as well as flexible Haber-Bosch technology will be required to manage variability. Techno-economic optimization models such as developed by Power-to-X Analytics provide cost optimization and unit sizing. Model inputs are the annual chemical production target, the renewable availability & price time series (on an hourly basis or higher resolution, on a horizon of at least a year), and technology & performance data (capital investment, energy intensity, flexibility, etc.). Model outputs are the optimized levelized cost of the chemical product, technology selection & sizing, and operational scheduling of units including production rates and storage inventories.
Click to enlarge. The effect of ammonia plant flexibility on the levelized cost of ammonia, from Matt Palys, Power-to-X Analytics (Dec 2025).
An example 50,000 tons per year wind to ammonia plant in Minnesota showcases the value of flexible ammonia production. Compared to a steady-state ammonia plant (without operational fluctuations), a flexible ammonia plant that can operate down to 10% of nominal capacity can reduce the levelized cost of ammonia by 40%, due to less wind curtailment, and lower battery and hydrogen storage requirements. The storage buffer then shifts to the ammonia storage capacity, which is significantly cheaper than batteries and hydrogen storage.
Aza Power: 100% ammonia-fueled engines
Also a University of Minnesota spin-out, Aza Power has developed an engine configuration based on turbulent jet ignition, allowing for engines with 100% ammonia as a fuel, including during start-up of the engine. Aza Power Systems aims to address both stationary and transportation markets, using retrofitting solutions for diesel engines by changing the diesel injectors with injectors optimized for ammonia. Ongoing demonstrations include a 150 kW-equivalent mobile power generator, and a 60 kWe mobile military generator (testing to begin in April 2026).
Click to enlarge. Aza Power’s Turbulent Jet Ignition Strategy, from Seamus Kane, Carbon-free ammonia combustion technologies (Dec 2025).
Initially, the focus at the University of Minnesota was on blending diesel with partial ammonia cracking prior to the engine, but the focus is now on pure ammonia combustion. High compression ratio spark ignition experiments were performed between 2020 and 2022, with current work at Aza Power mainly focused on the core technology, namely prechamber combustion turbulent jet ignition. Prechamber combustion turbulent jet ignition is also used in Formula 1 racing.
The technology combines spark ignition typical for a gasoline engine to already burn part of the fuel, with subsequent compression ignition to instantaneously burn the remaining fuel. This allows for burning the whole ammonia, despite its low flame speed, minimizing ammonia slip.
A benefit of the prechamber combustion turbulent jet ignition compared to conventional compression ignition and spark ignition is that pure ammonia can be used as a fuel (without a pilot fuel), without causing significant emissions profiles. For reference, the maritime engines are typically compression ignition engines, using around 5% pilot fuel to improve combustion properties. Emission profiles are further reduced by operating at the temperature and equivalence ratio where nitrous oxide emissions are minimal (<10 ppmv), while also minimizing nitrogen oxides (NOX) and ammonia slip emissions. After a DeNOx system, Aza’s engines are compliant with US EPA Tier IV emission limits. Note that such emission levels are easily treated with novel DeNOx systems that have been developed for four-stroke marine engines, where especially ammonia slip is a key issue. Even if emission profiles are higher during engine start-up, adequate emission treatment systems are already available to reach US EPA Tier IV emission limits.