PlasNifix, a Swiss cleantech startup founded in 2022, develops plasma-assisted ammonia synthesis technology which produces ammonia at a low temperature using green energy. This novel technology requires 40% less energy for ammonia production and can be run exclusively with green energy at zero carbon emissions.
Challenges: green ammonia
Ammonia (NH₃) is a crucial compound for agriculture. In 2021, the global production of ammonia was 185 million metric tons, with over 80% being used for fertilizer production. As the global population increases, so does the demand for ammonia.
However, ammonia production consumes about 2% of worldwide fossil fuel due to the energy-intensive nature of the process. This generates over 420 million tons of carbon dioxide (CO₂) annually, which accounts for 1.5% of global greenhouse gas emissions.
The primary method of ammonia production is the Haber-Bosch process carried out in a large industrial plant. The Haber-Bosch process converts hydrogen (H₂) and nitrogen (N₂) into ammonia. This process requires extreme reaction conditions involving high pressure and temperature, along with pure hydrogen. The high temperatures and pressures are intentionally engineered for the application of solid catalysts, such as Ru, Mo, or Fe-based catalysts, to attain significant yields of ammonia. The processes of hydrogen and nitrogen heating to temperatures exceeding 450 ºC and compression to 200 bars (20 MPa) requires substantial energy input and significantly contribute to carbon dioxide (CO₂) emissions.
Therefore, there is an urgent need to develop technologies for ammonia synthesis in a sustainable manner. The utilization of renewable energy to convert N₂ and green hydrogen into NH₃ represents a promising approach for the production of green ammonia production.
plasNifix has developed a plasma technology which synthesizes ammonia at a low temperature and pressure using nitrogen gas, hydrogen gas, gaseous catalysts, and renewable energy input. This technology reduces carbon dioxide emissions and energy consumption by a substantial amount. Furthermore, in contrast to solid catalysts used in the Haber-Bosch process, this technology uses gaseous catalysts that are uniformly dispersed throughout the plasma reactor to significantly promote ammonia production.
The diagram below illustrates the system and process of plasNifix plasma technology for ammonia synthesis.
Reactants of nitrogen and hydrogen gasses are fed into a mixing chamber in an optimal ratio of 1:9. This mixing ratio differs from the conventional Haber-Bosch method, which utilizes a 1:3 ratio. Therefore, plasNifix can process the ammonia synthesis with a high hydrogen content compared to the Haber-Bosch process, which results in more efficient ammonia production.
The reactant stream is then combined with gaseous catalysts in a subsequent mixing chamber. The stream of gaseous catalysts is composed of argon (3 – 13%), helium (6 – 25%), neon (10-25%), xenon (10-25%), and radon (1 – 13%). The gaseous catalysts comprise as much as 33% by molar fraction of the process gas.
The mixing reactants and gaseous catalysts are then fed into a plasma reactor. The plasma is generated by direct current discharges powered by renewable energy sources. In the plasma reactor, the synthesis of the ammonia takes place at ambient temperature and relatively low pressure of 5 bar.
plasNifix’s plasma ammonia synthesis has two advantages:
- With a small amount of energy input, it is possible to dissociate and ionize reactants and catalysts that are easily ionized, thereby accelerating the reactions. This significantly reduces energy consumption and permits plasma synthesis at a low temperature.
- The uniform distribution of gaseous catalysts throughout the reactor volume enables a three-dimensional scaling of the reaction sites, thereby substantially enhancing the efficiency of ammonia production.
The produced ammonia is then separated from the output stream of the plasma reactor. The remaining unreacted reactants and gaseous catalysts are recycled and enriched with new reactant gasses, so that a process gas with defined ratios of reactants and catalyst is again provided.
- WO2023025493A1 Method of nitrogen fixation in a plasma reactor
plasNifix Technology Applications
Green ammonia can be used as a carbon-neutral fertilizer, significantly reducing the carbon footprint of farming. Using green ammonia for fertilizer could drive down farming’s carbon footprint by as much as 90% for corn and small grain crops.
Green ammonia can be used as a transport fuel, replacing highly polluting gasoline, diesel, and propane to run engines, generators, and turbines. It has applications in transportation including heavy goods vehicles, trains, aviation, and shipping.
Green ammonia has the potential to be used for large-scale, long-term energy storage. It has nine times the energy density of Li-ion batteries, and three times that of compressed hydrogen, making it a competitive option against electrochemical batteries, pumped hydro, and capacitors to balance consumption and renewable generation. Countries including Japan, Australia, the Netherlands, and the United Kingdom have national plans to use green ammonia to store (and export) their renewable energy surpluses.
plasNifix is currently developing a custom plasma source for their plasma reactor.
plasNifix has raised a total of CHF10K in funding over a Grant round raised on Jul 27, 2023.
plasNifix is funded by Venture Kick.
Martin Poms is CEO.