“In the future farmers may produce their own fuel”
12 October 2021
Hello there Johannes Messinger, Professor at the Department of Chemistry who is working on a new method for producing fossil-free ammonia (NH3).
Why is this important?
“Ammonia is used in huge amounts and is a key component in the production of fertilisers and various chemicals. What is less well known is that it could also be used for long-term storage of hydrogen and as fuel. Today, it is mostly produced from nitrogen gas from the air and hydrogen gas extracted from natural gas (methane), which releases carbon dioxide into the air.”
What methods do you use?
“We are working on developing an electrochemical method in which nitrogen gas and water are directly combined to form ammonia without hydrogen gas as an intermediate. The only side product would be oxygen. To make such a process truly sustainable, the process should be driven by solar energy and the catalysts that are required for converting the water and nitrogen molecules into ammonia should consist of abundant elements such as iron, manganese and oxygen. We expect that this direct process could be more efficient, and that it could be realised in smaller units.”
What are the difficulties?
“We have thus far found conditions that allow a highly specific conversion of nitrogen gas to ammonia, but the production rates are minimal. We have now started the second phase of the project, in which we aim to develop new and more efficient catalysts that allow for efficient ammonia production under ambient conditions. In doing so we are drawing inspiration from the enzyme nitrogenase, which performs exactly this reaction. We want to become at least as good as this enzyme, but in a process that is more directly driven by solar light and is more applicable in a technological context!”
What do you hope for in the future when it comes to your way of producing ammonia?
“I think the main benefits are that small and local units could be built that will allow CO2-neutral production of ammonia. That could save transportation and make it possible to store solar energy for local use from summer to winter. An important aspect of this is that such a possibility would make a future renewable energy system more resilient. For example, farmers who often have huge farm buildings could place solar cells on them and use any excess electricity for ammonia production. They can then store it and convert it back to electricity when needed using special fuel cells, or use the ammonia as fuel for driving their tractors or to make fertilisers.”