Biomethane is a game-changer in ammonia production, according to new research. It offers a way to transform what is typically a large carbon emitter into a carbon neutral process.
In a study published in One Earth, environmental engineer Aurelian Istrate shows how adding biomethane to ammonia production could significantly reduce environmental impact. This is all the more important as ammonia is a key ingredient in synthetic fertilizers, essential to the nutrition of billions of people around the world.
Traditionally, ammonia is made by extracting hydrogen from natural gas, a process that releases a lot of carbon into the atmosphere. Electrolysis using renewable energy is an option, but it is expensive and not widely used.
Istrate’s idea is to use biomethane produced from food waste and agricultural residues. This renewable gas is chemically similar to natural gas (CH4), but the big difference is that it operates in a closed carbon cycle. The CO2 released during production was first captured by photosynthesis during plant growth, making it much more sustainable.
The study examines three methods of producing ammonia: conventional, electrolysis and biomethane. The results suggest that combining biomethane and carbon capture and storage (CCS) technology could produce carbon-neutral ammonia. Even with a mix of 44% biomethane and 56% natural gas combined with CCS, the process could achieve carbon neutrality.
What is particularly interesting is that this method can be used without new technology. CO2 separation is already part of biomethane and ammonia production, so the infrastructure is already in place. Biomethane is therefore a practical option for reducing emissions in agriculture without disrupting fertilizer supplies.
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