A century ago a fertiliser production process paved the way for increased food production across the globe through the use of ammonia-based nitrogen fertiliser.
Called the Haber-Bosch process, it works by combining nitrogen from the air and hydrogen using high pressure and heat, and its efficiency over other methods resulted in 50% of the world’s food producers relying on ammonia fertiliser.
However, despite its many benefits, the process isn’t cheap or environmentally friendly, accounting for 1-2% of global energy consumption and CO2 emissions.
In response to this, scientists from Germany’s Helmholtz Institute for Renewable Energy claim to have pioneered a new ammonia production process that could provide an alternative to the Haber-Bosch process, using off-the-shelf lasers to break the chemical bonds, a process needed for ammonia production.
They say it could be used with renewable energy to produce sustainable fertiliser, offering hope for an alternative to traditional methods at a time when traditionally produced fertiliser is both unsustainable and expensive.
The new process has broken all current energy use and yield records, Huize Wang, from the Helmholtz Institute for Renewable Energy, told chemistryworld.com.
“We have achieved an unprecedented yield under room temperature and atmospheric pressure conditions, notable when compared to other methods,” he said.
Victor Mougel, an expert in electrochemical transformation at ETS Zürich, said being able to be made at room temperature means the ammonia could be produced where it is needed, also saving on transportation costs.
“These alternative methods are potentially more sustainable than the Haber–Bosch process, which is very energy intensive as it operates at high temperature and pressure and contributes to carbon dioxide emissions,” he said.
“As the process works in ambient conditions it offers operational flexibility, as well as the environmental benefits with that.”
The next step is understanding how the method could be scaled up to be commercially viable, something Ifan Stephens, an expert in electrochemistry and nitrogen fixation at Imperial College London, is sceptical about.
“I’m not certain [these] high rates can be sustained for long periods of time,” he said.
“Moreover, the fact that it is a batch process, as opposed to a continuous process, would pose significant limitations to its viability.”
Researchers are trialling several different methods for scaling up production.