University of Sydney researchers have developed a lightning-based method for producing ammonia in gas form, offering an alternative approach to conventional synthesis with potential relevance for the transition to a hydrogen-based economy.
According to the university, the current method to generate ammonia, the Haber-Bosch process, is energy-intensive and typically requires large-scale infrastructure and proximity to low-cost natural gas to remain economically viable. Currently, 90% of global ammonia production is said to rely on this process.
Lead Researcher, Professor PJ Cullen from the University of Sydney’s School of Chemical and Biomolecular Engineering and the Net Zero Institute, stated: “Industry’s appetite for ammonia is only growing. For the past decade, the global scientific community, including our lab, wants to uncover a more sustainable way to produce ammonia that doesn’t rely on fossil fuels.”
“Currently, generating ammonia requires centralised production and long-distance transportation of the product. We need a low-cost, decentralised and scalable ‘green ammonia.’ In this research we’ve successfully developed a method that allows air to be converted to ammonia in its gaseous form using electricity. A huge step towards our goals.”
As noted, ammonia contains three hydrogen molecules, making it a potential carrier and source of hydrogen for energy applications, including storage and transport. Furthermore, it is considered a candidate for use as a carbon-free fuel.
It is understood that during the Haber-Bosch process, ammonia is made by combining nitrogen and hydrogen under high temperatures and pressure in the presence of a catalyst, while this new method to generate ammonia reportedly works by harnessing the power of plasma, by electrifying or “exciting” the air. As per the researchers, the latter one is a more “straightforward pathway” for ammonia production.
Cullen commented: “This new approach is a two-step process, namely combining plasma and electrolysis. We have already made the plasma component viable in terms of energy efficiency and scalability. To create a more complete solution to a sustainable ammonia productive, we need to push the energy efficiency of the electrolyser component.”
As revealed, the team is now working on making this new method more energy efficient and competitive compared to the Haber-Bosch process.