New research from UNSW Sydney could transform one of the world’s most pollution-heavy chemical industries, turning waste products into fertiliser while cleaning up waterways and slashing emissions.
UNSW engineers have tackled a longstanding challenge at the heart of global agriculture: how to produce urea fertiliser without the high emissions of fossil-fuel-based processes.
The innovation, detailed in Nature Communications, points to a path toward low-emission, circular fertiliser production powered by renewable energy.
Corresponding author Associate Professor and Scientia Fellow Dr Rahman Daiyan from UNSW Sydney’s School of Minerals and Energy Resources Engineering said the work is part of a broader effort to go beyond green ammonia and decarbonise the entire fertiliser supply chain.
“Urea is the fertiliser used to feed the crops for more than half of the world’s population,” Dr Daiyan said.
“But currently, it’s made from natural gas or coal.
“It’s a very fossil-fuel intensive, high-temperature, high-pressure technology with huge emissions.”
Industrial activity releases enormous quantities of carbon dioxide each year, about 40 billion tonnes in 2024, while nitrogen pollutants such as nitrate and nitrite from agriculture and industry contaminate waterways.
The UNSW research links these two global problems through an elegant solution: an electrochemical process that couples carbon dioxide and nitrogen pollutants to form urea.
“Making carbon and nitrogen bond together in a controlled and reliable way is extremely difficult,” said the study’s first author, UNSW PhD student Putri Ramadhany.
“To overcome this challenge, we designed a catalyst that works at an atomic scale and can hold carbon- and nitrogen-based molecules together long enough for them to react.”
The copper–cobalt catalyst developed by the team demonstrated exceptional synergy and significantly improved urea yields over existing systems.
According to Dr Daiyan, this offers a foundation for a circular process capable of transforming captured emissions into valuable fertiliser.
“We’ve been trying to look into pathways for decarbonising urea production,” he said.
“The vision is zero-carbon urea where we directly couple waste carbon dioxide with nitrogen pollutants using renewable electricity, rather than relying on ammonia as an intermediate.
“That allows us to run the system on solar and wind, avoid high temperatures and pressures and reduce emissions.”
The researchers are now moving beyond laboratory proof-of-concept to develop urea electrolysers, devices seen as key to commercial application.
Using electron-beam characterisation at the Australian Synchrotron, the team observed the reaction process in real time to understand how the materials behave under industrial conditions.
For Australia, the implications are significant.
Despite being a major agricultural exporter, the nation imports around 3.8 million tonnes of urea annually.
Dr Daiyan described this dependence as “a pity” and a strategic vulnerability.
Locally made, low-emission urea could strengthen supply chains while cutting pollution.
Dr Daiyan emphasised that the technology is designed to process unavoidable emissions from cement plants or biogenic sources rather than relying on costly air capture.
He views it as part of a global shift toward using waste carbon across sectors.
“At COP, I spoke to governments about the technological pathways we need,” he said.
“This is one of them – there’s enough carbon dioxide around.
“We just need to start thinking and investing in a circular economy.”
He expects the technology could reach industry partnerships within two to three years.
“Our work highlights how thoughtful catalyst engineering paired with real-time characterisation can turn environmental problems into opportunities,” he said.
