Researchers turn high-emissions waste into zero-carbon fertilizer

Researchers in Australia have developed a breakthrough process to turn waste products into fertilizer, slashing emissions from one of the world's most polluting industries.

Researchers used renewable electricity to trigger an electrochemical reaction coupling carbon dioxide with nitrogen pollutants such as nitrate and nitrite – common waterway contaminants from agriculture and industry – to form urea, bypassing fossil fuel-intensive traditional methods, a statement from Australia's University of New South Wales (UNSW) said on Monday.

"Urea is the fertilizer used to feed the crops for more than half of the world's population. 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," said UNSW Associate Professor Rahman Daiyan.

"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," said Daiyan, corresponding author of the study published in Nature Communications.

The copper-cobalt catalyst, designed at atomic scale, demonstrated a strong synergy for controlled carbon-nitrogen bonding, and improved urea production when compared with existing systems, the study showed.

Australia, a major agricultural exporter, imported 3.8 million tonnes of urea in 2024 due to limited domestic production, statistics showed.

The technology targets unavoidable emissions from cement factories and agricultural waste, the researchers said.