Global conflicts are threatening Australia’s supply of urea, a core ingredient in traditional fertilisers. It presents a serious food security threat that could find its solution in smart engineering.
As an industrial chemical that has become critical to Australian agriculture, urea underpins crop production across the nation and around the globe. It’s a synthetic source of nitrogen, which is vital for healthy growth and development of plants used across agriculture.
Simply explained, urea is a nitrogen-rich compound processed from ammonia and carbon dioxide. It enables farmers to supply nitrogen to soil at the scale required for national food production.
“Urea is one of a number of ammonia-derived fertilisers,” said Professor Douglas MacFarlane, Emeritus Sir John Monash Distinguished Professor of Chemistry at Monash University, and co-founder of fertiliser technology company Jupiter Ionics.
“Ammonia is the key fundamental chemical in this, to provide an important source of nitrogen to the soil and to the plant.”
Farmers appreciate urea partly because it is tried and tested, and partly because of its practical advantages.
“It tends to be easily transported. It’s not smelly. It’s reasonably easy to distribute as a pelletised solid. And it’s not explosive like ammonium nitrate, which is otherwise a good fertiliser.”
Those properties have made urea the dominant fertiliser globally, alongside products such as ammonium phosphate and ammonium nitrate – the culprit in the massive 2020 explosion in Beirut, Lebanon, which killed at least 218 people and caused more than 7000 injuries.
Why urea supply matters
Much of Australia’s urea supply comes from overseas, from territories that boast both large natural gas resources and major industrial facilities for ammonia and urea production.
“Today, ammonia is made predominantly from natural gas,” MacFarlane said.
Australia is not entirely without domestic fertiliser production, but capacity remains limited, which is curious for a nation with plentiful natural gas supply.
“Australia exports enormous quantities of liquefied natural gas. We are shipping it out from Queensland and from the north-west in very large quantities to other places where they make the fertilisers … and then we buy it back.”
The standard manufacturing process begins with steam methane reforming, converting natural gas into hydrogen and carbon dioxide. The hydrogen reacts with nitrogen extracted from the air to form ammonia, a key precursor for urea production.
This industrial pathway, the Haber–Bosch process, is extremely energy-intensive and typically operates on a massive scale. A report from the US Department of Energy said a modern plant delivers up to 3000 t of ammonia per day. This requires the equivalent of a continuous one gigawatt energy supply.
According to the International Energy Agency, “ammonia is the starting point for all mineral nitrogen fertilisers, forming a bridge between the nitrogen in the air and the food we eat. About 70 per cent of ammonia is used for fertilisers”.
Their problem is our problem
The relative lack of Australian production of ammonia and urea has created vulnerabilities in the supply chain that, during certain events, affect our nation’s food security.
“The Australian fertiliser industry is reliant on Middle East manufacturers/suppliers, particularly for urea supply,” said Stephen Annells, CEO of Fertilizer Australia. “Any disruption to that supply or shipping will impact Australian supply.”
Large export volumes of urea are shipped through the Persian Gulf and therefore through the troubled Strait of Hormuz.
“While much of the fertiliser required for sowing … is either in Australia or safely on its way, we are aware of cargoes booked for Australia that are delayed in the Persian Gulf,” Annells said.
Even with diversified supply chains, disruptions in such a central export hub can ripple across global markets.
“Australia does source urea fertiliser from other regions and will be seeking products from those regions,” Annells said. “This is a highly fluid situation, and its length and intensity will be the governing factor in how much Australian fertiliser supplies are disrupted and for how long.”
Can we engineer our way out?
Building a modern fertiliser plant is a major undertaking in terms of cost, resources and energy.
One such project currently underway in the Burrup Peninsula of Western Australia is Perdaman’s $6 billion urea plant, which AusTrade said will be one of the largest in the world.
“The Perdaman plant will convert natural gas from Woodside’s Scarborough Gas Project into an estimated 2.3 million t of urea per annum,” an AusTrade release said.
That project will see the creation of a traditional, large-scale, centralised production facility. But researchers are also now exploring alternative, decentralised methods and models.
READ: Perdaman’s $6.4 billion project set to be world’s largest single-train ammonia plant
Localised production
MacFarlane’s team at Jupiter Ionics has developed an electrochemical approach to ammonia production using electricity, water and nitrogen from the air.
“The production of ammonia is fundamentally a reduction reaction,” he said. “Electrons are the best and cheapest form of reducing agent.”
Instead of large centralised plants fed by natural gas, the technology could operate at farm or local region scales, powered by renewables.
“Our technology is capable of being rolled out on a highly distributed basis,” he said. “Imagine a shipping-container size. It draws about a megawatt of power, produces about a ton of ammonia a day, and uses about a ton and a half of water a day.”
That quantity of nitrogen could suit the requirements of a large, broadacre farm, or enable regional production networks or even farm-scale fertiliser systems. And because the process is driven by electricity, it could integrate with renewable energy systems.
“It can cycle up and cycle down, or even just switch off.”
This would allow facilities to absorb excess electricity from solar or wind generation. The challenge now is scaling the technology.
“Every time you increase the working area by a factor of ten, you uncover problems that you maybe weren’t completely ready for.”
Other work is also ongoing. Researchers at UNSW, for example, are looking into converting high-emissions waste streams – including carbon dioxide from industrial activity and nitrogen pollutants from agricultural practices – to produce urea.
For MacFarlane, the stakes extend far beyond chemistry.
“This is a major food security issue. Its solution is now mostly an engineering challenge, and there’s some chemistry in it, as well.”
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