From fuel to fertilizer, how green ammonia could help curb emissions

The Kenya Nut company is to become the first farm in the world to produce its own fossil fuel-free fertilizer on-site.

Using solar power to strip hydrogen from water, a small fertilizer plant on the farm will create an imperial ton of “green ammonia” every day.

Ammonia has long been used as a fertilizer but is typically formed from hydrogen isolated from natural gas rather than water, in a process that results in large volumes of emissions.

Given that global ammonia production accounts for 1.3% of energy-related CO2 emissions – not that far away from the aviation industry’s 2% – green ammonia could offer significant potential to decarbonize the agricultural sector. And there is also hope it could be used as a clean fuel alternative.

Ammonia is typically produced by combining hydrogen and nitrogen through a method known as the Haber-Bosch process. This so-called “brown ammonia” uses fossil fuels both to provide the hydrogen and the energy source. Each tonne of ammonia produced releases about 2 tonnes of greenhouse gas.

And we produce ammonia like this on a huge scale – it is estimated that around half the world is fed using synthetic nitrogen-based fertilizers.

Green ammonia, by contrast, relies on renewable energy, and derives its hydrogen from water and its nitrogen from air. This form of ammonia production is typically more expensive but is becoming cheaper, not least as renewable energy prices fall.

Aside from the significant benefit of producing fewer emissions, this process is also not reliant on natural gas in the same way as the production of brown ammonia. This is particularly relevant given that Russia is both a significant producer of ammonia and source of natural gas. Sanctions against Russia as a result of its invasion of Ukraine have caused fertilizer shortages and prices to skyrocket.

Around 70% of ammonia is used for fertilizers; the rest is used for industrial applications, including plastics, explosives, and synthetic fibres. Demand for ammonia is expected to grow significantly over the coming years as the population expands.

In addition to the uses above, there is growing interest in the potential of green ammonia as a sustainable fuel given its low carbon impact.

In particular, there is hope it may help reduce the carbon footprint of the shipping industry, although there are some hurdles, including around storage and distribution, which need to be overcome.

It is, however, likely to be easier and cheaper to store and transport than hydrogen, which is also touted as a potential clean fuel source. Because of this, ammonia may also find use as a hydrogen carrier.

And it also has potential as a replacement for fossil fuels in industrial processes and electricity generation. For example, ammonia may provide a long-term way of storing and transporting energy from renewable sources.

The production of green ammonia is in the early stages and significant investment and infrastructure will be needed to scale it up.

Alongside this, there are also safety considerations that come with transporting and storing ammonia due to toxicity.

Despite this, its development could be hugely beneficial to industries that are hard to decarbonize. The World Economic Forum’s First Movers Coalition is working together to come up with clean technology solutions for hard-to-abate sectors, including aluminium, aviation, chemicals, concrete, shipping, steel and trucking, which are responsible for 30% of global emissions.

For example, shipping and logistics group Höegh Autoliners joined the coalition in 2022 and has committed to running at least 5% of its deep-sea operations on either green ammonia or green methanol by 2030.

While bringing green ammonia to the fore is a priority, so too must be scaling down brown ammonia. Transforming agriculture and food systems to be less reliant on brown ammonia is a key part of this puzzle, particularly given a third of human-produced greenhouse gas emissions comes from food systems.

Balanced against this, however, is the need to produce high-quality low-emission food to feed a growing population, too many of whom already lack access to sufficient nutritious food.

The World Economic Forum is working with public, private and civil society partners on a Food Innovation Hubs initiative to drive forward developments in sustainable food production and consumption.

Meanwhile, 100 Million Farmers, another Forum initiative, aims to accelerate collective action among farmers to scale climate- and nature-friendly agricultural practices.

"Restoring soil health offers the world its second-largest carbon sink, freshwater retention and stewardship, biodiversity preservation, nutrient-dense foods and resilient livelihoods for farmers everywhere," says Tania Strauss, Head, Food and Water, World Economic Forum

"The innovation must not only be the technology but the way we partner with farmer communities to translate fit-for-purpose solutions, restore soil health and adapt to climate change."