Zero-carbon ammonia can be used to power ships and make the transport sector greener, a policy briefing by the British Royal Society shows. The research considers opportunities and challenges associated with the manufacture and future use of the product, today mainly known as a fertilizer.
“The report is not just about green ammonia, though that is our endpoint,” the chair project leader, Professor Bill David of the department of chemistry at University of Oxford, explained to Forbes.com. “It discusses transitioning away from ‘brown’ ammonia (made using a fossil fuel as the feedstock), through ‘blue’ ammonia (fossil fuel based but with carbon capture) to ‘green’ ammonia (from renewable energy, like air and water).”
The production of ammonia is one the most polluting after those of cement and steel, creating 1.8% of global CO2 emissions.
“Ammonia has had a profound global impact since the discovery of its synthesis from hydrogen and nitrogen by Haber and Bosch in Germany at the beginning of the 20th century,” the briefing reads. “The key role of ammonia today is as the basic feedstock for inorganic fertilizers that currently support food production for around half of the world’s population.”
On the other hand, “from an environmental perspective, ammonia represents a chronic hazard to terrestrial ecosystems as well as providing an increasing burden to air pollution.” It is not a greenhouse gas itself, but “it may be converted to nitrous oxide, an important contributor to radiative forcing of climate” and it “has a substantial indirect impact on climate through its role in particulate matter.”
Therefore, David added, the entire system needs to be decarbonized.
In the process to obtain green ammonia, hydrogen is produced through the electrolysis of water and nitrogen directly from air using an air separation unit. Finally, ammonia is produced using the Haber-Bosch process powered by sustainable electricity.
At that point, the chemical can be used as a medium to store and transport chemical energy, as a transport fuel, or to store thermal energy.
According to Adam Bond, CEO of AFC Energy, a developer of alkaline fuel cells which use hydrogen for electricity production, “significant investment is going into the development of low cost green ammonia generation around the world driven to a large part by the need to decarbonise the world’s fertiliser industry.”
“The parallel use of green ammonia to fuel sustainable power generation is a further key benefit to the vast sums moving into this market in recent years.”
The Royal Society pointed out that the main challenges are cost, of which about 85% is electricity. The cost of electricity in areas with abundant renewable potential, however, has decreased dramatically over the past decade.
The shipping is already experimenting on this technology, as the International Maritime Organisation pledged full decarbonization by 2050.
“The maritime industry has already identified the significant retrofitting potential for ammonia as a green fuel for shipping, noting its ease of storage, existing maritime networks and bunkering capabilities, flexible use in both combustion engines and fuel cells and potential relative to other decarbonization options,” reads the report.
Also Felix Leinemann, Head of Unit for Blue Economy Sectors, Aquaculture and Maritime Spatial Planning at the European Commission, mentioned the decarbonising of shipping during the European Shipping Week.
An example is the ShipFC consortium project, which has been awarded €10m funding from the European Union to deliver the world’s first high-power fuel cell to be powered by green ammonia. The initiative, run by a consortium and coordinated by the Norwegian cluster organization NCE Maritime CleanTech, started January this year and will be finalized in late 2023.
For the first time, an ammonia-powered fuel-cell will be installed on a vessel, allowing it to sail solely on the clean fuel for up to 3,000 hours annually.
The aim is to show that long-range zero-emission voyages with high power on larger ships is possible.
“An advantage of ammonia is high energy density compared to its alternatives, which makes it relatively well-suited for deep-sea applications. Furthermore there already exist established infrastructure and safety protocols for the production, transport and storage of ammonia,” Hege Økland, CEO of NCE Maritime CleanTech, told Forbes.com.
Some risks remain, as for other types of fuels. “The main risks of ammonia is its toxicity, however the fertilizer industry has more than 100 years of experience working with ammonia and there exist well established regulations in the industry that have been set up over the years,” Økland added.
“The project participants’ extensive knowledge within storage solutions, ship design and safety systems will keep risks related to the use of ammonia to a minimum.”