The newly published EU hydrogen strategy opens a new era in the development of the low carbon economy expected to achieve climate neutrality and clean energy transition in Europe.
Ammonia as the real workhorse
In the hydrogen economy, ammonia, the building block of fertilizers and many other chemicals, is one of the real workhorses. Ammonia is made from hydrogen and air, and it has huge potential as a mean to store hydrogen i.e. clean energy. We can say that ammonia is the ‘missing link’ in making decarbonisation a reality.
Ammonia is the only carbon-free fuel as its molecule contains only hydrogen and nitrogen (NH3). What is even more fascinating, when used it breaks down to only water and nitrogen.
As a fuel, ammonia brings the promise to decarbonise the maritime shipping sector reducing its emissions by 95% by 2035 and the demand could reach about 1 million tons ammonia per day (reference Lloyd’s Register Vessels 2030, how do we get there?). Indeed, with limited modifications and technology improvements, ammonia could be directly used in combustion engines of deep-sea vessels.
The ammonia molecule is also probably one of the best alternatives for the mid/long-term storage of electricity as chemical energy. As such it can be used in buffering a renewables-based electricity system by transforming electricity into hydrogen/ammonia when renewable energy is abundant and cheap and burned to produce electricity when needed.
Figure 1 – Beyond fertilizers, creation of the market for green ammonia
Figure 2 Ammonia as the most cost-effective energy carrier
Ammonia more hydrogen dense than hydrogen itself
Although it might seem a paradox, ammonia is a better hydrogen carrier than hydrogen itself. Storing and transporting hydrogen is a challenge as it is the smallest and lightest molecule in nature and it liquifies only at the extremely low temperature of – 253 degrees Celsius.
Ammonia, on the other hand, liquifies at -33 degrees Celsius and can be handled easily, similarly to liquified natural gas. Storing hydrogen under pressure is also possible but again, for the same volume ammonia has a 50% more hydrogen than hydrogen itself. Therefore, when hydrogen is needed, in many applications it makes more economical sense to transform, transport and use it as ammonia.
The nitrogen fertilizer industry is main hydrogen producer
With a share of 53%, the ammonia industry is today the biggest producer and user of hydrogen globally. Ammonia is already being produced and transported worldwide in huge quantities (180,000 tons annually) as it is the basis of many chemicals and very importantly the starting step for producing fertilizers (80% of the demand).
Ammonia is simply produced by reacting nitrogen from the air with hydrogen. Today, that hydrogen is obtained by splitting at high pressures and temperatures the natural gas (methane, CH4) with the help of steam. This splitting process (called steam methane reforming, SMR) generates important quantities of CO2.
A low carbon route involves underground storage of at least part of this CO2 and gives what is commonly called blue ammonia (SMR + Carbon capture and storage, CCS). On the other hand, when ammonia is produced from green electricity and water via electrolysis, or other sources of low carbon hydrogen, the process requires only air.
Green ammonia and low carbon fertilizer production in 2050
By 2050, under the right conditions, ammonia production could be based on decarbonised sources of energy, using alternatives sources of hydrogen and electrolysis based on renewable energy.
Figure 3 Green ammonia and low carbon fertilizer production in 2050
Barriers are many
However, several barriers remain for gradually switching production from SMR based hydrogen towards low carbon routes. Abundant and competitively priced clean electricity to produce hydrogen is a pre-condition for green ammonia to become competitive and challenge the current production technology.
In the EU, the fertilizer sector produces and consumes 3,1 million tonnes of hydrogen and is best placed to help upscale new technology in the most cost-effective way. (Fertilizers Europe press release).
Balancing EU’s climate ambitions with industrial competitiveness will be key to a successful implementation of this strategy.
Provided that schemes considered by the Commission such as the Carbon Border Adjustment Mechanism are in place to help maintain a level playing field between EU producers who are subject to carbon costs and non-EU producers who are not, European fertilizer producers should gain the confidence and the economic room to invest in new technologies”.
Cooperation of all stakeholders is required, including the EU, Member States and regional authorities in supporting industries in rolling out new technologies, for example by providing financial incentives, creating markets for low-carbon products, and partaking in the development of regional hydrogen resources.