Without green energy, there can be no green steel. However, the availability of cost-effective green energy production, be it hydrogen or electric power, varies widely across different regions, and transportation and storage options present substantial difficulties. To navigate these challenges, utilizing ammonia as a hydrogen carrier is also a viable solution for steel production. Given that ammonia is the chemical industry’s second-largest product by volume manufactured, its handling, storage, and transportation methods are reliable and well-established.
Advantages of ammonia
Transporting energy in the form of ammonia is a compelling one thanks to its characteristics, namely its higher energy density than hydrogen and its easily attainable liquefaction pressure and temperature, reducing the costs associated with its containment and transportation. Having a cost-effective carrier for long-distance energy transport and storage is key for countries like Germany, which may face limitations in domestic energy production or cost competitiveness and which will require importing energy in an economic way. In other words, the ammonia approach allows customers to circumvent geographical and economic constraints, accessing low-cost energy from afar.
Ammonia offers more advantages:
- Availability: Ammonia is one of the most widely produced chemicals globally, for various industrial applications, particularly in agriculture to make fertilizers.
- Energy density: While ammonia has a higher energy density compared to hydrogen by volume, it has a lower energy density by weight. This means that a smaller volume of ammonia can provide a similar amount of energy as hydrogen, making it more practical for transportation and storage.
- Reducing potential: When heated, ammonia can decompose into nitrogen and hydrogen gas, a mixture ideally suited to act as a reducing agent in steelmaking processes. This decomposition reaction can occur at temperatures easily achievable in a steel plant by using steelmaking offgases.
- Environmental considerations: Ammonia production can be decoupled from fossil fuel sources by using renewable energy sources for hydrogen production and subsequently converting it into ammonia.