In the transition towards a decarbonised economy in Spain and the world, green hydrogen, e-ammonia, e-methanol and Sustainable Aviation Fuels (SAFs) such as e-kerosene stand out as key alternatives to fossil fuels. Each of them plays a specific role in sectors such as industry, shipping and aviation, where emission reductions are necessary and challenging.
The diagram below illustrates how these fuels are produced and their interconnections, highlighting the role of green hydrogen as the basis for much of this:
Green hydrogen thanks to its versatility is a central component in the transition to a sustainable energy model. On its own it is capable of decarbonising different industries such as road transport, especially in heavy transport as we discussed in our blog Hydrogen in Heavy Duty Vehicles (HDV): Compressed Gaseous Hydrogen (CGH2) at 700 bar vs Liquid Hydrogen (LH2), or natural gas consuming industries such as steel, glass, ceramics and cement, as we mentioned in our other article on Natural gas combustion vs green hydrogen. However, it faces challenges such as high production costs and the complexities of storage and transportation, which require specialised infrastructure. Despite these challenges, its role as a base for other fuels establishes it as a key pillar in achieving the ‘Net Zero by 2050’ coalition.
E-ammonia, produced by Haber-Bosch synthesis, combines green hydrogen and nitrogen to form a compound with multiple applications. Its high energy density and ease of storage make it a viable alternative to hydrogen, especially over long distances. Moreover, its use is not limited to transport; it is also essential as a feedstock for fertilisers, where it is currently produced from grey hydrogen. However, it faces challenges such as toxicity, risks associated with its handling and production costs.
E-methanol, produced by combining green hydrogen and captured carbon dioxide, is presented as a clean and versatile fuel with applications in shipping and the chemical industry. However, challenges such as the availability of captured carbon dioxide on a large scale and production costs limit its mass adoption.
Sustainable aviation fuels are key to decarbonising the aviation industry. Within this category, e-kerosene, produced through the Fischer-Tropsch process combining green hydrogen and captured carbon dioxide, is chemically similar to fossil paraffin, making it compatible with existing infrastructure, from aircraft engines to airport storage systems, eliminating the need for significant modifications. E-kerosene not only offers significant lifecycle emissions reductions, but also contributes to the circular economy by reusing captured CO₂. However, its production faces significant challenges, such as high operational costs and limited availability of sustainable feedstocks. Despite these barriers, global momentum towards sustainable aviation is accelerating its adoption.
There is no single best solution for all applications. The choice depends on the characteristics of each project, taking into account factors such as the sector, economic conditions, existing infrastructure and the end consumer. This is because green hydrogen, e-ammonia, e-methanol and e-kerosene have complementary roles, with green hydrogen being the basis for many of these fuels, e-ammonia as an essential feedstock for sustainable fertilisers, e-methanol as a key fuel in the chemical industry, and PBS such as e-kerosene being key to decarbonising aviation.
If you are considering green fuels for your project, we help you lay the groundwork that addresses the entire ecosystem, from green hydrogen to the final fuel. At Lean Hydrogen, we are experts in designing tailored solutions that integrate these technologies.
Date: 01/07/2025
Author: Christian Preciado Cárdenas
Reviewer: Eugenio Trillo León
