Decarbonising Transport Fuels: An Overview of Feedstocks, Processes, Pathways

The world of fuels has become more complex than ever. In the past, road, air, and sea transportation almost exclusively relied on fossil fuels derived from oil. Occasionally, some road vehicles powered by natural gas or biofuels could be found.

However, climate change requires the rapid decarbonization of transportation. But how? The range of options has become overwhelming: battery-electric, fuel cells, various biofuels, waste and residues, ammonia, methanol, CCS approaches, new wind sails, and even nuclear propulsion for ships are now under discussion.

The chart provides an overview of the current and potential future fuel landscape in road, air, and maritime transportation.

• The left-hand column shows the feedstocks: fossil oil and gas, biomass, electricity, CO2, nitrogen, and, for maritime transport only, wind and nuclear fuels.
• To the right is a selection of the most important processes that turn these feedstocks into finished fuels. Many intermediate steps have been omitted for clarity.
• The fuel options are shown in the middle. First is a long list of options, followed by a selection of the most important fuels for individual transport modes that have significant market shares today or could gain relevance in the coming years.
• The transport modes are shown on the far right. In air and maritime transport, different paths are indicated depending on the size of the aircraft or ship. Therefore, two variants are shown here. 
• This column also shows efficiency measures as a „fuel strategy“ that is often overlooked. These measures can refer to vehicles or vessels, or to the organization of transport, such as in contrail management. Small-scale CCS can play a role on board ships.

The overview primarily focuses on fuel supply. Factors influencing transport demand are not included.

This is also a purely systematic overview. Market-dominant fuels are given the same status as niche solutions. A second version of this diagram will show the individual fuels at their true scale.

Chart: Decarbonising Transport Fuels: An Overview of Feedstocks, Processes, Pathways