Energy in the Future series: Biofuels and sustainability
Biofuels are typically grouped based on their fuel source. First-generation biofuels are produced directly from food crops, second-generation biofuels use non-food-based biomass sources such as crop waste, and third-generation biofuels use crops that are specifically grown and designed for the creation of biofuels such as algae and bacteria.
To reduce harmful emissions such as carbon dioxide and NOx, biofuels may be seen as the best short-to-mid-term solution for the rail industry due to their easy integration with existing technologies. It has been suggested that biodiesel is one of the most promising biofuels for the railway industry as it is similar to petroleum diesel. By having almost identical chemical properties, biodiesel can be blended with petroleum diesel to make up to 20% of the fuel composition without requiring any changes to the rolling stock and the distribution infrastructure. This could lead to a reduction in emissions, particularly along routes where electrification will not occur in the short-to-mid-term.