Production of Liquid Biofuels

Biofuels are solid, gaseous, and liquid fuels obtained from biomass conversion processes. Liquid biofuels include several products such as biodiesel, bioethanol, butanol, methanol, Fisher-Tropsch diesel, and vegetable oils.

Biofuels are addressed as low-carbon substitutes to fossil fuels and can help reducing greenhouse gas emissions in several sectors: power generation, transport, and hard-to-abate sectors such as chemical, cement, iron, and steel industry.

Biofuels are classified into: i) first-generationbiofuels, also referred to as conventional biofuels, produced from food or animal-feed crops; ii) second-generationbiofuelsobtained from non-edible dedicated energy crops, agricultural and forest residues, and municipal solid waste; iii) third-generationbiofuels obtained from dedicated cultures of algae and microalgae. Second and third-generation biofuels are also referred to as advanced biofuels.

Biofuels have the potential to be “carbon-negative” when coupled with advanced conversion techniques for carbon capture and storage (BECCS) or carbon capture and utilization (BECCU).

Biofuels generation may take place through several pathways: hydrolysis and fermentation, gasification, fast pyrolysis and upgrading, esterification, and Fischer-Tropsch processes.