Biofuels

Biofuels are fuels derived from biological materials or processes that convert renewable biomass into energy. They are used as alternatives or blends for conventional fossil fuels in transportation and, to a lesser extent, in heat and electricity.

The most common commercially important biofuels are bioethanol, biodiesel, and biogas. Bioethanol is produced by fermenting sugars or starches from crops such as sugarcane, corn, or wheat and is often blended with gasoline. Biodiesel is produced by transesterification of fats and vegetable oils or animal fats and can be used in diesel engines as a renewable substitute. Biogas, produced by anaerobic digestion of organic waste and energy crops, is primarily methane and can be burned for heat, power, or upgraded to biomethane for use as gas.

Advanced or second-generation biofuels use non-food biomass, such as agricultural residues, woody biomass, or algae, and aim to reduce competition with food. Production methods vary by feedstock: first-generation fuels rely on edible crops; second-generation fuels use non-edible or waste materials; third-generation focuses on algae and other novel feedstocks.

Feedstocks include sugarcane, corn, wheat, soybeans, rapeseed, palm oil, and residue materials. The environmental impact of biofuels depends on feedstock, land use, farming practices, and processing efficiency; lifecycle analyses show potential greenhouse gas reductions but also potential emissions from land use change and cultivation.

Policy and market drivers—such as mandates, incentives, and sustainability standards—have shaped production in regions like Brazil (large sugarcane ethanol), the United States (corn ethanol), and Europe (rapeseed biodiesel). Biofuels remain debated due to competing land demands, water use, biodiversity, and the variability of their climate benefits.