Biofuels are fuels produced from agricultural products (e.g., bioethanol, biodiesel).

Biofuels are typically used as a blend stock in conjunction with conventional oil-based fuel blend stocks to make diesel and gasoline.

The use of biofuels is largely driven by government mandates (such as RFS, LCFS, RED) that require a minimum level of biofuels blending or direct subsidies (eg blend credits).

The use of biofuels, both in volume and number of different types of fuel, continues to grow as concerns about climate change drive interest in new, low-carbon sources of liquid hydrocarbons.

Types of biofuels

There are a variety of different biofuels currently used to satisfy renewable fuels mandates, the most common are:

• Bioethanol - Ethanol produced from agricultural sugars or starch (from corn, sugarcane, beets or wheat) through a fermentation process. Also small amounts produced from conversion of cellulosic feedstocks

• Bio ETBE - gasoline blend component made from reacting bio ethanol with isobutylene (usually from refining crude oil). Most commonly used as a biofuel in Europe.

• Bio Jet - Kerosene or jet fuel produced from biomass. Currently most production come from hydroprocessing of vegetable oil (HVO). Other paths include gasification and Fischer-Tropsch conversion of biomass and alcohol to jet conversion (AtJ).

• Biodiesel (FAME) - diesel blend stock produced from vegetable oils or animal fats using a transesterification process. Yields a diesel blend stock that can be blended in low volumes (typically 5%), limited by cold flow properties

• Renewable diesel - high-quality diesel blendstock currently typically produced from hydroprocessing of vegetable oils or animal fats. It can also be produced through gasification and Fischer-Tropsch conversion of a wider range of biomass sources.