How are Biofuels Made?

Ethanol is an alcohol, the same found in beer and wine. It is made by fermenting any biomass high in carbohydrates through a process similar to brewing beer. Ethanol is mostly used as a fuel additive to cut down a vehicle’s carbon monoxide and other smog-causing emissions. But flexible-fuel vehicles, which run on gasoline and up to 85% ethanol, are widely available in India and elsewhere.

Pure biodiesel is made by combining alcohol with vegetable oil, animal fat, or recycled cooking greases. It can be used as an additive, or in its pure form as a 100% renewable alternative for diesel engines.

Other bio-based fuels include methanol and reformulated gasoline components. Methanol, commonly called wood alcohol, is currently produced from natural gas. However, it can also be produced from biomass. There are a number of ways to convert biomass to methanol, but the most common approach is called gasification. With gasification, the biomass is vaporized at high temperatures and impurities are removed. The biomass then passes through a catalyst and is converted into methanol.

What is Biofuel?

Biofuel is a fuel produced from organic material like plant materials, vegetable oil, animal fat, and cellulosic biomass.

Depending on the feedstock used, biofuel may qualify as carbon-neutral. This is achieved when the carbon dioxide absorbed by the plants equals the CO2 released when the fuel combusts.

Common Biofuel Types

Biodiesel

Biodiesel is produced from oils or fats using transesterification. The resulting liquid is similar in composition to fossil and mineral diesel. Consisting mostly of fatty acid methyl esters (FAMEs), biodiesel is the most common biofuel in Europe. Its feedstocks include animal fats, vegetable oils, soy, rapeseed, jatropha, mustard, flax, sunflower, palm oil, hemp and algae. Pure biodiesel (B100) currently reduces emissions by up to 60% compared to diesel. It can be used in any diesel engine when mixed with petroleum diesel. In fact, it is technically possible to run a diesel engine on pure biodiesel B100. However, biodiesel is most commonly blended with petroleum diesel (B5, B20, etc.) to avoid “gelling” in cold weather environments.

Ethanol

Ethanol fuel is the most common biofuel worldwide. It is produced by fermentation of sugars derived from wheat, corn, sugar beets, sugar cane, molasses and any sugar or starch from which alcoholic beverages can be made. The ethanol production methods used are enzyme digestion, fermentation of the sugars, distillation and drying.