Renewable fuels are energy sources that are produced from resources that can be replenished. Examples include hydrogen fuel or biofuels. They are different to non-renewablefuels like natural gas, petroleum and other fossilfuels. These sources may also include nuclear energy. There are many current initiatives to develop renewable fuels, and the technologies required to produce them.
Cellulosic biofuels
Cellulosic biomass biofuels are renewable, clean energy sources that are derived from biomass. This energy source is extremely promising in helping the US become energy independent. The National Renewable Energy Laboratory in Golden, Colorado has been developing cellulosic ethanol, since 1995. The company manages the National Bioenergy Center, which has developed cellulosic ethanol as a drop-in alternative to gasoline.
Biodiesel
Biodiesel is made of renewable resources and is cleaner than traditional petroleum diesel. It produces lower levels of emissions than petroleum diesel and can be biodegraded (as fast or faster as sugar). It has many positive effects on the environment as well as the economy. Biodiesel may be produced from locally grown crops. Some projects turn kitchen waste into biodiesel.
Bioethanol
Bioethanol is a form of renewable fuel. It can be made by fermenting sugars in the presence oxygen. The yeasts, facultative anaerobes which live in sugar-rich environment, are responsible for the fermentation process. Yeasts for bioethanol production are either cultured or can be taken from their natural habitats. For bioethanol production, yeasts from nature are the best choice because they are more efficient in converting sugars to ethanol.
Biomethane
While the biomethane industry is still relatively small, it is a promising one. It can also be used on existing infrastructure. The growth of the biomethane industry depends on policies aimed at decarbonising the gas supply.
Bio-diesel
Bio-diesel can be described as an alternative fuel, which is made from renewable resources. It is used in construction and manufacturing industries, as well as being one of the most preferred fuels by the U.S. government. As diesel-powered vehicle demand decreases, this renewable fuel is expected see significant growth. Diesel-powered cars make up less than 1% of passenger car sales in the U.S.
Bio-ethanol
Ethanol is a biofuel that is produced from fermentation of carbon-based fuels. These feedstocks, which use sunlight to generate energy, are renewable in that they return all the nutrients used for their growth back to the soil. Some of these feedstocks are sugar cane, bagasse, and sugar beets, as well as cellulose wastes.