Renewable fuels refer to energy sources that can be renewed. Examples include hydrogen fuel and biofuels. They are in contrast to non-renewable fuels, which are petroleum, natural gas, LPG, and other fossil fuels. These sources could also include nuclear fuels. There are numerous efforts underway to develop the technologies and fuels that renewable energy requires.
Cellulosic Biofuels
Cellulosic Biofuels are renewable and sustainable energy sources made from biomass. This energy source is extremely promising in helping the US become energy independent. The National Renewable Energy Laboratory, based in Golden Colorado, works on cellulosic ethanol from 1995 to date. The company manages the National Bioenergy Center, which has developed cellulosic ethanol as a drop-in alternative to gasoline.
Biodiesel
Biodiesel comes from renewable resources and has a cleaner burn than petroleum diesel. It produces lower levels of emissions than petroleum diesel and can be biodegraded (as fast or faster as sugar). It has many advantages for the environment, and the economy. Biodiesel is made from sustainable crops. Some projects even transform kitchen waste into biodiesel.
Bioethanol
Bioethanol, a renewable fuel, can be produced by fermenting sugars and oxygen. The yeasts, facultative anaerobes which live in sugar-rich environment, are responsible for the fermentation process. You can either isolate yeasts from their natural environment or grow them in culture. Yeasts are used for bioethanol production. Natural yeasts are better for bioethanol production because they are more efficient at converting sugars into ethanol.
Biomethane
Although the biomethane renewable fuels industry is very small, there is great potential for growth. It can be used on existing infrastructure. Policy changes that reduce the carbon footprint of gas supply will determine the future growth of the biomethane market.
Bio-diesel
Bio-diesel can be described as an alternative fuel, which is made from renewable resources. It is one of the preferred fuels of the U.S. government, and is also used in the manufacturing and construction industries. This renewable fuel will experience significant growth as diesel-powered vehicles become less popular. Currently, diesel-powered vehicles make up just 1% of passenger vehicle sales in the U.S.
Bio-ethanol
Ethanol, a renewable fuel, is made from the fermentation of carbon-based materials. These feedstocks have the ability to harvest sunlight and return nutrients to the earth. These feedstocks include sugar cane, sugar beets and bagasse as well as cellulose wastages.