Ethanol
Ethanol
Fermentation is the biochemical process that converts sugars into ethanol (alcohol). In contrast to biogas production, fermentation takes place in the presence of air and is, therefore, a process of aerobic digestion. Ethanol producers use specific types of enzymes to convert starch crops such as corn, wheat and barley to fermentable sugars. Some crops, such as sugar-cane and sugar beets, naturally contain fermentable sugars.
Ethanol has a higher octane than gasoline, but its energy content is only about two-thirds the energy content of gasoline. Most new cars are designed to run on a blend of gasoline and ethanol. "Gasohol" is a mixture of 90-percent unleaded gasoline and 10-percent denatured ethanol. With modification, spark ignition engines can run on 100-percent ethanol. E-85 fuel consists of 85-percent ethanol and 15-percent gasoline. The major automobile manufacturers in the United States now produce flexible fuel vehicles that can use either E-85 fuel or gasoline.
Ethanol may also be used as a hydrogen source for fuel cells. A recent paper by the Renewable Fuels Association concludes that there are no technical barriers to the use of ethanol in fuel cells. Because ethanol is easier to transport and store than hydrogen, fuel reforming (using a chemical process to extract hydrogen from fuel) may be a practical way to provide hydrogen to fuel cells in vehicles or for remote stationary applications. Ethanol is easier to reform than gasoline and most alternative fuels because of its relatively simple molecular structure.
Grain to Ethanol
Most of the ethanol produced in the United States today comes from grain (predominantly corn). In the wet mill process, grain is steeped and separated into starch, germ and fiber components. In the dry mill process, grain is first ground into flour and then processed without separation of the starch.
Wet milling is more common. After the grain is cleaned, it is steeped and then ground to remove the germ. Further grinding, washing and filtering steps separate the fiber and gluten. The starch that remains after these separation steps is then broken down into fermentable sugars by the addition of enzymes in the liquefaction and saccharification stages.
To produce ethanol, yeast is added to a slurry (or "mash"), which is a solution of fermentable sugars and water. The yeast ferments the sugars, producing a solution called beer. The beer solution contains about 10-percent to 12-percent ethanol. The rate of the conversion process depends on the amount of water in the slurry and its acidity, temperature and oxygen content. Up to a third of the original dry weight of the feedstock leaves the fermentation process as carbon dioxide. The solids that remain after the mash has fermented still contain nutrients suitable for use as livestock feed. Distilling the beer produces a solution of 80-percent to 95-percent ethanol.
Producers can use several methods of dehydration to purify the ethanol solution further to 100-percent (200-proof) alcohol for use as a motor fuel.
Biofuel 2.0 gets off ground in Kiwi airliner trial (The Register - Technology News via Yahoo! UK & Ireland News)
Oily desert nuts juice up righteous jumbo Air New Zealand has announced that its planned airliner biofuel test will be carried out using biodiesel made from jatropha nuts. Jatropha plants, able to survive in deserts, could offer a biofuel source which would not compete with food production or drive deforestation.… 'Read more
Biofuel 2.0 gets off ground in Kiwi airliner trial (The Register)
HAVRE - The public is invited to learn about biodiesel in Montana at a workshop, co-hosted by Montana State University-Northern, Ethanol Producers and Consumers and the Montana Department of Agriculture.'Read more
Workshop focuses on biodiesel (Billings Gazette)
Tremblays Bus Company won the school bus contract for next year, but its buses will be fueled with diesel not biodiesel. The schools had to go with the lowest bid regardless of the type of fuel because of the wording of the bid package.'Read more
School bus bid accepted for diesel, not biodiesel (Westport Shorelines)
With millions of Florida motorists now burning corn-ethanol in their gas tanks and landmark legislation pushing renewable biofuels nationwide, the upcoming third annual Farm to Fuel Summit in Orlando is preparing for a record crowd and global interest. 'Read more
Orlando summit hopes to cultivate biofuel ideas (Orlando Sentinel)
NSW will become the first state to mandate a minimum level of biodiesel use in motor vehicles as the state Government continues to defy an international backlash against biofuels.'Read more
Biodiesel mandate defies backlash (The Australian)
Perihelion Global (Pinksheets: PHGI), a development company with interests in natural resources, alternative energies, and advanced communications, today announced that the Company's Biodiesel product has met the latest ASTM D 6751 specifications required for US EPA registration and is now certified as fuel-grade Biodiesel.'Read more
Perihelion Global Opp, Alabama Facility Begins Commercial Production of Biodiesel; Meets Latest ASTM Biodiesel Fuel ... (Marketwire via Yahoo! Finance)
High gas prices and politics push companies toward the ‘holy grail' of biofuel: cellulosic ethanol. 'Read more
The race for nonfood biofuel (The Christian Science Monitor)
The nation's largest biodiesel plant opened Monday at the Houston Ship Channel, expanding Texas' lead as the biggest producer of the alternative fuel. 'Read more
Largest U.S. biodiesel plant opens at Ship Channel (Houston Chronicle)
KEARNEY — Kearney-based Renewable Fuel Technology Inc. will host a groundbreaking at 2 p.m. June 16 at its Republican Valley BioFuels site at the old Ag Valley Co-op property in Arapahoe.'Read more