State of Ethanol Production

Manufacturing

“In 2006 alone, the world produced 13,489,000,000 gallons of ethanol.”

There is already a great deal of ethanol production in progress, with more plants being built all the time. In 2006 alone, the world produced 13,489,000,000 gallons of ethanol. 1 The majority of these plants are in the United States and Brazil, but China, India, France, and Germany all produced ethanol as well. 1 Most of these plants produce between ten million and fifty million gallons of ethanol per year. 2 Other companies are building larger plants to produce up to one hundred fifteen million gallons of ethanol per year each. 2

The Process

The ethanol manufacturing process is a simple, clean, and economical operation. The process begins with a source material, which will be fermented and converted to ethanol fuel. In the United States this material is typically corn, but other options are available. For instance, in Brazil sugar cane is used as the source material. Research is underway to perfect a process called cellulosic ethanol that relies on plant matter, such as poplar, switchgrass, or wheatgrass as a manufacturing source instead of food material. 3

Steps

Ethanol manufacturingPhoto credit: Fred D. Thomson
  1. The source material must be milled to a meal to allow easier fermentation.
  2. The meal is mixed with water to form a semi-liquid called mash.
  3. Mash is combined with enzymes to convert the starch to sugar that can be fermented.
  4. Mash is piped into huge tanks where fermentation occurs. Typical fermentation takes about 40-50 hours.
  5. The fermented mash, now called beer, is pumped into a distillation process that separates the ethanol from everything else left over. This ethanol is about 190 proof.
  6. The ethanol is sent through a dehydration process that finally purifies the ethanol to nearly 100% purity or 200 proof.
  7. The pure ethanol is mixed with 5% of a denaturant such as regular gasoline. This ensures that the finished ethanol is not drinkable and allows the ethanol to be sold as a fuel, not as a alcoholic beverage.

References

  1. “Annual World Ethanol Production by Country”. Industry Statistics. 21 Mar 2008. RFA. 21 Mar 2008 <http://www.ethanolrfa.org/industry/statistics/#E>.
  2. “U.S. Fuel Ethanol Industry Biorefineries and Production Capacity.” Ethanol Biorefinery Locations. 21 Mar 2008. RFA. 21 Mar 2008 <http://www.ethanolrfa.org/industry/locations/>.
  3. Wu, Corinna. “Cellulose Dreams.” Science News. 25 August 2007: 120.
  4. “How Ethanol is Made.” Renewable Fuels Association. 16 Apr. 2008 <http://www.ethanolrfa.org/resource/made/>.