Dropping Water Use: Ethanol Producers Balance Cost and Conservation When Reducing Consumption
by Holly Jessen (Ethanol Producer Magazine) The results of a Google search of the words ethanol and water use are varied and interesting. Some of the information is up-to-date and lays out the industry’s dramatic reduction in water use in the past 10 years, to an industry average of less than 3 gallons of water per gallon of ethanol produced. Other articles contained dated and downright sensationalized information, pigeonholing the ethanol industry as a water guzzler.
That’s simply not the case, says Nandakishore Rajagopalan, associate director for applied research at the Illinois Sustainable Technology Center. While a few groups have either looked into building or have built an ethanol plant in a poorly chosen site where water is in short supply, the majority are located in places where there is enough water to go around.
…According to Water Footprint Network, from which the U.S. Geological Survey takes some of its water use statistics, the global average water footprint of corn is 1,222 liters of water per kilogram of corn. On the ethanol side, it estimates a global water footprint for corn ethanol at 2,854 liters of water per liter of ethanol produced—a number that is vastly larger than the water consumption figure cited by the ethanol industry. To keep that in perspective, however, the global average water footprint of beef is 15,400 liters per kilogram and the global average water footprint of chocolate is about 17,000 liters per kilogram.
…“Our survey showed that ethanol plants have been very successful in reducing their water consumption,” he (Steffen Mueller of the University of Illinois at Chicago) says. “The survey also indicated that many plants had plans to reduce their consumption even further.” Those are the most recent figures available and there are no specific plans to update them at this time. Currently under consideration, though, is a best-practices book to showcase all the energy and water efficiency measures ethanol plants have put into place since 2008, Mueller says. READ MORE and MORE (Ethanol Producer Magazine update May 2013)