Water use reduction opportunities in ethanol production

ENVR 194

Timothy C. Lindsey, tlindsey@wmrc.uiuc.edu, Pollution Prevention Program, Illinois Waste Management and Research Center, 1 E. Hazelwood Drive, Champaign, IL 61820
A 2002 survey by the USDA revealed that water consumption in dry grind ethanol plants ranged from <1 to 11 gallons of water per gallon of ethanol, with an average consumption of 4.7 gallons. Design specifications for the most recent plants are estimated to be closer to 3.5-4.5 gallons of water/gallon of ethanol produced. This level of water use, while much improved from a historical perspective, is still raising concern among some stakeholders as to its potential long-term impact on future water availability.

This presentation will examine the processes that use water to produce ethanol, the purpose served by the water, and the relative quantities used to accomplish each of the process steps. Options available to ethanol plants to reduce the level of water consumption will also be discussed.