Paper outlines ways to reduce energy use at ethanol plants

By Kris Bevill | May 29, 2012

The Great Plains Institute, a Midwest-focused sustainable energy development nonprofit organization, recently released a white paper outlining various methods that could be utilized by existing dry-mill corn ethanol plants to improve their efficiency rates and reduce greenhouse gas (GHG) emissions.

The paper was written with the intent of providing ethanol producers and policy makers with an overview of efficiency opportunities related to corn ethanol production. The paper also makes the case for new federal policies to be created in order to assist existing producers in carrying out efficiency upgrades. “In recent years, policymakers have tended to focus on advanced and cellulosic fuels,” the authors noted in the report. “While this is very important, this report indicates that additional focus should be given to supporting existing producers. Now that the volumetric ethanol excise tax credit for ethanol has expired and does not look likely to be renewed, the time is right for a discussion about new policies that assist the industry in improving their carbon intensity.”

Each stage of ethanol production offers the chance for efficiency improvement, according to the authors. The paper breaks down energy efficiency and carbon reduction opportunities into four broad categories—water use, industrial energy efficiency, alternative process fuel and coproducts—and offers several examples of various courses for improvement implemented by producers in each area. In the industrial energy efficiency category, for example, the authors highlight combined heat and power, co-location with a power plant or other large industrial facility, and waste heat recovery as efficiency improvement possibilities, and provide short lists of plants that have already taken these approaches. Under the coproducts category, the authors suggest that producers could reduce energy use and emissions by combining wet and dry distillers grains for local markets. They also highlight corn oil extraction, carbon capture and storage, and corn fractionation as additional steps that could be taken to further reduce overall energy use and GHG emissions.

It was noted by the authors that many of the technology improvements mentioned in the paper could also help advance the commercialization of next-generation biofuels and could be incorporated into future facilities. They also suggested that while a number of producers have adopted various technology improvements, a comprehensive analysis of the costs and benefits of efficiency improvement and emissions reduction methods is needed before many of the technologies will be adopted on a wide scale.