|Smith, Darrell -|
Submitted to: Carbon Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 10, 2013
Publication Date: April 1, 2013
Citation: Hatfield, J.L., Smith, D.D. 2013. Food and agricultural waste: Sources of carbon for ethanol production. Carbon Management. 4:203-213. Interpretive Summary: Agricultural processing produces a large amount of waste material which is often discarded into landfills where it contributes to carbon dioxide or other greenhouse gas release. There are millions of tons of these materials which range from old seed, food processing waste, whey, or sugarbeet tailings which have the potential to be used as sources of sugars for ethanol production. The approach used in this analysis was to evaluate the potential for ethanol production from these waste materials and to develop a concept for how waste materials should be evaluated. We developed a concept based on avoidance in which the amount of ethanol produced compared to amount produced from corn grain. Waste materials have the potential to replace 5.5 million acres of corn used for grain or roughly half of the corn production in Iowa. Waste materials can be evaluated to avoided energy, avoided water, and carbon release. We propose this concept to show the value of waste materials as low cost energy sources to meet the Renewable Fuel Standards. This information will be of use to policy-makers in evaluating alternative energy sources and to ethanol manufacturers to examine waste as a source of material for energy production.
Technical Abstract: In the past, wastes derived from agriculture products have met with limited success in the production of biofuels. Our objective in this report is to showcase a new and meaningful concept (called “avoidance”), to measure the environmental importance of converting these waste streams into energy. Agriculturally-derived wastes, specifically food waste and other byproducts, are excellent potential sources for meeting the federal Renewable Fuel Standard, calling for the production of advanced and cellulosic biofuels. In addition, the resultant stillage is converted into other useful byproducts, such as animal feed or synthetic biogas. Our goal is to provide an “energy avoidance” framework, showing the positive environmental impacts that occur when these waste sources are properly measured, and used to produce advanced and cellulosic biofuels, animal feed and biogas.