As productivity on the farm and in the ethanol plants increases, it is critical to understand the net impact of corn ethanol on the corn supply.
One of the frustrations for the corn ethanol industry in the whole indirect land use/lifecycle analysis debate is that the value of co-products such as distillers grains (DDGs) are often ignored.
Dave Vander Griend, president and CEO of
ICM Inc, has just released a
white paper on the subject, “Rethinking the value of corn ethanol co-products in lifecycle assessments.”
ICM is a Kansas-based company that has been building and designing ethanol plants since 1995, with a special emphasis on improved process design and energy efficiency.
Co-products underrated
According to Vander Griend the value of ethanol co-products is highly underrated. “Recognition of the co-products that come from ethanol production is absolutely fundamental to understanding the true value of corn as a food and energy crop,” he says.
Ethanol production returns about one third of the corn it utilizes in the form of DDGs for livestock feed. The nutritional value of that feed is actually 50% better than raw corn.
When harvesting a hectare of corn for ethanol production only half of the equivalent of that hectare is used to make ethanol. The other half is returned in nutritional value to feed livestock for the human food supply.
“This feed credit should be calculated when determining the overall demand for corn for ethanol production and the ultimate lifecycle analysis for ethanol,” Vander Griend says.
In a comparison between corn, switchgrass and sugarcane as feedstock for ethanol production, Vander Griend concludes: “All three of them will give you fuel, but when you look at which ones will give you food and fuel, you only have corn.”
He says if you count the food and feed value of corn utilized for ethanol, corn is actually the most efficient energy crop.
Energy crops | Sugar | Cellulose | Starch |
| Sugarcane | Switchgrass | Corn |
Tonnes/acre | 35 | 10 | 8.2 |
Yield (gallons) | 560 | 850 | 431 |
Feed credit | 0 | 0 | <50%> |
Net value* | 560 | 850 | 862 |
* 2 acres of corn to ethanol = 1 acre of feed grain displacement