53. How much ethanol can we get from one bushel of corn?
The industry average is slightly more than 2.5 gallons per bushel in addition to the high protein livestock feeds.
54. Will increased ethanol production affect the price of soybean meal and the profitability of growing soybeans?
Since increased ethanol production will mean increased distillers grains and gluten feed production, the initial response
of the protein feed market might be lower prices. The farmer reaction could then be to plant more corn and less soybeans.
Farmers generally realize that they will benefit any time they increase their market for anything they grow. With Eastern
Europe and the Consolidated Independent States (previ- ously the Soviet Union) opening their borders and trying to upgrade
their standard of living, there is so much potential for increased livestock feeding that the demand for protein could stay
ahead of production.
55. What is the difference between a wet and a dry mill ethanol plant?
The wet mill process soaks the corn kernels until the components are able to be separated mechanically. The germ is removed
for corn oil, the starch is removed for industrial or food uses or converting into sweeten- ers, ethanol, degradable plastics,
proteins, pharmaceuticals or a variety of high value consumer products. The remaining 60% protein gluten meal and 21% protein
gluten feeds are sold on the protein market.
The dry mill process grinds the corn to a flour and the entire product goes through the fermentation procedure where the
starch protein is converted to ethanol. After the ethanol is distilled off, the remainder is dried and sold as a 30% protein
product called Dried Distillers Grains with solubles (DDGs). The products of a wet mill have greater variety and therefore
a higher value than those form a dry mill, but the cost to build and operate a wet mill plant are higher. If the objective
of building a corn processing plant is to produce ethanol, it can be done at a lower cost with a dry mill plant.
56. Can ethanol be made from off-grade or damaged corn?
Yes. The ethanol yield from a bushel of corn is not significantly reduced even though the corn may be damaged. The use
of badly damaged corn will lower the value of the distiller's grains, and will affect the price that is paid for the damaged
corn by the ethanol processor.
57. Can aflatoxin-contaminated corn be used for ethanol production?
Yes, but there are limits on the use of the distillers grains if traces of aflatoxins remain.
58. Is it true that it takes more energy to produce a gallon of ethanol than is contained in that gallon?
No, it is not true. Ethanol contains about 76,000 (low heating value) BTUs per gallon. It takes about one fourth of that
amount to grow the corn and about one third of that to process the corn in a modern ethanol production facility. Some of the
processing costs should be allocated to the co-products that are produced with the ethanol. One should also consider the costs
that are saved when corn does not have to be moved into export channels.
59. Can ethanol be made just from corn?
No, ethanol can be made from products other than corn. Corn is the predominant feed stock today because of chronic corn
surpluses, low prices and wide availability. Other grains, plus sugar beets, potato wastes and cheese whey are currently being
used where they are available and competitively priced. It is also possible to convert cellulose materials to ethanol. Cellulo-
sic materials include grasses, trees, crop residues, wastepaper and even municipal solid waste! Cellulose to ethanol is currently
too expensive to compete with corn as a feed stock but new technologies might make it a commercial reality within the next
decade. Newly developed enzymes are being researched that will convert cellulose to sugars which can then be fermented into
ethanol This would mean not only having a greater supply of clean burning, renewable ethanol but would also reduce the volume
of waste entering our landfills.
60. What is left of the corn kernel after the ethanol is removed?
Only the starch is removed for ethanol, so all the protein, vitamins, minerals, and fiber, and some of the energy remain.
This is a very digestible human or livestock food.
61. How much does the corn increase in value after processing into ethanol and DDGs?
When one processes corn to ethanol, the initial value of the corn more than doubles. It may be said that instead of having
a $2.00 bushel of corn, a dry mill ethanol plant will produce $1 .00 worth of feed and $3.00 worth of fuel.