1. How Ethanol is
Produced
By: Josh Bochmann
Auto 480-002

3. Past, Present and Future

4. Dry Milling
 First the grain is ground into flour, often
referred to as meal.
 Next the meal is mixed with water to form a
mash. Enzymes are added to this mash to
convert the starch from the grain into sugar.
 The mash is then sent to a high temperature
cooker to reduce bacteria levels.
 After lowering the bacteria levels the mash
is cooled and transferred to the
fermentation tanks. Yeast is added during
to convert the sugar in to ethanol and
carbon dioxide.

5.  Once fermentation is complete the
ethanol is separated from the remaining
mash and sent to distillation.
 The ethanol is distilled and then mixed
with 5% gasoline to make it undrinkable.
This deters people from catching a buzz
at the local fill up station.
 The remaining mash is sent off to be
processed into corn syrup and food for
livestock.

7. Wet Milling
 First the grain is soaked in water and dilute
sulfurous acid for 24 to 48 hours. This separates
the grain in to its many component parts.
 The result is a slurry that is then sent through
grinders to separate out the germ. The
remaining fiber, gluten, and starch are further
separated from each other.
 The starch is then sent to be fermented. The
fermentation process is similar to the
fermentation process of dry milling
 The gluten, water, and fiber are further
processed to produced feed for livestock and
other products.

9. Dry Milling vs Wet Milling
Dry
 Short process time
 Fairly simple
process
 Low waste
production
 Waste is used for
feeding livestock
 Limited to certain
feedstocks
Wet
 Many feedstocks
can be used
 Process is more
involved
 Longer process time
 More waste
produced
 Waste is used to
produce many things

10. Virtual Tours
 http://vatour-
dev.com/system/tours/ascendant/patriot
/tourfiles/index.html
 http://www.ethanol.org/index.php?id=73

11. Sources
 http://www.ethanolrfa.org/pages/how-
ethanol-is-made
 http://en.wikipedia.org/wiki/Ethanol_fuel#Pro
duction_process
 http://www.thebioenergysite.com/articles/66
4/biofuel-production-greater-shares-of-
commodities-used
 http://econpapers.repec.org/article/agsjloag
b/90656.htm
 http://www.amg-eng.com/blog/corn-wet-
milling-vs-dry-milling/