Wet ethanol production process yields more ethanol and more co-products

Nov 09, 2009

Using a wet ethanol production method that begins by soaking corn kernels rather than grinding them, results in more gallons of ethanol and more usable co-products, giving ethanol producers a bigger bang for their buck - by about 20 percent.

"The conventional method has fewer steps, but other than distillers dried grains with soluble, it doesn't have any other co-products," said University of Illinois Agricultural Engineer Esha Khullar. "Whereas in both wet and dry fractionation processes, the result is ethanol, distillers dried grains with soluble, as well as germ and fiber. fiber oil for example can be extracted from the fiber and used as heart-healthy additives in buttery spreads that can lower cholesterol."

In comparing the wet and dry fractionation methods, Khullar's research team found that when using the wet fractionation method, the result is even higher ethanol concentrations coming out of the fermenter and better quality co-products than the dry method.

In the wet process, the are soaked, washing the germ, which Khullar says is a cleaner separation. "There's not a lot of starch sticking to the germ. That's why you get higher oil concentrations."

After the kernels are soaked they are ground to produce a slurry. The slurry is soaked with enzymes so that it raises the specific gravity to a point where the germ starts floating and can be fished out from the top.

Khullar explained that in the dry fractionation method, the kernel is crushed, flattening out the germ. "The germ is still attached to a certain part of the endosperm and you still have a few starch pieces sticking to it. You have a very high starch content germ from the dry fractionation and that lowers the oil content. That's why there's a big difference in the wet process versus the dry process."

Dry and wet fractionation methods have been developed to separate out the germ and pericarp fiber before fermentation which is more efficient because the and fiber are non-fermentable. "It's better to removed them before the process. That way you have more starch in the fermenter. And you don't have to heat them and bump them and cool them," Khullar said.

The process doesn't require developing any new equipment. "It's just a modification of things that are already being done in the corn processing industry and can be done pretty easily," Khullar said.

More information: Ethanol Production from Modified and Conventional Dry-Grind Processes Using Different Corn Types was published in a 2009 issue of Cereal Chemistry.

Source: University of Illinois at Urbana-Champaign (news : web)

Explore further: A refined approach to proteins at low resolution

add to favorites email to friend print save as pdf

Related Stories

Turning corn fiber into ethanol

Jun 01, 2006

Tony Pometto held up a laboratory flask swimming with little balls of mold. This, said the Iowa State University professor of food science and human nutrition, is the kind of fungus that Iowa State researchers have used to ...

Wheat may join corn in biofuels

Aug 07, 2007

British-led scientists have developed a new technology that might eventually enable motorists to use wheat, as well as corn, for biofuels.

Chemically squeezing every drop of ethanol from corn

Mar 09, 2006

Brent Shanks is going down to the molecules to find a little extra ethanol. Shanks, an Iowa State University associate professor of chemical and biological engineering, is leading a research team that's working to develop ...

Researchers use fungus to improve corn-to-ethanol process

May 27, 2008

Growing a fungus in some of the leftovers from ethanol production can save energy, recycle more water and improve the livestock feed that’s a co-product of fuel production, according to a team of researchers ...

Recommended for you

A refined approach to proteins at low resolution

19 hours ago

Membrane proteins and large protein complexes are notoriously difficult to study with X-ray crystallography, not least because they are often very difficult, if not impossible, to crystallize, but also because ...

Base-pairing protects DNA from UV damage

21 hours ago

Ludwig Maximilian University of Munich researchers have discovered a further function of the base-pairing that holds the two strands of the DNA double helix together: it plays a crucial role in protecting ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

defunctdiety
not rated yet Nov 09, 2009
giving ethanol producers a bigger bang for their buck - by about 20 percent

As always, the question is net energy gains.

How much more energy input do these extra steps require to realize this 20% "bigger bang"? Is this 20% increase in volume of ethanol only, or in general "product", including bi-products?