March 18, 2008

Food versus Fuel or Food and Fuel?



Variations of this quote can be seen everywhere.

Filling the 25-gallon tank of an SUV with pure ethanol requires over 450 pounds of corn -- which contains enough calories to feed one person for a year. - Full Article


It is an emotional plea that is meant to suggest that ethanol is taking food out of peoples mouths. But there is more to story than what the quote suggests.

The conversion of corn to ethanol creates co-products, in the case of dry mill ethanol plants the co-product is dry distillers grains (DDG), which like corn is used as feed.

From about 10 kg of corn feedstock, about 3.3 kg of DDG can be harvested that has 27% protein (Stanton, 1999).


So the amount of distillers grains that would be left after ethanol production from the 450 pounds of corn would be 150 pounds. At 27% protein content that would mean that the remaining distillers grains would contain 40.5 pounds of protein.

40.5 pounds of protein converts into 18,370 grams of protein. Since the average daily requirement for protein is .8 grams per kilogram of bodyweight, this is enough protein to satisfy the daily requirements of a 138 pound person for a year.

As you can see the situation isn't the either/or scenario that it is made out to be. Producing ethanol doesn't destroy the feed value of corn, instead it allows us to make fuel and a co-product with it's own feed value. In other words, it allows us to produce food and fuel.

9 comments:

Chaz said...

Why take $8.00+ per gallon corn oil (price at any grocery store in the MidWest) and turn it into ethanol to supplement $3.00 gasoline? It doesnt seem very economically sound to me! Even with the tax incentives.

mus302 said...

First off, you are mixing up your alternative fuels. Ethanol is made from the starch present in corn. Biodiesel is made from vegetable oils. Most biodiesel in this country is made from soybean oil. And producers wouldn't be paying that amount for vegetable oil. The price that you see at the store includes the costs of packaging, transport and several additional levels of profits that wouldn't be present in bulk oil. And oils meant for human consumption would naturally be more refined than bulk oil. For instance you wouldn't need to sanitize everything to produce bulk oil for oil bound for biodiesel.

Chaz said...

Thanks for the clarification.. always wondered about that.. are teh stacks available after the oil is pressed from the kernal? Some of the listed costs would be associated with any alternative fuel or product.

Chaz said...

OOoops I mean STARCHES not Stacks... are the starches available after the oil is pressed from the kernal?

mus302 said...

The amount of oil in corn is pretty low to begin with. Most ethanol plants don't extract out the oil, so it ends up being a part of the left overs, the distiller grains which get fed to livestock.

The processes that do extract the corn oil separate the corn kernel into all it's parts and all the parts get used for either livestock feed, human food, industrial uses and so forth.

One other thing to keep in mind that even when corn is used for ethanol or vegetable oils are used for biodiesel, there are other products produced at the same time which can be sold. In the case of ethanol the common co-product is distillers grains which is sold as animal feed. With biodiesel the co-product is glycerin which is used in many ways, including beauty products, medicines, soap, and even can be fed to livestock.

The sale of the co-products is a big part of making the entire operation profitable.

Chaz said...

I have raised cattle in the past and understand that corn will run through a cow pretty much as it does through humans, unless the corn is "cracked" or "rolled" (processed in some fashion) I understand that the DDG is a better "feed" for stock than the dry rolled or cracked version. It seems to me a lot of this "price" increase in commodities is a form of gouging(sp?)

Chaz said...

Can a producer process the kernal with an eye to all three elements - oil, ethanol, and DDG or are they limited to one or the other and DDG. On a side note.....commodity prices are through the roof (was told soybean oil gained $0.12 per pound in the month of February.(price is as of 3/10/08 = $0.82/lb FOB this in the range of
$6.50+/gallon)

mus302 said...

When ethanol is made from corn it uses the starch in the corn but leaves all the protein and minerals. So DDGs are high in protein, around 27% whereas corn is around 9% I think. In other words other than the starch it concentrates what is already there. And DDGs are a good substitute for soymeal since soymeal is fed for it's protein content. But there is a limit to how much DDGs can be fed in each animals diet. There are a lot of studies going on to determine the best ratio to feed at but in general it seems that cows can be fed about 20% or so DDGs, chicken and pigs around 10%.

Since DDGs cost less than corn and soymeal feeding them can be a good way for a livestock producer to cut feed costs.

I don't know all that must about commodity trading but given that the stock market and real estate market is down, it stands to reason that money would pour into commodities since they seem to hot right now.

mus302 said...

Well, there are two separate processes for making ethanol, dry mill plants and wet mill plants.

In a wet mill plant the corn kernel is separated into it's parts and then processed. So with wet mill plants you get corn oil, ethanol, corn gluten feed and other byproducts. Wet mill plants are more expensive to build but make a little more money since they have a wider variety of refined products that result.

Dry mill plants cost less to build and are the majority of all ethanol plants. With them the corn is ground into a meal, mixed with enzymes to convert the starch into sugar, then fermented and distilled. The results are ethanol and distillers grains. The corn oil can be extracted from the distillers grains and a few plants do that. But the results wouldn't be food grade corn oil. Corn oil extracted in this way would be meant mostly for being made into biodiesel.

I did a post on one of the companies that extracts corn oil from DDGs a while back.

GreenShift Executes Agreement with United Ethanol to Extract Corn Oil

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