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A new pretreatment process, eliminates expensive toxic acid baths in favor of ammonia. The treatment will help produce cheaper ethanol from plant waste, like these corn stalks shown here.  (Source:

Bruce Dale, University Distinguished Professor of chemical engineering and materials science at Michigan State University invented the cheaper and more efficient AFEX cellulosic ethanol pretreatment process, with the help of his doctoral student Ming Lau.  (Source: MSU)
A new process invented by Michigan State University helps to increase the yields of cellulosic ethanol at a reasonable premium

The world of cellulosic ethanol is a hot business.  GM has already backed two cellulosic ethanol companies, Coskata and Mascoma Corp., and many others are taking a serious look at the new type of fuel.  Essentially with the same advantages and disadvantages from a fuel perspective as normal ethanol, which it shares virtually the same chemical character with, the big bonus is that cellulosic ethanol can be made from plant waste of all times, reducing the price pressure produced by food-crop ethanol.

Using technology to produce cellulosic ethanol, the fruits and vegetables of food crops can ship to the market and the leftovers -- leaves, stalks, stems, and husks -- can be ground up and made into ethanol.  One of the first targets is corn stover, the leftovers from the corn harvest, somewhat of an ironic source as sugarcorn (the food) became one of the two main controversial sources of food-crop ethanol

Unfortunately, the processes to make cellulosic ethanol are still very inefficient.  And while there are acid pretreatments that can improve the performance, freeing up more sugars from the cellulose and hemicellulose in plants to be used in fermentation, these treatments are costly.  Typically the acidic product is toxic, so it must undergo intensive washing and detoxifying, leaching nutrients that could have been used in fermentation and raising the costs.

That's where Michigan State University comes in with a new patented process.  Bruce Dale, University Distinguished Professor of chemical engineering and materials science at the university, has invented a cheap pretreatment process using ammonia, called AFEX (ammonia fiber expansion).

Its 75 percent more efficient than with traditional enzyme treatments says Professor Dale, and is easier and more affordable than acid pretreatments.  The process frees up a lot of sugar to be used in the fermentation to produce more ethanol.

Professor Dale states, "Doctoral student Ming Lau and I have shown that it's possible to use AFEX to pretreat corn stover (cobs, stalks and leaves) and then hydrolyze and ferment it to commercially relevant levels of ethanol without adding nutrients to the stover.  It's always been assumed that agricultural residues such as corn stover didn't have enough nutrients to support fermentation. We have shown this isn't so."

He states, "Washing, detoxifying and adding nutrients back into the pretreated cellulose are three separate steps.  Each step is expensive and adds to the cost of the biofuel. Breaking down cellulose into fermentable sugars cost effectively has been a major issue slowing cellulosic ethanol production. Using AFEX as the pretreatment process can dramatically reduce the cost of making biofuels from cellulose."

Ming Lau, a coauthor of the project who shares the patent with Professor Dale adds, "The research also shows that the chemical compounds created when the stover goes through the AFEX process can improve the overall fermentation process.  This is at odds with the general perception that these compounds are detrimental and should be removed."

The pair is looking to set up a pilot plant at MBI International, a subsidiary of the MSU Foundation.  However, they already are also attracting commercial interest.  States Professor Dale, "There are several companies – including the Mascoma Corp., which plans to open one of the nation's first cellulosic ethanol plants here in Michigan – that may be interested in using this technology.  We are working to make the AFEX technology fit these companies' needs."

The new research is published in the current issue of Proceedings of the National Academy of Sciences (PNAS). 

The work was funded by the GLBRC, the MSU Research Foundation, and the Michigan Agricultural Experiment Station.  

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RE: I hate ethanol
By Danger D on 1/22/2009 6:11:56 PM , Rating: 1
Corn cost $8 a bushel in July, and food prices went up.
Today, corn closed well under $4. Guess what? Food prices are still going up.

General Mills, Nestle, Kellogg’s, and more are posting big profits as recently as last quarter. Oil companies posted record earnings this year too. And ethanol's apparently the villain. Go figure.

Take a look at a Twinkie and tell me how much of the cost of that Twinkie came from the farm and how much is due to packaging, advertising, brand development, transportation, etc. Fact: There's a nickle's worth of corn in a box of corn flakes.

And as for importing food. In 2008 we exported more corn than we ever have in the history of the United States, even with ethanol using a large percentage of the corn crop.
Please check your facts before accusing me of being from another planet.

RE: I hate ethanol
By Spuke on 1/22/2009 6:19:06 PM , Rating: 2
Please check your facts before accusing me of being from another planet.

RE: I hate ethanol
By JediJeb on 1/23/2009 3:39:29 PM , Rating: 2
This is very true. For decades the price of food has increased dramatically and yet a farmer today still gets the same price per pound for a steer as he did in 1970,( actually my father said this week it is less than back then). The increase in food prices because of more crops being used to produce ethanol is only an excuse to raise the price not a real reason to raise it.

Farming is one of the few businesses where you do not set the price of what you produce. If it costs you twice as much this year to produce your crop, the buyers usually just say Touch Luck and offer the same price, yet turn around and raise the price in stores and tell the public it was because it cost the farmers more to produce it.

Corn prices went up this year and farmers actually made a little money, yet in the past few years while their fuel prices tripled the price barely increased any, or sometimes fell. Watch the grain markets, if the weather forcasters say the midwest will have a nice summer with good rainfall and temps the price of corn will bottom out, if they say it will have drought or floods it will shoot through the roof. But let someone forcast a doubling or tripling of fuel prices and the price wont be effected at all. And since very few farmers have the storage capacity to store an entire years crop on site, they have to sell it at whatever price they get. For anyone who thinks farmers made out good this year because of the high price of corn, then ask yourself why there aren't more people trying to become farmers. It's because few people want to work 12-18 hour days 7 days a week 365 days a year for what amounts to lowest middle class wages if you are lucky, one bad storm can turn it into below minimum wage income if you are unlucky. It takes a passion for the work to make it as a farmer.

RE: I hate ethanol
By Penti on 1/24/2009 5:00:21 PM , Rating: 2
Yes US is a major food exporter, practically all of South America is depending upon you, and even here in Sweden/Europe we got american rice and such products.

Most grain is however not produced for human consumption, the quality is to poor and the farmers couldn't sell it as such. As it's produced to have high yield and to be used as feed. Eating beef effects tortilla prices more then the ethanol right now. However it does effect the market now as it's a new demand. We don't have as much grain in storage any more.

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