Growing Fuel
By Katie Allen

High corn demand drives a look at other alternatives for biofuels

The innovation of biofuels, including ethanol and biodiesel, has changed the role of farmers and added to their list of duties. To decrease U.S. dependence on foreign oil, President Bush has called for the use of 35 billion gallons of renewable fuels by 2017.

Of course, the ethanol industry has reacted and with current production is changing the fundamental demand curve for corn. Higher corn prices show the demand for the crop in a tug-of-war for both feed and energy. And the high price, which for a while crossed the $4 dollar per bushel mark and remains strong, has caused some lawmakers and agriculturalists to look at alternative ways to make ethanol.

The U.S. might grow enough corn annually to make 15 billion gallons of ethanol within the next 10 years, according to predictions, but the other 20 billion gallons will have to come from other sources to meet the president’s goal. One option under review is ethanol derived from cellulose.

Inputs such as native grasses, trees, wheat straw and even algae, are among new energy forms of plant cellulose used to make ethanol. Cellulosic biofuels might eventually help meet the demand for renewable fuels and relieve the demand for more corn, but the process is in the process of trial and error and has many obstacles to overcome before it is a major source of biofuel.

POET, which operates 20 corn-based ethanol facilities across the Midwest, is currently trying its hand at the cellulosic ethanol industry. An addition to the company’s operating corn-based ethanol facility in Emmetsburg, Iowa, will use corn cobs and corn fiber from kernels to make cellulosic ethanol. The expansion is known as Project LIBERTY (Launch of an Integrated Bio-refinery with Eco-Sustainable and Renewable Technologies in Y2009).

Headquartered in Sioux Falls, South Dakota, POET is working with the U.S. Department of Energy to construct the $200 million cellulosic ethanol plant in Emmetsburg, Iowa. The Department of Energy will provide up to $80 million in grant funding toward construction of the new facility.

Jeff Broin, President and CEO of POET, said the new facility, once completed, will take Emmetsburg from a 50-million gallon to a 125-million gallon facility. Corn cobs and fiber, he said, will generate 11 percent more ethanol per bushel, 27 percent more ethanol per acre. In addition, 83 percent less fossil energy and 20 percent less water will be used to operate the plant as it sequentially produces corn-based and cellulosic ethanol.

“Our situation recognizes synergies between the two processes,” Broin said.

Both corn and corn cobs can generate between 85 to 100 gallons of ethanol per ton, Broin said. POET intends to pay between 30 to 60 dollars per ton for corn cobs delivered. Grain corn earns much more per ton, but Broin said that’s due to the high-valued co-products of distillers dried grains and carbon dioxide from corn ethanol.

“There is a tremendous amount of cellulose wasted today that can be converted into energy,” Broin said. “Farmers are able to get about three quarters of a ton of corn cobs per acre, giving them an opportunity to increase revenues $25 to $45 per acre.”

Broin said POET will focus on using corn cobs and corn fiber to make cellulosic ethanol until the new facility runs successfully. Then the company will look into expanding other corn-based facilities with cellulosic operations and possibly using other feedstuffs.

“Today, cellulosic is more expensive,” Broin said. “In 7 to 10 years, we’re hoping to make the process very competitive [with corn-based ethanol].”

Ron Plain, agricultural economist at the University of Missouri, said whichever method costs less will expand more rapidly. He said that higher corn prices have driven up the cost to make corn-based ethanol, but right now, using corn is still a cheaper, simpler process.

“If scientists can develop a low-cost method of converting cellulose into ethanol, then less corn will be used to produce ethanol, and the price of corn will fall, ” Plain said.

To understand the challenges, it’s important to understand how cellulosic ethanol differs from corn-based ethanol. Plain said the difference is in the source material used—cellulose and starch.

“There is no difference in the ethanol,” he said.

Corn-based ethanol is made by converting starch into sugars and using yeast to convert the sugars into ethanol. New plants need to be built in order to make cellulosic ethanol, as the process is much different and more costly than with using corn, Plain said.

There are several ways to convert cellulose into ethanol, Plain explained: chemical hydrolysis, enzymatic hydrolysis and gasification.

Broin said with cellulosic ethanol, complex sugars have to be broken down by enzymes, which is more difficult than breaking down glucose in starch. Along with that, the pre-treatment for cellulose is much more intense than with corn.

“We’re working on new pre-treatment processes that collaborate new enzymes and are more cost-effective,” Broin said.
Broin added that POET is also working with multiple machinery manufacturers to give farmers more options for collection and storage of corn cobs and will set up several educational meetings around Emmetsburg when the facility is completed.

Still, it’s a challenge to build new plants and ask farmers to grow and sell cellulosic materials with an uncertain market. This has caused a lot of attention in Washington with the 2007 farm bill set to release this fall.

The Biofuels Innovation Program (BIP), proposed in a bi-partisan bill by Sen. John Thune (R-SD) and Sen. Ben Nelson (D-NE), would provide financial and technical assistance to landowners who produce native perennial energy crops, like switchgrass, jojoba and other quick-growing trees. At the same time, the bill encourages construction of new biomass refineries.

Kyle Downey, spokesperson for Sen. Thune, said the BIP stemmed from the current “corn-based ethanol wall.”

“Eventually, only so much corn can be produced for ethanol,” Downey said. “We can’t devote all of our corn to ethanol.”
Downey said the program is designed to encourage farmers to make use of their crop residue and produce grasses, small trees and other cellulosic inputs through cost-share programs for planting and eventual delivery to the bio-refineries. The program would ensure that energy-dedicated crops and bio-refineries are established at the same time.

“You need to ensure the availability of biomass crops when you build a bio-refinery,” Downey said.

Downey said using biomass materials could open up bio-refineries in regions that aren’t suited for growing corn but are able to grow the other materials.

“Across the country, other regions could be opened up for ethanol production,” he said.

The BIP initiative will play a role in the farm bill debate, as studies are underway to garner interest of biomass producers, areas to build the refineries and the economic impact of the new refineries in a particular area.

But it might take a while for communities to see the economic impact of cellulosic biofuels. “I think we are many years from having the technology to make ethanol from cellulose as cheaply as we can from corn,” Plain said.


The path to cellulosic ethanol

Chemical hydrolysis – cellulose is mixed with a mild acid under heat and pressure, or a strong acid with less heat and pressure, Water is added to form simple sugars, and the acid is neutralized. The sugar is separated, and yeast is added to ferment the ethanol. The ethanol is then distilled.

Enzymatic hydrolysis – after a pre-treatment process, various enzymes are used sequentially to break cellulose into glucose molecules, much like what bacteria do in the digestive system of ruminants. The sugar is separated, and the yeast is added to ferment the ethanol. The ethanol is then distilled.

Gasification – cellulose is partially combusted to make carbon monoxide, carbon dioxide and hydrogen. Clostridium ljungdahlii, a microorganism, converts the compounds into ethanol and water. The ethanol is then distilled from the water.

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