corn stover

Iowa has a big batch of cellulosic ethanol, and California’s buying

Iowa corn farmers always have a bunch of junk lying around after every harvest — corn cobs, stalks and leaves. California, meantime, was in dire need of the type of non-food-based fuel that can be squeezed out of those corn leftovers. Now both states have a deal that serves their interests, as well as those of the public.

On Nov. 1 DuPont held the grand opening of what’s billed as the largest cellulosic ethanol plant in the world, in Nevada, Iowa. Sen. Charles Grassley and Gov. Terry Branstad were on hand to sing the praises of the technology. When it’s fully up and DuPont-plant2running, sometime this year, the facility is expected to produce 30 million gallons of ethanol a year.

California’s oil refineries will buy most of that ethanol, to be blended into the state’s gasoline supply. Under the state’s Low Carbon Fuel Standard, established in 2007 by Gov. Arnold Schwarzenegger’s executive order, the carbon intensity of all transportation fuels must be reduced by 10 percent by 2020.

According to the state state Energy Commission:

Petroleum importers, refiners and wholesalers can either develop their own low carbon fuel products, or buy LCFS Credits from other companies that develop and sell low carbon alternative fuels, such as biofuels, electricity, natural gas or hydrogen.

The overall goal is to reduce greenhouse-gas emissions (GHG) in the state, and not just the ones that come out of the tailpipe: “Lifecycle” emissions are taken into account, including those created when the feedstocks are grown and the fuel transported.

Cellulosic ethanol has a special premium under the California program, because it produces 60 percent fewer lifecycle GHG emissions than gasoline. Making the fuel from those Iowan cobs, stalks and leaves — called corn stover — brings an even greater benefit, 90 percent.

“When you compare cellulosic ethanol to corn-based ethanol, there is a significant difference in greenhouse-gas emissions,” said Steven Ogle, cellulosic ethanol commercial leader for DuPont Industrial Biosciences.ethanol

That surely will be good news to the 19 million Americans who drive a flex-fuel vehicle, which can take any blend of gasoline or ethanol, up to E85. About 1 million FFVs are in California, many of them pickups and SUVs, and using more cellulosic could help the state reach its targets, as well as assuage drivers of their guilt for mashing on the accelerator. After some legal wrangling, California’s Air Resources Board re-adopted the Low Carbon Fuel Standard in September.

So how is corn-stover ethanol made? DuPont is buying up stover from more than 500 farmers who operate within 30 miles of the $225 million plant in Nevada. At full capacity, 375,000 tons of the stuff will be shipped to the plant each year. The product is harder to break down than sugar and corn, so it must be ground up, then mixed with enzymes that further decompose it. The stew is then fermented to get the sugars out, and distilled to produce ethanol, or “moonshine.” And off it goes onto a train headed for sunny California.

Here’s a DuPont chart that shows the process:

DuPontThe knock on cellulosic, or non-food-based, ethanol has always been that production has been too skimpy to be taken seriously as a large-scale transportation fuel. That slow curve is bending, thanks to the DuPont endeavor and others by POET and Quad County Corn Processors. The federal Renewable Fuel Standard calls for the amount of cellulosic ethanol being produced to ramp up from 123 million gallons last year to 230 million in 2016.

Cellulosic ethanol is the type of ethanol everyone can get behind, even ethanol-hating environmental groups. Cellulosic is made from inedible plants, or the junk left over from harvested crops. So it sidesteps the whole debate about land use and the food vs. fuel red herring, which has plagued corn-derived ethanol like an invasive species.

Of course, ethanol can be made from a great many other inedible plants, and DuPont already has signed a deal with China to license its proprietary technology (including the enzymes it developed). The potential exists to make the fuel just about anywhere, using corn or other feedstocks that are plentiful.

“Whatever the indigenous crop is, in South America or Europe or Asia Pacific, we likely will have a solution to get them the cellulosic ethanol they need,” Ogle said. “It just so happens that for our first one, it made a lot of sense to do this in Iowa.”

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