Ethanol’s corn versus wheat debate might have to be broadened to include another crop, American researchers have found.
Nancy Nichols, a microbiologist with the U.S. Department of Agriculture’s Agricultural Research Service, said preliminary data shows peas could also be a nice fit for the industry in certain regions of North America.
Although primarily thought of as a protein crop, peas also contain a substantial amount of starch, which is the key ingredient in ethanol.
But not all starch is created equal when it comes to generating the alternative fuel. Cornstarch is the industry standard by which all other crops are judged.
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“We were very happy to learn that when we set up the fermentation to actually convert the pea starch to ethanol, it worked just as well as the corn,” Nichols said.
Her team dry-milled peas into flour, separated the protein from the starch and used enzymes and yeasts to ferment the starch’s sugars into ethanol.
While the pea starch fermented just as readily as corn, it produced much less ethanol: 7.7 litres per bushel versus 12.7 litres per bu. from corn.
“We’re not directly comparing apples to apples because you start with less starch when you’re using peas,” Nichols said.
So why would ethanol plants want to use an ingredient that produces less fuel?
Nichols said it depends on how much revenue the facilities can generate from the pea protein that is extracted at the beginning of the process, which can be sold into high value human consumption markets or into feed markets along with the distillers dried grains.
If sales of the extra protein can cover the costs of separating starch from protein and can make up for the difference in ethanol output, then peas would be just as viable as corn, especially in areas such as North Dakota where the crop is grown extensively and corn would have to be imported.
The next step of the research project will determine the answer to that question.
Researchers will use economic modeling studies to determine whether using pea starch could be profitable.
Nichols said studies will incorporate peas at 10 and 20 percent into corn-based ethanol facilities to see how that affects ethanol output.
