New corn a breakthrough in biofuel

Canada’s ethanol industry wishes it was more like Brazil, where sugarcane is easily and efficiently converted to biofuel.

Agriculture Canada scientists and university biofuel experts are developing a novel use for corn that might level the playing field.

Instead of using corn grain to make ethanol, the scientists are proposing a process similar to sugar­cane: squeeze the sugar out of corn stalks and convert the corn “juice” directly to ethanol.

After years of research and collecting suitable corn germplasm from around the globe, Lana Reid, an Agriculture Canada corn breeder in Ottawa and her colleague, Malcolm Morrison, have bred several experimental corn varieties with high sugar content in the stalk.

In February, the two published a paper on their research in Agronomy Journal, High Stalk Sugar Corn: A Potential Biofuel Crop for Canada.

In the paper, the scientists said turning grain corn into ethanol is inefficient. The energy balance of corn grain ethanol is 1.4:1. That’s the amount of energy a unit of fuel contains relative to the energy required to produce the unit of fuel.

For sugarcane ethanol, the energy balance is around 8:1.

Converting corn stalks to ethanol could rival the energy balance of sugarcane.

“The combined sugar and biomass of high stalk sugar corn would be analogous to the energy balance ratio of 8.0 to 9.0 assessed for sugarcane or sweet sorghum,” Reid and Morrison wrote in the paper.

Most grain corn varieties have stalk sugar content of about five percent. Morrison and Reid have developed hybrids, suitable for Canada’s climate, with significantly higher concentrations of sugar.

“We set a target of 16 percent and we’ve reached that with some of our experimental hybrids,” Reid said. “Which beat sugarcane, at 12 to 14 percent.”

The paper was published six months ago and has generated significant interest. Scientists in China and Europe are looking into high stalk sugar corn.

In Canada, the Grain Farmers of Ontario is funding a three-year project to evaluate the agronomics and economics of turning high sugar corn stalks into ethanol.

Brandon Gilroyed, a University of Guelph, Ont., scientist who specializes in anaerobic digestion and biofuels, is part of the team studying what is being called sugarcorn.

“With grain corn you have to break the corn up, you have to use enzymes to break the starch down into sugars. The sugars are what get fermented,” he said.

“In this case (sugar from corn stalks) you’re not dealing with starch, you’re just dealing with the juice…. So you take away all of that upstream process, which would have a huge economic impact on the ethanol industry.”

Robert Nicol, also a biofuel researcher at the University of Guelph, told Ontario Grain Farmer that sugarcorn produces “excellent ethanol.” “Whether it supplements corn grain or is the basis for a new corn-to-ethanol process altogether, the next step is to engage industries in the idea of a new feedstock.”

Reid said sugarcorn can be grown on the Prairies because farmers can harvest the stalks at the traditional silage time.

“In Western Canada you don’t even need a variety that’s going to mature.”

Gilroyed said the concept is practical because North American farmers know how to grow corn and distillers are skilled at converting sugar into ethanol.

“This is an interesting way to get around some of the problems associated with (grain corn ethanol), without having to introduce some radical technologies.”

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