In Washington, Scientists with USDA’s Agricultural Research Service have found that barley grain can be used to produce ethanol, and the leftover byproducts-barley straw, hulls, and dried distillers grains (DDGS)-can be used to produce an energy-rich oil called bio-oil. The bio-oil could then be used either for transportation fuels or for producing heat and power needed for the grain-to-ethanol conversion. The barley work was conducted by several scientists at the ARS Eastern Regional Research Center at Wyndmoor, Pa. The researchers produced bio-oil from all three barley byproducts using a technology called “fast pyrolysis,” an intense burst of heat delivered in the absence of oxygen. In the lab, a kilogram of barley straw and hulls yielded about half a kilogram of bio-oil with an energy content of about half that of No. 2 diesel fuel oil. The energy content of bio-oil made from barley DDGS, including DDGS contaminated with mycotoxins, which can’t be used to supplement livestock feed, was even higher, about two-thirds of the level in No. 2 diesel fuel oil. However, the bio-oil was more viscous and had a shorter shelf life than bio-oils produced from straw or hulls. The process also created a solid byproduct called “biochar” that might improve the water-holding capacity and nutrient content of soils.
More background on the story from the Digest