Pyrolysis of ethanol coproducts

• New uses for ethanol coproducts are needed as the industry continues to grow.
• Distillers dried grains with solubles and other coproducts are energy dense.
• Energy can be extracted from coproducts using pyrolysis to form bio-oils and bio-chars.
• DDGS bio-oils and bio-chars are similar to those produced from other biomaterials.
• DDGS bio-oils and bio-chars produced could add value to coproducts but require further study.

The need for new value-added applications for ethanol coproducts grows as the U.S. ethanol industry continues to expand. Distillers dried grains with solubles (DDGS), corn gluten meal (CGM), and corn gluten feed (CGF) are the primary coproducts of ethanol manufacturing and are mainly utilized as animal feed. This study examined the use of pyrolysis to extract value from these grains. Characterization of the resulting bio-oil and bio-char included mass density, thermal conductivity, thermal diffusivity, apparent viscosity, kinematic viscosity, and energy content. The bio-oils produced from these ethanol coproducts require some changes to be used commercially. The tar present in the crude bio-oils caused them to have densities greater than one, and caused the oil viscosity to be shear thinning. The pH of these bio-oils is less acidic and thus more favorable than other bio-oils which could be due to the differences in the feedstock composition.