Optimization of the Pyrolysis of Distillers Dried Grains with Solubles
As the quantity of distillers dried grains with solubles (DDGS) produced in the U.S. continues to expand, so too does the need for value-added applications. This study examined the use of extracting energy from DDGS using pyrolysis. Various pyrolysis parameters were used to produce bio-oil and bio-char from DDGS. Characterization of the bio-oil and bio-char included mass density, thermal conductivity, thermal diffusivity, apparent viscosity, and energy content and was used to determine optimal processing parameters. The bio-oil produced from DDGS was found to be comparable to bio-oils produced from other biomass, but also had some more desirable characteristics. Heating values were determined to range from 16.7 to 27.6 MJ/kg (7,200 to 11,800 Btu/lb), while the pH ranged from 4.2 to 5.5. The mass density of the bio-oils produced in this study ranged from 0.839 to 1.007 g/cm3, which is lower than that of other known pyrolysis oils (1.16-1.28 g/cm3). This type of application could expand the portfolio of coproduct uses, and thus improve the sustainability of the industry.