Converting Condensed Distillers EMISSIONS Solubles (CDS) to Slow Release Fertilizers and Adsorbents for Phosphorous

University of Minnesota/Kenneth Valentas

It has been reported that a magnesium oxide-biochar nanocomposite will adsorb phosphorous and nitrates from aqueous medium. This has significant implications for reducing phosphate and nitrate runoff from agricultural operations and also for functioning as a slow release fertilizer for controlled phosphorous application. These nanocomposite were made by dry pyrolysis from biomass such as sugar beet tailings, tomato leaves and the like.

Utilizing biomass such as beet tailings or tomato leaves is problematic since energy must be provided to dry the biomass for dry pyrolysis to form the biochar, and handling and transport of such materials are, at best, difficult and expensive with microbial action likely to degrade and alter the material prior to processing.

For wet biomass, such as condensed distiller’s solubles (CDS), Hydrothermal Carbonization (HTC) is the preferred technology for producing a char from the standpoints of efficacy and simplicity of the process and the favorable energetics. The resulting magnesium-hydrochar is expected to exhibit functional advantages compared to a biochar product. Furthermore, CDS is readily accessible at all corn ethanol plants. We propose utilizing HTC technology to convert CDS to a hydrochar that will be processed in various ways to yield three valueadded products.