Reintroduced solids increase inhibitor levels in a pretreated corn stover hydrolysate.
Following detoxification of the liquid hydrolysate produced in a corn stover pretreatment process, inhibitor levels are seen to increase with the re-addition of solids for the ensuing hydrolysis and fermentation processes. The solids that were separated from the slurry before detoxification of the liquor contain approx 60% (w/w) moisture, and contamination occurs owing to the diffusion of inhibitors from the moisture entrained in the porous structure of the corn stover solids into the bulk fluid. This evidence suggests the need for additional separation and detoxification steps to purge residual inhibitors entrained in the moisture in the solids. An overliming process to remove furans from the hydrolysate failed to reduce total organic acids concentration, so acids were removed by treatment with an activated carbon powder. Smaller carbon doses proved more efficient in removing organic acids in terms of grams of acid removed per gram of carbon powder. Sugar adsorption by the activated carbon powder was minimal.
Berson
R Eric
RE
Department of Chemical Engineering, University of Louisville, Louisville, Kentucky 40292, USA. eric.berson@louisville.edu
Young
John S
JS
Hanley
Thomas R
TR
D002606:Charcoal / Q000737:chemistry*; D005591:Chemical Fractionation / Q000379:methods; D003470:Culture Media / Q000737:chemistry*; D005663:Furans / Q000737:chemistry*; D006868:Hydrolysis; D035261:Plant Components, Aerial / Q000737:chemistry*; D013464:Sulfuric Acids / Q000737:chemistry*; D014867:Water / Q000737:chemistry*; D003313:Zea mays / Q000737:chemistry*
D003470:Culture Media; D005663:Furans; D013464:Sulfuric Acids; D014867:Water; D002606:Charcoal; C033158:sulfuric acid