Detoxification of actual pretreated corn stover hydrolysate using activated carbon powder.

A technique for the removal of acetic acid from an actual pretreated corn stover hydrolysate was investigated. A powdered form of activated carbon previously shown to be effective in the removal of acetic acid from a synthetic hydrolysate was utilized. The method proved to be effective at lowering acetic acid levels while exhibiting minimal adsorption of the desired sugars from the hydrolysate, although at a lower efficiency in the actual hydrolysate than in the synthetic hydrolysate. Results are obtained for temperatures between 25 and 35 degrees C and agitation rates between 150 and 350 rpm in shake flasks. Adsorption isotherm and kinetic rate data are presented. Temperature differences over this range did not have an effect on adsorption characteristics. Five stages of detoxification were necessary to lower acetic acid concentration to the maximum 2 g/L desired for fermentation.