Detoxification of C5 rich prehydrolysate from FPInnovations modified TMP-Bio process for lactic acid fermentation
University of New Brunswick
This work studied a combination of methods for detoxifying prehydrolysate produced by FPInnovations’ modified TMP-Bio process from hard wood chips for fermentation based bio-refining. The optimal conditions for pH adjustment based removal of fermentation inhibiting compounds was investigated as well as the results of further refining overlimed pressate by membrane filtration in order to remove additional inhibitors. Initial pH adjustment to 11 with continual stirring in a 25°C water bath removed between 14-19% of the total phenols detected in the pressate (in vanillin equivalents), while reducing the concentration of xylose by 25-28%. Samples were subsequently passed through membrane filtration at 200Da, removing up to 28% of the acetic acid detected after overliming. Dilute pressate samples treated with this combination of detoxification steps was fermentable by Bacillus coagulans, consuming 97% or greater of the available xylose within 24 hours.