DETOXIFICATION OF JAPANESE WHITE BIRCH WOOD HEMICELLULOSE HYDROLYSATE WITH A CARBONACEOUS SORBENT PREPARED FROM BIRCH WOOD HYDROLYSIS RESIDUE

During hydrothermal treatment of lignocelluloses, a wide range of compounds that inhibit microbial metabolism are formed. To eliminate inhibition, an acid hydrolysate of Japanese white birch (Betula platyphylla var. japonica) wood was detoxified with different carbonaceous sorbents, a dehydration product prepared from the birch wood hydrolysis residue, steam- and ZnCl2-activated charcoals. Furfural and low molecular weight phenols in the hydrolysate were successfully removed by these sorbents, whereas the concentrations of neutral sugars and acetic acid stayed almost constant. Sorption capacities of the steam-activated charcoal were superior to those of the other sorbents. However, when the dose of the dehydration product prepared from the birch wood hydrolysis residue was increased up to 125 g L-1, the concentrations of furfural and phenols in the hydrolysate decreased by their harmless levels to the yeast, Candida magnoliae.