Impact of bleaching on subcritical water- and Formosolv-pretreated tulip tree to enhance enzyme accessibility

Recent advances in alcohol and organic acid fractionation of lignocellulosic biomass

Organosolv fractionation is a promising process to separate lignocellulosic biomass for the preparation of multiply products including biofuels, chemicals, and materials. This review presents the state of art of different processes applying alcohols and organic acids to treat lignocellulosic biomass for the production of ethanol, lignin, xylose, etc. The major organosolv technologies using ethanol, formic acid, and acetic acid, are intensively introduced and discussed in depth. In addition, the structural modifications of the major components of lignocelluloses, the technical processes, and the applications of the products were also summarized. The object of the review is to provide recent information in the field of organosolv process for the integrated biorefinery. The perspectives of the challenge and opportunity related to this topic are also presented.

Evaluation of hot compressed water pretreatment and enzymatic saccharification of tulip tree sawdust using severity factors

Tulip tree sawdust was pretreated using hot compressed water with different pretreatment severities (LogR0, 3.05-5.01) by varying reaction temperatures (180-220°C) and residence time (1-30 min). It is found that the chemical composition and physicochemical properties of the pretreated products can be characterized and correlated with severity. Removal of most of the xylan and other hemicellulosic sugars from the raw material was observed at a severity of 4.5. Thus, the residual solids were recovered with increased cellulose and lignin contents. Nearly complete glucan conversion was achieved after 48 h of hydrolysis with 10 FPU/g of wet residual solid obtained above a severity of 4.8. The characteristics of the pretreated solids according to the pretreatment severity were strongly related with the glucose yield. The removal of structural barriers to the enzyme attack was the dominant factor affecting enzyme accessibility to the substrate.