Reductive Catalytic Fractionation of Lignocellulosic Biomass: Unveiling of the Reaction Mechanism

This work studied the reaction pathways involved in the depolymerization of cellulose and hemicellulose during the fractionation of lignocellulosic biomass using an isopropyl alcohol/ water mixture as a solvent with the Raney-Ni catalyst. Model molecules such as cellulose and hemicellulose derived-products (glucose, sorbitol, erythrose, xylose, xylitol, glycerol) were used to understand the role of the catalyst on the depolymerization of these lignocellulosic fractions. The fractionation of sugar cane bagasse with the Raney-Ni catalyst was performed, a correlation between the different products formed, and the possible reaction pathways were proposed. The results obtained in this work show that the appropriate balance between hydrogenation and hydro-genolysis capacity might tune the select i v i t y to the desired product. It is important to notice that Raney-Ni is an unsupported catalyst. The support may add acidity, basicity, or redox properties that may play an important role in the determination of product distribution.

Automated summary

This study investigated the depolymerization reactions of cellulose and hemicellulose during the fractionation of lignocellulosic biomass using an isopropyl alcohol/water mixture and the Raney-Ni catalyst. Model molecules and the fractionation of sugar cane bagasse were used to understand the role of the catalyst and propose reaction pathways. The results showed that the selectivity to desired products could be tuned by balancing hydrogenation and hydro-genolysis capacity, and the support of the catalyst played an important role in product distribution.