Lignin oil from lignin-first biorefinery with a reusable catalyst was applied to obtain jet fuel aromatics and polyurethane feedstock.

Poplar wood was rapidly fractionated via a flow-through reaction using aqueous solutions of an acid hydrotrope (AH), p-toluenesulfonic acid (p-TsOH), at temperatures below 98 °C. 13C–1H two-dimensional nuclear magnetic resonance (NMR) spectroscopic analyses demonstrated that the AH-solubilized lignins (AHLs) from a range of fractionation conditions with yields up to approximately 80% had a very high content of β-aryl-ether linkages compared to milled wood lignin (MWL) with a low enough condensation to facilitate subsequent reductive catalytic depolymerization resulting in a lignin monomer yield of over 30%. Gel-permeation chromatographic (GPC) and differential scanning calorimetric (DSC) analyses showed that the AHLs have high molecular weights and low glass transition temperatures T g. These AHLs also have a pinkish color suitable for applications such as cosmetics and dye dispersants. AH fractionation (AHF) preserved the cellulose fraction as solid fibers also with a light pinkish color for the materials market and solubilized up to approximately 90% of xylan which can be converted to furfural using p-TsOH in the spent liquor without additional catalysts. The advantages herein are the use of one recyclable industrial chemical such as p-TsOH in an aqueous system below water boiling temperature to valorize all three major fractions of lignocelluloses in a short time frame, with very promising yields and well-preserved lignin and cellulose structure.

Reductive catalytic fractionation (RCF) is a promising lignin-first biorefinery strategy which yields a deeply depolymerized lignin and nearly theoretical amounts of lignin monomers with reductive catalysts. The immediate stabilization with...

A key challenge in biomass catalytic conversion, especially in pilot and practical scales, is the stability of the catalyst and its support. Depolymerization of Kraft lignin, which is characterized by structural recalcitrance and poison (metal and ash) rich nature, is a good model reaction to demonstrate the above challenge in biomass conversion. In the present study, the potential of SiC-based catalyst (commercially available SiC nanofiber-supported Ni and W, NiW/SiC) in lignin depolymerization was investigated. The results indicate the SiC-based catalyst is a milder catalyst than the state-of-the-art activated carbon-supported catalyst under the identical conditions and supplies a higher liquid product yield. More importantly, the NiW/SiC catalyst can be easily regenerated by coke combustion and subsequent acid washing, which cannot be achieved by either carbon or metallic oxidesupported catalysts. The performance of the regenerated catalyst with only 4% Ni input is almost unchanged compared with that of the fresh catalyst. These results illustrate that SiC combines the advantages of common supports such as activated carbon and metallic oxides and may be generally applicable as catalyst support in biomass conversion.