The Impact of Biomass and Acid Loading on Methanolysis during Two-Step Lignin-First Processing of Birchwood

We optimized the solvolysis step in methanol for two-step lignin-first upgrading of woody biomass. Birchwood was first converted via sulfuric acid methanolysis to cellulose pulp and a lignin oil intermediate, which comprises mixture oligomers C5 sugars solvent. The impact reaction temperature (140–200 °C), loading (0.24–0.81 wt%, dry biomass), methanol/biomass ratio (2.3/1–15.8/1 w/w) time (2 h 0.5 h) investigated. At high biomass loadings (ratio < 6.3/1 w/w), operation at elevated pressure facilitates delignification by keeping liquid phase. A degree goes together large extent with sugar release, mostly form methyl xylosides. Gel permeation chromatography heteronuclear single quantum coherence NMR fractions obtained (0.81 wt%) low (15.8/1 revealed extensive cleavage ?-O-4? bonds during acidolysis 180 °C 2 h. an 2.3/1 w/w (0.24 wt%), more could be preserved, i.e., about 33% after 47% reactivity extracted fragments confirmed second hydrogenolysis step. Reductive treatment Pd/C under mild conditions led disappearance ether linkages molecular weight reduction hydrotreated oil.