Catalytic Conversion of Nonfood Woody Biomass Solids to Organic Liquids

摘要: This Account outlines recent efforts in our laboratories addressing a fundamental challenge of sustainability chemistry, the effective utilization biomass for production chemicals and fuels. Efficient methods converting renewable solids to liquid fuels would reduce society's dependence on nonrenewable petroleum resources while easing atmospheric carbon dioxide burden. The major nonfood component is lignocellulose, matrix biopolymers cellulose, hemicellulose, lignin. New approaches are needed effect facile conversion lignocellulose other chemical precursors without formation intractable side products with sufficient specificity give economically sustainable product streams. We have devised novel catalytic system whereby feedstocks organosolv lignin, even composites such as sawdust transformed into organic liquids. reaction medium supercritical methanol (sc-MeOH), catalyst copper-doped porous metal oxide (PMO) prepared from inexpensive, Earth-abundant starting materials. transformation occurs single stage reactor operating at 300-320 °C 160-220 bar. reducing equivalents these transformations derived by reforming MeOH (to H2 CO), which thereby serves "liquid syngas" present case. Water generated deoxygenation processes quickly removed water-gas shift reaction. Cu-doped PMO multiple purposes, catalyzing substrate hydrogenolysis hydrogenation well reactions. one-pot "UCSB process" quantitative, giving little or no biochar residual. Provided an overview catalysis studies beginning reactions model compound dihydrobenzofuran that help define key occurring. initial step phenyl-ether bond hydrogenolysis, this followed aromatic ring hydrogenation. complete disassembly more complex lignin monomeric units, largely propyl-cyclohexanol derivatives then described. Operational indices based (1)H NMR analysis also presented facilitate holistic evaluation streams within several hours consist derivatives. Lastly, we describe application methodology types wood (pine sawdust, etc.) cellulose fibers. distribution, albeit still complex, displays unprecedented selectivity toward aliphatic alcohols methylated thereof. These observations clearly indicate solid combined sc-MeOH capable breaking down substrates markedly deoxygenated units increased hydrogen content. Possible implementations promising larger scale discussed.