Lignin hydroconversion on MoS2-based supported catalyst: Comprehensive analysis of products and reaction scheme

RMN+ECI2D+BJF:MNG:DLA:CLO:CGEInternational audienceThe hydroconversion of a wheat straw soda lignin was studied in a batch reactor, in tetralin solvent, with a NiMoS/Al2O3 catalyst under H-2pressure at 350 degrees C. Gaseous, solid and liquid products wereseparated, quantified and detailed analyses were performed in order todescribe and to understand the various reactions occurring versusresidence time. In those operating conditions, the weakest beta-O-4 andalpha-O-4 ether linkages of the lignin were first cleaved. The ligninwas thus progressively converted into smaller hydrogenated anddeoxygenated fragments called lignin residues which were extensivelycharacterized by GPC and NMR. In the liquid phase, smaller monomers anddimers were identified by GC x GC/MS and quantified by GC x GC/FID. Theevolution of these molecules was investigated as a function of residencetime in order to investigate the catalytic transformation scheme oflignin. (C) 2015 Elsevier B.V. All rights reserved