Catalytic Lignin Depolymerization of Corn Stover

The aim of this work was to find from mass balances the extent of the catalytic depolymerization reaction of Corn Stover lignin. A reaction extent of 77.2% by weight of the final product was found with respect to a total lignin content in the biomass sample of 14.5%. For this, a 20 L Parr BSTR reactor, nickel catalyst on carbon support and methanol as solvent were used. The input biomass was previously sieved (0.15 mm to 50 mm) and free of dust. After the reaction, pressure filtration was used to eliminate solids and for liquid-liquid separation a rotary evaporator was used where methanol was removed, resulting in a solution rich in lignin. Then, the lignin-rich samples were subjected to a gas chromatography flame ionization detector (GC-FID) where 11 compounds were identified, including: vanillin 20.8%, methoxyisoeugenol 22.6%, coniferyl alcohol 25.6% and dimethylphenylpiperazinium 29.6%. This depolymerized lignin is then used as the main component of a resin that represents a safe alternative to formaldehyde in the production of composite boards and wood adhesives. Additionally, give added value to the lignin that remains as waste in the paper industry and biorefineries.