Pine wood was processed into vanillin (up to 18 wt. % based on the lignin) and cellulose (typically 84-93 % of the initial amount in the wood) by one-stage catalytic oxidation, followed by enzymatic hydrolysis of the resulting cellulose into glucose (reducing sugar yield up to 70 % based on the cellulose). Correlation between the cellulose conversion in hydrolysis and the lignin 2 content in the post-oxidation lignocellulosic material was established, conforming to the general trend for the products of various delignification methods. The obtained results demonstrate the practical possibility of efficient two-step processing of wood into vanillin and glucose.

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This research deals with a process of catalytic oxidation of flax shives to vanillin and pulp. Catalytic oxidation of flax shives with molecular oxygen allows two main products to be obtained—vanillin with a yield of up to 12 wt.% of lignin, and pulp. Final forms of the catalyst particles (Cu2O and CuO) are agglomerates or monocrystals 0.5–5 µm in size. Acid prehydrolysis of the shives does not affect the oxidation, in contrast to pine-wood oxidation. Lignin prehydrolysis and oxidation was suggested as illustrate this difference. The dependence of the vanillin formation rate on stirring speed was studied. Minimum alkali consumption in the process was attained with a mild stirring speed of the reaction mass.