Catalytic Oxidation of Flax Shives into Vanillin and Pulp

Abstract

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.