AbstractsChemistry

A new method for the extraction of native lignin from spruce (soft) wood has been developed using high pressure catalytic hydrogenation in acid and alkaline hydrolytic media. The preferential hydrogenation and inactivation of the reactive centres responsible for polymerization-condensation reactions and amorphous lignin formation have been affected during the hydrolytic extraction without reduction of the aromatic nucleus. Yields of aromatic C6-C-C and C6-C-C-C products amounting to 12.6% of the initial Klason lignin were identified. In addition, completely distillable hydroaromatic products amounting to 60 - 65% calculated on the original Klason lignin content of the wood were obtained. Aromatic and hydroaromatic dimeric units of the (C6-C3 ) types were isolated and proof has been obtained that a carbon to carbon linkage between these units exists to a considerable extent in the simple lignin structures isolated.