A process for digesting wood

The application describes the disclosure that the delignification of carbohydrate-type material can be accomplished by treatment with gaseous mixtures of highly volatile primary and/or secondary amines and steam. The digestion takes place in the temperature range from 120 DEG C to 250 DEG C and in the pressure range from 12 to 70 bar and, in the case of spruce wood being digested, already leads to residual lignin contents of about 1% by weight in the course of a treatment time of about 3 hours. In the digestion by the process according to the invention, products having a high steam volatility are formed. By letting down the gaseous reaction mixture to pressures from 1 to 10 bar and simultaneous cooling to temperatures from 20 DEG C to 120 DEG C, the resulting lignin degradation products are precipitated. Depending on the precipitation conditions, a 60 to 80% by weight aqueous solution of the degradation products is obtained.