Process for upgrading low-quality wood.

摘要

A process for upgrading low-quality wood comprising a softening stage, wherein one or more sections of low-quality wood are heated, in the presence of an aqueous medium and at a pressure which is at least the equilibrium pressure of said medium at the operating temperature, to a temperature in the range of from 120 to 160 DEG C and maintaining said temperature until the temperature difference between the centre and the outer parts of the sections is less than 20 DEG C, which is followed by heating to a temperature in the range from 160 to 240 DEG C for not more than 1 hour until the temperature difference between the centre and the outer parts of the sections is less than 20 DEG C, a dewatering stage and a curing stage.