Process for monitoring the dissolution of lignin during alkaline decomposition

摘要

Process for monitoring the content of a lignin fraction which is dissolved in the course of boiling during an alkaline delignification process of wood or other vegetable material, in particular during sulphate or soda anthraquinone boiling. The process is based on the UV absorption of lignin, and the lignin content of the boiling liquor can be determined in each case on the basis of the UV absorption and also on the basis of a separately determined absorption coefficient which depends mainly on the boiling process, the boiling stage and the starting material.