EXTRACTION OF VALUABLE COMPONENTS FROM BARK

摘要

The present invention relates to a process for the extraction of valuable components from a tannin-rich bark raw-material, by carrying out an alkaline cooking step, followed by acid precipitation to separate the valuable components from the remaining bark pulp. The invention also relates to the use of said process on a bark side stream of a chemical pulping plant, whereby the liquor remaining after the extraction of the present process is returned to a stream of the wood pulping process, typically to a black liquor stream, while the spent pulp can be processed further, e.g. by bleaching to give dissolved pulp.