Metod i samband med impregnering och kokning av lignocellulosamaterial: Polysulfide pulping process
1997 (Swedish)Patent (Other (popular science, discussion, etc.))
The invention relates to a process for producing pulp from cellulosic fiber material with improved polysulfide regeneration alone or in combination with polysulfide cooking. The cellulosic fiber material is impregnated with polysulfide before cooking followed by extraction of spent cooking liquor. A portion of the spent cooking liquor is gasified to hydrogen sulphide and treated to form an acidic gas comprising hydrogen sulphide and carbon dioxide. The acidic gas is reacted under conditions providing a hot stream of elemental sulphur, said stream admixed with an alkaline liquor containing sulphide. An alkaline polysulfide liquor is thus formed which is added during cooking or impregnation. During cooking is a portion of the extracted spent cooking liquor recycled to the impregnation step and a desired polysulfide concentration in the impregnation step is maintained by adding polysulfide liquor.
Place, publisher, year, edition, pages
IdentifiersURN: urn:nbn:se:kth:diva-49195OAI: oai:DiVA.org:kth-49195DiVA: diva2:459382
SE 9703365 (2001-05-23)
JP 2003526740 A (2003-09-09)2011-11-252011-11-252013-08-09Bibliographically approved