SE0100010L - Process and plant for purification of impure condensate arising from the production of cellulose pulp - Google Patents

Abstract

The process steam from the last evaporation stage and the unclean condensate are introduced into the first unit of a combined stripper/condenser while the rest of the steam flows to another condensers. The process steam and unclean condensate are brought to flow in opposite directions to cause a direct heat exchange resulting to the separation of volatile compounds from the condensate. Purification of unclean condensate emanated from pulp production of chemical or semichemical pulp including evaporation of spent liquor under utilization of a cleaning plant having series coupled condensers comprises: (a) the process steam from the last evaporation stage and the unclean condensate are introduced into a combined stripper/condenser in opposite directions to cause a direct heat exchange, resulting separation of volatile compounds from the condensate; (b) the rest of the process steam flows to another condensers while the remaining process steam is cooled down indirectly leading to the contaminated water and turpentine to be condensed and collected together. Methanol is condensed from the first collected condensate that separates from the turpentine content. Turpentine is removed from the plant and the residual condensate leads back to the combined stripper/condenser. Methanol and primary cleaned condensate is collected at the bottom and is removed from the plant or will be further purified. An Independent claim is also included for a plant for purifying of unclean condensate emanated from pulp production.