Incineration of the concentrated malodorous gases in the recovery boiler

Recovery boiler burner has been applied as the main treatment unit of the concentrated non-condensable gases since summer 1993 in a Finnish Pulp Mill. This application has until now had no harmful effects on the recovery boiler emissions, materials or performance. Recovery boiler treatment is an economical, safe and odorless option as a preliminary treatment system of the non-condensable gases. The black liquor dry solids content must be above 70 % and the carbonate content in the recovery boiler dust between 5 - 10 % to buffer the excess SO2 generated.