Patent ID: 8500954
Filing Date: 2013-08-06
Classification: D21C

Abstract:
1. A method for processing black liquor of a pulp mill to recover the chemicals and energy therein, the method comprising feeding the black liquor into a pyrolysis reactor having a substantially oxygen-free space, feeding into the pyrolysis reactor sand heated in a fluidised-bed boiler, whereby the black liquor is pyrolized and forms gaseous components and solid matter, said solid matter comprising the sand, solid carbon and soda leading the gaseous components formed in the pyrolysis reactor on for utilization, separating the sand from the solid matter formed in the pyrolysis reactor thereby forming a remaining solid matter comprising soda and the solid carbon and returning the sand to the fluidised-bed boiler, adding water to the remaining solid matter, into which the soda in the solid matter is dissolved forming a soda-water, separating and returning the solid carbon in the soda-water to the fluidised-bed boiler and then returning the soda-water solution to the pulp process.