Pyrolysis method in connection with a boiler and a pyrolysis apparatus

Abstract

A pyrolysis apparatus comprises a furnace () operating by fluidized bed combustion, a pyrolyzer () and flow paths, which connect the furnace () and the pyrolyzer () for arranging the circulation (C) of carrier material of the fluidized bed combustion between the furnace and the pyrolyzer .The apparatus also comprises a supply inlet () for supplying fuel to be pyrolyzed to the pyrolyzer (), fluidizing gas supply means () arranged in the pyrolyzer for fluidizing the mixture of carrier material and fuel, and an outlet () for taking condensible gaseous substances separated from the fuel to be pyrolyzed out of the pyrolyzer (), and a condenser for condensing the condensible gaseous substances. The carrier material circulation is arranged at the furnace () by a cocurrent principle along the flow path of hot flue gases, which comprises a separator () located higher than the pyrolyzer (), which separator is arranged to separate carrier material from flue gases, while the circulation also comprises a connecting conduit () between the separator () and the pyrolyzer () for moving the carrier material by gravity to the pyrolyzer (), and a return path () between the pyrolyzer () and the furnace () for returning the carrier material to the furnace (). The outlet () is arranged in the chamber formed by the pyrolyzer () in its upper part in a space above the fluidized mixture of carrier material and fuel in order to remove the condensible gaseous substances from the pyrolyzer.