The invention discloses a thermal pyrolysis combination method and device and relates to a
coal chemical industry technology. A fuel is pyrolyzed in a low-speed
bed pyrolyzing furnace, the generated semicoke is discharged from the bottom of the pyrolyzing furnace, sent into a circulating fluid
bed gasifier by virtue of a semicoke returning device so as to be subjected to gasification, and
coal gas generated by the gasifier, carrying
solid particles, enters in a
cyclone separator; the gasification temperature of the gasifier is 900-1,200 DEG C, the fuel
thermal pyrolysis temperature in the thermal pyrolyzing furnace is 50-200 DEG C lower than the temperature of the gasifier;
pyrolysis gas generated in the pyrolyzing furnace is introduced into the upper part of the gasifier or introduced into the
cyclone separator together with the
coal gas generated in the gasifier; and the
solid particles gathered by the
cyclone separator are sent above the dense phase area of the pyrolyzing furnace by virtue of the returning device so as to provide heat for
pyrolysis of the fuel. The method and device disclosed by the invention are used for
pyrolysis and gasification of coal,
biomass and other carbon-containing fuels, the generated
coal gas has the advantages of high thermal value and low
tar content, and the
system is simple.