Secondary pyrolysis and waste heat recycling system for biomass pyrolysis gas

The invention discloses a secondary pyrolysis and waste heat recycling system for biomass pyrolysis gas, belongs to the technical field of renewable energy and is applicable to a biomass pyrolysis gas and coal co-production system. The secondary pyrolysis and waste heat recycling system includes steps of pyrolysis gas purification and dust removal, gas preheating, secondary pyrolysis and waste heat gradient recycling. The pyrolysis gas is subjected to ceramic filtration and high-pressure electrostatic field combined dust removal and purification to remove powdered carbon and other solid impurities in the pyrolysis gas, the biomass pyrolysis gas is preheated, and secondary pyrolysis is performed to remove wood tar in the pyrolysis gas. Gas waste heat generated after pyrolysis is subjected to two-stage recycling, so that waste heat gradient utilization can be achieved, and system heat energy utilization rate can be increased. An upper heating furnace body and a lower heating furnace body of a secondary pyrolysis furnace are mounted in a split way, guide helixes are arranged in reaction tubes, and the honeycomb design is applied to a catalytic reactor, so that pyrolysis process parameters can be adjusted conveniently. By the secondary pyrolysis and waste heat recycling system, gas purification effect and energy utilization efficiency are improved.