Piggybacked Pyrolyzer and Thermal Oxidizer With Enhanced Exhaust Gas Transfer

Abstract

A waste treatment system is disclosed having: (1) a pyrolyzer comprising an inner and outer chamber, wherein the inner chamber further comprises a syngas outlet; (2) a thermal oxidizer comprising an elongated combustion chamber; (3) an exhaust gas transfer duct fluidly coupled to the combustion chamber of the thermal oxidizer and the outer chamber of the pyrolyzer; and (4) a particulate separator for removing particulates from the syngas. In preferred embodiments the pyrolyzer and the thermal oxidizer are aligned in piggybacked configuration, such that the hot exhaust gases from the thermal oxidizer are shunted back to the outer chamber of the pyrolyzer. Preferred thermal oxidizer and the exhaust gas transfer duct are configured to allow a three second residence time of the syngas, such that the system operates at an efficiency of at least 15 therms (thm) per ton of municipal waste.

1 . A continuous waste processing device for pyrolytically treating municipal waste, comprising:
 a pyrolyzer comprising an inner chamber that carries a waste stream, an outer chamber that provides heat to the inner chamber to sustain pyrolysis, and wherein the inner chamber further comprises a syngas outlet for directing the flow of syngas produced during pyrolysis;   a thermal oxidizer that produces hot exhaust gases from oxidation of the syngas, the thermal oxidizer comprising an elongated combustion chamber;   an exhaust gas transfer duct fluidly coupled to the elongated combustion chamber of the thermal oxidizer and the outer chamber of the pyrolyzer for directing the flow of hot exhaust gases from the thermal oxidizer to the outer chamber of the pyrolyzer; and   a particulate separator for removing particulates from the syngas, wherein the particulate separator is fluidly coupled to the syngas outlet and disposed upstream of the thermal oxidizer, and wherein the syngas entering the particulate separator does not need to be cooled before entering the particulate separator.   
     
     
         2 . The device of  claim 1 , further comprising the pyrolyzer and thermal oxidizer disposed such that a vertical line exists that passes through at least some portion of the pyrolyzer and at least some portion of the thermal oxidizer. 
     
     
         3 . The device of  claim 1 , wherein the pyrolyzer and the thermal oxidizer each have a bottom and the bottom of one is at least elevated 2 meters relative to the bottom of the other to increase the efficiency of the system. 
     
     
         4 . The device of  claim 3 , further comprising a saddle comprising a ceramic material disposed between the pyrolyzer and the thermal oxidizer for support. 
     
     
         5 . The device of  claim 3 , wherein the exhaust gas transfer duct extends from sides of each of the pyrolyzer and the thermal oxidizer. 
     
     
         6 . The device of  claim 1 , wherein the pyrolyzer and the thermal oxidizer configured to have a side by side configuration. 
     
     
         7 . The device of  claim 6 , wherein the exhaust gas transfer duct extends from an end of each of the pyrolyzer and the thermal oxidizer. 
     
     
         8 . The device of  claim 1 , wherein each of the pyrolyzer and thermal oxidizer are at least 5 meters long. 
     
     
         9 . The device of  claim 1 , wherein the thermal oxidizer has a length within 20% of a length of the pyrolyzer. 
     
     
         10 . The device of  claim 1 , wherein the elongated combustion chamber and the exhaust gas transfer duct are sized and dimensioned to allow at least a three second residence time to ensure substantially complete combustion of the syngas. 
     
     
         11 . The device of  claim 1 , wherein the elongated combustion chamber and the exhaust gas transfer duct of the thermal oxidizer are sized and dimensioned to allow at least a two second residence time to ensure substantially complete combustion of the syngas. 
     
     
         12 . The device of  claim 1 , wherein the syngas entering the thermal oxidizer is mixed with fossil fuel such that the syngas being combusted in the thermal oxidizer comprises less than 25% fossil fuel. 
     
     
         13 . The device of  claim 1 , wherein each of the pyrolyzer, thermal oxidizer and the exhaust gas transfer duct are configured to have a cross sectional area of at least 1 m 2 . 
     
     
         14 . The device of  claim 1 , wherein each of the pyrolyzer, thermal oxidizer and the exhaust gas transfer duct are configured to have a cross sectional area of at least 5 m 2 . 
     
     
         15 . The device of  claim 1 , wherein each of the pyrolyzer, thermal oxidizer and the exhaust gas transfer duct have a cross sectional area that is substantially the same. 
     
     
         16 . The device of  claim 1 , wherein the pyrolyzer and thermal oxidizer are configured to operate at an efficiency of at least 15 thm per ton of municipal waste. 
     
     
         17 . The device of  claim 1 , wherein the pyrolyzer and thermal oxidizer are configured to operate at an efficiency of at least 10 thm per ton of municipal waste. 
     
     
         18 . The device of  claim 1 , wherein the particulate separator is a multiclone separator.