Pyrolysis systems
View Patent ↗Systems and methods are disclosed for pyrolysis of waste feed material. Some systems include a main retort and a secondary retort. Syngas is produced by pyrolysis in the main retort, and is then mixed with combustion air and ignited, in some cases to produce energy. Carbon char travels to the secondary retort and is exhausted from the system through an airlock.
1. A pyrolysis device comprising:
a combustion chamber containing one or more burners configured to generate hot flue gases;
a main retort, disposed within the combustion chamber, configured to at least partially pyrolyze a feedstock delivered to the retort, thereby generating syngas;
a syngas relief conduit, into which syngas flows from the main retort;
a flue gas relief duct, into which flue gas is exhausted from the combustion chamber, the flue gas relief duct being separate from the combustion chamber and having a first end in sealing fluid communication with the combustion chamber;
wherein the syngas relief duct is disposed within the flue gas relief duct; and
a mixing chamber, into which the syngas flows from the syngas relief duct and the flue gas flows from the flue gas relief duct.
2. The device of claim 1 further comprising a mixing baffle and distribution cone within the mixing chamber, configured to direct gas outwardly within the mixing chamber.
3. The device of claim 2 further comprising a combustion gas inlet and an afterburner element positioned downstream of the distribution cone.
4. The device of claim 1 further comprising a secondary retort in fluid communication with the retort and configured to receive solid residues from the main retort.
5. The device of claim 4 wherein the secondary retort is mounted on expansion rollers to allow relative movement of the main retort and secondary retort.
6. The device of claim 5 wherein the secondary retort and main retort are connected by a rigid conduit.
7. The device of claim 1 further comprising a thermal oxidizer chamber in fluid communication with the mixing chamber, and an afterburner system disposed within the thermal oxidizer chamber.
8. The device of claim 1 wherein, during use, the temperature of the gases within the flue gas relief duct and the syngas relief duct is within +/−25 degrees F. of the temperature of the flue gas and syngas in the combustion chamber and main retort, respectively.
9. The device of claim 7 further comprising an expansion chamber in fluid communication with the thermal oxidizer chamber.
10. The device of claim 9 further comprising a plurality of mixing baffles disposed within the expansion chamber.
11. The device of claim 9 further comprising, downstream of the expansion chamber, a blower configured to draw a vacuum on the expansion chamber, thermal oxidizer chamber, and mixing chamber.
12. The device of claim 1 wherein the clearance between an outer wall of the syngas relief duct and an inner wall of the flue gas relief duct is selected such that the flow rate of the gases within the ducts is from about 30 to 60 feet/second.