Methods and apparatus for pyrolyzing material

Abstract

Methods and systems for substantially continuously treating comminuted material containing carbon and hydrogen, for example, used tires, are provided. The methods include the steps of introducing the tire material to an elongated chamber, transferring the tire material through the elongated chamber, heating the tire material to a temperature sufficient to pyrolyze the material to produce a gaseous stream; discharging the gaseous stream from the chamber, and cooling at least some of the gaseous stream to liquefy components of the stream. The transfer may be effected by a flexible, center-less screw conveyor to minimize material buildup in the vessel. The cooling of the gaseous stream may be practiced by reverse condensation. One or more re-usable fuel streams are provided by aspects of the invention.

1 . A method of treating one or more feed materials containing carbon and hydrogen compounds in an elongated pyrolysis chamber having an inner surface, at least one material inlet, and at least one outlet, the method comprising:
 (1) introducing the feed material into the material inlet of the pyrolysis chamber;   (2) continuously conveying the feed material through the pyrolysis chamber while substantially simultaneously removing build-up of feed material or the pyrolysis products thereof from the inner surface of the pyrolysis chamber;   (3) maintaining a temperature of the feed material and pryolysis products thereof within the pyrolysis chamber at a level sufficiently high to pryolyze the feed material to form gaseous hydrocarbons, and   (4) discharging the gaseous hydrocarbons from the at least one outlet of the pyrolysis chamber.   
     
     
         2 . The method as recited in  claim 1 , wherein the one or more feed materials comprise comminuted tires. 
     
     
         3 . The method as recited in  claim 1 , wherein the method further comprises extracting air from the feed material prior introducing the feed material to the pyrolysis chamber. 
     
     
         4 . The method as recited in  claim 1 , wherein said continuously conveying the feed material comprises rotating a helical centerless screw within the pyrolysis chamber, the helical center-less screw having a plurality of screw flights sized to a provide clearance between the flights and the interior surface of the pyrolysis chamber. 
     
     
         5 . The method as recited in  claim 1 , wherein the temperature comprises a temperature between about 450 degrees C. and about 475 degrees C. 
     
     
         6 . The method as recited in  claim 1 , wherein the method further comprises discharging a least one liquid hydrocarbon. 
     
     
         7 . The method as recited in  claim 1 , wherein the method further comprises discharging at least one of CO and H 2 . 
     
     
         8 . The method as recited in  claim 1 , wherein the method further comprises cooling the material near the outlet of the elongated pyrolysis chamber. 
     
     
         9 . The method as recited in  claim 1 , further comprising using at least some of the gaseous hydrocarbons produced in the practice of maintaining the temperature. 
     
     
         10 . An apparatus for pryolyzing one or more feed materials containing carbon and hydrogen compounds, the apparatus comprising:
 (1) an elongated pyrolysis chamber having an inner surface, one or more inlets for introducing the feed material, and one or more outlets;   (2) means for continuously conveying the feed material and pyrolysis products thereof through the pyrolysis chamber while substantially simultaneously removing any build-up of feed material and the pyrolysis products from the inner surface of the pyrolysis chamber;   (3) means for maintaining the temperature within the pyrolysis chamber at a level sufficiently high to pryolyze at least some of the feed material to gaseous hydrocarbons; and   (4) means for discharging the gaseous hydrocarbons through the one or more outlets.   
     
     
         11 . The apparatus as recited in  claim 10 , wherein the pyrolysis chamber comprise a horizontally-positioned, cylindrical vessel having a diameter of about 12 inches to about 16 inches. 
     
     
         12 . The apparatus as recited in  claim 11 , wherein the pyrolysis chamber comprises a length of about 30 feet to about 40 feet. 
     
     
         13 . The apparatus as recited in  claim 10 , wherein the pyrolysis chamber comprises a plurality of elongated pyrolysis chambers. 
     
     
         14 . The apparatus as recited in  claim 10 , wherein the means for continuously conveying the feed material comprises a rotating helical center-less screw mounted for rotation within the pyrolysis chamber, the helical center-less screw having a plurality of flights sized to a provide clearance between the flights and the interior surface of the pyrolysis chamber. 
     
     
         15 . The apparatus as recited in  claim 14 , wherein the means for continuously conveying the feed material further comprises an initial portion comprising means for reducing a size of the feed material. 
     
     
         16 . The apparatus as recited in  claim 10 , wherein the pyrolysis chamber further comprises means for cooling the pyrolysis products. 
     
     
         17 . The apparatus as recited in  claim 10 , further comprising means for using at least some of the gaseous hydrocarbons produced in the practice of maintaining the temperature. 
     
     
         18 . The apparatus as recited in  claim 10 , further comprising means for minimizing the introduction of air to the pyrolysis chamber. 
     
     
         19 . The apparatus as recited in  claim 18 , wherein the means for minimizing the introduction of air comprises a double air lock. 
     
     
         20 . A method for substantially continuously treating comminuted material containing carbon and hydrogen, the method comprising:
 introducing the comminuted material to an elongated chamber having little or no oxygen;   transferring the comminuted material through the elongated chamber;   heating the comminuted material to a temperature sufficient to pyrolyze the comminuted material to produce gaseous hydrocarbons and at least some carbon-containing solids;   discharging the gaseous hydrocarbons from the chamber;   cooling at least some of the gaseous hydrocarbons to liquefy the hydrocarbons; and   discharging the carbon-containing solids from the chamber.   
     
     
         21 . The method as recited in  claim 20 , wherein transferring comprises transferring while minimizing buildup of the comminuted material and the carbon-containing solids on an insider surface of the elongated chamber. 
     
     
         22 . The method as recited in  claim 21 , wherein minimizing the buildup of material and solids comprises conveying a scraping device over the inside surface of the elongated cylinder. 
     
     
         23 . The method as recited in  claim 22 , wherein conveying a scraping device comprises transferring the material with a center-less screw conveyor having at least one flight that bears against the inside surface of the elongated chamber. 
     
     
         24 . The method as recited in  claim 20 , wherein cooling at least some of the gaseous hydrocarbons comprises passing the gaseous hydrocarbons in heat exchange relationship with a cooler fluid. 
     
     
         25 . The method as recited in  claim 24 , wherein the gaseous hydrocarbons are discharged at a first temperature, and wherein passing the gaseous hydrocarbons in heat exchange relationship with a cooler fluid comprises passing the gaseous hydrocarbons at the first temperature in heat exchange relationship with a fluid having a second temperature lower than the first temperature to produce a first cooler stream of gaseous hydrocarbons at a third temperature lower than the first temperature. 
     
     
         26 . The method as recited in  claim 25 , wherein passing the gaseous hydrocarbons in heat exchange relationship with a cooler fluid further comprises passing the gaseous hydrocarbons at the third temperature in heat exchange relationship with a fluid having a fourth temperature lower than the third temperature to produce a second cooler stream of gaseous hydrocarbons at a fifth temperature lower than the third temperature. 
     
     
         27 . The method as recited in  claim 20 , wherein the comminuted material containing carbon and hydrogen comprises comminuted tires. 
     
     
         28 . The method as recited in  claim 20 , wherein heating the comminuted material to a temperature sufficient to pyrolyze the comminuted material comprises heating the comminuted material to at least 400 degrees C. 
     
     
         29 . A method from producing liquid hydrocarbons from comminuted carbon and hydrogen containing material, the method comprising:
 introducing the comminuted material to a chamber having little or no oxygen;   heating the comminuted material to a temperature sufficient to produce gaseous hydrocarbons at a first temperature;   cooling the gaseous hydrocarbons to condense a first liquid hydrocarbon from the gaseous hydrocarbons and a first cooler stream of gaseous hydrocarbons at a second temperature lower than the first temperature; and   cooling the first cooler stream of gaseous hydrocarbons to a third temperature, lower than the second temperature, to condense a second liquid hydrocarbon from the first cooler stream of gaseous hydrocarbons and a second cooler stream of gaseous hydrocarbons.   
     
     
         30 . The method as recited in  claim 29 , wherein the first liquid hydrocarbon has a greater density than the second liquid hydrocarbon. 
     
     
         31 . The method as recited in  claim 29 , wherein the method further comprises cooling the second cooler stream of gaseous hydrocarbons to a fourth temperature, lower than the third temperature, to condense a third liquid hydrocarbon from the second cooler stream of gaseous hydrocarbons and a third cooler stream of gaseous hydrocarbons. 
     
     
         32 . The method as recited in  claim 29 , wherein the comminuted material containing carbon and hydrogen comprises comminuted tires. 
     
     
         33 . The method as recited in  claim 29 , wherein heating the comminuted material to a temperature comprises heating the comminuted material to at least 400 degrees C. 
     
     
         34 . A treatment apparatus for comminuted material containing carbon and hydrogen, the apparatus comprising:
 an elongated cylindrical chamber having a first end and a second end;   a centerless helical screw conveyor mounted for rotation in the elongated cylindrical chamber;   means for rotating the centerless helical screw conveyor to transfer the comminuted material from the first end to the second end; and   means for heating the cylindrical chamber to a temperature sufficient to produce gaseous hydrocarbons from the comminuted material.   
     
     
         35 . The treatment apparatus as recited in  claim 34 , wherein the centerless helical screw conveyor comprises a helical bar. 
     
     
         36 . The treatment apparatus as recited in  claim 35 , wherein the helical bar has a rectangular cross section. 
     
     
         37 . The treatment apparatus as recited in  claim 36 , wherein the helical bar has a square cross section having 1-inch sides. 
     
     
         38 . The treatment apparatus as recited in  claim 34 , wherein the centerless helical screw conveyor comprises a centerless helical screw conveyor having variable flight pitch. 
     
     
         39 . A system for processing comminuted material containing carbon and hydrogen to produce liquid hydrocarbons, the system comprising:
 a comminuted material feeder;   a hopper adapted to receive the comminuted material from the feeder;   at least one valve adapted to receive the comminuted material from the hopper;   an elongated cylindrical chamber having a first end adapted to receive the comminuted material from the at least one valve with little or no oxygen;   a centerless helical screw conveyor mounted for rotation in the elongated cylindrical chamber, and adapted to transfer the comminuted material from the first end of the chamber to the second end;   means for heating the cylindrical chamber to a temperature sufficient to produce gaseous hydrocarbons from the comminuted material at a first temperature and carbon-containing solids;   at least one discharge from the chamber for the gaseous hydrocarbons;   a first heat exchanger adapted to cool the gaseous hydrocarbons to a second temperature lower than the first temperature and condense a first liquid hydrocarbon from the gaseous hydrocarbons and a first cooler stream of gaseous hydrocarbons at a second temperature lower than the first temperature;   a second heat exchanger adapted to cool the first cooler stream of gaseous hydrocarbons to a third temperature, lower than the second temperature, to condense a second liquid hydrocarbon, different from the first liquid hydrocarbon, from the first cooler stream of gaseous hydrocarbons and a second cooler stream of gaseous hydrocarbons; and   a discharge at the second end of the chamber for the carbon-containing solids.