Apparatus and method for recovering marketable products from scrap rubber

A method for purifying hydrocarbon condensate produced by a scrap rubber pyrolysis system, comprising the steps of:

• mixing the hydrocarbon condensate with a filter aid selected to attract particulate contaminants in the hydrocarbon condensate under conditions which permit the filter aid to form aggregates with particulate contaminants therein;
• removing the aggregates of filter aid and contaminants from the hydrocarbon condensate;
• heating the hydrocarbon condensate;
• and,
• removing polycyclic aromatics from the heated hydrocarbon condensate.

A system for processing scrap rubber to produce marketable end products, the system comprising:

• a. a scrap rubber pyrolysis system, comprising:
• (1) a weigh belt conveyor for receiving scrap rubber shreds, the weigh belt conveyor determining a weight of the shreds and delivering the shreds at a controlled rate based upon the weight;
• (2) a bucket conveyor receiving the shreds from the weigh belt conveyor;
• (3) a hopper receiving the shreds from the bucket conveyor;
• (4) a deoxygenator receiving the shreds from the hopper and providing the shreds under conditions effectively excluding oxygen therefrom;
• (5) a pyrolysis vessel receiving the shreds from the deoxygenator, the pyrolysis vessel passing the shreds as a bed through the vessel under a constant temperature condition so that the shreds remain within the pyrolysis vessel at a sufficient duration to allow for complete pyrolysis of the shreds into carbon black and pyrolysis gas and to allow for desorption of the pyrolysis gas from the surface of the carbon black;
• (6) a centrifugal separation means for receiving the pyrolysis gas from the pyrolysis vessel, removing entrained carbon black particles and returning them to the deoxygenator under conditions effectively excluding oxygen therefrom;
• (7) a condensate separation assembly receiving pyrolysis gas from the centrifugal separation means and dividing the pyrolysis gas into a hydrocarbon condensate fraction and a vapor fraction;
• (8) a carbon black screening assembly removing gross contaminants and ferrous particles from the carbon black provided by the pyrolysis vessel;
• b. a plasticizer oil purification system comprising:
• (1) a liquid holding tank receiving the hydrocarbon condensate from the scrap rubber pyrolysis system;
• (2) a mixing vessel receiving hydrocarbon condensate from the liquid holding tank and mixing the hydrocarbon condensate with a filter aid under conditions which aggregates of particulate contaminants in the hydrocarbon condensate and the filter aid are formed;
• (3) a filter aid removal assembly for removing the aggregates of filter aid and contaminants from the hydrocarbon condensate received from the mixing vessel;
• (4) a polycyclic aromatic removal assembly receiving the hydrocarbon condensate from the filter aid removal assembly and removing polycyclic aromatics from the hydrocarbon condensate;
• c. A carbon black purification and refinement system comprising:
• (1) an enclosed carbon black holding tank for receiving carbon black from the scrap rubber pyrolysis system;
• (2) a jet mill for milling the carbon black into particles of a selected average size in the presence of dry air;
• (3) a valve dispensing carbon black from the carbon black holding tank to the mill at a controlled rate;
• (4) a screening device adapted to separate oversized contaminants from the milled carbon black;
• (5) a magnetic separator adapted to remove ferrous particles from the milled carbon black;
• and,
• (6) a carbon black storage vessel for collecting purified milled carbon black.

A system for purifying hydrocarbon condensate obtained from a scrap rubber pyrolysis system comprising:

• a. a liquid holding tank for temporary storage of hydrocarbon condensate;
• b. a mixing vessel adapted to receive hydrocarbon condensate from the liquid holding tank and to mix the hydrocarbon condensate with a filter aid under conditions which permit particulate contaminants in the hydrocarbon condensate to form aggregates with the filter aid;
• c. a filter aid removal assembly for removing the aggregates of filter aid and contaminants from the hydrocarbon condensate received from the mixing vessel;
• d. a means for heating the hydrocarbon condensate received from the filter air removal assembly;
• and,
• e. a polycyclic aromatic removal assembly adapted to receive the heated pyrolysis oil from the filter aid removal assembly and to remove polycyclic aromatic contaminants from the pyrolysis oil.

A system for processing scrap rubber comprising:

• means for pyrolyzing scrap rubber shreds to produce a pyrolysis gas and a carbon black mixture;
• means for milling the carbon black mixture to produce milled carbon black particles of a selected average particle size;
• means for removing oversized contaminant particles from the milled carbon black mixture;
• means for removing ferrous contaminants from the milled carbon black;
• means for removing a substantial amount of entrained particles from the pyrolysis gas;
• means for separating the pyrolysis gas from which entrained particles have been removed into a hydrocarbon condensate fraction and a vapor fraction;
• means for mixing the hydrocarbon condensate with a filter aid selected to attract particulate contaminants in the hydrocarbon condensate under conditions which permit the filter aid to form aggregates with the particulate contaminants;
• means for removing the aggregates of filter aid and contaminants from the hydrocarbon condensate;
• and,
• means for removing polycyclic aromatic contaminants from the hydrocarbon condensate.

A pyrolysis process for pyrolyzing a comminuted solid hydrocarbon material to form pyrolysis gas and solids, comprising the steps of:

• introducing the material into a first heating zone under conditions effectively excluding oxygen therefrom;
• retaining the material in the first heating zone for a first duration time while maintaining a first constant temperature sufficient to cause the shreds to dissociate into pyrolysis gas and solids;
• transferring the pyrolysis gas and solids into a second heating zone;
• retaining solids in the presence of the pyrolysis gas in the second heating zone for a second duration time and at a second constant temperature sufficient to ensure desorption of pyrolysis gas from the surface of the solids;
• and,
• removing the pyrolysis gas and solids from the second heating zone.

A pyrolysis process for pyrolyzing a comminuted solid hydrocarbon material to form pyrolysis gas and solids, comprising the steps of:

• introducing the material into a first heating zone at a constant input rate under conditions effectively excluding oxygen therefrom;
• passing the material as a bed through the first heating zone at a first rate, the first heating zone maintained at a first constant temperature selected to pyrolyze the material into pyrolysis gas and solids;
• passing the solids as a bed in the presence of the pyrolysis gas through a second heating zone at a constant second rate, the second heating zone maintained at a second constant temperature selected to ensure desorption of pyrolysis gas remaining on the surface of the solids;
• and,
• removing the pyrolysis gas and solids from the second heating zone at a constant output rate;
• whereby the amounts of material, pyrolysis gas, and solids are maintained in a steady state, and solids and pyrolysis gas removed from the second heating zone are not reintroduced into either the first heating zone or the second heating zone.

A process for pyrolyzing scrap rubber, comprising:

• heating the scrap rubber in a pyrolysis vessel in the absence of oxygen at a selected vessel temperature sufficient to decompose the material into a pyrolysis gas stream with entrained particulate matter and a hot carbon black solids stream;
• removing entrained particles from the pyrolysis gas stream through centrifugal action;
• and,
• condensing a selected hydrocarbon condensate fraction of the pyrolysis gas stream from which entrained particulate matter has been removed.