Pyrolysis method and system for recycled waste

Abstract

A pyrolysis method and system are provided that enhances the production of C3 and C4 alkanes in the resulting pyrolysis effluent. More particularly, the disclosed pyrolysis method and system may be configured to enhance the production of C3 and C4 alkanes due to the use of certain pyrolysis catalysts and more intense pyrolysis conditions.

1 - 22 . (canceled) 
     
     
         23 . A method of making a pyrolysis effluent, said method comprising:
 (a) introducing a pyrolysis feed into a pyrolysis unit, wherein said pyrolysis feed comprises at least one recycled waste, wherein said recycled waste contains not more than 1 weight percent of polyvinyl chloride; and   (b) pyrolyzing at least a portion of said pyrolysis feed in the absence of hydrotreatment or hydrogenation, at a temperature of at least 550° C., to thereby form a pyrolysis effluent comprising a combined C3/C4 hydrocarbon content of at least 10 weight percent.   
     
     
         24 . The method according to  claim 23 , wherein said recycled waste comprises post-consumer waste and/or post-industrial waste. 
     
     
         25 . The method according to  claim 24 , wherein said post-consumer waste comprises a waste plastic, a waste rubber, a textile, modified cellulose, wet-laid products, or combinations thereof. 
     
     
         26 . The method according to  claim 25 , wherein said pyrolysis feed comprises at least 30 weight percent of at least one four post-consumer wastes. 
     
     
         27 . The method according to  claim 26 , wherein said recycled waste comprises at least one recycled waste plastic. 
     
     
         28 . The method according to  claim 27 , wherein said pyrolysis feed comprises at least 30 weight percent of at least one recycled waste plastic. 
     
     
         29 . The method according to  claim 27 , wherein said pyrolysis feed comprises at least 30 weight percent of polyethylene and/or polypropylene. 
     
     
         30 . The method according to  claim 23 , wherein said pyrolysis effluent comprises at least 40 weight percent of a pyrolysis oil. 
     
     
         31 . The method according to  claim 24 , wherein said pyrolysis oil comprises an aromatic content of less than 15 weight percent. 
     
     
         32 . The method according to  claim 23 , wherein said pyrolysis effluent comprises at least 20 weight percent of said pyrolysis gas. 
     
     
         33 . The method according to  claim 23 , wherein said pyrolysis gas comprises a C3 hydrocarbon content of at least 1 weight percent. 
     
     
         34 . The method according to  claim 23 , wherein said pyrolysis gas comprises a C4 hydrocarbon content of at least 1 weight percent. 
     
     
         35 . The method according to  claim 23 , wherein said pyrolysis gas comprises a combined C3/C4 hydrocarbon content of at least 20 weight percent. 
     
     
         36 . The method according to  claim 23 , wherein said pyrolyzing of step (b) occurs in the absence of a pyrolysis catalyst. 
     
     
         37 . The method according to  claim 23 , wherein said pyrolyzing of step (b) occurs at a temperature of not more than 1,100° C. 
     
     
         38 . The method according to  claim 37  wherein said pyrolyzing of step (b) occurs in a pyrolysis unit, wherein said pyrolysis unit comprises a fluidized bed reactor, a transported bed reactor, an ablative (vortex) reactor, an extruder reactor, a microwave reactor, a fixed bed reactor, a vacuum reactor, an autoclave reactor, a rotary kiln, or a tubular reactor. 
     
     
         39 . The method according to  claim 38 , wherein said pyrolyzing of step (b) occurs at a residence of at least 0.1 seconds and less than 10 seconds. 
     
     
         40 . The method according to  claim 23 , wherein said pyrolyzing of step (b) occurs in the presence of a pyrolysis catalyst.