Pyrolysis method and system for variable recycle waste feedstocks
A pyrolysis method and system are provided that may utilize a recycled plastic feedstock that comprises various types of waste plastics or a feedstock that comprises various types of waste plastics and at least one crude post-industrial liquid waste. The disclosed pyrolysis method and system may be configured to convert various types of waste plastics, including post-customer and post-industrial wastes, and/or crude post-industrial liquid wastes into useful pyrolysis oils.
1 . A method of making recycle content pyrolysis oil (r-pyoil), said method comprising:
(a) introducing a pyrolysis feed into a pyrolysis unit, wherein said pyrolysis feed comprises (1) a waste plastic chosen from high density polyethylene, low density polyethylene, polypropylene, or combinations thereof, and containing not more than 5 weight percent of polyvinyl chloride and/or polyethylene terephthalate and (2) at least 1 weight percent of at least one industrial byproduct, wherein said industrial byproduct comprises:
(i) at least one liquid byproduct produced during cracking of ethane and/or propane,
(ii) at least one liquid byproduct produced during manufacture of products derived from ethylene and/or propylene, and
(iii) at least one waste stream derived from production of synthetic fibers,
(iv) at least one waste stream derived from production of acetyl,
(vi) at least one oxygenated hydrocarbon having a carbon chain length of C6-C24,
(vii) distillers grain,
(viii) at least one liquid hydrocarbon comprising at least 75 weight percent of C2-C25 aliphatic hydrocarbons and less than 10 weight percent of aromatics,
(ix) at least one post-industrial waste plastic,
(x) at least one post-consumer waste oil,
(xi) at least one post-industrial lubrication oil, or
(xii) combinations thereof; and
(b) pyrolyzing at least a portion of said pyrolysis feed in said pyrolysis unit thereby forming a pyrolysis effluent comprising r-pyoil and r-pyrolysis gas; and further comprising
(c) cracking at least a portion of said r-pyoil, combined with a non-recycle hydrocarbon stream comprising at least 50 weight percent C2-C4 hydrocarbons, wherein said r-pyoil is present in an amount of at least 1 weight percent and not more than 30 weight percent, and wherein said non-recycle hydrocarbon stream is present in an amount of at least 65 weight percent, based on the total combined weight of said r-pyoil and non-recycle hydrocarbon stream, in a cracking furnace to form an olefin-containing effluent, wherein said olefin-containing stream comprises at least 60 weight percent of ethylene and/or propylene based on the weight of the olefin-containing effluent stream; wherein said pyrolysis effluent has a C 8+ content of at least 15 weight percent, based on the total weight of said pyrolysis effluent; and wherein said pyrolysis effluent comprises not more than about 25 weight percent total aromatics, based on the total weight of said pyrolysis effluent.
2 . The method according to claim 1 , wherein said pyrolysis feed comprises at least 2 weight percent of at least one industrial byproduct.
3 . The method according to claim 1 , wherein said pyrolysis unit operates at a temperature of 325° C. to 800° C.
4 . The according to claim 1 , wherein said pyrolysis unit comprises an extruder.
5 . The method according to claim 4 , wherein said pyrolyzing occurs at a residence time in the range of 0.1 to 10 seconds.
6 . The method of claim 1 , wherein said industrial byproduct comprises:
(i) at least one liquid byproduct produced during the cracking of ethane and/or propane,
(ii) at least one liquid byproduct produced during the manufacture of products derived from ethylene and/or propylene, or combination thereof.
7 . The method of claim 1 , wherein the pyrolysis feed is chosen from polyethylene and polypropylene.
8 . A method of making recycle content pyrolysis oil (r-pyoil), said method comprising:
(a) introducing a pyrolysis feed into a pyrolysis unit, wherein said pyrolysis feed comprises at least comprises (1) a waste plastic chosen from high density polyethylene, low density polyethylene, polypropylene, or combinations thereof, and containing not more than 5 weight percent of polyvinyl chloride and/or polyethylene terephthalate and (2) at least 1 weight percent of at least one crude industrial waste liquid,
(b) pyrolyzing at least a portion of said pyrolysis feed in said pyrolysis unit thereby forming a pyrolysis effluent comprising r-pyoil and r-pyrolysis gas; and further comprising
(c) cracking at least a portion of said r-pyoil, combined with a non-recycle hydrocarbon stream comprising at least 50 weight percent C 2 -C 4 hydrocarbons, wherein said r-pyoil is present in an amount of at least 1 weight percent and not more than 30 weight percent, and wherein said non-recycle hydrocarbon stream is present in an amount of at least 65 weight percent, based on the total combined weight of said r-pyoil and non-recycle hydrocarbon stream, in a cracking furnace to form an olefin-containing effluent, wherein said pyrolyzing and cracking are done in said cracking furnace; wherein said pyrolysis effluent has a C 8+ content of at least 15 weight percent, based on the total weight of said pyrolysis effluent; and wherein said pyrolysis effluent comprises not more than about 25 weight percent total aromatics, based on the total weight of said pyrolysis effluent [wherein said olefin-containing stream comprises at least 60 weight percent ethylene and/or propylene based on the weight of the olefin-containing effluent stream.
9 . The method according to claim 8 , further comprising pyrolyzing at least one recycled waste with said at least one crude industrial waste liquid in said pyrolysis unit.
10 . The method according to claim 8 , further comprising providing a source of said crude industrial waste liquid.
11 . The method according to claim 10 , wherein said source of the crude industrial waste liquid comprises a chemical manufacturing plant.
12 . The method according to claim 10 , wherein said source of the crude industrial waste liquid comprises a thermal cracker, a catalytic cracker, a demethanizer, a gasifier, or a quench tower.
13 . The method according to claim 12 , wherein said crude industrial waste liquid comprises (i) at least one liquid byproduct produced during cracking of ethane and/or propane, (ii) at least one liquid byproduct produced during manufacturing of products derived from ethylene and/or propylene, (iii) at least one waste stream derived from production of synthetic fibers, (iv) at least one waste stream derived from production of acetyl, (v) at least one oxygenated hydrocarbon having a carbon chain length of C6-C24, (vi) at least one liquid hydrocarbon comprising at least 75 weight percent of C2-C25 aliphatic hydrocarbons and less than 10 weight percent of aromatics, (vii) at least one post-consumer waste oil, (vii) at least one post-industrial lubrication oil, or (ix) combinations thereof.