RECOVERY OF VALUABLE CHEMICAL PRODUCTS FROM RECYCLE CONTENT PYROLYSIS OIL
It has been discovered that high volumes of valuable recycle content products may be directly derived from waste plastic pyrolysis effluent. More particularly, one or more valuable recycle content hydrocarbons, such as aromatics and diolefins, can be separated from recycle content pyrolysis oil prior to further treatment in a downstream cracker facility. Consequently, by recovering these valuable recycle content products upstream of the cracking facility, one can optimize recovery and utilization of recycle content products from waste plastics.
1 . A chemical recycling process comprising:
(a) thermally pyrolyzing waste plastic to produce a pyrolysis oil stream;
(b) separating at least a portion of the pyrolysis oil stream into a raffinate stream and an extract stream, wherein the raffinate stream is depleted in aromatics and/or diolefins relative to the pyrolysis oil stream and the extract stream is enriched in aromatics and/or diolefins relative to the pyrolysis oil stream; and
(c) introducing at least a portion of the raffinate stream into a cracker furnace.
2 . The process according to claim 1 , further comprising recovering the aromatics and/or the diolefins from the extract stream.
3 . The process according to claim 1 , further comprising producing one or more hydrocarbons with at least a portion of the diolefins from the extract stream.
4 . The process according to claim 1 , further comprising producing one or more fuels with at least a portion of the aromatics from the extract stream.
5 . The process according to claim 1 , wherein the raffinate stream comprises not more than 20 weight percent of benzene, ethyl benzene, toluene, xylenes, styrene, and diolefins, based on the total weight of the raffinate stream.
6 . The process according to claim 1 , wherein the raffinate stream comprises not more than 20 weight percent of total diolefins, based on the total weight of the raffinate stream.
7 . The process according to claim 1 , wherein the extract stream comprises at least 20 weight percent of benzene, ethyl benzene, toluene, xylene, and styrene, based on the total weight of the extract stream; and not more than 20 weight percent of cyclopentadiene, dicycloplentadiene, pentadiene, hexadiene, cyclohexadiene, and/or derivatives thereof based on the total weight of the extract stream.
8 . The process according to claim 1 , wherein the separating of step (b) comprises solvent extraction.
9 . The process according to claim 1 , wherein the thermally pyrolyzing of step (a) occurs in the substantial absence of a catalyst material at temperature of at least 625° C.
10 . A chemical recycling process comprising:
(a) thermally pyrolyzing waste plastic to produce a pyrolysis effluent;
(b) condensing at least a portion of the pyrolysis effluent to thereby form a pyrolysis oil stream and a pyrolysis gas stream;
(c) separating at least a portion of the pyrolysis oil stream into a raffinate stream and an extract stream, wherein the raffinate stream is depleted in aromatics and/or diolefins relative to the pyrolysis oil stream and the extract stream is enriched in aromatics and/or diolefins relative to the pyrolysis oil stream;
(d) combining at least a portion of the raffinate stream with a cracker feed to form a combined cracker feed;
(e) cracking at least a portion of the combined cracker feed in a cracker furnace to form a cracked product;
(f) compressing at least a portion of the cracked product in at least one compressor to form a compressed product; and
(g) separating at least one hydrocarbon from the compressed product to thereby form a recycle content hydrocarbon stream.
11 . The process according to claim 10 , wherein the raffinate stream is depleted in aromatics and diolefins relative to the pyrolysis oil stream and the extract stream is enriched in aromatics and diolefins relative to the pyrolysis oil stream.
12 . The process according to claim 10 , wherein the separating of step (c) comprises solvent extraction.
13 . The process according to claim 10 , wherein the thermally pyrolyzing of step (a) occurs in the substantial absence of a catalyst material.
14 . The process according to claim 10 , wherein the pyrolysis oil stream comprises at least 10 weight percent of benzene, based on the total weight of the pyrolysis oil stream.
15 . A chemical recycling process comprising:
(a) thermally pyrolyzing waste plastic to produce a pyrolysis effluent;
(b) condensing at least a portion of the pyrolysis effluent to thereby form a pyrolysis oil stream and a pyrolysis gas stream;
(c) separating at least a portion of the pyrolysis oil stream into a raffinate stream and an extract stream, wherein the raffinate stream is depleted in aromatics and/or diolefins and the extract stream is enriched in aromatics and/or diolefins;
(d) combining at least a portion of the raffinate stream with a cracker feed to form a combined cracker feed;
(e) cracking at least a portion of the combined cracker feed in a cracker furnace to form a cracked product; and
(f) subjecting at least a portion of the extract stream to a chemical process so as to synthesize a chemical derivative and/or a polymer therefrom.
16 . The process according to claim 15 , wherein the pyrolysis oil stream comprises at least 5 weight percent of total diolefins based on the total weight of the pyrolysis oil stream.
17 . The process according to claim 15 , wherein the thermally pyrolyzing of step (a) occurs in a pyrolysis reactor within a pyrolysis facility and the cracker furnace is located within a cracker facility, wherein the pyrolysis facility and the cracker facility are co-located.
18 . The process according to claim 15 , wherein the raffinate stream comprises not more than 20 weight percent of benzene, ethyl benzene, toluene, xylenes, styrene, and diolefins, based on the total weight of the raffinate stream.