Note: Descriptions are shown in the official language in which they were submitted.
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SYSTEM AND METHOD FOR PRODUCING UN-HYDROGENATED AND
HYDROGENATED C9+ COMPOUNDS
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of priority to U.S. Provisional
Patent
Application No. 62/874,401, filed July 15, 2019, the entire contents of which
are hereby
incorporated by reference in their entirety.
FIELD OF INVENTION
[0002] The present invention generally relates to the processing of
pyrolysis gasoline
(pygas). More specifically, the present invention relates to a process of
processing pyrolysis
gasoline to produce un-hydrogenated C9+ hydrocarbons and hydrogenated C9+
hydrocarbons.
BACKGROUND OF THE INVENTION
[0003] A common process in the refining of hydrocarbon feedstocks,
such as naphtha,
is steam cracking. In the steam cracking (pyrolysis) process, the hydrocarbon
feedstock is
superheated in a reactor to temperatures as high as 750-950 C. For the
cracking process, a
dilution steam generator supplies dilution steam to the reactor to reduce the
partial pressure of
the hydrocarbons. The superheated hydrocarbons are then rapidly cooled
(quenched) to stop
the reactions after a certain point to optimize cracking product yield.
Pyrolysis gasoline is one
of the products of the cracking process and may include components such as
aromatics, olefins,
and/or diolefins, among others. Typically, the pygas is hydrogenated before
further processing
to produce finished products such as benzene, toluene, and xylene (BTX).
[0004] Gasoline hydrogenation units (GHU) are commonly used in the
chemical
industry to saturate unstable compounds such as diolefins and styrene. Olefins
and sulfur
compound are also hydrogenated to meet final product specifications. After
hydrogenation,
different product cuts are separated based on downstream demand. For example,
after
hydrogenation of pyrolysis gasoline, a C9+ Cut is normally separated at a
deoctanizer to produce
hydrogenated wash oil and hydrogenated C9+ residue.
[0005] WO 2018/002810 Al relates to a separation system for
separating a feed stream
comprising C6+ hydrocarbons, the system comprising: i) a first distillation
column for
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producing a first light stream comprising C6- hydrocarbons and a first heavy
stream comprising
C7+ hydrocarbons, wherein the first distillation column is operated between a
lowest pressure
and a highest pressure, ii) a second distillation column for producing a
second light stream
comprising C6- hydrocarbons and a second heavy stream comprising C7+
hydrocarbons,
wherein the second distillation column is operated between a lowest pressure
and a highest
pressure, wherein the lowest pressure of the second distillation column is
higher than the
highest pressure of the highest distillation column and iii) a heat exchanger
comprising a first
reboiler for reboiling a part of the first heavy stream to produce a first
boiled heavy stream and
a second condenser for condensing the second light stream to produce a second
condensed light
stream, wherein the first reboiler and the second condenser are arranged such
that heat released
from the second condenser is used as heat for the first reboiler.
BRIEF SUMMARY OF THE INVENTION
[0006] As described above, conventional processes for processing of
pyrolysis gasoline
produce hydrogenated C9+ hydrocarbons. However, there is also a demand for un-
hydrogenated C9+ hydrocarbons. As far as is known, presently, there is no
process that
produces both un-hydrogenated and hydrogenated products concurrently. A
solution to address
this deficiency of conventional processes has been discovered. The disclosed
process is
premised on separating un-hydrogenated C9+ hydrocarbons from pyrolysis
gasoline upstream
of a GHU so that un-hydrogenated C9+ hydrocarbons can be recovered as a
product and/or
hydrogenated C9+ hydrocarbons can be recovered as a product. The discovered
process
provides the flexibility of producing (1) only un-hydrogenated C9+
hydrocarbons (separation
upstream of GHU and not further hydrogenated), (2) un-hydrogenated C9+
hydrocarbons and
hydrogenated C9+ hydrocarbons (separation upstream of GHU and GHU operated to
process
only a portion of the un-hydrogenated C9+ hydrocarbons), or (3) only
hydrogenated C9+
hydrocarbons (GHU operated to process all of the un-hydrogenated C9+
hydrocarbons).
[0007] Embodiments of the invention include a method of processing
pyrolysis
gasoline, where the method involves separating a pyrolysis gasoline stream to
produce a first
stream comprising primarily un-hydrogenated C9+ compounds. According to
embodiments of
the invention, the separating of the pyrolysis gasoline is carried out
upstream of the
hydrogenation unit.
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[0008] Embodiments of the invention include a method of processing
pyrolysis
gasoline to concurrently produce a first stream comprising primarily un-
hydrogenated C9+
compounds and a second stream comprising hydrogenated C9+ hydrogenated
compounds. The
method includes separating a pyrolysis gasoline stream to produce the first
stream comprising
primarily un-hydrogenated C9+ compounds and further includes hydrogenating a
portion of the
first stream to produce the second stream comprising hydrogenated C9+
hydrogenated
compounds.
[0009] The following includes definitions of various terms and
phrases used throughout
this specification.
[0010] The terms "about" or "approximately" are defined as being close to
as
understood by one of ordinary skill in the art. In one non-limiting embodiment
the terms are
defined to be within 10%, preferably, within 5%, more preferably, within 1%,
and most
preferably, within 0.5%.
[0011] The terms "wt.%", "vol.%" or "mol.%" refer to a weight,
volume, or molar
percentage of a component, respectively, based on the total weight, the total
volume, or the
total moles of material that includes the component. In a non-limiting
example, 10 moles of
component in 100 moles of the material is 10 mol.% of component.
[0012] The term "substantially" and its variations are defined to
include ranges within
10%, within 5%, within 1%, or within 0.5%.
[0013] The terms "inhibiting" or "reducing" or "preventing" or "avoiding"
or any
variation of these terms, when used in the claims and/or the specification,
include any
measurable decrease or complete inhibition to achieve a desired result.
[0014] The term "effective," as that term is used in the
specification and/or claims,
means adequate to accomplish a desired, expected, or intended result.
[0015] The use of the words "a" or "an" when used in conjunction with the
term
"comprising," "including," "containing," or "having" in the claims or the
specification may
mean "one," but it is also consistent with the meaning of "one or more," "at
least one," and
"one or more than one."
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[0016] The words "comprising" (and any form of comprising, such as
"comprise" and
"comprises"), "having" (and any form of having, such as "have" and "has"),
"including" (and
any form of including, such as "includes" and "include") or "containing" (and
any form of
containing, such as "contains" and "contain") are inclusive or open-ended and
do not exclude
additional, unrecited elements or method steps.
[0017] The process of the present invention can "comprise," "consist
essentially of,"
or "consist of' particular ingredients, components, compositions, etc.,
disclosed throughout the
specification.
[0018] The term "primarily," as that term is used in the
specification and/or claims,
means greater than any of 50 wt.%, 50 mol.%, and 50 vol.%. For example,
"primarily" may
include 50.1 wt.% to 100 wt.% and all values and ranges there between, 50.1
mol.% to 100
mol.% and all values and ranges there between, or 50.1 vol.% to 100 vol.% and
all values and
ranges there between.
[0019] Other objects, features and advantages of the present
invention will become
apparent from the following figures, detailed description, and examples. It
should be
understood, however, that the figures, detailed description, and examples,
while indicating
specific embodiments of the invention, are given by way of illustration only
and are not meant
to be limiting. Additionally, it is contemplated that changes and
modifications within the spirit
and scope of the invention will become apparent to those skilled in the art
from this detailed
description. In further embodiments, features from specific embodiments may be
combined
with features from other embodiments. For example, features from one
embodiment may be
combined with features from any of the other embodiments. In further
embodiments,
additional features may be added to the specific embodiments described herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] For a more complete understanding, reference is now made to the
following
descriptions taken in conjunction with the accompanying drawings, in which:
[0021] FIG. 1 shows a system for processing pyrolysis gasoline to
produce a stream
comprising primarily un-hydrogenated C9+ compounds, according to embodiments
of the
invention;
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[0022] FIG. 2 shows a process for processing pyrolysis gasoline to
produce a stream
comprising primarily un-hydrogenated C9+ compounds, according to embodiments
of the
invention;
[0023] FIG. 3 shows a system for processing pyrolysis gasoline to
produce a stream
comprising primarily un-hydrogenated C9+ and hydrogenated wash oil compounds,
according
to embodiments of the invention; and
[0024] FIG. 4 shows a process for processing pyrolysis gasoline to
produce a stream
comprising primarily un-hydrogenated C9+ and hydrogenated wash oil compounds,
according
to embodiments of the invention.
[0025] FIG. 5 shows a system and process for processing pyrolysis gasoline
to produce
un-hydrogenated C9+ and un-hydrogenated wash oil compounds, according to an
embodiment
of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0026] Gasoline hydrogenation units (GHU) are commonly used to
saturate unstable
compounds such as diolefins and styrene found in pyrolysis gasoline. Olefins
and sulfur
compounds are also hydrogenated to meet final product specifications. After
hydrogenation,
different product cuts are separated based on downstream demand. For example,
after
hydrogenation of pyrolysis gasoline, a C9+ Cut is normally separated at the
deoctanizer to
produce hydrogenated wash oil and hydrogenated C9+ residue. This process,
however, does
not contribute to meeting the demand for un-hydrogenated C9+ products. A
solution to address
this deficiency of the conventional process has been discovered. The
discovered process is
premised on separating un-hydrogenated C9+ hydrocarbons from pyrolysis
gasoline upstream
of a GHU so that un-hydrogenated C9+ hydrocarbons can be recovered as a
product and as
hydrogenated C9+ hydrocarbons can likewise be recovered as a product.
[0027] FIG. 1 shows system 10 for processing pyrolysis gasoline to produce
a stream
comprising primarily un-hydrogenated C9+ compounds (e.g., un-hydrogenated
hydrocarbons),
according to embodiments of the invention. FIG. 2 shows process 20 for
processing pyrolysis
gasoline to produce a stream comprising primarily un-hydrogenated C9+
compounds, according
to embodiments of the invention. System 10 may be used to implement process
20.
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[0028] According to embodiments of the invention, process 20
includes, at block 200,
separating pyrolysis gasoline stream 100, in separation unit 121 to produce
stream 101 (C9+
compounds/stream), which comprises primarily un-hydrogenated C9+ compounds.
Wash oil is
used to control the build-up of polymers on cracked gas compressors, turbines,
seals, and heat
exchangers. A good wash oil has a fairly high initial boiling point so that it
won't immediately
flash to vapor, combined with a high C9+ aromatic content for dissolving
polymeric
compounds. The wash oil described herein is hydrogenated to saturate the
dienes before using
to control the build-up of polymers. Stream 101 may include 10 to 100 wt.% C9+
compounds
and all ranges and values there between, including ranges of 10 to 20 wt.%, 20
to 30 wt.%, 30
to 40 wt.%, 40 to 50 wt.%, 50 to 60 wt.%, 60 to 70 wt.%, 70 to 80 wt.%, 80 to
90 wt.%, and
90 to 100 wt.%, and 0 to 90 wt.% wash oil and all ranges and values there
between, including
ranges of 0 to 10%, 10 to 20%, 20 to 30%, 30 to 40%, 40 to 50%, 50 to 60%, 60
to 70%, 70 to
80%, 80 to 90%, and 90 to 100%.
[0029] According to embodiments of the invention, block 201 includes
flowing at least
a portion of stream 101 to GHU reactor 115 and hydrogenating that portion or
all of stream
101 in GHU reactor 115 to produce stream 102 comprising hydrogenated C9+
compounds (e.g.,
hydrogenated hydrocarbons). In other words, in embodiments of the invention,
all of stream
101 may be hydrogenated or, as shown in FIG. 1, stream 101 may be separated
into stream
101-1 and stream 101-2 and only stream 101-1 is hydrogenated in GHU reactor
115. In some
embodiments, GHU reactor 115 is not operated and, instead, is bypassed such
that stream 101
is flowed to flash drum 116 so that only un-hydrogenated C9+ compounds are
produced. In this
way, system 10 is adapted to have the flexibility to produce (1) only un-
hydrogenated C9+
compounds (GHU reactor 115 not operated), (2) un-hydrogenated C9+ compounds
and
hydrogenated C9+ compounds (GHU reactor 115 operated to process only a portion
of the un-
hydrogenated C9+ compounds), or (3) only hydrogenated C9+ compounds (GHU
reactor 115
operated to process all of the un-hydrogenated C9+ compounds). According to
embodiments
of the invention, the reaction conditions in GHU reactor 115 include a
temperature in a range
of 100 to 200 C and all ranges and values there between including ranges of
100 to 110 C,
110 to 120 C, 120 to 130 C, 130 to 140 C, 140 to 150 C, 150 to 160 C, 160 to
170 C, 170
to 180 C, 180 to 190 C, and 190 to 200 C, a pressure in a range of 10 to 30
bar and all ranges
and values there between including ranges of 10 to 12 bar, 12 to 14 bar, 14 to
16 bar, 16 to 18
bar, 18 to 20 bar, 20 to 22 bar, 22 to 24 bar, 24 to 26 bar, 26 to 28 bar, and
28 to 30 bar, a
WHSV of 2 to 8 h-1 and all ranges and values there between including ranges of
2 to 3 h-1, 3 to
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411-1, 4 to 511-1, 5 to 611-1, 6 to 711-1, and 7 to 811-1, and in the presence
of a catalyst comprising
Ni/A1203 to Pd/A1203.
[0030] At block 202, according to embodiments of the invention,
stream 102, which
comprises hydrogenated C9+ compounds is flowed to flash drum 116, wherein
stream 102 is
separated to produce stream 103 comprising hydrogenated wash oil and stream
104 comprising
hydrogenated C9+ compounds. In embodiments of the invention, stream 103
comprises 0 to 90
wt.% wash oil and all ranges and values there between including ranges of 0 to
10 wt.%, 10 to
20 wt.%, 20 to 30 wt.%, 30 to 40 wt.%, 40 to 50 wt.%, 50 to 60 wt.%, 60 to 70
wt.%, 70 to 80
wt.%, and 80 to 90 wt.%, and stream 104 comprises 10 to 100 wt.% hydrogenated
C9+
compounds and all ranges and values there between including ranges of 10 to 20
wt.%, 20 to
30 wt.%, 30 to 40 wt.%, 40 to 50 wt.%, 50 to 60 wt.%, 60 to 70 wt.%, 70 to 80
wt.%, 80 to 90
wt.%, and 90 to 100 wt.%.
[0031] In embodiments of the invention, separating pyrolysis gasoline
stream 100 (at
block 200) comprises, as shown at block 201-1, distilling the pyrolysis gas
stream in
depentanizer column 112 to produce stream 105 as an overhead stream comprising
primarily
C4 and Cs compounds and stream 106 as a bottoms stream comprising primarily
C6+
compounds. In this way, according to embodiments of the invention, a C4 to C5
fraction is
separated as an un-hydrogenated stream upstream of any GHU. This provides an
advantage
where valuable diene components can be separated from this stream. In
embodiments of the
invention, separating pyrolysis gasoline stream 100 further includes, at block
201-2, flowing
stream 106 from depentanizer column 112 to deoctanizer column 113 and
distilling stream 106
in deoctanizer column 113 to produce stream 107 comprising primarily C6 to C8
compounds
and un-hydrogenated C9+ compounds/stream 101. More specifically, at
deoctanizer column
113, un-hydrogenated BTX is flowed from the top for deoctanizer column 113 and
un-
hydrogenated C9+ compounds are flowed from the bottom of deoctanizer column
113. The un-
hydrogenated C9+ compounds can be used un-hydrogenated or, if necessary, can
be
hydrogenated by passing through GHU reactor 115. This is possible because
system 10 has
the flexibility to be operated in any mode, either hydrogenated, un-
hydrogenated, or a
combination of both. In embodiments of the invention, a separation flash drum
can be installed
before GHU reactor 115, where an overhead un-hydrogenated wash oil and bottom
un-
hydrogenated C9+ residue can be produced. The separation of the un-
hydrogenated C9+
compounds/stream 101 can require the operation of deoctanizer column 113 at
low
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temperature, for example, 70 to 100 C and all ranges and values there between
including
ranges of 70 to 75 C, 75 to 80 C, 80 to 85 C, 85 to 90 C, 90 to 95 C, and 95
to 100 C, on
the reboiler and at high vacuum, for example 0.04 to 0.9 bara and ranges and
values there
between including ranges of 0.04 to 0.1 bara, 0.1 to 0.2 bara, 0.2 to 0.3
bara, 0.3 to 0.4 bara,
.. 0.4 to 0.5 bara, 0.5 to 0.6 bara, 0.6 to 0.7 bara, 0.7 to 0.8 bara, and 0.8
to 0.9 bara. Low
temperature can be achieved by using the reboiler condensate. And to reduce
fouling, a fouling
inhibitor can be injected in the deoctanizer column and/or the depentanizer
column. Thus, as
shown in FIG. 1, TBC package 120 supplies 4-tert-Butylcatechol (TBC), an
organic chemical
compound, as a fouling inhibitor to depentanizer column 112 and deoctanizer
column 113.
[0032] Process 20 may further include, at block 203, flowing stream 107
from
deoctanizer column 113 to GHU reactor 114 and hydrogenating stream 107 in GHU
reactor
114 to produce stream 108 comprising benzene, toluene, and xylene. According
to
embodiments of the invention, the reaction conditions in GHU reactor 114
include a
temperature in a range of 100 C to 200 C and all ranges and values there
between including
ranges of 100 to 110 C, 110 to 120 C, 120 to 130 C, 130 to 140 C, 140 to
150 C, 150 to
160 C, 160 to 170 C, 170 to 180 C, 180 to 190 C, and 190 to 200 C, a
pressure in a range
of 10 to 30 bar and all ranges and values there between including ranges of 10
to 12 bar, 12 to
14 bar, 14 to 16 bar, 16 to 18 bar, 18 to 20 bar, 20 to 22 bar, 22 to 24 bar,
24 to 26 bar, 26 to
28 bar, and 28 to 30 bar, a WHSV of 2 to 811-1 and all ranges and values there
between including
ranges of 2 to 311-1, 3 to 411-1, 4 to 511-1, 5 to 611-1, 6 to 711-1, and 7 to
811-1, and in the presence
of a catalyst comprising Ni/A1203 to Pd/A1203.
[0033] According to embodiments of the invention, process 20,
includes, at block 204,
flowing stream 105 from depentanizer column 112 to stabilizer 117 and
processing stream 105
in stabilizer 117 to produce stream 109 comprising fuel gas and stream 110
comprising
primarily C4 and C5 compounds. Block 205 involves flowing stream 110 from
stabilizer 117
to GHU reactor 118 and hydrogenating stream 110, in GHU reactor 118, to
produce stream
111 comprising primarily hydrogenated C4 and C5 compounds, in embodiments of
the
invention. According to embodiments of the invention, the reaction conditions
in GHU reactor
118 includes a temperature in a range of 40 to 140 C and all ranges and
values there between
.. including ranges of 40 to 50 C, 50 to 60 C, 60 to 70 C, 70 to 80 C, 80
to 90 C, 90 to 100
C, 100 to 110 C, 110 to 120 C, 120 to 130 C, and 130 to 240 C, a pressure
in a range of
20 to 40 bar and all ranges and values there between including ranges of 20 to
22 bar, 22 to 24
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bar, 24 to 26 bar, 26 to 28 bar, 28 to 30 bar, 30 to 32 bar, 32 to 34 bar, 34
to 36 bar, 36 to 38
bar, and 38 to 40 bar, a WHSV of 10 to 1611-1 and all ranges and values there
between including
ranges of 10 to 1111-1, 11 to 1211-1, 12 to 1311-1, 13 to 1411-1, 14 to 1511-
1, and 15 to 1611-1, and
in the presence of a catalyst comprising Ni/A1203 to Pd/A1203.
[0034] Process 20 may further include, at block 206, flowing stream 111
from GHU
reactor 118 to cracker 119 and subjecting stream 111 to cracking conditions in
cracker 119 to
form C2 to C4 light olefin, LPG, and H2 in cracker effluent stream 122.
[0035]
FIG. 3 shows system 30 for processing pyrolysis gasoline to produce a stream
comprising primarily un-hydrogenated C9+ compounds, according to embodiments
of the
invention. FIG. 4 shows process 40 for processing pyrolysis gasoline to
produce a stream
comprising primarily un-hydrogenated C9+ compounds, according to embodiments
of the
invention. System 30 may be used to implement process 40. System 30, according
to
embodiments of the invention, includes the elements 100 to 122 of system 10 as
well as further
elements 300 to 309. Likewise, process 40, in embodiments of the invention,
includes
operating elements 100 to 122 to carry out steps of blocks 200 to 206 as
described in process
20.
[0036]
Process 40 as implemented by system 30, like process 20 implemented by
system 10, includes blocks 200 to 206, in embodiments of the invention, except
that GHU
reactor 118 is not required as reactor 304 can hydrogenate stream 110 and GHU
reactor 114 is
similarly not required. Process 40 further includes, at block 400, routing
stream 103, stream
107, and stream 110 to feed drum 300 where they are combined to form combined
stream 301.
Hydrogenation of the combined stream 301 may be carried out by injecting
hydrogen stream
302, as shown at block 401, to form hydrogenated combined stream 303. Block
402 involves,
in embodiments of the invention, flowing hydrogenated combined stream 303 to
reactor 304,
where hydrogenated combined stream 303 is subjected to reaction conditions
sufficient to
saturate diolefins and partially saturate the olefins.
According to embodiments of the
invention, stream 305 is used to heat hydrogenated combined stream 303 in heat
exchanger
306. At block 403, stream 305 is separated in separator 307 to form vapor
stream 308
comprising water and H2 and stream 309. At block 404, stream 309 is split into
two portions,
.. stream 309-1 and stream 309-2. In embodiments of the invention, at block
405, stream 309-2
is recycled to reactor 304. At block 406, stream 309-1 is separated to form a
BTX stream, a
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stream comprising primarily hydrogenated wash oil, a fuel gas stream and a
stream comprising
primarily Cs compounds.
[0037] Although embodiments of the present invention have been
described with
reference to blocks of FIG. 2 and FIG. 4, it should be appreciated that
operation of the present
invention is not limited to the particular blocks and/or the particular order
of the blocks
illustrated in FIG. 2 and FIG. 4. Accordingly, embodiments of the invention
may provide
functionality as described herein using various blocks in a sequence different
than that of FIG.
2 and FIG. 4. It should be noted that, in FIG. 1 and FIG. 3, a stream shown
from a first element
or apparatus to a second element or apparatus is a disclosure that the first
element or apparatus
is in fluid communication with the second element or apparatus in a manner
such that the flow
of the stream shown, or described in the specification, can take place.
[0038] The systems and processes described herein can also include
various equipment
that is not shown and is known to one of skill in the art of chemical
processing. For example,
some controllers, piping, computers, valves, pumps, heaters, thermocouples,
pressure
.. indicators, mixers, heat exchangers, and the like may not be shown.
[0039] In the context of the present invention, at least the
following 20 embodiments
are shown. Embodiment 1 is a method of processing pyrolysis gasoline. The
method includes
separating a pyrolysis gasoline stream to produce a first stream containing
primarily un-
hydrogenated C9+ compounds. Embodiment 2 is the method of embodiment 1 wherein
the first
stream contains 98 to 100 wt.% C9+ compounds. Embodiment 3 is the method of
embodiment
1 further including hydrogenating a portion of the first stream to produce a
second stream
containing hydrogenated C9+ hydrogenated compounds. Embodiment 4 is the method
of
embodiment 3, wherein the hydrogenating of the first portion of the first
stream is carried out
under reaction conditions including a temperature in a range of 100 C to 200
C, a pressure in
a range of 10 bar to 30 bar, a WHSV of 211-1 to 811-1, and in the presence of
a catalyst containing
Ni/A1203 to Pd/A1203. Embodiment 5 is the method of either of embodiments 3 or
4 further
including separating the second stream to produce a third stream containing
hydrogenated wash
oil and a fourth stream containing hydrogenated C9+ residue. Embodiment 6 is
the method of
embodiment wherein third stream contains 0 to 90 wt.% wash oil and the fourth
stream
contains 10 to 100 wt.% hydrogenated C9+ compounds. Embodiment 7 is the method
of either
of embodiments 5 or 6, further including subjecting the third stream to
reaction conditions to
hydrogenate the third stream. Embodiment 8 is the method of embodiment 1,
wherein the
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separating of the pyrolysis gasoline stream includes distilling the pyrolysis
gas stream in a
depentanizer column to produce a fifth stream containing primarily C4+
compounds and a sixth
stream containing primarily C6+ compounds. Embodiment 9 is the method of
embodiment 8
wherein the separating of the pyrolysis gasoline stream further includes
distilling the sixth
stream in a deoctanizer column to produce a seventh stream containing
primarily C6 to C8
compounds and the first stream. Embodiment 10 is the method of embodiment 9
including
hydrogenating the seventh stream to produce an eighth stream containing
benzene, toluene, and
xylene. Embodiment 11 is the method of embodiment 10, wherein the
hydrogenating of the
seventh stream is carried out under reaction conditions including a
temperature in a range of
100 C to 200 C, a pressure in a range of 10 bar to 30 bar, a WHSV of 2 11-1
to 8 11-1, and in
presence of a catalyst containing Ni/A1203 to Pd/A1203. Embodiment 12 is the
method of
embodiment 8 further including processing the fifth stream in a stabilizer to
produce a ninth
stream including fuel gas and a tenth stream containing primarily C4 and C5
compounds.
Embodiment 13 is the method of embodiment 12 further including hydrogenating
the tenth
stream to produce an eleventh stream containing primarily C4 and C5 compounds.
Embodiment
14 is the method of embodiment 13, wherein the hydrogenating of the tenth
stream is carried
out under reaction conditions including a temperature in a range of 40 C to
140 C, a pressure
in a range of 20 bar to 40 bar, a WHSV of 10 11-1 to 16 11-1, and in presence
of a catalyst
containing Ni/A1203 to Pd/A1203. Embodiment 15 is the method of either of
embodiments 13
or 14 further including subjecting the eleventh stream to cracking conditions
to form C2 to C4
light olefins, LPG, and H2.
[0040]
Embodiment 16 is method of processing pyrolysis gasoline. The method
includes concurrently producing (1) a first stream containing primarily un-
hydrogenated C9+
compounds and (2) a second stream containing hydrogenated C9+ hydrogenated
compounds,
wherein the producing includes separating a pyrolysis gasoline stream to
produce the first
stream containing primarily un-hydrogenated C9+ compounds and hydrogenating a
portion of
the first stream to produce the second stream containing hydrogenated C9+
hydrogenated
compounds. Embodiment 17 is the method of embodiment 16 further including
producing a
stream containing primarily un-hydrogenated C4+ compounds.
[0041] Embodiment 18 is a method of processing pyrolysis gasoline. The
method includes
separating a pyrolysis gasoline stream to produce a first stream containing
primarily un-
hydrogenated C9+ compounds and hydrogenating a portion of the first stream to
produce a
11
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second stream containing hydrogenated C9+ compounds. The method further
includes
separating the second stream to produce a third stream containing hydrogenated
wash oil and
a fourth stream containing hydrogenated C9+ residue The separating of the
pyrolysis gasoline
stream includes distilling the pyrolysis gas stream in a depentanizer column
to produce a fifth
stream containing primarily C4+ compounds and a sixth stream containing
primarily C6+
compounds. The method also includes distilling the sixth stream in a
deoctanizer column to
produce a seventh stream containing primarily C6 to C8 compounds and the first
stream. In
addition, the method includes processing the fifth stream in a stabilizer to
produce a ninth
stream containing fuel gas and a tenth stream containing primarily C4 and Cs
compounds. The
method further includes combining the third stream, the seventh stream, and
the tenth stream
to form a combined stream and flowing the combined stream to a reactor.
Embodiment 19 is
the method of embodiment 18, further including subjecting the combined stream
to reaction
conditions sufficient to form a reactor effluent. Embodiment 20 is the method
of embodiment
19 further including processing the reactor effluent to produce a BTX stream,
a stream
containing primarily hydrogenated wash oil, a fuel gas stream and a stream
containing
primarily C5 compounds.
EXAMPLES
[0042] The present invention will be described in greater detail by way
of specific
examples. The following examples are offered for illustrative purposes only,
and are not
intended to limit the invention in any manner. Those of skill in the art will
readily recognize a
variety of noncritical parameters which can be changed or modified to yield
essentially the
same results.
Example 1
Producing un-hydrogenated C9+ compounds from pyrolysis gasoline
[0043] A first cut model was built in Aspen-Plus V10 Software. Simulations
were
performed according to an embodiment of the current disclosure as shown in
FIG. 5. Separated
streams containing C4 - C5 compounds, un-hydrogenated C6 to C8 compounds, un-
hydrogenated wash oil, un-hydrogenated C9+ residues were obtained from a
pyrolysis gasoline
stream. The pyrolysis gasoline stream contained C4 compounds, C5 compounds,
benzene,
toluene, xylene, styrene, indene, indane, dicyclopentadiene (DCPD),
methyldicyclopentadiene
(MDCPD), and others (e.g. other C6-C8 paraffinic and olefinic components, and
C9+ paraffinic,
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olefinic, napthenic and aromatic components). The pyrolysis gasoline stream
was distilled in a
depentanizer column to obtain a stream containing the C4 and Cs compounds from
the top of
the column, and a C6+ stream containing un-hydrogenated C6+ compounds from the
bottom of
the column. The C6+ stream contained benzene, toluene, xylene, styrene,
indene, indane,
DCPD, MDCPD and the other. The C6+ stream was distilled in a deoctanizer
column to obtain
a C6-8 stream containing un-hydrogenated C6 to C8 compounds from the top of
the column, and
a C9+ stream containing un-hydrogenated C9+ compounds from the bottom of the
column. The
C6_8 stream contained benzene, toluene, xylene and a portion of other (e.g. C6-
C8 paraffinic and
olefinic components,). The C9+ stream contained styrene, indene, indane, DCPD,
MDCPD and
a portion of the other (e.g. C9+ paraffinic, olefinic, napthenic and aromatic
components). The
C9+ stream was separated in a separation flash drum to obtain a stream
containing un-
hydrogenated wash oil from the top and a stream containing un-hydrogenated C9+
residues
from the bottom. The compositions, flow rate of the streams are provided in
Tables 1-7. A TBC
package, containing 4-tert-Butylcatechol (TBC) as fouling inhibitor, was
supplied to the
depentanizer column, deoctanizer column and the flash drum to reduce fouling.
Table 1: Pyrolysis gasoline stream
Compounds Ton/hour
C4 0.59
CS 11.16
Benzene 14.07
Toluene 2.94
Xylene 0.31
Styrene 1.39
Indene 0.58
Indane 0.22
DCPD 1.95
MDCPD 0.3
Others 6.97
Total 40.49
Table 2: C4-05 stream
Compounds Ton/hour
C4 0.59
CS 11.16
Total 11.75
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Table 3: C6+ stream
Compounds Ton/hour
Benzene 14.07
Toluene 2.94
Xylene 0.31
Styrene 1.39
Indene 0.58
Indane 0.22
DCPD 1.95
MDCPD 0.3
Others 6.97
Total 28.74
Table 4: C6-8 stream
Compounds Ton/hour
Benzene 14.00
Toluene 2.78
Xylene 0.2
Others 3.72
Total 20.7
Table 5: C9+ stream
Compounds Ton/hour
Styrene 0.71
Indene 0.58
Indane 0.22
DCPD 1.86
MDCPD 0.3
Others 4.59
Total 8.04
Table 6: Wash oil
Compounds Ton/hour
Styrene 0.65
Indene 0.48
Indane 0.18
DCPD 1.55
MDCPD 0.18
Others 3.32
Total 6.35
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Table 7: C9+ residue stream
Compounds Ton/hour
Styrene 0.06
Indene 0.1
Indane 0.04
DCPD 0.31
MDCPD 0.12
Others 1.05
Total 1.69
[0044] Although embodiments of the present application and their
advantages have
been described in detail, it should be understood that various changes,
substitutions and
alterations can be made herein without departing from the spirit and scope of
the embodiments
as defined by the appended claims. Moreover, the scope of the present
application is not
intended to be limited to the particular embodiments of the process, machine,
manufacture,
composition of matter, means, methods and steps described in the
specification. As one of
ordinary skill in the art will readily appreciate from the above disclosure,
processes, machines,
manufacture, compositions of matter, means, methods, or steps, presently
existing or later to
be developed that perform substantially the same function or achieve
substantially the same
result as the corresponding embodiments described herein may be utilized.
Accordingly, the
appended claims are intended to include within their scope such processes,
machines,
manufacture, compositions of matter, means, methods, or steps.
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