Title of Invention

"A PROCESS FOR PRODUCING ETHYLBENZENE OR CUMENE"

Abstract A process for producing phenol and methyl ethyl ketone, the process comprising: (a) contacting a feed comprising benzene and a C4 alkylating agent under alkylation conditions with catalyst comprising a molecular sieve having an X-ray diffraction pattern including d-spacing maxima at 12.4±0.25, 6.9+0.15, 3.57+0.07 and 3.42+0.07 Angstrom to produce an ailcylation effluent comprising sec-butylbenzene, (b) oxidizing the sec-butylbenzene from (a) to produce a hydroperoxide; and (c) cleaving the hydroperoxide from (b) to produce phenol and methyl ethyl ketone.
Full Text A PROCESS OF USING A HIGH ACTIVITY CATALYST FOR THE TRANSALKYLATION OF AROMATICS
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a process for the transalkylation of
aromatics, particularly the transalkylation of polyisopropylbenzene(PIPB) with benzene to produce cumene and the transalkylation of polyethylbenzene(PEB) with benzene to produce ethylbenzene. Ethylbenzene is a valuable commodity chemical and is used in the production of styrene monomer. Cumene (isopropylbenzene) is also a valuable commodity chemical and is used in the production of phenol and acetone.
[0002] Presently, ethylbenzene is often produced by a liquid phase
alkylation process from benzene and ethylene in the presence of an alkylation catalyst. The liquid phase process operates at a lower temperature than its vapor phase counterpart. One advantage of the liquid phase alkylation is a lower yield of undesired by-products, polyalkylated aromatic compound(s). The alkylation of aromatic hydrocarbon compounds employing zeolite catalysts is known and, understood in the art. U.S. Patent 5,334,795 describes the liquid phase alkylation of benzene with ethylene in the presence of MCM-22 to produce ethylbenzene; and U.S. Patent 4,891,458 discloses liquid phase alkylation and transalkylation processes using zeolite beta.
[0003] Zeolite-based catalysts are used in the alkylation of benzene with
propylene to produce cumene. U.S. Patent 4,992,606 discloses a process for preparing cumene using MCM-22 in liquid phase.
[0004] Commercial alkylation processes for the production of
ethylbenzene and cumene typically produce certain polyalkylated by-products in addition to ethylbenzene and cumene. The polyalkylated aromatic compound(s) may be transalkylated with benzene or other alkylatable aromatic compound(s) to produce ethylbenzene or cumene. This transalkylation reaction may be accomplished by feeding the polyalkylated aromatic compound(s) through a transalkylation reactor operated under suitable conditions and in the presence of a
transalkylation catalyst. Also, the polyalkylated aromatic compound(s) may be recycled to an alkylation reactor in the presence of an alkylation catalyst that is capable of performing the transalkylation reaction. The polyalkylated aromatic compound(s) typically include bi-alkylated benzenes (e.g., bi-ethylbenzene(s) or bi-isopropylbenzenes) and tri-alkylated benzene(s) (e.g., tri-ethylbenzenes or tri-isopropylbenzenes). Commercial transalkylation catalysts typically have bi-alkylated benzenes conversion of about 50 wt.% to 90 wt.%, but low tri-alkylated benzenes conversion (e.g., less than 20 wt.%) under the same conditions. U.S. Patent No. 5,557,024 discloses a process for preparing short chain alkyl aromatic compounds using MCM-56 and the use of zeolite catalysts such as MCM-22, zeolite X, zeolite Y and zeolite beta for the transalkylation of the polyalkylated aromatic compound(s).
[0005] However, none of these references contemplate a transalkylation
process with a transalkylation catalyst which is maintained under conditions sufficient to yield a ratio of bi-alkylated aromatic compound(s) conversion over tri-alkylated aromatic compound(s) conversion in a range of from about 0.5 to about 2.5 at a temperature less than 300°C.
SUMMARY OF THE INVENTION
[0006] In one embodiment, this invention relates to a process for
producing an alkylated aromatic compound from polyalkylated aromatic compound(s) having bi-alkylated aromatic compound(s) and tri-alkylated aromatic compound(s), comprising the step of contacting alkylatable aromatic compound(s) with the polyalkylated aromatic compound(s) at a transalkylation condition in the presence of a transalkylation catalyst, wherein the transalkylation catalyst is maintained under conditions sufficient to yield a ratio of bi-alkylated aromatic compound(s) conversion over tri-alkylated aromatic compound(s) conversion in a range of from about 0.5 to about 2.5, preferably, about 0.5 to about 1.5, even more preferably, about 0.5 to about 1, still more preferably about 0.75 to about 1.25, and most preferably, about 0.9 to about 1.2. In another embodiment, the alkylated aromatic compound is cumene, wherein the ratio of bi-alkylated aromatic compound(s) conversion over tri-alkylated aromatic
compound(s) conversion in a range of from about 0.5 to about 1, preferably,
about 0.5 to 0.9, and most preferably, about 0.6 to about 0.9.
[0007] In another embodiment, this invention relates to a process for
producing an alkylated aromatic compound, comprising the steps of:
contacting an alkylatable aromatic compound with an alkylating agent under alkylation conditions in the presence of an alkylation catalyst, to produce an alkylation effluent having an alkylated aromatic compound and polyalkylated aromatic compound(s) including bi-alkylated aromatic compound(s) and tri-alkylated aromatic compound(s); and contacting the polyalkylated aromatic compound(s) with a feedstock having the alkylatable aromatic compound in the presence of a transalkylation catalyst to provide a transalkylation effluent which comprises 'additional alkylated aromatic compound, wherein the transalkylation catalyst is maintained under conditions sufficient to yield a ratio of a bi-alkylated aromatic compound(s) conversion over a tri-alkylated aromatic compound(s) conversion in a range of from about 0.5 to about 2.5.
[0008] In one aspect of any of the above embodiments, the transalkylation
catalyst comprises at least one of MCM-22, MCM-36, MCM-49, MCM-56, zeolite beta, faujasite, mordenite, PSH-3, SSZ-25, ERB-1, ITQ-1, ITQ-2, zeolite Y, Ultrastable Y (USY), Dealuminized Y, rare earth exchanged Y (REY), ZSM-3, ZSM-4, ZSM-18, ZSM-20, and any combination thereof.
[0009] In a preferred embodiment of this invention, the transalkylation
catalyst is zeolite Y. In another preferred embodiment of this invention, the transalkylation is a zeolite having a zeolite type of FAU.
[0010] In one embodiment, the alkylated compound is cumene, the
alkylatable aromatic compound(s) includes benzene, and the polyalkylated compound(s) include polyisopropylbenzene(s). In another embodiment, the alkylated aromatic compound is ethylbenzene, the alkylatable aromatic compound(s) includes benzene, and the polyalkylated aromatic compound(s) includes polyethylbenzene(s).
[0011] In one aspect of any of above embodiment, the transalkylation
conditions include a temperature of 150 to 260°C and a pressure of 696 to 4137
kPa-a (101 to 600 psia), a WHSV based on the weight of the polyalkylated
aromatic compounds of about 0.5 to 100 hr-1, a mole ratio of the alkylatable
aromatic compound to the polyalkylated aromatic compounds of 1:1 to 10:1.
[0012] In another aspect of any of above embodiment, the bi-alkylated
aromatic compound(s) conversion is in the range of about 25 wt.% to about 95 wt.%. In yet another aspect of any of above embodiment, the bi-alkylated aromatic compound(s) conversion is in the range of about 45 wt% to about 75 wt.%.
[0013] In one aspect of any of the above embodiment, the alkylation
catalyst comprises at least one of MCM-22, MCM-36, MCM-49, MCM-56, and any combination thereof.
[0014] In one preferred embodiment, the alkylated aromatic compound is
ethylbenzene, the alkylatable aromatic compound comprises benzene, the
alkylating agent comprises at least 10 mol.% ethylene, the polyalkylated aromatic
compound(s) comprise polyethylbenzenes(s). In another preferred embodiment,
the alkylated aromatic compound is cumene, the alkylatable aromatic compound
comprises benzene, the alkylating agent comprises propylene, and the
polyalkylated aromatic compound(s) comprise polyisopropylbenzenes(s).
[0015] In one embodiment of this invention, the alkylating agent
comprises at least one of a concentrated alkene feedstock, a dilute alkene feedstock, or any combination thereof.
[0016] hi another embodiment, this invention relates to a method for
retrofitting an existing an ethylbenzene or cumene plant(s) to produce ethylbenzene or cumene.
[0017] In another embodiment, this invention relates to a method for
retrofitting an existing an ethylbenzene or cumene plant(s) having a heat integration between an alkylation reactor and a transalkylation reactor to produce ethylbenzene or cumene. In another embodiment, this invention relates to a method for retrofitting an existing an ethylbenzene or cumene plant(s) having a
de-coupled heat integration between an alkylation reactor and a transalkylation reactor to produce ethylbenzene or cumene.
[0018] In one embodiment, this invention relates to a method for selecting
an alkylation catalyst for a process have an alkylation step and a transalkylation step, the method comprising the steps of:
(a) selecting a transalkylation catalyst having at least one of zeolite having a
zeolite structure type of FAU, *BEA, MWW, MTW, and any combination
thereof, wherein the transalkylation is maintained under conditions
including temperature and pressure to ensure to yield a ratio of a bi-
alkylated aromatic compound(s) conversion over a tri-alkylated aromatic
compound(s) conversion in a range of from about 0.5 to about 2.5; and
(b) selecting an alkylation catalyst having at least one of MCM-22, MCM-36,
MCM-49, MCM-56, and any combination thereof, wherein the alkylation
catalyst is sufficiently active to maintain at least 90 mol.% alkene
conversion at a temperature range from about 50°C below the temperature
of step (a) to about 100°C above the temperature of step (a).
[0019] In yet another embodiment, this invention relates to a method for
selecting a transalkylation catalyst for a process have an alkylation step and a transalkylation step, the method comprising the steps of:
(a) selecting an alkylation catalyst having at least one of MCM-22, MCM-36,
MCM-49, MCM-56, and any combination thereof, wherein the alkylation
catalyst is maintained under conditions including temperature and pressure
to ensure at least 90 mol.% alkene conversion; and
(b) selecting a transalkylation catalyst having at least one of zeolite having a
zeolite structure type of FAU, *BEA, MWW, MTW, and any combination
thereof, wherein the transalkylation is sufficiently active to yield a ratio of
a bi-alkylated aromatic compound(s) conversion over a tri-alkylated
aromatic compound(s) conversion in a range of from about 0.5 to about 2.5
in a temperature range from about 100°C below the temperature of step (a)
to about 50°C above the temperature of step (a).
[0020] In one aspect of any above embodiments, the transalkylation
catalyst is maintained under conditions sufficient to yield a ratio of bi-alkylated
aromatic compound(s) rate-constant over tri-alkylated aromatic compound(s) rate-constant in a range of from about 0.5 to about 4.
DETAILED DESCRIPTION OF THE INVENTION
[0021] The present invention relates to a process of using that exhibits
unexpectedly higher relative catalytic activity as compared to conventional
transalkylation catalyst. The catalyst comprises at least one of MCM-22, MCM-
36, MCM-49, MCM-56, zeolite beta, faujasite, mordenite, PSH-3, SSZ-25, ERB-
1, ITQ-1, ITQ-2, zeolite Y, Ultrastable Y (USY), Dealuminized Y, rare earth
exchanged Y (KEY), ZSM-3, ZSM-4, ZSM-18, ZSM-20, and any combination
thereof. The transalkylation catalyst is maintained under conditions sufficient to
yield a ratio of bi-alkylated aromatic compound(s) conversion over tri-alkylated
aromatic compound(s) conversion in a range of from about 0.5 to about 2.5,
preferably, about 0.5 to about 1.5, even more preferably, about 0.5 to about 1, still
more preferably about 0.75 to about 1.25, and most preferably, about 0,9 to about
1.2. In another embodiment, the alkylated aromatic compound is cumene, wherein
the ratio of bi-alkylated aromatic compound(s) conversion over tri-alkylated
aromatic compound(s) conversion in a range of from about 0.5 to about 1,
preferably, about 0.5 to 0.9, and most preferably, about 0.6 to about 0.9.
[0022] A molecular sieve typically contains at least two elements selected
from the group consisting of Si, Al, P, Ge, Ga and Ti, most particularly selected
from Si, Al and Ti. Exemplary molecular sieves useful for transalkylation have
the structure types FAU, *BEA, MTW, MWW, and any combination thereof. See
"Atlas of Zeolite Structure Types", W.H. Meier, D.H. Olson, C.H. Baerlocher,
Elsevier, 4th Edition, 1996, the disclosure of which is incorporated herein by
reference. Particularly suitable molecular sieves include zeolite beta, zeolite Y,
MCM-22, and ZSM-12.
[0023] The invention also relates to a process for producing a
monoalkylated aromatic compound wherein an alkylation step, carried out under at least partial liquid phase conditions, an alkylatable compound is reacted with an alkylating agent, to produce a monoalkylated aromatic end product as well as a polyalkylated compound, which is separated and fed to a transalkylation process
step. In the transalkylation step, which is also preferably conducted under at least partial liquid phase conditions, the polyalkylated end product is contacted in a transalkylation reactor with an alkylatable aromatic compound in the presence of a transalkylation catalyst to produce a monoalkylated compound. The alkylation and the transalkylation catalysts comprise at least one of MCM-22, MCM-36, MCM-49, MCM-56, zeolite beta, faujasite, mordenite, PSH-3, SSZ-25, ERB-1, ITQ-1, ITQ-2, zeolite Y, Ultrastable Y (USY), Dealuminized Y, rare earth exchanged Y (REY), ZSM-3, ZSM-4, ZSM-18, ZSM-20, and any combination thereof.
[0024] The term "aromatic" when used in reference to the alkylatable
compounds which are useful herein is to be understood in accordance with its art-recognized scope which includes alkyl-substituted and unsubstituted mono- and polynuclear compounds. Compounds of an aromatic character that possess a heteroatom are also useful provided they do not act as catalyst poisons under the reaction conditions selected.
[0025] Substituted aromatic compounds that may be alkylated in
accordance with the present invention, such as alkylatable aromatic compounds, must possess at least one hydrogen atom directly bonded to the aromatic nucleus. The aromatic rings can be substituted with one or more alkyl, aryl, alkylaryl, alkoxy, aryloxy, cycloalkyl, halide, and/or other groups that do not interfere with the alkylation reaction.
[0026] Suitable aromatic hydrocarbons include benzene, naphthalene,
anthracene, naphthacene, perylene, coronene, and phenanthrene, with benzene being preferred.
[0027] Generally the alkyl groups which can be present as substituents on
the aromatic compound contain from 1 to about 22 carbon atoms and usually from
about 1 to 8 carbon atoms, and most usually from about 1 to 4 carbon atoms.
[0028] Suitable alkyl substituted aromatic compounds, such as alkylating
agents, include toluene, xylene, isopropylbenzene, normal propylbenzene (n-propylbenzene), alpha-methylnaphthalene, ethylbenzene, mesitylene, durene, cymenes, butylbenzene, pseudocumene, o-diethylbenzene, m-diethylbenzene, p-diethylbenzene, isoamyibenzene, isohexylbenzene, pentaethylbenzene,
pentamethylbenzene; 1,2,3,4-tetraethylbenzene; 1,2,3,5-tetramethylbenzene, 1,2,4-triethylbenzne; 1,2,3-trimethylbenzene, m-butyltoluene; p-butyltoluene; 3,5-diethyltoluene; o-ethyltoluene; p-ethyltoluene; m-propyltoluene; 4-ehtyl-m-xylene; dimethylnaphthalenes; ethylnaphthalene; 2,3-dimethylanthracene; 9-ethylanthracene; 2-methylanthracene; o-methylanthracene; 9,10-dimethylphenanthrene; and 3-methyl-phenathrene. Higher molecular weight alkylaromatic hydrocarbons can also be used as starting materials and include aromatic hydrocarbons such as are produced by the alkylation of aromatic hydrocarbons with olefin oligomers. Such products are frequently referred to in the art as alkylate and include hexylbenzene, nonylbenzene, dodecylbenzene, pentadecylbenzene, hexyltoluene, nonyltoluene, dodecyltoluene, pentadecytoluene, etc. Very often alkylate is obtained as a high boiling fraction in which the alky] group attached to the aromatic nucleus varies in size from about C6 to about C12.
[0029] Reformate containing substantial quantities of benzene, toluene
and/or xylene constitutes a particularly useful feed for the alkylation process of this invention.
[0030] The alkylating agents that may be useful in the process of this
invention generally include any aliphatic or aromatic organic compounds having one or more available alkylating aliphatic groups capable of reaction with the alkylatable aromatic compound.
[0031] Preferably, the alkylating agent employed herein has at least one
alkylating aliphatic group possessing from 1 to 5 carbon atoms. Examples of such
alkylating agents are olefins such as ethylene, propylene, the butenes, and the
pentenes; alcohols (inclusive of monoalcohols, dialcohols and trialcohols) such as
methanol, ethanol, the propanols, the butanols, and the pentanols; aldehydes such
as formaldehyde, acetadehyde, propionaldehyde, butyraldehyde, and n-
valeraldehyde; and alkyl halides such as methyl chloride, ethyl chloride, the
propyl chlorides, the butyl chlorides and the pentyl chlorides.
[0032] Mixtures of light olefins are especially useful as alkylating agents
in the alkylation process of this invention. A mixture of concentrate alkene stream having at least 80 mol.% alkene and a dilute alkene stream having about 10 mol.%
to 80 mil.% alkene may be used for this invention. Accordingly, mixtures of ethylene, propylene, butenes, and/or pentenes which are major constituents of a variety of refinery streams, e.g., fuel gas, gas plant off-gas containing ethylene, propylene, etc., naphtha cracker off-gas containing light olefins and refinery FCC propane/propylene streams, are useful are useful alkylating agents herein. For example, a typical FCC light olefin stream possesses the following composition:
Wt.% Mole %
Ethane 3.3 5.1
Ethylene 0.7 1.2
Propane 4.5 15.3
Propylene 42.5 46.8
Isobutane 12.9 10.3
n-Butane 3.3 2.6
Butenes 22.1 18.32
Pentanes 0.7 0.4
[0033] Reaction products which may be obtained from the process of the
invention include ethylbenzene from the reaction of benzene with ethylene, cumene from the reaction of benzene with propylene, ethyltoluene from the reaction of toluene with ethylene, cymenes from the reaction of toluene with propylene, and sec-butylbenzene from the reaction of benzene and n-butenes. Preferably, the process of the invention relates to the production of ethylbenzene by the alkylation of benzene with ethylene followed by the transalkylation of the diethylbenezene by-products with additional benzene; the production of cumene by the alkylation of benzene with propylene followed by the transalkylation of the diispropylbenzene by-products with additional benzene.
[0034] In one embodiment of the invention, the alkylation process of this
invention is conducted such that the organic reactants, i.e., the alkylatable aromatic compound and the alkylating agent, are brought into contact with an alkylation or transalkylation catalyst in a suitable alkylation or transalkylation reaction zone such as, for example, in a flow reactor containing a fixed bed of the
catalyst composition, under effective alkylation conditions. Such conditions
include a temperature of from about 0°C to about 500°C (32°F to 932°F), and
preferably between about 50°C and about 300°C (122°F to about 572°F), more
preferably, between about 100 to about 285°C (212 to 545°F), a pressure of 689 to
4601 kPa-a (100 to 667 psia), preferably, a pressure of 1500 to 3500 kPa-a (218 to
508 psia), a WHSV based on alkene for overall reactor of 0.1 to 10 hr-1,
preferably, 0.2 to 2 hr-1, more preferably, 0.5 to 1 hr-1, or a WHSV based on both
alkene and benzene for overall reactor of 10 to 100 hr-1, preferably, 20 to SOhr"1, a
molar ratio of alkylatable aromatic compound to alkylating agent of from about
0.1:1 to about 50:1, and preferably can be from about 0.5:1 to about 10:1.
[0035] The reactants can be in either the vapor phase or partially or
completely in the liquid phase and can be neat, i.e., free from intentional admixture or dilution with other material, or they can be brought into contact with the zeolite catalyst composition with the aid of carrier gases or diluents such as, for example, hydrogen and nitrogen.
[0036] In another embodiment of the invention, when benzene is alkylated
with ethylene to produce an alkylation reactor effluent that contains ethylbenzene.
The alkylation reaction is preferably carried out in the liquid phase under
conditions including a temperature between 300°F and 600°F (about 150°C to
316°C), more preferably between 400°F and 500°F (about 205°C and 260°C), a
pressure up to about 3000 psig (20865 kPa), more preferably between 400 and 800
psig (2869 and 5600 kPa), a weight hourly space velocity (WHSV) between about
0.1 and 20 hr-1, more preferably between 0.5 hr-1 and 6 hr-1, based on the ethylene
feed, and a ratio of the benzene to the ethylene in the alkylation reactor from 1:1
to 30:1 molar, more preferably from about 1:1 to 10:1 molar.
[0037] In still another embodiment of the invention, when benzene is
alkylated with propylene to produce an alkylation reactor effluent that contains
cumene. The alkylation reaction may also take place under liquid phase
conditions including a temperature of up to about 482°F (250°C), e.g., up to about
302°F (150°C), e.g., from about 50°F to about 257°F (10°C to 125°C); a pressure
of about 250 atmospheres (25,000 kPa) or less, e.g., from about 1 to about 30
atmospheres (100 kPa - 3000 kPa); and an aromatic hydrocarbon weight hourly
space velocity 5 hr-1 to about 250 hr-1, preferably from 5 hr-1 to 50 hr-1.
[0038] The alkylation or transalkylation catalyst that may be useful in this
invention is a crystalline molecular sieve preferably selected from MCM-22 (described in detail in U.S. Patent No. 4,954,325), MCM-36 (described in detail in U.S. Patent 5,250,277), MCM-49 (described in detail in U.S. Patent 5,236,575), MCM-56 (described in U.S. Patent 5,362,697), and zeolite beta (described in detail in U.S. Patent 3,308,069).
[0039] One embodiment of this invention is a method of selecting a
transalkylation catalyst based on the selection of the alkylation catalyst or verse visa. By selecting one catalyst of these two interrelated reactions (alkylation and transalkylation), the preferred reaction conditions and corresponding product composition are determined. Based on the selection of one of these two reactions, the selection of the catalyst for another reaction can be determined based on the results to be achieved.
[0040] In one embodiment, this invention relates to a method for selecting
an alkylation catalyst for a process have an alkylation step and a transalkylation step, the method comprising the steps of:
(a) selecting a transalkylation catalyst having at least one of zeolite having a
zeolite structure type of FAU, *BEA, MWW, MTW, and any combination
thereof, wherein the transalkylation is maintained under conditions
including temperature and pressure to ensure to yield a ratio of a bi-
alkylated aromatic compound(s) conversion over a tri-alkylated aromatic
compound(s) conversion in a range of from about 0.5 to about 2.5; and
(b) selecting an alkylation catalyst having at least one of MCM-22, MCM-36,
MCM-49, MCM-56, and any combination thereof, wherein the alkylation
catalyst is sufficiently active to maintain at least 90 mol.%, preferably 95
mol.%, even more preferably, 99 mol.%, alkene conversion at a
temperature range from about 50°C below the temperature of step (a) to
about 100°C above the temperature of step (a).
[0041] In yet another embodiment, this invention relates to a method for
selecting a transalkylation catalyst for a process have an alkylation step and a transalkylation step, the method comprising the steps of:
(a) selecting an alkylation catalyst having at least one of MCM-22, MCM-36,
MCM-49, MCM-56, and any combination thereof, wherein the alkylation
catalyst is maintained under conditions including temperature and pressure
to ensure at least 90 mol.%, preferably 95 mol.%, even more preferably,
99 mol.%, alkene conversion; and
(b) selecting a transalkylation catalyst having at least one of zeolite having a
zeolite structure type of FAU, *BEA, MWW, MTW, and any combination
thereof, wherein the transalkylation is sufficiently active to yield a ratio of a bi-
alkylated aromatic compound(s) conversion over a tri-alkylated aromatic
compound(s) conversion in a range of from about 0.5 to about 2.5 in a temperature
range from about 100°C below the temperature of step (a) to about 50°C above the
temperature of step (a).
[0042] The alkylation reactor effluent contains the excess aromatic feed,
monoalkylated aromatic compounds (such as ethylbenzene or cumene),
polyalkylated aromatic compounds (such as polyethylbenzene or
polyisopropylbenzene), and various impurities. The aromatic feed is recovered by
distillation and recycled to the alkylation reactor. Usually a small bleed is taken
from the recycle stream to eliminate unreactive impurities from the loop. The
bottoms from the benzene distillation are further distilled to separate
monoalkylated product from polyalkylated products and other heavies.
[0043] The term "polyethylbenzene" (PEB) in reference to the
polyalkylated aromatic compounds which are useful herein is to be understood in
accordance with its art-recognized scope which includes, by way of illustration
and not limitation, diethylbenzene (DEB) and triethylbenzene (TEB).
[0044] The term "polyisopropylbenzene" (PIPB) in reference to
polyalkylated aromatic compounds which are useful herein is to be understood in accordance with its art-recognized scope which includes, by way of illustration and not limitation, diisopropylbenzene (DIPB) and triisopropylbenzene (TIPB).
[0045] The polyalkylated products separated from the alkylation reactor
effluent are reacted with alkylatable aromatic feed in a transalkylation reactor, which may or may not be separated from the alkylation reactor, over a suitable transalkylation catalyst. According to the invention, the transalkylation catalyst comprises at least one of MCM-22, MCM-36, MCM-49, MCM-56, zeolite beta, faujasite, mordenite, PSH-3, SSZ-25, ERB-1, ITQ-1, ITQ-2, zeolite Y, Ultrastable Y (USY), Dealuminized Y, rare earth exchanged Y (KEY), ZSM-3, ZSM-4, ZSM-18, ZSM-20, and any combination thereof.
[0046] The transalkylation reaction of the invention is conducted under at
least partial liquid phase conditions such that the polyalkylated aromatics react with additional alkylatable aromatic compounds to produce additional monoalkylated product. Suitable transalkylation conditions include a temperature of 100°C to 260°C (212°F to 500°F), a pressure of 696 to 5100 kPa-a (101-740 psia), a WHSV based on the weight of the polyalkylated aromatic compounds of about 0.5 to 200 hr-1, and alkylatable aromatic compounds /polyalkylated benzene weight ratio 0.5:1 to 20:1. Preferably, a temperature of 150 to 260°C and a pressure of 696 to 4137 kPa-a (101 to 600 psia), a WHSV based on the weight of the polyalkylated aromatic compounds of about 0.5 to 100 hr-1, a mole ratio of the alkylatable aromatic compound to the polyalkylated aromatic compounds of 1:1 to 10:1
[0047] In one embodiment of this invention, there is a heat integration
between the alkylation reactor and the transalkylation reactor. For example, the effluent from the alkylation reactor may be used to heat the feed stream of the transalkylation reactor. The effluent from the alkylation reactor may be used to generate steam. In another embodiment of this invention, the heat integration between the alkylation reactor and the transalkylation reactor can be de-coupled. The advantage of de-coupling the heat integration between the alkylation reactor and the transalkylation reactor is that the conditions of the alkylation reactor can be independent determined to the conditions of the transalkylation reactor. Therefore, it is possible to achieve optimum results of these two reactions independently.
[0048] Reaction rate-constants were calculated using methods known to
those skilled in the art. See "Principles and Practice of Heterogeneous Catalyst", J.M. Thomas, W.J. Thomas, VCH, 1st Edition, 1997, the disclosure of which is incorporated herein by reference. Reaction rate constants were calculated for both DEB and TEB under reaction conditions (temperature, pressure, and WHSV) and the ratio of these reaction rate constants was then calculated to examine the relative rates of DEB and TEB conversion. The reactions were assumed to be first order with respect to DEB and TEB and zero order with respect to benzene since it is in excess.
[0049] In another embodiment of this invention, the process of this
invention can be used to retrofit existing ethylbenzene or cumene plant. In yet another embodiment of this invention, the process of this invention can be used to retrofit existing AlCl3 or BF3 plant. The retrofitting can be done by replacing existing processes and catalysts with the processes and catalysts of this invention. The advantage of retrofitting existing plants is low cost.
[0050] In one embodiment of this invention, the transalkylation catalyst is
maintained under conditions sufficient to yield a ratio of bi-alkylated aromatic compound(s) rate-constant over tri-alkylated aromatic compound(s) rate-constant in a range of from about 0.5 to about 4, preferably, about 0.5 to 1.5, even more preferably, about 0.5 to about 1, still more preferably about 0.75 to about 1,25, and most preferably, about 0.9 to about 1.2. In another embodiment, the alkylated aromatic compound is cumene, wherein the ratio of bi-alkylated aromatic compound(s) conversion over tri-alkylated aromatic compound(s) conversion in a range of from about 0.5 to about 1, preferably, about 0.5 to 0.9, and most preferably, about 0.6 to about 0.9.
[0051] When the polyalkylated aromatics are polyisopropylbenzenes and
are contacted with benzene to produce cumene in a transalkylation reactor, the transalkylation conditions preferably include a temperature 50°F to about 100°F (100°C to 200°C), a pressure of 20 to 30 barg (2100-3100 kPa), weight hourly space velocity of 10 to 72 hr-1 on total feed and benzene/PIPB weight ratio 1:1 to 6:1.[0052] When the polyalkylated aromatics are polyethylbenzenes and are
contacted with benzene to produce ethylbenzene in a transalkylation reactor, the transalkylation conditions preferably include a temperature of 428oF to about 500oF (220 to 260°C), a pressure of 20 to 30 barg (2100 - 3100 kPa-a), weight hourly space velocity of 2 to 6 hr-1 on total feed and benzene/PEB weight ratio 2:1
to 6:1.
[0053] The effluent from the transalkylation reactor is blended with
alkylation reactor effluent and the combined stream distilled to separate the
desired monoalkylated product
[0054] The present invention will be described in the following examples.
Example : Transalkylation of PEB to EB
[0055] The transalkylation feed used in Example was prepared as follows. Chemical
grade benzene and para- and meta-diethylbenzene were purified by percolation over activated alumina. The purified diethylbenzene were mixed 2:1 by weight (parameta). The purified benzene and polyethylbenzenes were mixed 2:1 weight ratio and stored under nitrogen. A gas chromatograph (GC) analysis of the feed provided the composition by weight shown in Table 1.
[0056] Two catalysts were tested for transalkylation reaction, a
conventional commercial transalkylation catalyst (low activity catalyst) is made using a zeolite with a structure type of MOR, a Si/Al2 of about 35, a surface area of about 390 m2/g, and extruded to form 1/16" diameter cylindrical extrudates with 20 wt,% alumina. A high activity transalkylation catalyst is made with a zeolite with a structure type of FAU, a Si/Al2 ratio of about 30, a surface area of about 780 m2/g and extruded to form 1/16" diameter cylindrical extrudates with 20 wt% alumina.
[0057] Liquid feed, which has a composition as shown in table 1, was
introduced with calibrated diaphragm pump. A 12.7 mm (1/2') pipe was used for the reaction vessels and contained 30-35g of catalyst operated in a downflow configuration in isothermal mode. The operating pressure for all experiments was 3204 KPa-a (465 psk). Temperature, Weight Hourly Space Velocity (WHSV) and Benzene:Polyethylbenzene (B:PEB) ratio are indicated in the table along with the
corresponding Diethylbenzene (DEB) and triethylbenzene (TEB) conversion and their corresponding first order rate constants (k). The total product was chilled and analyzed with an off-line gas chromatograph equipped with a flame ionization detector. Results are shown in Table 2.
Table 1:

(Table Removed)
Table 2:

(Table Removed)
[0058] The high activity transalkylation catalyst of this invention has a
surprisingly low ratio of DEB conversion over TEB conversion which is in the
range of 0.9 to 1.18, in comparison with conventional transalkylation catalyst
having a ratio of DEB conversion over TEB conversion of 3.
[0059] The high activity transalkylation catalyst of this invention has a
surprisingly low ratio of DEB rate-constant over TEB rate-constant which is in the
range of 0.875 to 1.2, in comparison with conventional transalkylation catalyst
having a ratio of DEB rate-constant over TEB rate-constant of 4.5.
[0060] All patents, patent applications, test procedures, priority
documents, articles, publications, manuals, and other documents cited herein are fully incorporated by reference to the extent such disclosure is not inconsistent with this invention and for all jurisdictions in which such incorporation is permitted.
[0061] When numerical lower limits and numerical upper limits are listed
herein, ranges from any lower limit to any upper limit are contemplated.
[0062] While the illustrative embodiments of the invention have been
described with particularity, it will be understood that various other modifications will be apparent to and can be readily made by those skilled in the art without departing from the spirit and scope of the invention. Accordingly, it is not intended that the scope of the claims appended hereto be limited to the examples and descriptions set forth herein but rather that the claims be construed as encompassing all the features of patentable novelty which reside in the present invention, including all features which would be treated as equivalents thereof by those skilled in the art to which the invention pertains.






We Claim
1. A process for producing ethylbenzene or cumene comprising the step of contacting alkylatable aromatic compound(s) which comprises benzene, with a polyalkylated aromatic compound(s) which comprises bi-alkylated aromatic compound(s) and tri-alkylated aromatic compound(s), said bi-alkylated aromatic compound(s) selected from the group consisting of diethylbenzene and diisopropylbenzene, said trialkylated compound(s) selected from the group consisting of triethylbenzene and triisopropylbenzene, at transalkylation conditions, said transalkylation conditions comprises a temperature of 150 to 260°C and a pressure of 696 to 4137 kPa-a (101 to 600 psia), a WHSV based on the weight of said polyalkylated aromatic compounds of 0.5 to 100 hr-1, a mole ratio of said alkylatable aromatic compound to said polyalkylated aromatic compounds of 1:1 to 10:1, in the presence of a transalkylation catalyst, said transalkyltion catalyst comprises at least one of MCM-22, MCM-36 MCM-49 MCM-56 zeolite beta faujasite, mordenite, PSH-3, SSZ-25, ERB-1, ITQ-1, ITQ-2, zeolite beta, Ultrastable Y (USY), Dealuminized Y, rare earth exchanged Y (REY), ZSM-3, ZSM 4, ZSM-18, ZSM-20, and any combination thereof, to produce a transalkylation effluent comprising said ethylbenzene or cumene, wherein the ratio of diethylbenzene conversion over triethylbenzene conversion is in a range of from 0.5 to 2.5 or the ratio of diisopropylbenzene conversion over triisopropylbenzene conversion is in a range of from 0.5 to 1.0
2. The process as claimed in claim 1, wherein said transalkylation catalyst has a zeolite type of FAU.
3. The process as claimed in claim 2, wherein said transalkylation catalyst is zeolite Y.
4. The process as claimed in any preceding claim, wherein the conversion of diethylbenzene or diisopropylbenzene is in the range of 25 wt.% to 95 wt.%.
5. The process as claimed in any preceding claim, wherein the conversion of diethylbenzene or diisopropylbenzene is in the range of 45 wt.% to 75 wt.%.

6. The process as claimed in any preceding claim, optionally comprising the step of contacting said alkylatable aromatic compound with an alkylating agent under alkylation conditions and in the presence of an alkylation catalyst, to produce an alkylation effluent which comprises said polyalkylated aromatic compound(s).
7. The process as claimed in claim 6, optionally comprising the step of separating said alkylation effluent to recover said polyalkylated aromatic compound(s).
8. The process as claimed in any one of claims 1 or 6, optionally comprising the step of separating said alkylation effluent or said transalkylation effluent, to recover said alkylated aromatic compound.
9. The process as claimed in any one of claims 6 to 8, wherein said alkylating agent comprises ethylene or propylene feedstock.
10. The process as claimed in claim 9, wherein said alkylating agent comprises at least one of a concentrated ethylene or propylene feedstock, a dilute ethylene or propylene feedstock of at least 10 mol.% ethylene or propylene, or any combination thereof.

Documents:

6751-DELNP-2007-Abstract-(13-03-2012).pdf

6751-DELNP-2007-Abstract-(29-11-2011).pdf

6751-delnp-2007-abstract.pdf

6751-DELNP-2007-Assignment.pdf

6751-DELNP-2007-Claims-(13-03-2012).pdf

6751-DELNP-2007-Claims-(29-11-2011).pdf

6751-delnp-2007-claims.pdf

6751-delnp-2007-Correspodence Others-(03-01-2012).pdf

6751-DELNP-2007-Correspondence Others-(13-03-2012).pdf

6751-DELNP-2007-Correspondence Others-(29-11-2011).pdf

6751-DELNP-2007-Correspondence-Others-(05-07-2010).pdf

6751-delnp-2007-correspondence-others-1.pdf

6751-DELNP-2007-Correspondence-Others.pdf

6751-DELNP-2007-Description (Complete)-(05-07-2010).pdf

6751-delnp-2007-description (complete).pdf

6751-DELNP-2007-Form-1-(13-03-2012).pdf

6751-DELNP-2007-Form-1-(29-11-2011).pdf

6751-delnp-2007-form-1.pdf

6751-delnp-2007-form-18.pdf

6751-DELNP-2007-Form-2-(13-03-2012).pdf

6751-DELNP-2007-Form-2-(29-11-2011).pdf

6751-delnp-2007-form-2.pdf

6751-delnp-2007-Form-3-(03-01-2012).pdf

6751-DELNP-2007-Form-3-(13-03-2012).pdf

6751-DELNP-2007-Form-3-(29-11-2011).pdf

6751-delnp-2007-form-3.pdf

6751-DELNP-2007-Form-5-(29-11-2011).pdf

6751-delnp-2007-form-5.pdf

6751-DELNP-2007-GPA-(29-11-2011).pdf

6751-DELNP-2007-GPA.pdf

6751-delnp-2007-pct-101.pdf

6751-delnp-2007-pct-210.pdf

6751-delnp-2007-pct-220.pdf

6751-delnp-2007-pct-237.pdf

6751-delnp-2007-pct-304.pdf

6751-delnp-2007-pct-401.pdf

6751-delnp-2007-pct-409.pdf

6751-delnp-2007-pct-416.pdf

6751-DELNP-2007-Petition-137-(29-11-2011).pdf


Patent Number 251879
Indian Patent Application Number 6751/DELNP/2007
PG Journal Number 16/2012
Publication Date 20-Apr-2012
Grant Date 13-Apr-2012
Date of Filing 31-Aug-2007
Name of Patentee EXXONMOBIL CHEMICAL PATENTS INC,
Applicant Address 5200 BAYWAY DRIVE, BAYTOWN, TEXAS 77520-5200, USA
Inventors:
# Inventor's Name Inventor's Address
1 BRIAN MAERZ 48 RUTHELLEN ROAD, CHELMSFORD, MASSACHUSETTS 01824,USA
2 MICHAEL C. CLARK 25988 TALAMORE DRIVE, CHANTILLY, VIRGINIA 20152,USA
3 CARLOS N. LOPEZ 2521 COLVIN ROAD, AMISSVILLE, VIRGINIA 20106, USA
4 CHUNG-MING CHI 65 DONNA ROAD, NEEDHAM, MASSACHUSETTS 02494, USA
5 VIJAY NANDA 15518 WOODEN OAK COURT, HOUSTON, TEAS 77059, USA
PCT International Classification Number C07C 6/12
PCT International Application Number PCT/US2006/006539
PCT International Filing date 2006-02-24
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 60/666,974 2005-03-31 U.S.A.