Improved alkylaromatic production process

(54) Title: PROCESS TO PREPARE A MONOALKYLATED AROMATIC COMPOUND IN

A REACTION ZONE (51) Int.CI .: C10G 50/00; C07C 2/66 (30) Unionist Priority: 02/09/2007 US 60 / 900,638 (73) Holder (s): EXXONMOBIL CHEMICAL PATENTS INC.

(72) Inventor (s): MICHAEL C. CLARK; CHRISTINE N. ELIA; FREDERICK Y. LO; MATTHEW J. VINCENT

DESCRIPTION REPORT OF THE INVENTION PATENT FOR PROCESS

TO PREPARE A MONOALKYLATED AROMATIC COMPOUND IN

A REACTION AREA.

BACKGROUND OF THE INVENTION

The present invention relates to a process mechanism for producing alkylaromatics, especially monoalkylaromatic compounds, for example ethylbenzene, cumene and sec-butylbenzene.

The alkylaromatic compounds ethylbenzene and cumene, for example, are valuable chemicals on the market that are used industrially for the production of styrene monomer and co-production of phenol and acetone respectively. In fact, a common pathway for the production of phenol comprises a process that involves alkylation of benzene with propylene to produce cumene, followed by oxidation of the cumene to the corresponding hydroperoxide, and then dividing the hydroperoxide to produce equal molar amounts of phenol and acetone. Ethylbenzene can be produced by a number of different chemical processes. A process that has achieved a significant degree of commercial success is vapor-phase alkylation of benzene with ethylene in the presence of a solid acidic ZSM-5 zeolite catalyst. Examples of such ethylbenzene production processes are described in US Patent Nos. 3,751,504 (Keown), 4,547,605 (Kresge) and 4,016,218 (Haag).

Another process that has achieved significant commercial success is the liquid phase process to produce ethyl benzene from benzene and ethylene since it operates at a lower temperature than the vapor phase counterpart and thus tends to result in lower by-product yields. For example, US Patent No. 4,891,458 (Innes) describes the liquid-phase synthesis of ethylbenzene with Beta zeolite, while US Patent No. 5,334,795 (Chu) describes the use of MCM-22 in the liquid phase synthesis of ethylbenzene,

Cumene has been commercially produced for many years by liquid alkylation of benzene with propylene over a Friedel-Crafts catalyst, particularly phosphoric acid or solid aluminum chloride. More recently, however, zeolite-based catalyst systems have been found to be more active and selective for the propylation of benzene into cumene. For example, US Patent No. 4,992,606 (Kushnerick) describes the use of MCM-22 in liquid alkylation of benzene with propylene.

Typically, zeolite catalysts employed in hydrocarbon conversion processes, such as aromatics alkylation, are in the form of cylindrical extrudates. However, it is known from, for example, US Patent No. 3,966,644 (Gustafson), that shaped catalyst particles having a high surface to volume ratio, such as those having a polylobal cross section, can produce improved results in processes that are limited in diffusion, such as residue hydrogenation .

In addition, it is known from US Patent No. 4,441,990 (Huang) that a particle of polylobal catalyst having a centrally located non-cylindrical opening can reduce the diffusion path for reagents and the pressure drop across beds of filled catalyst while minimizing catalyst loss due to breakage, abrasion and crushing. In particular, Example 8 of the '990 patent describes that hollow trilobed and quadrilobed ZMS-5 catalysts are more active and selective for benzene ethylation at 410 ° C and pressure of 2169 kPa-a (absolute pascal kilo) than solid cylindrical catalysts the same length. Under these conditions, the reagents are necessarily in the vapor phase.

Common commercial catalysts used most often for these process mechanisms are 0.159 cm cylindrical extruders or 0.127 cm squares. The anterior extrudates are approximately 1550 to 1600 microns in size, and the posterior ones are approximately 1250 to 1300 microns in size.

Existing alkylation processes to produce alkylaromatic compounds, for example ethylbenzene and cumene, inherently produce polyalkylated species as well as the desired monoalkylated product. It is therefore normal to transalkylate the polyalkylated species with additional aromatic feed, for example benzene, to produce additional monoalkylated product, for example ethylbenzene or cumene, either by recycling the polyalkylated species to the alkylation reactor or, more often, by feeding the polyalkylated species to a reactor. separate transalkylation process. Examples of catalysts have been used in the alkylation of aromatic species, such as alkylation of benzene with ethylene or propylene, and in the transalkylation of polyalkylated species, such as polyethylbenzenes and polyisopropylbenzenes, and are listed in US Patent No. 5,557,024 (Cheng) and include MCM-49, MCM-22, PSH-3, SSZ-25, zeolite X, zeolite Y, Beta zeolite, acid-free mordenite and TEA-mordenite. Transalkylation on a small crystal form (<0.5 micron) of TEA-mordenite is also described in US Patent 6,984,764 (Roth et al.).

Where the alkylation step is carried out in the liquid phase, it is also desirable to conduct the transalkylation step under liquid phase conditions. However, operating at relatively low temperatures, liquid phase processes impose increased requirements on the catalyst, particularly in the transalkylation step where bulky polyalkylated species must be converted to additional monoalkylated product without producing unwanted by-products. This proved to be a significant problem in the case of cumene production where existing catalysts either did not show the desired activity or resulted in the production of significant amounts of by-products such as ethylbenzene and n-propylbenzene.

US Patent No. 6,888,037 (Dandekar et al) describes a process for producing cumene comprising the step of contacting benzene and propylene under conditions at least partial liquid phase alkylating with a particulate molecular sieve alkylation catalyst, wherein the particles of said alkylation catalyst have a surface area to volume ratio of about 203.20 cm less than 508.00 cm '¹. According to US Patent No. 6,888,037, benzene liquid propylation, unlike benzene liquid ethylation, is sensitive to intraparticle (macroporous) diffusion limitations. In particular, by selecting the particle shape and size of the alkylation catalyst such that the surface-to-volume ratio is within the specified range, the intraparticle diffusion distance can be decreased without excessively increasing the pressure drop across the first bed of catalyst. As a result, the activity of the catalyst for the propylation of benzene can be increased, while at the same time the selectivity of the catalyst for unwanted polyalkylated species, such as diisopropylbenzene (DlPB), can be reduced.

US Patent Application Serial Number 60 / 808,192 describes a process for producing a monoalkylated aromatic compound in an alkylation reaction zone, said process comprising the steps of (1) providing said alkylation reaction zone with an alkylatable aromatic compound, an alkylating agent , and a catalytic particulate material; and (2) contacting said alkylatable aromatic compound and said alkylating agent with said catalytic particulate material in said alkylation reaction zone maintained under alkylation conditions, to form a product comprised of said monoalkylated aromatic compound and aromatic compound (s) polyalkylated (s), where most of said catalytic particulate material has a surface area to volume ratio greater than about 79 cm¹.

In accordance with the present description, it was unexpectedly found that the reaction of the present description conducted in the presence of a specific catalyst manufactured from the extrudate to comprise particulate catalytic material within the narrow range of about 125 microns to about 790 microns in size and having an effectiveness factor, defined below, increased from about 25% to about 750% of that of the original extrudate, yields a unique combination of activity and selectivity while not subjecting the process to an unacceptable pressure drop across the catalyst bed. This is especially the case when the process involves liquid phase alkylation for the manufacture of monoalkylated product, particularly for liquid phase alkylation from benzene to ethylbenzene or cumene. This avoids the demand in many cases for the difficult transalkylation reaction for the conversion of unwanted bulky polyalkylated species in such a process.

SUMMARY OF THE INVENTION

According to the present description, an improved process is provided to selectively produce a desired monoalkylated aromatic compound comprising the step of contacting an alkylatable aromatic compound in an reaction zone with an alkylating agent in the presence of catalyst comprising a porous crystalline material under conditions at least partial liquid phase, the catalyst manufactured from the extrudate to comprise catalytic particulate material of about 125 microns to about 790 microns in size and having an effectiveness factor, defined below, increased from about 25% to about 750% of that of the original extrudate . One aspect of the present description is an improved alkylation process for the selective production of monoalkyl benzene in a reaction zone comprising the step of reacting benzene with an alkylating agent under sufficient alkylation conditions to cause alkylation in the presence of an alkylation catalyst comprising a material porous crystalline, the catalyst manufactured from the extrudate to comprise catalytic particulate material of about 125 microns to about 790 microns in size and having an effectiveness factor, defined below, increased from about 25% to about 750% of that of the original extrudate . The catalyst for use in the present process can comprise, for example, a material from the MCM-22 family, a crystalline molecular sieve having the Beta zeolite structure, or a sieve having an x-ray diffraction pattern including d-spacing maximums at 12.4 ± 0.25, 6.9 ± 0.15, 3.57 ± 0.07 and 3.42 ± 0.07 Angstroms, the catalyst manufactured from the extrudate to comprise catalytic particulate material of about 125 microns to about 790 microns in size and having an effectiveness factor, defined below, increased from about 25% to about 750% of that of the original extrudate . More particularly, the catalyst for use here can comprise a crystalline molecular sieve having the Beta structure, a material of the MOM-22 family, for example MCM-22, or a mixture thereof.

The catalyst for use in the present description preferably comprises a material of the MCM-22 family, such as for example a crystalline silicate having the structure of MCM-22, PSH-3, SSZ-25, ERB-1, ITQ-1,

ITQ-2, ITQ-30, MCM-36, MCM-49, MCM-56 and mixtures thereof.

DETAILED DESCRIPTION OF THE INVENTION

All patents, patent applications, testing procedures, priority documents, articles, publications, manuals, and other documents cited here are fully incorporated by reference to the extent that such description is not inconsistent with this description and for all jurisdictions in that such incorporation is permitted.

When lower numerical limits and upper numerical limits are listed here, ranges from any lower limit to any upper limit are considered.

As used in this report, the term structure type is used in the sense described in Atlas of Zeolite Framework Type, 2001.

As used here, the numbering scheme for the Periodic Table Groups is used as in Chemical and Engineering News, 63 (5), 27 (1985).

The term material from the MCM-22 family (or material from the MCM-22 family or molecular sieve from the MCM-22 family), as used here, includes:

molecular sieves made from a common first-grade crystalline building block of a unit cell having the MWW structure topology. A unit cell is a spatial arrangement of atoms that is covered in three-dimensional space to describe the crystal as described in the Atlas of Zeolite Framework Types, 5a. edition, 2001, whose complete content is incorporated as a reference;

molecular sieves made from a common second-degree building block, a two-dimensional coverage of such unit cells of type MWW structure, forming a monolayer of a unit cell thickness, preferably a unit cell thickness c;

molecular sieves made from common second-degree building blocks, layers of one or more unit cell thicknesses, where the layer of more than one unit cell thickness is made from stacking, filling, or bonding of at least two monolayers of a thick unit cell of unit cells having the MWW structure topology. The stacking of such second-degree building blocks can be in a regular shape, an irregular shape, a random shape, and any combination thereof; or molecular sieves made by any regular or random two-dimensional or three-dimensional combination of unit cells having the MWW structure topology.

The MCM-22 family materials are characterized by having an x-ray diffraction pattern including d-spacing maximums at 12.4 ± 0.25, 3.57 ± 0.07 and 3.42 ± 0.07 Angstroms (calcined or as synthesized). The materials of the MCM-22 family can also be characterized by having an x-ray diffraction pattern including d-spacing maximums at 12.4 ± 0.25, 6.9 ± 0.15, 3.57 ± 0, 07 and 3.42 ± 0.07 Angstroms (calcined or as j

synthesized). The x-ray diffraction data used to characterize the molecular sieve is obtained by standard techniques using the copper K-alpha pair as the incident radiation and a diffractometer equipped with a scintillation counter and associated computer as the collection system. Materials belonging to the MCM-22 family include MCM-22 (described in US Patent No. 4,954,325), PSH-3 (described in US Patent No. 4,439,409), SSZ-25 (described in US Patent No. 4,826,667), ERB-1 (described in European Patent No. 0293032), ITQ-1 (described in US Patent No. 6,077,498), ITQ-2 (described in International Patent Publication No. WO97 / 17290 ), ITQ-30 (described in International Patent Publication No. W02005118476), MCM-36 (described in US Patent No. 5,250,277), MCM-49 (described in US Patent No. 5,236,575), MCM-56 (described in US Patent No. 5,362,697), and UZM-8 (described in US Patent No. 6,756,030). The complete contents of the patents are hereby incorporated by reference.

It should be noted that the molecular sieves of the MCM-22 family described above are distinguished from conventional large pore zeolite alkylation catalysts, such as mordenite, in which the MCM-22 family materials have 12 ring surface pockets members that do not communicate with the 10-member molecular sieve inner pore system.

The zeolitic materials designated by IZA-SC as being of MWW topology are multilayer materials that have two pore systems appearing from the presence of both 10 and 12 membered rings. The Atlas of Zeolite Framework Types classifies five materials differently named as having this same topology: MCM-22, ERB-1, ITQ-1, PSH-3, eSSZ-25.

Molecular sieves of the MCM-22 family have been found to be useful in a variety of hydrocarbon conversion processes. Examples of the molecular sieve of the MCM-22 family are MCM-22, MCM-49, MCM-56, ITQ-1, PSH-3, SSZ-25, and ERB-1. Such molecular sieves are useful for the alkylation of aromatic compounds. For example, US Patent No. 6,936,744 describes a process for producing a monoalkylated aromatic compound, particularly cumene, comprising the step of contacting a polyalkylated aromatic compound with an alkylatable aromatic compound under at least partial liquid phase conditions and in the presence of a transalkylation catalyst to produce the monoalkylated aromatic compound, wherein the transalkylation catalyst comprises a mixture of at least two different crystalline molecular sieves, where each molecular sieve is selected from beta zeolite, zeolite Y, mordenite and a material having an x-ray diffraction pattern including d-spacing maximums at 12.4 ± 0.25, 6.9 ± 0.15, 3.57 ± 0.07 and 3.42 ± 0.07 Angstroms.

The present description relates to an improved process mechanism for producing monoalkylated aromatic compounds, particularly ethylbenzene, cumene or sec-butylbenzene, by liquid or partial alkylation of an alkylatable aromatic compound, particularly benzene. More particularly, the present process uses a catalyst composition comprising a porous crystalline material, the catalyst manufactured from the extrudate to comprise catalytic particulate material of about 125 microns to about 790 microns in size and having an effectiveness factor, in defined below, increased from about 25% to about 750% of that of the original extrudate, more specifically from about 260 microns to about 700 microns in size with an effectiveness factor, defined below, increased from about 50% to about 650% of that of the original extrudate. The catalyst composition for use in the present description will comprise catalytic particulate material having an external surface area to volume ratio greater than about 79 cm '¹, more specifically larger than about 79 cm '¹ about 374 cm '¹.

The effectiveness factor is commonly defined as the reaction rate in the presence of mass transport limitations divided by the reaction rate without mass transport limitation. A detailed discussion of the effectiveness factor can be found in general studies on this subject, such as Mass Transfer in Heterogeneous Catalysis by CN Satterfield; and Mass Transfer in Heterogeneous Catalysis, Robert Krieger Publishing Co., Malabar, FL, 1980, ed. original MIT Press, Cambridge, MA, 1970, incorporated herein by reference. In some circumstances when the catalyst deactivates during measurement, the reaction rate constant is measured excluding the effect of catalyst deactivation, such as the measured reaction rate constant exceeding the reaction rate prior to deactivation. In this description, the effectiveness factor is calculated as the rate constant of the alkylation reaction of the catalyst being tested divided by the rate constant of the alkylation reaction without limiting mass transfer. The calculation of the rate constant of the alkylation reaction is based on a solution for the expression of the second order rate in a batch reactor which can also be found in Elements of Chemical Reaction Engineering, Fogler, H. Scott, PTR Prentice-Hall, Inc., 1992, §8.3.1 & §5.6.2. Further details for cumene batch testing can be found in the subsequent section Test sequence for making cumene in a batch test. The second order rate constant measured under conditions without mass transfer limitation is calculated by estimation from the measured rates where the maximum reaction rate would be with an infinitely small particle, where the rate constant is measured under conditions without deactivation, such as exceeding the reaction rate before deactivation

The term aromatic in reference to the alkylatable aromatic compounds that can be useful as a feed load here should be understood according to their scope recognized in the art. This includes substituted and unsubstituted alkyl mono- and polynuclear compounds. Compounds of an aromatic character that have a heteroatom can also be useful as long as sufficient catalytic activity is maintained under the selected reaction conditions.

Substituted aromatic compounds that can be alkylated here must have at least one hydrogen atom directly attached to the aromatic nucleus. Aromatic rings can be replaced with one or more alkyl, aryl, alkaryl, alkoxy, aryloxy, cycloalkyl, halite, and / or other groups that do not interfere with the alkylation reaction.

Suitable aromatic compounds include benzene, naphthalene, anthracene, naphthene, perylene, coronene, and phenanthrene, with benzene being preferred.

Generally, alkyl groups that may be present as substituents on the aromatic compound contain from 1 to about 22 carbon atoms and generally from about 1 to 8 carbon atoms, and more generally from about 1 to 4 carbon atoms.

Suitable alkyl-substituted aromatics include toluene, xylene, isopropylbenzene, n-propylbenzene, alpha-methylnaphthalene, ethylbenzene, mesitylene, durene, cimenes, butylbenzene, pseudocumene, o-diethylbenzene, m-diethylbenzene, p-diethylbenzene, p-diethylbenzene , pentaethylbenzene, pentamethylbenzene; 1,2,3,4-tetraethylbenzene; 1,2,3,5-tetramethylbenzene; 1,2,4-triethylbenzene; 1,2,3-trimethylbenzene, m-butyltoluene; p-butyltoluene; 3,5-diethyl toluene; o-ethyltoluene; p-ethyltholuene; m-propyltoluene; 4-ethyl-m-xylene; dimethylnaphthalenes; ethylnaphthalene; 2,3-dimethylanthracene; 9-ethylanthracene; 2-methylanthracene; o-methylanthracene; 9,10-dimethylphenanthrene; and

3-methyl-phenanthrene. Alkylaromatic compounds of higher molecular weight can also be used as starting materials and include aromatic organics such as are produced by the alkylation of aromatic organics with olefin oligomers. Such products are often referred to in the art as alkylated and include hexylbenzene, nonylbenzene, dodecylbenzene, pentadecylbenzene, hexiltoluene, noniltoluene, dodeciltoluene, pentadeciltoluene, etc. Very often the alkylate is obtained as a high boiling fraction where the alkyl group attached to the aromatic nucleus varies in size from about C₆ about Ci₂. When cumene or ethylbenzene is the desired product, the present process produces acceptably small by-products such as n-propyl benzene and xylenes respectively. These by-products made in such examples can be less than about 100 ppm by weight.

Reformed containing a mixture of benzene, toluene and / or xylene is a particularly useful feed for the alkylation process of this description.

Alkylating agents that may be useful in the process of this description generally include any aliphatic or aromatic organic compound having one or more available alkylating aliphatic groups capable of reaction with the alkylatable aromatic compound, preferably with the alkylating group having 1 to 5 carbon atoms. Examples of suitable alkylating agents are olefins such as ethylene, propylene, butenes such as, for example, 1-butene, 2-butene or isobutylene, and pentenes; alcohols (including mono-alcohols, dialcools, trialcools, etc.) such as methanol, ethanol, propanols, butanols, and pentanols; aldehydes such as formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, and n-valeraldehyde; and alkyl halides such as methyl chloride, ethyl chloride, propyl chlorides, butyl chlorides, and pentyl chlorides, and so on. Mixtures of these compounds can also be useful, such as, for example, mixtures of propylene and propanol.

Mixtures of light olefins are useful as alkylating agents in the alkylation process of this description. Thus, mixtures of ethylene, propylene, butenes, and / or pentenes which are the main constituents of a variety of refinery streams, for example, combustible gas, residual gas from gas plant containing ethylene, propylene, etc., residual gas naphtha crackers containing light olefins, FCC propane / propylene refinery chains, etc. are useful alkylating agents. For example, a typical FCC light olefin chain has the following composition:

<td></td><td>% by weight</td><td>% of Mois</td>

<td>Ethane</td><td> 3,3</td><td> 5,1</td>

<td>Ethylene</td><td> 0,7</td><td> 1,2</td>

<td>Propane</td><td> 4,5</td><td> 15,3</td>

<td>Propylene</td><td> 42,5</td><td> 46,8</td>

<td>Isobutane</td><td> 12,9</td><td> 10,3</td>

<td>n-Butane</td><td> 3,3</td><td> 2,6</td>

<td>Butenos</td><td> 22,1</td><td> 18,32</td>

<td>Pentanes</td><td> 0,7</td><td> 0,4</td>

Reaction products obtainable from the process of the present description 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, cimenes from the reaction of toluene with propylene, and sec-butylbenzene from reaction of benzene and n-butenes. Particularly preferred process mechanisms of the description refer to the production of cumene by the alkylation of benzene with propylene and the production of ethylbenzene by the alkylation of benzene with ethylene.

The reagents can be partially or completely in the liquid phase and can be pure, that is to say free from intentional mixing or dilution with other material, or they can be brought into contact with the catalyst composition with the aid of carrier gases or diluents such as, for example, hydrogen, methane and / or nitrogen.

The alkylation process of this description can be conducted in such a way that the organic reagents, i.e., the alkylatable aromatic compound and the alkylating agent, are brought into contact with the catalyst presently required in a suitable reaction zone under effective alkali conditions. Such conditions include a temperature of about 0 ° C to about 500 ° C, preferably about 10 ° C to about 260 ° C, a pressure of about 20 to about 25000 kPa-a, preferably about 100 to about 5500 kPa-a, an alkylated aromatic compound to alkylating agent molar ratio of about 0.1: 1 to about 50: 1, preferably from about 0.5: 1 to about 10: 1, and an hourly space mass mass velocity (WHSV) based on the alkylating agent of about 0.1 to 500 h '¹, preferably from about 0.1 to about 100 h '¹.

When benzene is alkylated with ethylene to produce ethylbenzene, the alkylation reaction is preferably carried out in the liquid phase under conditions including a temperature of about 150 ° C to about 300 ° C, more preferably from about 170 ° C to about 260 ° C; a pressure up to about 20400 kPa-a, more preferably from about 2000 kPa-a to about 5500 kPa-a; an hourly space mass velocity (WHSV) based on the ethylene alkylating agent of about 0.1 to about 20 h '¹, more preferably from about 0.5 to about 6 h '¹; and a benzene to ethylene ratio in the alkylation reaction zone of about 0.5: 1 to about 100: 1 molar, preferably 0.5: 1 to 50: 1 molar, more preferably about 1: 1 to about 30: 1 molar, more preferably about 1: 1 to about 10: 1 molar.

When benzene is alkylated with propylene to produce cumene, the reaction can also occur under liquid phase conditions including a temperature of up to about 250 ° C, preferably up to about 150 ° C, for example, from about 10 ° C to about 125 ° C; a pressure of about 25000 kPa-a or less, for example, from about 100 to about 3000 kPa-a; the hourly space mass speed (WHSV) based on the propylene alkylating agent of about 0.1 h '¹ about 250 h¹, preferably about 1 h '¹ about 50 h '¹; and the benzene to propylene ratio in the alkylation reaction zone of about 0.5: 1 to about 100: 1 molar, preferably 0.5: 1 to 50: 1 molar, more preferably about 1: 1 to about 30: 1 molar, more preferably about 1: 1 to about 10: 1 molar.

When benzene is alkylated with a butene to produce sec-butylbenzene, the reaction can also occur under liquid phase conditions including a temperature of up to about 250 ° C, preferably up to about 150 ° C, for example, about 10 ° C to about 125 ° C; a pressure of about 25000 kPa-a or less, for example, from about 1 to about 3000 kPa-a; a spatial hourly mass velocity (WHSV) based on the butene alkylating agent of about 0.1 h '¹ about 250 h '¹, preferably about 1 h¹ about 50 h¹; and a benzene to butene ratio in the alkylation reaction zone of about 0.5: 1 to about 100: 1 molar, preferably 0.5: 1 to 50: 1 molar, more preferably about 1: 1 to about 30: 1 molar, more preferably about 1: 1 to about 10: 1 molar.

The reaction zone useful for the present description due to the small particle size of the catalyst can be, for example, in a fixed bed operation with low linear speed so as not to create an unacceptable pressure drop; in a continuous agitated tank reactor (CSTR); in a boiling bed operation in an upflow mode, such that the catalyst moves in a boiling mode; or in a slurry circuit in which the catalyst and the feed charge form a free slurry pumped through a tube serving as the reactor.

A fixed bed operation usable in the present description with low linear speed so as not to create an unacceptable pressure drop is shown in Elements of Chemical Reaction Engineering, Fogler, H. Scott, PTR Prentice-Hall, Inc., 1992, §4.4 &amp; §8.3.2, and Perry's Chemical Engineers' Handbook, 7a. ed., Perry, Robert H. and Green, Don W., McGraw-HilI Companies, Inc., 1997, §23, incorporated herein by reference.

A continuous agitated tank reactor (CSTR) usable in the present description is represented in Elements of Chemical Reaction Engineering, Fogler, H. Scott, PTR Prentice-Hall, Inc., 1992, §8.3.1 &amp; §5.6.2, and Perry's Chemical Engineers' Handbook, 7a. ed., Perry, Robert H. and Green, Don W., McGraw-HilI Companies, Inc., 1997, §23, incorporated herein by reference.

A boiling bed usable in the present description operating in an upflow mode such that the catalyst moves in a boiling mode, is shown in Perry's Chemical Engineers' Handbook, 7a. ed., Perry, Robert H. and Green, Don W., McGraw-HilI Companies, Inc., 1997, §23, incorporated herein by reference.

A slurry reactor in which the catalyst and feed charge form free slurry agitated in a tank or pumped through a tube serving as the usable reactor in the present description is represented in Chemical and Catalytic Reaction Engineering :, Carberry, James J. , McGraw-HilI, Inc., 1976, §10.6 and Perry's Chemical Engineers' Handbook, 7a. ed., Perry, Robert H. and Green, Don W., McGraw-HilI Companies, Inc., 1997, §23, incorporated herein by reference.

The catalyst for use in the present description may comprise a crystalline molecular sieve having the Beta zeolite structure (described in US Patent No. 3,308,069) or a type of MWW structure such as, for example, those having a radius diffraction pattern -x including maximum d-spacing at 12.4 + 0.25, 6.9 ± 0.15, 3.57 ± 0.07 and 3.42 ± 0.07 Angstroms. Examples of MWW frame type materials include MCM-22 (described in US Patent No. 4,954,325), PSH-3 (described in US Patent No. 4,439,409), SSZ-25 (described in US Patent No. 4,826,667), ERB-1 (described in European Patent No. 0293032), ITQ-1 (described in US Patent No. 6,077,498), ITQ -2 (described in US Patent No. 6,231,751), ITQ-30 (described in WO 2005-118476), MCM-36 (described in US Patent No. 5,250,277), MCM-49 (described in US Patent No. No. 5,236,575) and MCM-56 (described in US Patent No. 5,362,697). The catalyst can include the molecular sieve in an unbound or self-bonded form or, alternatively, the molecular sieve can be combined in a conventional manner with an oxide binder as detailed below. For the improvement of the present description, the average particle size of the catalyst manufactured from the extrudate must be from about 125 microns to about 790 microns in size and has an increased effectiveness factor of about 25% to about 750% with respect to the original extruded. More specifically, the catalyst manufactured from the extrudate will be from about 260 microns to about 700 microns in size with an effectiveness factor increased by about 50% to about 650%. Also, the external surface area for the catalyst volume ratio will be greater than about 79 cm '¹, preferably greater than about 79 cm '¹ about 374 cm '¹.

For the reaction process of the present description, the effluent alkylation reactor contains excess aromatic feed, monoalkylated product, polyalkylated products, and various impurities. The aromatic feed is recovered by distillation and recycled to the alkylation reactor. Generally, a small bleed is removed from the recycling stream to eliminate non-reactive impurities from the circuit. The distillation bottoms can also be distilled to separate the monoalkylated product from polyalkylated and other heavy products.

Any polyalkylated products separated from the alkylation reactor effluent can be reacted with additional aromatic feed in a transalkylation reactor, separated from the alkylation reactor, over a suitable transalkylation catalyst. The transalkylation catalyst can comprise one or more mixtures of crystalline molecular sieves having the structure of Beta zeolite, Y zeolite, mordenite or a material of the MCM-22 family 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 Angstroms.

The x-ray diffraction data used to characterize the catalyst structures above are obtained by standard techniques using the copper K-alpha pair as the incident radiation and a diffractometer equipped with a scintillation counter and associated computer as the collection system . Materials having the above x-ray diffraction lines include, for example, MCM-22 (described in US Patent No. 4,954,325), PSH-3 (described in US Patent No. 4,439,409), SSZ-25 ( described in the US Patent No. 4,826,667), ERB-1 (described in European Patent No. 0293032), ITQ-1 (described in US Patent No. 6,077,498), ITQ-2 (described in US Patent No. 6,231,751), ITQ30 (described in WO 2005-118476), MCM-36 (described in US Patent No.

5,250,277), MCM-49 (described in US Patent No. 5,236,575) and MCM-56 (described in US Patent No. 5,362,697), with MCM-22 being particularly preferred.

Beta zeolite is described in US Patent No. 3,308,069. Zeolite Y and mordenite occur naturally but can also be used in one of its synthetic forms, such as Ultra-stable Y (USY), which is described in US Patent No. 3,449,070, Y exchanged for rare earth (REY), which is described in the US Patent No. 4,415,438, and TEA-mordenite (i.e., synthetic mordenite prepared from a reaction mixture comprising a tetraethylammonium targeting agent, R), which is described in US Patent Nos. 3,766,093 and 3,894. 104. However, in the case of TEA-mordenite for use in the transalkylation catalyst, the particular synthesis regimes described in the mentioned patents lead to the production of a mordenite product composed of predominantly large crystals with a size greater than 1 micron and typically around 5 to 10 microns. It has been found that controlling the synthesis so that the resulting TEA-mordenite has an average crystal size of less than 0.5 microns results in a transalkylation catalyst with materially enhanced activity for liquid phase aromatic transalkylation.

The small crystal TEA-mordenite desired for transalkylation can be produced by crystallization of a synthesis mixture having a molar composition within the following variations:

<td></td><td>Usable</td><td>Preferred</td>

<td>R / R + Na + =</td><td> &gt;0,4</td><td> 0,45-0,7</td>

<td>OH- / SiO2 =</td><td> &lt;0,22</td><td> 0,05-0,2</td>

<td>SY / AI2 =</td><td> &gt;30-90</td><td> 35-50</td>

<td>H₂O / OH =</td><td> 50-70</td><td> 50 -60</td>

Crystallization of this synthesis mixture is carried out at a temperature of 90 to 200 ° C, for a time of 6 to 180 hours.

The catalyst for use in the present description can include a matrix or binder of inorganic oxide material. Such matrix materials include synthetic or naturally occurring substances as well as inorganic materials such as clay, silica and / or metal oxides. The latter may be naturally occurring in the form of gelatinous precipitates or gels including mixtures of silica and metal oxides. Naturally occurring clays that can be composed with the inorganic oxide material include those from the montmorillonite and kaolin families, whose families include the sub-bentonites and the kaolin commonly known as Dixie, McNamee, Georgia and Florida clays or others in which the constituent main mineral is halloysite, kaolinite, diquite, nacrite or anauxite. Such clays can be used in the raw state as originally mined or initially subjected to calcination, acid treatment or chemical modification.

Specific usable matrix materials or catalyst binders employed here include silica, alumina, zirconia, titania, silicaalumina, silica-magnesia, silica-zirconia, silica-thorium, silica-beryllium, silicitania as well as ternary compositions such as silica-alumina-thorium , silica-alumina-zirconia, silica-alumina-magnesia and silica-magnesia-zirconia. The matrix can be in the form of a cogel. A mixture of these components can also be used.

The relative proportions of crystalline molecular sieve and binder or matrix, if present, can vary widely with the content of crystalline molecular sieve ranging from about 1 to about 99 weight percent, and more generally in the range of about 30 to about 80 percent by weight of the total catalyst. Of course, the catalyst can comprise a self-bonding molecular sieve or a non-bonding molecular sieve, thus being about 100% crystalline molecular sieve.

The catalyst for use in the present description, or its crystalline molecular sieve component, may or may not contain added functionalization, such as, for example, a Group 6 metal (for example, Cr and Mo), Group 7 (for example, Mn and Re) or Groups 8, 9, and 10 (for example, Co, Ni, Pd and Pt), or phosphorus.

The catalyst for use in the present description must be manufactured from the extrudate and having an average particle size within the narrow range of about 125 to about 790 microns and has an increased effectiveness factor of about 25% to about 750% of that of the original extrudate, for example, from about 260 to about 700 microns in size with an effectiveness factor increased from about 50% to about 650% of that of the original extrudate. It can be done, for example, by reducing the particle size of 0.159 cm cylindrical extruded or 0.127 cm formed, for example, trilobed or quadrilobed, extruded by crushing or sieving. A summary of the molecular sieves and / or zeolites, in terms of production, modification and characterization of molecular sieves, is described in the book Molecular Sieves - Principies of Synthesis and Identification; (R. Szostak, Blackie Academic &amp; Professional, London, 1998, 2nd ed.). In addition to molecular sieves, amorphous materials, mainly silica, aluminum silicate and aluminum oxide, have been used as adsorbent and catalyst supports. Various techniques known for a long time, such as spray drying, pelletizing, granulation and extrusion, have been and are used to produce macrostructures in the form of, for example, spherical particles, extrudates, granules and tablets of both microporous and other types of porous materials. for use in catalysis, adsorption and ion exchange. A summary of these techniques is described in Catalyst Manufacture, AB Stiles and TA Koch, Marcei Dekker, New York, 1995.

Non-limiting examples of the present description involving an alkylation mechanism are described with reference to the following experiments. In the experiments, catalyst activity is defined by reference to the kinetic rate constant that is determined by assuming second-order reaction kinetics. For a discussion of determining the kinetic rate constant, the reference is directed to Heterogeneous Reactions: Analysis, Examples, and Reactor Design, Vol. 2: Fluid-Fluid-Solid Reactions by LK Doraiswamy and Μ. M. Sharma, John Wiley &amp; Sons, New York (1994) and Chemical Reaction Engineering by O. Levenspiel, Wiley Eastern Limited, New Delhi (1972).

Test Catalysts

In these experiments, tested catalyst materials are listed below:

Material 1: MCM-49 catalyst was prepared by extruding a mixture of 80% by weight of MCM-49 crystals and 20% by weight of alumina in solid squared extrudates having a diameter of 0.127 cm and a length of 0.635 cm (in then MCM-49 quadruple catalyst). The resulting catalyst particles had a surface area to volume ratio of 78 cm '¹ and an effectiveness factor of 0.18.

Material 2: it was prepared from Material 1 by crushing and sieving the 0.127 cm MCM-49 square catalyst for a range of particle sizes from 250 to 297 microns. The resulting catalyst particles had a surface area to volume ratio of 344 cm '¹ and an effectiveness factor of 0.65. The increase in the effectiveness factor of the Material 1 catalyst was 261%.

Material 3: MCM-22 catalyst was prepared by extruding a mixture of 65% by weight of MCM-22 crystals and 35% by weight of alumina in solid cylindrical extrudates having a diameter of 0.159 cm and a length of 0.635 cm ( then MCM22 cylindrical catalyst). The resulting MCM-22 cylindrical catalyst particles had a surface area to volume ratio of 34.6 cm '¹ and an effectiveness factor of 0.08.

Material 4: was prepared from Material 3 by crushing and sieving the 0.159 cm cylindrical MCM-22 catalyst for a range of particle sizes from 250 to 297 microns. The resulting catalyst particles had a surface area to volume ratio of 344 cm¹ and an effectiveness factor of 0.55. The increase in the effectiveness factor of the Material 3 catalyst was 587%.

Material 5: a Beta zeolite catalyst that was prepared by extruding a mixture of 80% by weight of Beta zeolite crystals and 20% by weight of alumina in solid quadruple extruded extracts having a diameter of 0.127 cm (1/20 inch) and a length of 0.635 cm (then Beta-square catalyst). The resulting beta-square catalyst particles had a surface area to volume ratio of 78 cm '¹ and an effectiveness factor of 0.21 based on the measured second order rate constant exceeding the reaction rate before deactivation and without mass transport limitations.

Material 6 was prepared from Material 5 by crushing and sieving the 0.127 cm Beta square-based catalyst for a range of particle sizes from 250 to 297 microns. The resulting catalyst particles had a surface area to volume ratio of 344 cm '¹ and an effectiveness factor of 0.73 based on the measured second order rate constant exceeding the reaction rate before deactivation and without mass transport limitations. The increase in the effectiveness factor of Catalyst Material 5 is 347%.

Catalyst reactivity measurement procedure

Batch testing equipment

A 300 ml Parr batch reaction vessel for making cumene and a 600 ml Parr batch reaction vessel for making ethylbenzene were each equipped with a catalyst basket with stirring rod and static was used for activity measurements and selectivity. The reaction vessels were provided with two removable vessels for the introduction of benzene and propylene or ethylbenzene respectively. Feed pre-treatment

Benzene

Benzene was obtained from a commercial source. The benzene was passed through a pre-treatment vessel (2L Hoke vessel) containing equal parts (by volume) 13X molecular sieve, 4A molecular sieve, Engelhard Clay F-24, and Selexsorb CD (in order of entry and exit) ), and then through a 250 ml vessel containing MCM-22 catalyst. All feed pre-treatment materials were dried in an oven at 260 ° C for 12 hours before use.

Propylene and Ethylene

Propylene and ethylene were obtained from a source of commercially specialized gases and were polymer-type. Propylene and ethylene were passed through a 300 ml vessel containing pre-treatment materials in the following order:

The. 150 ml 5A molecular sieve

B. Selexsorb 150 ml CD

Both guard bed materials were dried in an oven at 260 ° C for 12 hours before use.

Nitrogen

The nitrogen was of ultra high purity and obtained from a source of commercial special gases. The nitrogen was passed through a 300 ml vessel containing pre-treatment materials in the following order:

The. 150 ml 5A molecular sieve

B. Selexsorb 150 ml CD

Both guard bed materials were dried in an oven at 260 ° C for 12 hours before use.

Catalyst preparation and loading

A 2 gram sample of catalyst was dried in an air oven at 260 ° C for 2 hours. The catalyst was removed from the oven and immediately 1 gram of catalyst was weighed. Quartz chips were used to align the bottom of the basket followed by loading the catalyst into the basket on top of the first layer of quartz. Quartz chips were then placed on top of the catalyst. The basket containing the catalyst and quartz chips was placed in an oven at 260 ° C overnight in air for about 16 hours.

The reactor and all lines were cleaned with a suitable solvent (such as toluene) before each experiment. The reactor and all lines were air dried after cleaning to remove all traces of cleaning solvent. The basket containing the catalyst and the quartz chips was removed from the oven and immediately placed in the reactor and the reactor was immediately assembled.

Test sequence for making cumene in batch test

The reactor temperature was set at 170 ° C and purged with standard 100 cubic centimeters per minute (sccm) of ultra high purity nitrogen for 2 hours. After nitrogen purged the reactor for 2 hours, the reactor temperature was reduced to 130 ° C, nitrogen purging was discontinued and the reactor opening closed. A quantity of 156.1 grams of benzene was loaded into a 300 ml transfer vessel, in a closed system. The benzene vessel was pressurized at 790 kPa-a with nitrogen of ultra high purity and the benzene was transferred in the reactor. The agitator speed was set to 500 rpm and the reactor was left to equilibrate for 1 hour.

A 75 ml Hoke transfer vessel was then filled with 28.1 grams of liquid propylene and connected to the reactor vessel, and then connected with 2169 kPa-a of ultra high purity nitrogen. After the one-hour benzene stirring time elapsed, propylene was transferred from the Hoke vessel to the reactor. The 2169 kPa-a nitrogen source was kept connected to the propylene vessel and opened to the reactor during the complete run to keep the reaction pressure constant during the test. Samples of liquid product were taken at 30, 60, 120, 150, 180 and 240 minutes after adding propylene.

Test sequence for making ethylbenzene in a batch test

The reactor temperature was set at 170 ° C and purged with 100 sccm of ultra high purity nitrogen for 2 hours. After nitrogen purged the reactor for 2 hours, the reactor temperature was reduced to 220 ° C, nitrogen purging was discontinued and the reactor opening closed. A quantity of 195 grams of benzene was loaded into a 600 ml transfer vessel, carried out in a closed system. The benzene vessel was pressurized at 790 kPa-a with nitrogen of ultra high purity and the benzene was transferred in the reactor. The agitator speed was set to 500 rpm and the reactor was left to equilibrate for 1 hour. After a one hour benzene stirring time, 39.4 grams of ethylene was introduced into the reactor. A 2169 kPa-a nitrogen source was kept connected to the reaction vessel during the complete run to maintain a constant reaction pressure during the test. Samples of liquid product were taken at 30, 60, 120, 150, 180 and 240 minutes after adding ethylene.

Test sequence for making cumene in a fixed bed test

These experiments were conducted on a fixed bed in a 0.95 cm OD tubular reactor or 1.9 cm fixed bed in a downward configuration. The reactor furnace was controlled in isothermal mode. The catalyst was dried out of line at 260 ° C in air for 2 hours before loading into the reactor. Experiments were conducted with catalyst like all extrudates loaded in the 0.95 cm reactor. The catalyst bed was axially centered in the middle zone of the furnace. The catalyst used was in the form of the extrudate, spray dried form, or crushed extrudate and sized to 250 microns to 297 microns depending on the experiment. All catalysts were filled with inert sand to fill the interstitial voids. Reaction conditions were 125 ° C, 2169 kPa-a and the benzene / propylene molar ratio was 2.8 / 1. Speed ​​in hourly space weight was adjusted during the experiments and varied from 1 h '¹at 320 h '¹ on a propylene base.

When starting a reactor, the reactor was brought to a reaction pressure of 2169 kPa-a with nitrogen of ultra-high purity, and heated to a reaction temperature of 125 ° C before introducing the feed. The catalyst was left to equilibrate for 1 to 2 days to obtain a fixed state before the data was collected.

The MCM-49 quadruple catalyst (Material 1), the MCM-22 cylindrical catalyst (Material 3), and the 250 to 297 micron (average 274 micron) catalysts prepared from it by crushing and sieving (Materials 2 and 4 , respectively) were tested according to the cumene batch test procedure. The MCM-49 quadrilobed catalyst (Material 1) and the 250 to 297 micron (average 274 micron) catalyst prepared from the same by crushing and sieving (Material 2) were tested according to the ethylbenzene batch test procedure . The MCM-49 quadruple catalyst (Material 1), the Beta cylindrical catalyst (Material 5), and the 250 to 297 micron (average 274 micron) catalysts prepared from it by crushing and sieving (Materials 2 and 6, respectively ) were tested according to the cumene fixed bed procedure.

Example 1

In these experiments, cumene was manufactured by contacting 5.55 parts by weight of benzene and 1 part by weight of propylene in the batch fluid reactor using the procedure detailed above for the test sequence for making cumene in a batch test on catalysts individually selected from Materials 1, 2 and 3. Cumene (isopropylbenzene, IPB) and diisopropylbenzene (DIPB) products were collected from each experiment and it was found that the catalyst for use in the present description, ie Material 2, provided about 30% reduction in the DIPB ratio / IPB. Also, Material 2 yielded about 288% more activity than Material 1, and about 600% more activity than Material 3.

Example 2

In these experiments, cumene was manufactured by contacting 5.55 parts by weight of benzene and 1 part by weight of propylene in the batch fluid reactor using the procedure detailed above for the test sequence for making cumene in a batch test on catalyst comprising the 0.127 cm MCM-49 (Material 1) quadrilobed catalyst and the 250 to 297 micron catalyst prepared from it by crushing and sieving (Material 2). Cumene (isopropylbenzene, IPB) and diisopropylbenzene (DIPB) products were collected from each experiment and it was found that Material 2 again provided a 30% reduction in the DIPB / IPB ratio.

Example 3

In these experiments, cumene was manufactured by contacting 5.55 parts by weight of benzene and 1 part by weight of propylene in the batch fluid reactor using the procedure detailed above for the test sequence for making cumene in a batch test on catalyst comprising the cylindrical catalyst MCM-22 (Material 3) and the catalyst of 250 to 297 microns prepared from it by crushing and sieving (Material 4). The cumene (isopropylbenzene, IPB) and di26 isopropylbenzene (DIPB) products were collected from each experiment and it was found that the Material 4 catalyst provided a 13% reduction in the DIPB / IPB ratio.

Example 4

In these experiments, ethylbenzene was manufactured by contacting 0.95 part by weight of benzene and 1 part by weight of ethylene in the batch slurry reactor using the procedure detailed above for Test Sequence for Making Ethylbenzene in a batch test on catalyst comprising the 0.127 cm checkered MCM-49 catalyst (Material 1) and the 250 to 297 micron catalyst prepared from it by crushing and sieving (Material 2). Ethylbenzene (EB) and diethylbenzene (DEB) products were collected from each experiment and it was found that the Material 2 catalyst provided a 23% reduction in the DEB / EB ratio.

Example 5

In these experiments, cumene was manufactured by contacting 5.2 parts by weight of benzene and 1 part by weight of propylene in the fixed bed micro-reactor using the procedure detailed above for the test sequence for making cumene in a fixed bed test on catalyst comprising the 0.127 cm MCM-49 quadrilobed catalyst (Material 1) and the 250 to 297 micron catalyst prepared from it by crushing and sieving (Material 2). Cumene (isopropylbenzene, IPB) and diisopropylbenzene (DIPB) products were collected from each experiment and it was found that Example 8 provided a 54% reduction in the DIPB / IPB ratio.

Example 6

In these experiments, cumene was manufactured by contacting 5.2 parts by weight of benzene and 1 part by weight of propylene in the batch slurry reactor using the procedure detailed above for Test Sequence for Making Cumene in a batch test on catalyst comprising the beta-square catalyst (Material 5) and the 250 to 297 micron catalyst prepared from it by crushing and sieving (Material 6). The cumene (isopropylbenzene, IPB) and diisopropylbenzene (DIPB) products were collected from each experiment and it was found that Catalyst Material 6 provided a 65% reduction in the DIPB / IPB ratio before deactivation.

Example 7

In a simulated CSTR reaction conducted in the liquid phase at 130 ° C, 2413 kPa-a of inlet pressure and WHSV of 76.5 h '¹ based on propylene, the catalyst volume of 16.8 m³ comprising catalyst material 1, feed load comprising 25 parts by weight of propylene and 75 parts by weight of benzene, conversion of propylene was 32.4%. By stimulating the same reaction of CSTR with catalyst comprising the MCM-49 square catalyst having been crushed and sieved to reach 250 to 297 microns in size (Material 2), the conversion of propylene was found to be 66.2%. This example shows that in a continuous agitated tank reactor, catalyst particles sized to meet the requirements of the present description are effective in increasing the conversion of propylene in reaction with benzene in the liquid phase.

All patents, patent applications, testing procedures, articles, publications, and other documents cited here are fully incorporated by reference so that the extension of such description is not inconsistent with this description and for all jurisdictions in which such incorporation is permitted.

When lower numerical limits and upper numerical limits are listed here, variations from any lower limit to any upper limit are contemplated.

While the illustrative embodiments of the description have been described in particular, it will be understood that several other modifications will be apparent and can be readily made by those skilled in the art without departing from the spirit and scope of the description. Consequently, it is not intended that the scope of the claims appended herein be limited to the examples and descriptions shown but consequently that the claims are constructed to include all the features of patentable novelty that reside in the present description, including all the features that would be treated as equivalent. the same by those skilled in the technique to which the description belongs.