JPH04187647A - Method of aromatic change and its catalyst - Google Patents

Abstract

PURPOSE: To obtain a monoalkyl aromatic compound in a high yield by alkylating an aromatic compound in the presence of a molecular sieve catalyst by subjecting the polyalkyl compound separated from the reaction product to alkyl transformation and recirculating the reaction mixture in a separation process.

CONSTITUTION: An aromatic compound and a 2-4C alkylation agent are fed to a reaction zone containing a molecular sieve catalyst for the alkylation of an aromatic compound and are reacted at such a temperature and under a such pressure as to maintain the aromatic compound liquid. The alkylated product is sent to a first separation zone where a low boiling point fraction comprising aromatic compounds is separated from a high boiling point fraction comprising the alkylated product. The latter fraction is then sent to a second separation zone where a low boiling point fraction comprising monoalkyl compounds are separated from a high boiling point fraction comprising the polyalkyl compound. Finally, the polyalkyl compound and the aromatic compound from the first separation zone are fed to a transform reaction zone containing a molecular sieve transformation catalyst to cause disproportionations, and the reaction product is sent to the first separation zone.

COPYRIGHT: (C)1992,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides aromatic conversion processes involving alkylation and transalkylation steps involving aromatic compounds containing zeolite catalysts, which are useful in the illicit process, and in particular aromatic conversion processes involving 02-C, benzene using alkylating agents. An alkylation-transalkylation process comprising alkylation of feedstock and liquid phase alkylation of the resulting polyalkylbenzene, treatment of the alkylation product in a separation zone, and recycling of at least a portion of the alkylation product to the separation zone. Regarding.

The present invention summarizes aromatic conversion processes and catalysts useful therein, as well as 62 to 62-C with recovery of monoalkylated aromatic products and liquid phase alkyl transfer of polyalkyl products.
4 Alkylation and transalkylation steps involving alkylation of aromatic substrates using alkylating agents. Specifically, a benzene feedstock is fed to an alkylation zone operated under liquid or vapor phase conditions and the product is fed to an alkyl transfer zone operated under low temperature liquid phase conditions.

In an aromatic conversion process over molecular sieve catalysts such as zeolite Y or Beta under liquid phase conditions, the aromatic feed containing water is passed through a dehydration zone to dehydrate the water content to less than 100 ppm, preferably 50 ppm or less. feed the raw materials. Certain molecular sieve catalysts consist of hydrogen zeolite beta with high surface area and low sodium content.

At least 600 m2 of modified zeolite beta
/g and a sodium content of less than 0.04% by weight Na 20. Modified zeolite beta is produced from as-synthesized zeolite beta by intermediate calcination at temperatures between 400 and 700° C. for a period of 2 hours or more, followed by ion exchange treatment.

Molecular 7-builds and their use in aromatic conversion are well known in the chemical processing and refining industries. Aromatic conversion reactions of considerable commercial importance are e.g. the production of yutyltoluene, kiln, ethylbenzene, cumene or higher alkylaromatics and disproportionation reactions such as toluene disproportionation, xy/lene isomerization or polyalkylbenzene monomerization. Including the alkylation of aromatic compounds in the alkylation of alkylbenzenes. Such alkylation, rearkyl transfer or other aromatic conversion steps may be carried out under conditions in which a liquid phase, a vapor phase or both liquid and vapor phases are present.

An example of vapor phase alkylation is found in Dwyer, US Pat. No. 4,107,224. Here, vapor phase ethylation of benzene over a zeolite catalyst is accomplished in a downstream reactor. The product from the reactor is recycled to the alkylation reactor where the polyethylbenzenes are transalkylated with benzene and then passed through a separation system where the ethylbenzene product is recovered. Dwyer catalysts are characterized as having a constraint index in the range of about 1 to 12, and ZSM-5(8,3), ZSM-11C8, with a constraint index in parentheses.
7), ZSM-12 (2), ZSM-35 (4,5),
Contains ZSM-38(2) and similar materials. In particular, various molecular 7-benzenes, including zeolite beta (force index 0.6), are disclosed as having force indexes outside the range suitable for the Dwyer ethylbenzene production process.

US Pat. No. 3,551,510 to Pollitzer et al. discloses an alkylation-alkylation process in which the product from an alkylation reaction zone is passed directly to an alkylation zone. In the Politzur patent, alkylation is characterized as an olefinic compound. Carry out using an alkylating agent over a solid phosphoric acid alkylation catalyst. Olefinic compounds include monoolefins, diolefins, polyolefins, actylene hydrocarbons,
It may be selected from materials such as alkyl halides, alcohols, ethers and esters. The product from the alkylation reaction zone containing polyethylbenzene is fed to the transalkylation reaction zone along with an aromatic substrate, such as benzene. The alkyl transfer zone contains an acid-extracted crystalline aluminosilicate catalyst, particularly mordenite, and is operated in upflow mode.

Typical conditions for alkyl rearrangement are liquid space-time velocity of 1.0, 5
Includes a pressure of 0.00 psig and a temperature of 250°C.

The product from the alkyl rearrangement zone is fed to a separation zone from which the polyalkyl aromatic, e.g. polyethylbenzene, is recovered and recycled to the alkylation zone.

Other alkylation-alkyl transfer methods are described by Ward (Ward et al.
) is disclosed in US Pat. No. 4,008,290. Similar to Politzer, the Ward patent discloses the use of a solid phosphoric acid catalyst in the alkylation zone. In Ward's patent, benzene and propylene are reacted to form cumene. The product from the alkylation reactor is distributed in such a way that in principle a portion of the benzene and cumene is recycled to the alkylation reactor. In principle, benzene, cumene, propane and other parts containing di- and tri-isopropylbenzene are fed to the separation zone. In the separation zone, the di- and tri-isopropylbenzene-enriched fluids are separated and fed along with the benzene to an alkyl transfer zone containing a solid phosphoric acid catalyst. The cumene-rich effluent from the alkyl transfer zone is recycled to the separation zone.

US patent bundle 4,169゜1 by White
No. 11 discloses an alkylation-alkylation process for the production of ethylbenzene using crystalline aluminosilicate in an alkylation and transalkylation reactor. The catalysts in the alkylation and transalkylation reactors are the same or different and have a silica/alumina molar ratio between 2 and 80, preferably between 4 and 12, preferably with a low sodium content of less than 0.5 wt% Na2O. of zeolite. Typical zeolites include X1Y, L,
BXZSIV! A water vapor stabilized Y zeolite containing about 0.2% Na 20 containing molecular 7-5 and omega crystal types is preferred. The alkylation reactor is operated in a downflow mode and under temperature and pressure conditions where some liquid phase is present. Alkyl transfer reactors, which are described as generally requiring higher than optimal temperatures for alkylation to achieve maximum alkyl transfer efficiency, are also operated in downflow mode.

In the Wide patent, the product from the alkylation reactor is cooled and fed to a benzene column from which benzene is recycled to the alkylation reactor. The bottom fraction from the benzene column is fed to an ethylbenzene column from which ethylbenzene is recovered as a process product.

A third section is operated to provide the bottom product from the ethylbenzene column to a substantially pure diethylbenzene overhead fraction comprising 10-90%, preferably 20-60% of the total diethylbenzene fed to the column. column.

The diethylbenzene overhead fraction is recycled to the alkylation reactor while the remaining diethylbenzene as well as triethylbenzene and higher molecular weight compounds are fed together with the benzene to the transalkylation reactor. The effluent from the alkyl transfer reactor is recycled to the benzene column.

U.S. Pat. No. 4,77 by Barger et al.
No. 4.377 discloses an alkylation/transalkylation process similar to the Wide process described above, which includes the use of separate alkylation and transalkylation reaction zones and recycling of the transalkylated product to an intermediate separation zone. . In Berger's method, temperature and pressure conditions are adjusted so that the alkylation and transalkyl reactions occur essentially in the liquid phase. Alkyl transfer catalysts are X-type, Y-type, metastable-Y, L-
aluminosilicate molecularan-7' containing type, omega type and mordenite type zeolite J)
The latter, preferably the catalyst used in the 1° alkylation reaction zone is a solid phosphoric acid-containing material. Aluminosilicate alkylation catalysts can also be used and
．． Water varying from 0.01 to 6% by volume is fed to the alkylation reaction zone. The product from the alkylation reaction is fed to the jth and second separation zones. Water is collected in a first separation zone. In the second separation zone, the intermediate aromatic products as well as the trialkylaromatics and heavier products are separated, leaving the implant only the dialkylaromatic components or, in the case of the ethylbenzene production process, diethylbenzene. or in the case of cumene production to the alkyl transfer zone with diisopropylbenzene. A benzene substrate is also fed to the transalkylation zone for the transalkylation reaction, and the product from the transalkylation zone is recycled to the first separation zone. The alkylation and alkyl transfer zones may be operated in a downflow, upflow or horizontal flow configuration.

As previously mentioned, various zeolitic molecular sieves are known for use in alkylation and/or transalkyl processes. As described in U.S. Pat. No. 4,107,224 to Dwyer, supra, certain molecular sieves containing zeolite beta are found to be unsuitable for use in the production of relatively low molecular weight alkylbenzenes such as ethylbenzene. It has some characteristics. In contrast to the relatively low molecular weight alkylbenzenes disclosed in the Dwyer et al. patent, U.S. Pat. Discloses the use of MoLz-1-nilar sheep in manufacturing. In the Young patent, a relatively long chain alkylating agent having one or more reactive alkyl groups of at least five carbon atoms is used for the alkylation of benzene in the presence of a crystalline zeolite alkylation catalyst. use The reactants can be in the vapor or liquid phase, and the zeolite catalyst can be modified or unmodified. Suitable zeolite catalysts include zeolite beta, Z SM-4, ZSM-20, ZSM, -38 and its naturally occurring integrants such as zeolite omega and others. As described in the Young patent, zeolites have alumina extraction and one or more metal components, such as No. 118. III, ■, ■A
and various chemical treatments, including combinations with Group I metals. This zeolite can be steamed.
The second can be subjected to heat treatment including calcination in air, hydrogen or inert gas. Specifically disclosed is the reaction of benzene and l-dodecane on zeolite beta (Si02/Al203=175) at 250° C. and 600 pslg in a flow reactor.

U.S. Pat. No. 4,185,040 by Ward et al. describes an alkylation process using a molecular sieve catalyst with a low sodium content that is said to be particularly useful for the production of ethylbenzene from hachenzene and hyethylene and cumene from benzene and propylene. Disclose. Zeolite Na
The 20 content is 0.7% by weight or less, preferably 0.5% by weight or less. Examples of suitable olides include X, Y, L, B, ZSM-5 and Omega crystal type molecules, water vapor stabilized hydrogen Y
Zeolites are preferred. Especially those disclosed are 0.2%
It is a steam stabilized ammonium Y zeolite containing Na2O. The alkylation process can be carried out either in upward or downward flow, with the latter being preferred and preferably under conditions of temperature and pressure such that at least some liquid phase is present. The olefin alkylating agent may be used until it is consumed. Ward et al. state that in the absence of a liquid phase, rapid catalyst deactivation occurs under most alkylation conditions.

Other alkylation methods are disclosed in European Patent Application No. 272.830 by Ratcliffe et al. The Ratkritshue process uses a molecular sieve alkylation catalyst that has been treated to improve selectivity in monoalkylation, particularly the propylation of benzene to produce cumene. Selectivity is said to be increased by at least 10% by first depositing carbonaceous material on the catalyst and then burning the resulting carbon containing catalyst particles. Special zeolitic crystalline molecules include those selected from the group of Y zeolite, fluorinated Y zeolite, X zeolite, zeolite beta, zeolite and zeolite omega. Zeolites can be modified to achieve reduced alumina content and reduced sodium content. A preferred heptaolide is first ammonium exchanged to a sodium content of about 0.6 to 5.0% by weight, expressed as NaO, and then ammonium exchanged in the presence of water vapor to a sodium content of about 315 to 900% by weight.
When calcined at a temperature of 0.degree. C. and then steam-calcined zeolite is ammonium exchanged and expressed as Na2O, 1.
Y zeolite is produced by obtaining a product having less than 0% by weight of sodium, preferably less than about 0.2% by weight of sodium.

Zeolite Beta, mentioned in certain references above, is a crystalline aluminosilicate that has applications in many industrial processes, including as a catalyst in various hydrocarbon conversion reactions such as hydrocracking, hydroisomerization and dewaxing. It is a molecular sieve zeolite. Like many other molecular sieve zeolites, zeolite beta is synthesized by hydrothermal decomposition of a reaction mixture consisting of /lica, alumina, alkaline earth metals, and organic templating agents. The organic agent acts as a template in the nucleation and growth of zeolite beta crystals. - Once the crystals have formed, it is common practice to carry out a calcination treatment to remove organic substances from the interstitial channels of the molecular sieve network.

Crystalline zeolite beta, fixed by its X-ray diffraction pattern, and the basic method for its production are described in U.S. Pat.
No. 08,069. As disclosed in the patent by Wadlinger et al., the chemical composition of as-synthesized zeolite beta is characterized by the following formula: [X m (1,01-x) TEA] AIO□・y
si02.WH20, where X is less than l, m is at least one cation, usually an alkali metal or alkaline earth metal, more particularly sodium, n is the valence of m, and y is from about 5 to about 100, W is about 4, and TEA represents tetraethylammonium ion.

As described in Watlinger et al., zeolite beta can be produced from a mixture in water of suitable raw materials of tetramethylammonium hydroxide and sodium oxide (or hydroxide), alumina, and silica. Typical reaction mixture compositions in terms of molar ratios are within the following ranges: S 10
2/ A l xo 3-about lO to about 200; Na2O
/tetraethylammonium hydroxide (TEAOH) - about 0 to 0.1; TEA OH/S i O2 - about 0.
1 to 1.0; H20/TEAOH--about 20 to about 75 degrees. The resulting reaction mixture may be heated at a temperature of about 75 to about 200 DEG C. until crystallization of the molecular sieve occurs. The crystallized product can be separated from the reaction mixture by filtration or centrifugation, then washed with water and dried to remove water from the molecular sieve network. The product may then be calcined in air or an inert atmosphere to remove the templating agent as described above.

The Wadlinger patent discloses that catalytic materials can be made by calcining the original sodium form of zeolite beta and/or replacing most of the sodium ions with other metals or ammoniacal cations. Particularly noted in the Wadlinger patent (Example 2) is a composition containing 0.7 mole percent Na2O upon calcining at 55 DEG C. in air.

Disclosed in Example 8 is a product produced by treating the dried product with a 2% ammonium chloride solution that was continuously exchanged for 48 hours.

After washing excess free chloride ions, the catalyst is dried and calcined under 1000 °C for 3 hours to produce acid beta aluminosilicate with 0.07% Na content.

Various other methods are known for the synthesis of zeolite beta. European patent application No. 1 by Rubin
No. 59,846 uses a templating agent formed by a combination of dimethylbenzylamine and a benzyl halide, 30
The synthesis of zeolite beta with solica/alumina molar ratios up to 0 is disclosed. Hydrothermal decomposition to form crystals is carried out at temperatures below 175° C. to avoid undesirable side effects.

When used as an absorbent or catalyst, the zeolite beta produced by the Lupine application can be at least partially dehydrated by heating in an air or nitrogen atmosphere at a temperature of about 200 to 600'C' for about 1 to 48 hours. obtain.

The newly synthesized zeolite beta has approximately 5 inorganic cations.
It can be decomposed by heating to temperatures up to 50°C for 1 to 48 hours. Zeolite beta prepared by the Lupine process can have the original cations attached replaced by a variety of other cations, including hydrogen, ammonium, and metal cations, and mixtures thereof.

According to European Patent No. 165,208 by Bruce et al., the molten silica/alumina component used to provide a silica/alumina molar ratio in the synthesized product of about 20 to 250 is either halogenated or A method for making zeolite beta similar to that disclosed in the above-referenced Lupine application is disclosed, except that dibenzyldimethylammonium hydroxide is used.

Preparation of Zeolite Beta similar to that disclosed in European Patent Application I, supra, in U.S. Pat. No. 4,642,226 by Calvert et al. A method is disclosed. The reaction mixture in the Calvert patent is heated at a temperature of about 80 to about 175°C for about 1 to about 120 days. The Calvert patent states that zeolite beta can be either organic nitrogen-containing alkali metal-containing forms, alkali metal forms, and hydrogen forms or other monovalent or polyvalent cationic forms. The Calvert patent also discloses that zeolite beta can be used in sufficient combination with metal components such as hydrogenated components such as tungsten, vanadium, molybdenum, rhenium, nickel, cobalt, chromium, manganese, or noble metals such as platinum or palladium. . The patent further states that zeolite beta is at least partially dehydrated when used as either an absorbent, catalyst or hydrocarbon conversion catalyst. Chlorides, nitrates and sulfates are disclosed as ion exchangers. Calvert et al.
．． A zeolite beta with 11% Na by weight is disclosed.

Other methods of making zeolite beta are disclosed in European Patent Application No. 164,939 by Calvert et al.

The synthesis method disclosed herein is said to be cheaper than fully crystalline zeolite Beta which is dealuminated to give the corresponding silica/alumina molar ratio of partially crystalline zeolite beta with extremely high silica/alumina ratios. Similar to that in the above-mentioned literature, except that a tetraethylammonium bromide or hydroxide templating agent is used to generate the aqueous product. The decomposition period in this method is 9
The period is between about 1 and 70 degrees at a temperature of 0 to 200 degrees Celsius. The phosphoric acid/alumina molar ratio of the zeolite beta produced here is 20 to 1000, and preferably 200 or more.

European Patent Application No. 186.447 by Kennedy et al. discloses the use of zeolite beta in catalytic cracking processes.

Zeolite Beta is used as-synthesized for subsequent calcinations and can be either low or high silica/alumina activity. This can be synthesized using trivalent structural ions other than aluminum to be produced, such as borosilicate, boraminosilicate, gallosilicate or galloaluminosilicate structural isotypes, which are considered to be the constituent forms of zeolite beta. Zeolite beta can be acid extracted to produce a high silica/alumina product.

As mentioned above, various aromatic conversion steps can be carried out in either or both the liquid and vapor phases. It is generally accepted that at the relatively high temperatures involved in vapor phase reactions, water present in the feed fluid is detrimental to the reaction process. While there are various possible reasons for the adverse effects of water, the most prevalent adverse effect is catalyst deactivation due to multilayer aluminization. For example, US Pat. No. 4, by Chen et al.
No. 197.214 describes the preparation of various crystallized zeolite molecules by the inclusion of metal ions such as zinc, such as ZSM-5, ZSM-11, ZSM-12, ZSM-
No. 35, ZSM-38, a method for modifying faujasite, mordenite, and erionite is disclosed. Chun et al. found that high-temperature steam acts through a hydrolysis reaction, resulting in a loss of structural aluminum with the loss of bound protons.
It is stated that a decrease in catalyst activity occurs. The hydrolysis reaction is said to be extremely slow at temperatures below about 800"F. However, at elevated temperatures above 900"F, the reaction rate is fast enough to affect the long-term stability of the zeolite catalyst.

In some cases, water can be tolerated under the temperature conditions involved during vapor phase reactions. For example, the above-mentioned patent to Dwyer states that water and hydrogen sulfide are acceptable for faster aging of the catalyst, but are deleterious to some extent during the process. Steam stabilized zeolites are disclosed as useful in aromatic conversion processes, including alkylation, such as during the production of ethylbenzene or cumene. Thus, the aforementioned patent to Ward et al. discloses that steam stabilized hydrogen Y zeolites are preferred for the alkylation of benzene in producing ethylbenzene or cumene.

The use of steam-stabilized zeolites in the production of high molecular weight alkylbenzenes is disclosed in the above-mentioned Young patent, where a relatively high molecular weight alkylating agent is used in either the vapor phase or the liquid phase. Zeolite catalyst in an atmosphere containing about 5% to about 100% water vapor from about 1/4 to about 1/4
It may be subjected to a modification treatment including steaming for a period in the range of about 100 hours.

In hydrocarbon conversion processes, including olefin conversion, water may or may not be allowed in the feed stream depending on the properties of the molecular sieve used. For example, U.S. Pat. No. 4,551,4 by Miller et al.
No. 38 discloses the oligomerization of olefins on molecular sieves characterized as intermediate pore sizes, such as 23M-5, ZSM-11, and soricalides, with effective pores in the range of about 5 to 6.5 angstroms. Miller's patent states that the raw material should be less than 10ppm, preferably 10ppm.
It is disclosed that it should contain less than ppm of water and have low concentrations of sulfur and nitrogen. On the other hand, molecular sieves with a somewhat large pore size, especially steam-stabilized zeolite Y, are used as C2-C automotive fuels.

When used in olefin conversion, water stabilizes the catalyst and
and is described as an effective co-raw material to reduce the rate of deactivation. Also, U.S. Patent No. 4 by Rabo et al.
No. 740,648, co-fed water is described as a particularly desirable diluent that tends to aid in the durability of zeolite Y catalysts against coking and aging.

According to the present invention, an alkyl alkyl compound comprising alkylation of an aromatic substrate using a C2-C, alkylating agent and liquid phase transalkylation of a polyalkyl product coupled with separation of a vessel to recover a monoalkylated aromatic product. An alkyl transfer method is provided. In one aspect of the invention, both the alkylation and the alkylation are carried out in the liquid phase over a molecular sieve aromatic alkylation and transfer catalyst. The product from the alkylation reaction zone can be recycled to the alkylation reaction zone and operated to produce a low-boiling frucnion consisting of an aromatic substrate and a high-boiling 7-fracsion consisting of a mixture of monoalkylated and polyalkylated aromatics. feed into the separation zone. The high boiling fraction is fed to a second low boiling fraction consisting of the desired monoalkylated product and a high boiling fraction consisting of the polyalkylated product.

At least a portion of the polyalkylated fraction containing substantially all dialkylated and trialkylated aromatics is fed along with the aromatic substrate to a transalkylation reaction zone containing a molecular sheet alkyl transfer catalyst. The alkyl transfer zone disproportionates the polyalkylated fraction under liquid phase conditions to achieve a disproportionated product with a reduced polyalkylated aromatic content and an increased monoalkylated aromatic content. Manipulate. At least a portion of the disproportionated product is fed to the first separation zone.

In a particular application of the invention for the production of ethylbenzene or cumene, the product from the alkyl transfer zone is fed to a third separation zone from which benzene and monoalkylbenzene fractions (ethylbenzene or cumene) are recovered. and recirculated to the separation zone.

In another embodiment of the present invention, the benzene raw material and C2~
C. An alkylating agent is fed to an alkylation reaction zone containing a molecular sieve alkylation catalyst and operated to produce an alkyl product consisting of a mixture of monoalkyl and polyalkylbenzenes. In this embodiment of the invention, the alkylation zone can be operated under liquid phase or vapor phase conditions, with the product from the alkylation zone being subjected to the separation steps described above. The alkyl transfer reaction zone is operated at an average temperature below the average temperature of the alkylation reaction zone and under conditions that maintain the benzene liquid phase. In a particular application of this embodiment of the invention to a process employing vapor phase ethylation of benzene followed by liquid phase alkyl transfer, the average temperature of the alkyl transfer reaction zone is at least 100° C. lower than the average temperature of the alkylation reaction zone. It is something.

In a further aspect of the invention comprising alkylation of a benzene feedstock using an alkylating agent, the alkylation catalyst is selected from the group consisting of Zeolite Beta, Zeolite Omega, and Zeolite Y, and the alkylation reactor is selected from the group consisting of Zeolite Beta, Zeolite Omega, and Zeolite Y; The benzene feedstock is operated under conditions that keep it in the liquid phase. The effluent from the alkylation reactor is subjected to a separation step along the lines described above, followed by separation to recover the desired monoalkylbenzene product, such as ethylbenzene or cumene, and substantially all dialkylbenzene-containing At least a portion of the polyalkylbenzene fraction, including a portion of the amount and major trialkylbenzene content, is fed to an alkyl transfer zone containing an alkyl transfer catalyst selected from the group consisting of zeolite Y1, zeolite beta, and zeolite omeca. Preferably, the alkylation catalyst also comprises zeolite beta and the alkyl transfer catalyst zeolite beta or zeolite Y.

More specifically, in embodiments of the invention directed to the production of ethylbenzene, the alkylation reaction takes place over a zeolite beta alkylation catalyst. The product from the alkylation reaction zone is fed to a benzene separation zone. A high boiling fraction consisting of an ethylbenzene polyethylbenzene mixture is fed from the benzene separation zone to the ethylene separation zone. This zone is operated to produce a low boiling product fraction consisting of ethylbenzene and a high boiling heptad fraction consisting of polyethylbenzene containing up to 5% by weight of ethylbenzene. The polyethylbenzene fraction is fed together with benzene to an alkyl transfer zone preferably containing a zeolite Y alkyl transfer catalyst.

Further in accordance with the features of the present invention, a modified hydrogen zeolite beta of high surface area and low sodium or other alkali metal content is of good activity and aging quality when used as a catalyst in hydrocarbon conversion reactions. Molecular sieves are given. In addition, the method for producing such modified zeolite beta according to the present invention and the alkylation catalyst comprising zeolite beta described herein can be used to prepare a relatively low molecular weight alkyl under mild temperature conditions including liquid phase conditions. A method for alkylating aromatic substrates using alkylating agents is provided. A preferred embodiment of the present invention is to perform alkylation of benzene using ethylene in the production of ethylbenzene under alkylation conditions such that the amount of ethylbenzene in the liquid phase and produced xylene is 0.03% or less based on the amount of ethylbenzene produced. It is.

In another embodiment of the invention, the liquid phase alkylation process is carried out such that at least 1 mol %, preferably at least 2 mol %, of the alkylating agent is dissolved in the aromatic substrate.
It is carried out using a plurality of reaction stages coupled in series operated at an average temperature below 300° C. with the alkylating agent injected into intermediate stages.

In one feature of the invention, the modified zeolite beta has a crystal structure of at least 600 m2/g, preferably at least 650 m2/g based on the crystal structure of zeolite beta.
It has a surface area of 2/g. Further according to a feature of the invention,
Hydrogen zeolite beta is combined with a binder to provide a molecular sieve in which the surface area of the zeolite beta based on the molecular sieve and binder is at least 450 m2/g.

In a further feature of the invention, a hydrogen zeolite beta is provided which has a sodium content of less than 0.04% by weight Na2O in the crystal structure of the zeolite beta. Preferably, the sodium content is 0.02% by weight Na2
Less than 0.

Other embodiments of the present invention include methods for producing hydrogen zeolite beta derived from alkali metal modification, including zeolite beta synthesized by hydrothermal decomposition of a reaction mixture containing an organic templating agent. Synthetic zeolite beta may be produced by any suitable technique, such as those described in Wadlinger et al., Calvert et al. or European Patent Applications. During the process, the synthesized zeolite beta is treated with an ion exchange medium in order to protonate at least a portion of the active sites of the zeolite by exchanging alkali metal ions. The ion-exchanged zeolite is then calcined at a temperature in the range of 400 to 700°C for a period of at least 2 hours, preferably in the range of 2 to 10 hours.

The calcined zeolite beta is again treated with an ion exchange medium to protonate additional active site moieties by exchanging additional alkali metal ions. The ion-exchanged zeolite from this step is mixed with a binder to produce a ground zeolite-binder mixture. This mixture is pelletized by extrusion or any other suitable technique and the resulting pellets are then dried.

In a preferred embodiment of the invention, the ion exchange step is accomplished by repeatedly dipping the zeolite beta into an ion exchange medium consisting of an aqueous solution of an ammonium salt.

In a further feature of the invention, the intermediate calcination step between the ion exchange treatment steps is performed to reach a surface area based on the crystal structure of zeolite beta that is at least twice the surface area of the as-synthesized zeolite beta. Carry out under sufficient time and temperature conditions.

Additionally, in embodiments of the invention, a zeolite molecular sieve catalyst having a pore size greater than 6.5 angstroms is used to pass the feedstock containing at least one aromatic compound and having water entrained therein to a dehydration zone. A liquid phase aromatic conversion method is provided. In the dewatering zone, water is removed to provide a dehydrated feedstock with a water content of less than 100 ppm, preferably 50 ppm or less.

The dehydrated feedstock is then fed to a reaction zone containing a molecular sieve catalyst preferably selected from the group consisting of zeolite Y and zeolite beta.

The reaction zone is operated at temperature and pressure conditions sufficient to maintain the reactor contents in the liquid phase and also to allow the conversion reaction to proceed in the presence of a catalyst.

Certain embodiments of the invention include liquid phase alkylation of aromatic substrates, particularly the ethylation of benzene in which the feedstock is dehydrated to produce ethylbenzene to reduce the water content below 100 ppm, as described above. A further feature of the invention includes transalkylation of a feedstock containing a polyalkylbenzene component and a mixture of benzene components to produce a disproportionated product consisting of monoalkylbenzene. At least a portion of the feed to the transalkylation reaction zone is dehydrated to 100 pp.
A feedstock containing both a polyalkylbenzene and a benzene component is provided having a total water content of less than or equal to m.

Other embodiments of the invention reduce the aromatic substrate/alkylating agent molar ratio sequentially when passing from one stage to another. A method for liquid phase alkylation of aromatic substrates using C2-C4 alkylating agents in a multistage reaction system is provided. In this aspect of the invention, the reaction step is operated under temperature and pressure conditions that cause alkylation of the aromatic substrate, wherein the pressure is at or above the vapor pressure of the aromatic substrate at alkyl reaction conditions and the vapor pressure of the alkylating agent. It is below pressure. The raw materials consisting of aromatic substrate and alkylating agent are fed to the first reaction stage in relative amounts that provide a first molar ratio of aromatic substrate to alkylating agent. An effluent consisting of a mixture of aromatic substrate and alkylated product is recovered from each reaction zone and fed to the next subsequent reaction stage. An alkylating agent is fed together with the effluent to the next subsequent reaction step, and a final molar ratio of the aromatic substrate to the alkylating agent for the final reaction step is less than the first molar ratio fed to the first said reaction step. The overall progression through a multi-stage reaction system reduces the molar ratio of aromatic substrate to amount of alkylating agent giving a molar ratio.

Preferably, the multi-stage reaction system in this embodiment of the invention produces less than 0.05% by weight of xylene, preferably less than 0.03% by weight, as described above, based on the amount of ethylbenzene produced. It consists of 3 to 8 reaction stages operated under conditions that result in the monoethylation of benzene.

Figures 1a-1c and 2a-2c are graphs illustrating alkyl transfer experiments performed using two different zeolite Y catalysts.

Figures 3a-3C are graphs illustrating the results of experiments conducted on the alkyl rearrangement of diethylbenzene using other zeolite Y catalysts.

Figures 4a-40 are a series of graphs illustrating experiments performed with rare earth zeolites.

Figures 5a, 5b and 6 are graphs further illustrating experiments using zeolite Y catalysts.

FIG. 7 is a simple flow diagram illustrating one embodiment of the present invention in which a polyethylbenzene fraction is subjected to a residue extraction step prior to alkyl rearrangement.

FIG. 8 is an illustration of a modification of the process of FIG. 7 in which the product from the transalkylation reactor is subjected to a separation step prior to recycling.

FIG. 9 is a simplified illustration of another embodiment of the present invention in which the bottom hexalactone from an ethylbenzene column is fed directly to a transalkylation reactor, with the product of the transalkylation reactor being fed to a downstream separation zone. It is an explanatory diagram.

FIG. 1O is a flow diagram illustrating an improvement to the embodiment of FIG. 9.

FIG. 11 is an illustration of a special embodiment of carrying out the invention using multiple series-coupled reaction steps.

FIG. 12 is a graph showing the results of an experiment involving dehydration of a feed fluid to a transfer alkyl reaction over a zeolite Y catalyst.

FIG. 13 is a graph showing the results of an experiment involving dehydration of a feed fluid to a transalkyl reaction carried out over another Zeolite Y catalyst.

A preferred application of the invention includes liquid phase alkylation over a zeolite beta alkyl catalyst coupled with liquid phase alkylation over a molecular sieve alkyl transfer catalyst selected from the group consisting of zeolite Y and zeolite beta. Particularly preferred embodiments of the invention include the use of zeolite Beta as the alkylation catalyst and zeolite Y as the alkyl transfer catalyst. However, other molecular sieve catalysts may be used in carrying out the present invention, as described below.

Furthermore, although a preferred application of the invention is in the use of liquid phase alkylation combined with liquid phase alkylation, the present invention is applicable to liquid phase alkylation and transalkylation production as disclosed in the above-mentioned Dwyer patent, for example. This can be carried out using vapor phase alkylation coupled with appropriate recycling of the material to the separation zone.

In its more general aspect, the present invention generally describes alkylating agents of the type disclosed in the above-mentioned patents by Boritzer et al. This includes aromatic alkylation and coupled alkyl transfer using oxidizing agents. The most widely used alkylating agents are ethylene and propylene, which are applied in the production of ethylbenzene and cumene, respectively. The invention has particular application to the ethylation of benzene under conditions such that the yield of by-product xylene is reduced, and the invention is particularly described with reference to the production of ethylbenzene together with the accompanying polyethylbenzene. It will be.

As mentioned above, a conventional process for producing ethylbenzene involves recycling the polyethylbenzenes separated from the ethylbenzene product to an alkylation reactor where they are transalkylated to form ethylbenzene.

A byproduct of this process is increased xylene yield in the effluent from the alkylation reactor. The presence of xylene complicates downstream processing and separation steps. A particular effect of the significant xylene content in the product stream is the operation of the distillation column to remove ethylbenzene from the top to give a substantial ethylbenzene content of often 15-20% in the bottom polyethylbenzene fraction. is often necessary. For example, ethylbenzene produced according to the present invention can be used in the production of styrene by catalytic dehydrogenation. The boiling points of ortho-xylene and styrene are very close to each other within 1°C. As with practical processes, ethylbenzene specifications require very low xylene content, typically less than 2000 ppm. To meet this specification, it is usually necessary to operate the ethylbenzene column under mild distillation conditions resulting in high ethylbenzene content in the bottom fraction as described above. The present invention minimizes xylene formation during the manufacturing process by conducting the polyethylbenzene alkyl transfer in a separate reactor under relatively mild liquid phase conditions. This allows ethylbenzene recycle to be reduced by limiting the ethylbenzene content in the polyethylbenzene fraction to 5% or less by weight, and if preferred further reducing the xylenes produced to about 2% or less by weight of ethylbenzene. Catalysts are used to minimize

Preferred features of the invention include separating a substantial portion of the diethylbenzene for recycle to the alkylation zone, as disclosed in the Waid patent, supra, or separating a substantial portion of the diethylbenzene for recycle to the alkylation zone, as disclosed in the Patent to Berger, supra, above. In contrast to using dialkylbenzene-only transalkylation to separate trialkyl aromatics, it involves feeding a polyethylbenzene fraction containing both diethylbenzene and triethylbenzene and high molecular weight compounds to a transalkylation reactor. In this regard, depending on the arrangement of the interface of the transalkylation reactor and the polyethylbenzene or other separation zone, substantially all of the diethylbenzene and substantially or most of the triethylbenzene content may be transferred to the transalkylation reactor. supply to. In either case, the net effect of this embodiment of the invention is that recycle to the alkyl reactor is limited to benzene and lighter components such as ethylene, while most if not all triethylbenzene is converted to diethylbenzene. and are retained in the system for final conversion to benzene and ethylbenzene. This provides considerable advantages over conventional methods not only in terms of the reduction in xylene produced as mentioned above, but also in terms of final product yield.

In experiments for the present invention, many catalysts were
It was used for alkyl transfer studies carried out in a spilled-bed reactor, ie only the liquid phase was in contact with the catalyst. The feedstock used in this experiment was an approximately 1:1 mixture of polyethylbenzene over-rad fractions from a commercial operation using vapor phase alkylation of benzene to produce benzene and ethylbenzene. Representative raw materials used in the experiments had the compositions shown in Table 1 below.

Table 1 Non-aromatic 0.32 Benzene
50.241 Toluene
o, oo.

Ethylbenzene 6.117p+ 1
4-xylene o, oo.

Styrene 0.0630-xylene 0.066 cumene
3.973n propylbenzene
7.816m1ρethyltoluene 1,3.5-1-limethylbenzene 0.1280
-Ethyltoluene 0.3561, 2.4
- Trimethylbenzene 0.5361, 2.3-
Trimethylbenzene 0.401m-diethylbenzene 14.8080+p-diethylbenzene 7.328butylbenzene
1.653 Heavy substances 4.42
In nine experiments, the average pressure was approximately 300 psia;
The pressure drop across the reactor is then approximately 5-15 psi.
It was within the range of The temperature profile through the reactor is relatively constant, with endotherms from inlet to outlet below 10°C;
Usually it was below 56C. Experiments began at relatively low temperatures, typically below 100°C, and were gradually increased as described below.

Space velocity is 6 hours based on total hydrocarbon supply -'
(LHSV) was held relatively constant. The conversion and selectivity of diethylbenzene to ethylbenzene was determined as a function of catalyst life (duration of experiment) as well as the production of various other components, including xylene.

In the first tests, the catalyst used was commercially available zeolite Y
(herein defined as Catalyst A), the inlet temperature was gradually increased to about 235°C, and the average temperature rise through the reactor was stabilized at only 1 or 2°C.

The results of this experiment are shown in Sections 1a-1c, where % diethylbenzene conversion, % selectivity to ethylbenzene C1
Ortho-xylene production 0, ppIIk, temperature, T, and °C, respectively, are plotted against the catalyst life A1 hour on the horizontal axis, curve 1■,
Plot as I2, 14 and 16. As can be seen from examination of the data in Figure 81, the diethylbenzene conversion stabilized at about 32-37% for a reaction time of about 237°C, with the catalyst showing little deactivation over the course of the experiment. Didn't show it.

The selectivity to ethylbenzene was essentially 100%. During the experiment, 0-xylene production was approximately 400-500
It was stable at ppm.

Other tests were carried out using experimental zeolite Y, defined as catalyst B. The results of this experiment are shown in Figures 2a-2c, where curves 18, 19, 21 and 22 are respectively diethylbenzene conversion plotted as a function of catalyst life A;
C, selectivity to ethylbenzene, O- in SSppm
FIG. 2 is a diagram of xylene, 0% and temperature, T. In this experiment, the catalyst was used for approximately 400 hours, and the temperature after initiation increased slightly over time to a final value of approximately 240°C. As can be seen, the diethylbenzene conversion was relatively good at approximately 30-40% at relatively mild temperatures.

Selectivity to ethylbenzene was greater than 90% and virtually 100% during most of the experiment. The O-xylene content of the product fluid was stable at about 90 o ppm.

Further tests were conducted using another zeolite Y defined as Catalyst C. Diethylbenzene conversion, selectivity and results as a function of time and temperature are shown here in Figures 3a-30. In Figure 3, curves 24, 25, 27 and 2
8 is a diagram of diethylbenzene conversion, ethylbenzene selectivity, O-xylene content (ppm), 0 and temperature, T, °C as a function of catalyst life on the horizontal axis. As shown in Figure 3, the diethylbenzene conversions are slightly better than those for Catalysts A and B by comparison, and are generally
It was in the range of 0-50%. Selectivity to ethylbenzene was greater than 90% in dogs and virtually 100% in the majority of experiments. 0-xylene content is approximately 800~9 Q Op
It was stable at pm.

The catalyst showed little deactivation over the period of the experiment and
.

The results for catalysts using rare earth zeolite Y, defined as catalyst, in further tests are shown in Figures 4a-40, where curves 30, 32, 33 and 35 represent diethylbenzene conversion as a function of catalyst life, respectively. FIG. 2 shows a diagram of conversion rate, conversion to ethylbenzene, ppllh O-xylene and temperature. The catalyst showed relatively good results with diethylbenzene conversion in the range of 40-50%.

The initial selectivity was about 100%, and the selectivity decreased slightly to about 90% towards the end of the experiment. While good conversions and selectivities were achieved, the reaction temperature increased to about 270° C. after about 210 hours of experimentation, which was substantially higher than the previous Zeolite Y.

The raw materials for the experiments depicted in Figures 1-4 generally consisted of the compositions shown in Table 1. However, the first exam (
The feed for catalyst A) contained no ortho-xylene and the feed for the second run (catalyst B) contained approximately 0.02% para and menu xylene.

Additional experiments under the conditions described above were carried out using three additional catalysts: Catalyst E, a cation exchange resin obtained from Rohm & Haas under the designation Amberlys L l 5; Catalyst F, a cation exchange resin designated 3998; Harshaw
- Super acidic alumina and catalyst G obtained from Filtroj, Union named N1-Cn 9040
Nickel modified mordenite obtained from Carbide.

Due to the difficulty of the experiment, Catalyst E had low diethylbenzene conversion and the experiment took approximately 50 hours and 15 hours to complete.
No ethylbenzene was produced at a temperature of 5°C. Catalyst F produced diethylbenzene conversions ranging from about 1O to 20% at a degrees ranging from about 300 to 450°C, with selectivity to ethylbenzene being less than 50% for the most part. Catalyst G was operated for 100 hours at temperatures ranging up to 350°C and showed almost no conversion of diethylbenzene.

The zeolite Y catalysts defined above as catalysts A and B were also trickled down in the presence of a substantially gaseous phase.
le) Used in bed reactor. Fresh and regenerated catalysts were used. This experiment was carried out at a pressure of about 330 psig, a nominal space velocity of about 10 h-' (L HSV), and about 300 °C for fresh catalyst A, about 300-400 °C for fresh catalyst B, and regenerated catalyst. Approximately 200℃ in case of
The average reactor temperature was

Initial diethylbenzene conversion was about 24% for fresh Catalyst A, but it dropped rapidly after a few hours. The catalyst is then regenerated and under less severe temperature conditions of about 200°C the initial diethylhensen conversion is about 60°C.
%, but this again decreased to only a few % after about 24 hours.

With fresh Catalyst B, the initial diethylbenzene conversion was over 50%, but this decreased to about 20% after about 5 hours, and then to only a few percent. When the regenerated catalyst B is operated at a low temperature of about 200°C, it loses about 58%
shows an initial diethylbenzene conversion rate of 27
After some time, it decreased to about 27%, and the experiment was terminated at this point.

Additional experiments were conducted using zeolite Y, defined above as catalyst B, in which the feedstock was relatively pure diethylbenzene mixed with approximately equal parts of benzene.

Unlike the feedstocks used in the experiments of Figures 1-4, the pure diethylbenzene feedstock contains only very small amounts of decomposable materials or other conversion reactions such as deethylation to produce xylenes, and It also did not contain xylene. The composition of the raw materials used in this experiment is shown in Table 1 below.

Table ■ Ingredients Weight% Non-aromatic 0.01 Benzene
56.58 toluene
0.09 Ethylbenzene 0.01
Xylene o, ooo.

n-RP-BZ O, 02m,
p-ethylbenzene 0.030-ethyltoluene 0.01124 trimethylbenzene 5ee-5U-BZ O,471
23 trimethylbenzene m, diethylbenzene 27.62o, p-diethylbenzene 14.27n-BU-BZ
O,35 heavy substances
0.54 In this test, the inlet and outlet pressures were held at 310 and 305 psig, respectively. The average temperature of the reactor was increased approximately linearly over time from an initial value of about 198°C to a final value of about 298°C. The space velocity generally drops to about 5.8-6.0 hours-' except at about two-thirds of the way through the test, when it drops to about 5.1-' before recovering to a higher value.
(L HS V) Within range! : [I had it.

The results of this test are shown in Figures 5 and 6. In FIG. 5a, curve 38 is a diagram of temperature, T, versus time for catalyst A on the horizontal axis. In Figure 5b, curves 40 and 41 are plots of % selectivity and % ethylbenzene conversion, respectively, for ethylbenzene. Curve 42 is a diagram of the total xylene produced, X, in ppm based on the amount of ethylbenzene produced. FIG. 6 shows the relationship between ethylbenzene conversion and temperature. Curve 43 is a diagram of the ethylbenzene conversion rate, C, on the vertical axis versus the temperature, T, on the horizontal axis.

As shown by the data shown in Figure 5, the xylene produced remained low throughout the test. No xylene was formed until the temperature increased to about 260° C. (generally corresponding to a decrease in space velocity to about 5.1 h −1 as described above). The % conversion remained good until the temperature rose above 2800C.

As shown in Figure 6, the ethylbenzene conversion rate is approximately 200
It remained about 50% over the temperature range ~290<0>C, with the optimum range appearing to be about 210-280<0>C.

Still referring to the figures, Figures 7-10 are 70-diagrams illustrating different embodiments of the present invention. For purposes of discussion, the present invention is applied to the production of ethylbenzene by the reaction of ethylene with benzene, and the alkylation reaction is carried out using zeolite beta, zeolite Y or zeolite omega as the alkylation catalyst in an effluent liquid phase alkylation process. Assume that the reaction is carried out in a reactor. However, as mentioned above and discussed in detail below, the alkylation step could be carried out as a reaction in the vapor phase using a catalyst such as a silicate or ZSM-5.

Referring first to FIG. 7, lines 51 and 52, respectively.
A feed stream 50 containing ethylene and benzene supplied via the
It is reduced to a level of Oppm or less, preferably about 50 ppm or less, and then passed to alkylation reaction zone 56.

The alkylation reactor, which may consist of a plurality of series-coupled adiabatic reactors with an intermediate injector of ethylene and also an intercooler, maintains the benzene in the liquid phase and dissolves at least 2 mole percent ethylene in the benzene. For this purpose, it is typically operated at an average temperature of 220° C. and a sufficient pressure of about 600 psia or more. Instead of using an adiabatic reactor, one or more with suitable cooling devices used to maintain a substantially constant temperature (with little or no temperature difference) from the inlet to the outlet of the reactor. An isothermal reactor can be used. A reserve operated to provide a light overrad fraction containing benzene and a heavy liquid fraction containing benzene, ethylbenzene separation zone 61 which feeds the effluent from the alkylation reactor to the alkylation input via line 59 It is fed to a fractionation column 58.

The product from pre-fractionation zone 58 is fed via line 6° to benzene separation zone 61. The overrad fraction from column 61 contains residual 1)(7) benzene, which is recycled via line 62 to the alkylation reactor input.

The heavy bottoms fraction from column 61 is fed via line 64 to ethylbenzene separation zone 65. Of course, the overrad fraction from column 65 consists of ethylbenzene that is fed to storage or any suitable product destination. As an example, ethylbenzene can be used as a feed stream for a styrene plant, where styrene is produced by dehydrogenation of ethylbenzene. The bottom fraction containing polyethylbenzene, heavy aromatics and only a small amount of ethylbenzene, preferably less than 5% as described above, is fed to a polyethylhensen separation zone 68. The bottom 7 sections of column 68 consist of the residue. Overhead fractionation from column 68 containing polyethylbenzene, triethylbenzene (usually in relatively small quantities), and a small amount of ethylbenzene is fed to transalkylation reaction zone 72 . By minimizing the amount of ethylbenzene recovered from the bottom of column 65, the ethylbenzene content of the transalkyl feed stream is kept low to direct the transalkylation reaction in the direction of ethylbenzene production. The polyethylbenzene hexalactone recovered from the top via line 70 is mixed with benzene fed via line 73 and then fed to the transalkyl reactor 72. The molar ratio of benzene to polyethylbenzene should be at least 1:1 and preferably within the range 1:1 to 4:1.

The product from the alkylation reactor containing benzene, ethylbenzene and a reduced amount of polyethylbenzene is fed to benzene column 61 via line 75.

In the process shown in FIG. 7, the alkylation reaction is carried out in a liquid phase by dehydrating the raw material fed to the alkylation reactor. As mentioned above, the present invention can be carried out using vapor phase alkylation followed by liquid phase alkylation, and in such reactions, depending on the catalyst used, a significant amount of water is introduced into the alkylation reactor. may be included in the raw materials. In this case, it may be necessary to carry out the dehydration of the feedstock to the alkyl rearrangement reactor separately.

Such dehydration can be carried out at any point upstream of the transalkylation reactor, and if necessary dehydration is
This should be done with respect to the fresh benzene feedstock fed through the reactor, as well as with respect to the polyethylene component produced during the alkylation reaction.

FIG. 8 is an improvement on the process disclosed in FIG. 7, in which the product of the transalkylation reactor is further processed before being recycled to the separation system. The embodiment of FIG. 8 is particularly useful when relatively high conversions are achieved in the alkyl transfer reactor. In the embodiment of FIG. 8, the alkylation reactor and separation system are similar to FIG. 7, and similarly components are designated with the same reference symbols. However, the distillation is operated to produce a bottom purge stream that removes the product from the alkyl transfer reactor via line 78 and a recycle stream that is recovered via line 80 and fed to the benzene column. A second separation zone 77 is fed which may take the form of a column.

A purge stream containing heavy hydrocarbons is withdrawn from the system, thus providing a partially single pass system with no recycling of high molecular weight hydrocarbons.

FIG. 9 further illustrates another embodiment of the present invention in which the polyethylbenzene fraction recovered from the ethylbenzene column is directly subjected to an alkylation reaction. In Figure 9,
System components that are the same as those shown in FIGS. 7 and 8 are given similar reference numerals. As shown in FIG. 9, the product from ethylbenzene column 65 is mixed with benzene fed via line 82 and transferred to alkyl transfer reactor 84.
supply to. The entire polyethylbenzene fraction is now subjected to an alkyl rearrangement. The conditions used in reactor 84 are similar to those described above, with the ratio of benzene to polyethylbenzene ranging from about 1:1 to 4:1.

It will be appreciated that the method depicted in FIG. 9 is similar to that of FIG. 8, except that the entire bottom fraction from the ethylbenzene column is subjected to an alkyl transfer reaction. The ethylbenzene content of the input to the alkyl transfer reactor was reduced to 5
% or less, preferably 2% or less, is particularly important here in achieving conditions that promote the alkylation reaction. The products from the alkyl transfer reactor are removed via line 85 from the recycle stream, primarily benzene and ethylbenzene, and a bottom consisting primarily of C5 and COO hydrocarbons such as ethyltoluene, cumene, butylbenzene, etc., which are removed from the recycle stream by barge line 88. A host transalkylation separation zone 86 is fed which may take the form of a distillation column operated to produce an overrad fraction consisting of frucunion. The over-rad fraction is recycled to the benzene column through line 89 as before.

The embodiment of FIG. 1O is similar to that in which the transalkyl transfer reactor product is split and a portion is fed directly to the benzene column 6 via line 92, and the remainder is fed to a separation zone operated as described above. is similar to FIG. 1O. The arrangement of FIG. 10 provides a system that maintains low concentrations of 09 and C1o hydrocarbons in the system and reduces the energy costs of operating column 86. Typically, about 60% or more of the transalkylation reactor product is recycled directly to Penguin column 61 and the remainder is sent to separation zone 86.

As mentioned above, one of the zeolite catalysts that are useful as aromatic alkylation catalysts is zeolite beta, and certain embodiments of the present invention are suitable for use when modified under relatively mild liquid phase alkylation conditions. zeolite beta aromatic alkylation catalyst. The invention has particular application to the ethylation of benzene under mild liquid phase conditions with little or no xylene formation, and the invention is specifically described with reference to the production of ethylbenzene. However, other alkylation reactions may be utilized in carrying out the present invention. For example, the invention can be applied to the reaction of propylene and benzene to produce cumene. Also,
While olefinic alkylating agents are commonly used, other alkylating agents such as those disclosed in the above-mentioned Boritzer et al. patents may be used, such as alkynes, alkyl halides, alcohols, ethers, and esters. Other aromatic substrates such as toluene and xylene may also be subjected to alkylation according to the invention.

The activity of the zeolite beta utilized in the present invention suggests that zeolite beta is unsuitable for use under the relatively harsh conditions involved in the vapor phase ethylation of benzene due to its low forcing index. patent and the technology found in the above-mentioned Young patent which limits its application to relatively long chain length alkylating agents. Dwyer's patent for producing ethylbenzene under relatively severe temperature conditions of 900°C or higher, i.e., 650-900"F, preferably 700-850T, states that zeolite beta can be produced under the high temperature conditions involved in the Bewyer process, as mentioned above. of aromatic substrates can be used as catalysts in the ethylation of aromatic substrates.

The present invention proceeds in direct opposition to these prior art techniques. In the present invention, zeolite beta is a low molecular weight (C2-C
4) It is a highly effective catalyst for the alkylation of aromatic substrates using alkylating agents. Furthermore, this one is 300
It is an effective alkylating agent under mild liquid phase conditions, including temperatures at or below 0 C, giving high conversion efficiency and high selectivity for monoalkylation. As mentioned above, these mild reaction conditions produce negligible xylene;
And the production of ethylbenzene takes place, which for all practical purposes does not exist. Crystalline zeolite beta, which is fixed by its X-ray diffraction pattern, and its basic method of preparation are described in U.S. Pat. No. 3,308 to Wadlinger, supra.
No. 069. As described herein, zeolite beta is synthesized by hydrothermal decomposition of a reaction mixture consisting of silica, alumina, an alkali metal or alkaline earth metal oxide or hydroxide, and an organic templating agent.

The zeolite beta catalyst used in this embodiment of the invention is preferably of very low sodium content, which can be easily prepared by the novel process described in detail below.

Low sodium content zeolite beta is known per se in the art. For example, Wadlinger's patent was exchanged continuously for 48 hours with a 2% solution of ammonium chloride.

A zeolite beta produced by processing the dried product resulting from a cracking process is disclosed.

After washing until it is free of excess chloride ions,
The catalyst was dried and calcined for 3 hours under 1,000 ℃, 0.
An acid beta aluminosilicate with a 0.7% Na content is produced. The above-mentioned patent by Calvert et al. also contains relatively low sodium contents, such as 0.14% by weight and 0.14% by weight.
A zeolite beta with 11% Na by weight is disclosed.

The preferred zeolite beta of the present invention is characterized by a substantially lower sodium content than that disclosed in the Wadlinger et al. and Calvert et al. patents. It is also characterized by a very high surface area, in particular with respect to at least 600 m2/g based on crystalline zeolite beta.

Suitable zeolite beta has a low sodium content, expressed as Na2O, of less than 4% by weight, preferably less than 0.02% by weight. The preferred zeolite beta is produced by a calcining process using a series of ion exchangers and as-synthesized zeolite beta as starting material. Synthesized zeolite beta may be produced by hydrothermal decomposition of a reaction mixture by any suitable method, such as those disclosed in the above-mentioned US patents by Wadlinger et al. and Calvert et al., and the above-mentioned European patent applications.

In producing the modified zeolite beta according to the present invention, the as-synthesized zeolite beta is subjected to multiple successive ion exchange and calcination treatments, with extremely low sodium content and substantially the same Watlinger as described above. achieve a molecular sieve product with a sodium content below the sodium content of acid zeolite beta produced by patents such as Acid Zeolite Beta. Additionally, the final molecular sieve product has a substantially higher surface area than previously obtained for zeolite beta. This embodiment of the invention involves an initial ion exchange treatment of as-synthesized zeolite beta followed by calcination followed by ion exchange to achieve an ultra-low sodium content and high surface area product.

Although the invention is not limited by theory, the invention will not be destroyed by a subsequent calcination step conducted under essentially anhydrous conditions;
Alternatively, the initial ion exchange treatment is believed to remove a substantial portion of the sodium or other alkali metal ions incorporated during the synthesis, so that no undesirable changes occur in the crystal structure of the zeolite beta. Together with the initial ion exchange treatment, this calcination step results in an increase in the surface area of the zeolite beta by at least twice the surface area of the as-synthesized zeolite.

The intermediate calcination step is effective in decomposing the organic nitrotemplating agent within the pore structure of zeolite beta and opens the molecular sieve channels to facilitate subsequent ion exchange treatment. After the initial calcination step, an ion exchange treatment is again performed to protonate an additional portion of the active sites in the zeolite by exchanging sodium or other alkali metal ions. This second ion exchange treatment results in a zeolite beta with a very low sodium content of less than 0.04% by weight Na 20 and a high surface area of at least 600 m2/g based on the zeolite beta crystal structure. A preferred ion exchange medium is an ammonium salt. The zeolite beta resulting from the second ion exchange treatment is mixed with a binder, berentized and dried;
It is then subjected to another calcination step to convert the ammonium-exchanged active sites to acidic (H+) active sites.

The as-synthesized zeolite beta used as a starting material for the present invention can be prepared by any suitable process such as that disclosed in the above-mentioned Wadlinger et al. and Calvert et al. patents and the above-mentioned European patent applications. It can be synthesized by hydrothermal decomposition of other alkali metal oxides as well as organic templating agents.

Typical decomposition conditions are from slightly below the boiling point of water to about 170'C at a pressure equal to or greater than the vapor pressure of water at the temperature involved! Including temperatures ranging up to. The resulting reaction mixture should be maintained under mild mixing, such as stirring, for a period ranging from about one day to several months in order to achieve the desired degree of crystallization in forming the zeolite product. Lower temperatures usually require longer periods of time to achieve the desired crystal formation. For example, at temperatures of about 100°C, crystal growth occurs over a period ranging from about 1 to 4 months, while at temperatures close to the upper limits mentioned above, e.g. 160°C, the decomposition period ranges from 1 or 2 days to about 1 week. It can be.

At intermediate temperatures of about 120-140'C, the decomposition temperature can be several weeks, perhaps 2-4 weeks.

Any suitable templating agent may be used in producing the zeolite beta molecular sieve crystal structure, and as indicated in the above references, suitable templating agents include tetraethylammonium hydroxide and halides such as chloride. Included are tetraethylammonium as well as dibenzyldimethyl-ammonium hydroxide or halogenides such as dibenzyldimethylammonium chloride. The reaction components may vary from techniques well known in the art to provide zeolite beta products of various silica/alumina ratios. Typically, the reaction mixture used to synthesize zeolite beta molecular sieves contains a composition within the following ratios:
SiO□: 5-2000H-/5iC12:
0. l-0,2M/5i (h: 0.
01-1-OR/SiO□: 0.1-2.0
In the table above, R is a nitrogenous organic templating agent, such as a tetraethylammonium group, and M is an alkali metal ion, usually, but not necessarily, sodium. To further describe zeolite beta and its synthesis method,
Reference may be made, in particular, to patents and patent applications, including US Pat. No. 3,308,069 (Wadlinger et al.) and US Pat.

As explained above, the critical first step in carrying out the method of the invention is prior to the high temperature calcination designed to remove the main portion of the templating agent from the internal crystalline molecular sieve network. It consists in treating as-synthesized zeolite beta with an ion exchange medium. The resulting product of the hydrothermal decomposition process resulting in crystallization of zeolite beta is washed and subjected to a process to remove water from the product, including dehydrating the product of water retained within the internal crystalline pores. The drying process can be carried out at a temperature of usually substantially less than 200°C, such as about 150°C. Typically 40, which causes decomposition of the templating agent.
High calcination temperatures of 0° C. or higher should be avoided at this process step.

The ion exchange medium may contain any reagent suitable for protonating active sites in the molecular sieve structure by exchanging sodium or other alkali metal ions incorporated during the crystallization process. The ammonium salts described in detail below are suitable ion exchange agents and the invention will be described in detail with reference to the use of such ion exchange agents. However, it should be recognized that other ion exchange agents compatible with acidifying the active sites in the molecular sieve network may be used in practicing the present invention. For example, ion exchange may be accomplished using aqueous solutions of mineral acids such as hydrochloric acid, nitric acid or sulfuric acid or low molecular weight organic acids such as formic acid, acetic acid or propionic acid. The use of acids, especially strong mineral acids, is undesirable in preparing and modifying zeolite beta for certain applications because dealumination of the zeolite can occur. In addition, organic salts such as ammonium acetate and primary, secondary or tertiary amine salts incorporating low molecular weight alkyl substituents such as methyl and ethyl groups may be used. Examples of such amine salts include alkylammonium chlorides and nitrates such as ethylammonium nitrate, methylammonium nitrate, trimethylammonium nitrate, and amine salts may be used as well. Ion exchange agents also include quaternary ammonium salts, again based on low molecular weight alkyl groups.

As mentioned above, customary inorganic ammonium salts such as ammonium nitrate, ammonium sulfate, ammonium carbonate or ammonium chloride are used as ion exchange agents. Ammonium nitrate is particularly preferred because it decomposes during heating following the ion exchange step to ammonia and nitric acid producing water and nitrogen oxides generated from the catalyst product. Salts such as ammonium sulfate are generally not advantageous over ammonium nitrate due to their substantially higher decomposition temperatures. In some cases, sulfur may also be incorporated into the molecular sieve structure by replacing structural oxygen.

Preferably, each initial ion exchange treatment comprises soaking the zeolite beta in a fresh ion exchange solution.
It is done in two separate steps. During the first step and preferably during both ion exchange steps, the zeolite beta remains immersed in the medium until the exchange system reaches equilibrium between ammonium and sodium (or other alkali metal) ions.

As an example, using a 2N ammonium nitrate solution, the zeolite beta can be first soaked in the ion exchange solution at a temperature of 50-90<0>C for a period of about 1-5 hours. At the end of the first treatment, the zeolite beta is recovered from the solution, washed with water and then immersed in a fresh solution of 2N ammonium nitrate. The time and temperature conditions here may be similar to the first immersion.

At the end of the first ion exchange treatment, the ammonium exchanged zeolite beta is then subjected to a high temperature calcination treatment. The calcination process is carried out at a temperature and time sufficient to generate at least a major portion, preferably substantially all, of the templating agent from the mesopore spaces of the molecular sieve network channels. The calcination temperature should be at least 400°C. Usually 700
C or lower, but higher temperatures may also be used. Calcination should normally be carried out for a period of about 2 to 10 hours, although shorter periods of up to about 1 hour at higher temperatures may be suitable.

Calcination can extend beyond 10 hours, but there is usually no reason to calcinate for long periods of time. Preferably, the surface area at the end of this calcination step is at least twice the surface area of the as-synthesized zeolite beta. As shown by the examples below, a three-fold or more increase in surface area can be achieved at the end of the calcination process.

The first calcination step is followed by a second ion exchange treatment,
This results in an increase in the surface area of the zeolite beta and a further decrease in the content of sodium or other alkali metal ions. This calcining ion exchange treatment, like the first treatment, is preferably carried out in two stages by dipping the zeolite beta twice into fresh ion exchange solution. The time and temperature parameters used in the second set of ion exchange treatments are the same as those used in the first set.
may be similar to that involved in ion exchange treatment.

At the end of the second set of ion exchange treatments, the zeolite beta typically has at least twice the surface area of the original starting material and no more than 0.04 wt.% Na2O calculated as Na2O, typically more than 0.602 wt.% Na2O. It will have a very low sodium content.

When the resulting zeolite beta is used as a catalyst, it is usually mixed with a binder such as an alumina salt, gamma/alumina, or other refractory oxide to form a ground zeolite beta binder mixture. The mixture is then pelletized by any suitable technique such as extrusion and then! Dry the resulting pellet. At this point, the pelletized binder zeolite product is calcined under conditions sufficient to decompose the ammonium ions on the active sites so that the zeolite beta can reach the acid (H+) form. As an example to illustrate the invention, an as-synthesized zeolite beta having a silica/alumina ratio of about 20-5o and containing tetraethylammonium hydroxide as a retained templating agent was used as the starting material. The as-synthesized zeolite beta has an initial surface area of 210 m2/g and approximately 0.5
It had a sodium content of ~1% Na2O. The as-synthesized zeolite beta was subjected to ammonium ion exchange treatment by immersing 100 g of the catalyst in an aqueous solution of ammonium nitrate with 2 normality. Immersed in ion exchange medium.

The zeolite beta was then separated from the ion exchange solution, washed and retreated with a fresh solution of 2N ammonium nitrate again at 85° C. for a period of 2 hours. The surface area at the end of the second ammonium exchange stage was 247 m2/g and the sodium content was less than 0.11.

Next, add ammonium-exchanged zeolite beta to about 56
Calcined for 2 hours at a temperature of 0°C. The surface area at the end of the calcination process was 666 m2/g.

A two-step process in which the calcined, exchanged and calcined zeolite beta is cooled and then each step uses the same ion exchange medium and extends for 2 hours under the same conditions used during the first treatment. The sample was subjected to a second ion exchange treatment including . At the end of the third ammonium exchange step (first stage of the second treatment), the surface area of zeolite beta is further reduced to 708
m2/g. The surface area at the end of the final ion exchange treatment was 815 m2/g. At the end of the final ion exchange step, the sodium content was reduced to a value that cannot be measured using atomic absorption techniques. Based on this analysis, the Na2O content was substantially less than 1100 pp.

Ammonium zeolite beta was peptized and mixed with alumina in a ratio of 4 parts zeolite beta to 1 part alumina binder. The resulting plastic-like zeolite binder mixture was extruded to produce pellets having a size of approximately 1/16", and the resulting pellets were then calcined at 560° C. for 2 hours. The final zeolite binder mixture based The surface area of the product was 642 m''/g.

The modified zeolite beta produced according to the present invention can be used in the various catalytic applications mentioned above or in other applications such as selective absorbents. When used as a catalyst, it is often desirable to incorporate the metal component into a zeolite beta binder matrix. Suitable metal components include those found in Groups VIB and II of the Periodic Table. Special metals include chromium, molybdenum, tungsten, vanadium, iron, cobalt, nickel, copper, platinum and palladium.

In experiments conducted regarding the present invention, the above-mentioned high surface area,
Zeolite beta with ultra-low sodium content was used as a catalyst in the reaction of ethylene and benzene to produce ethylbenzene. The experiment was conducted at a nominal temperature of 200℃.
The procedure was carried out in an upflow reactor heated by a sand bath set at . The reactor was based on a zeolite-binder mixture as described above and had a surface area of 642 m2/g.
/16" catalyst in the form of pellets 3.6 g (7, Om
Q) was included. Benzene was fed to the bottom of the reactor at a rate that gave a space velocity (L HS V) of 1 for 10 hours. Ethylene was fed to give a benzene/ethylene molar ratio of 5.2, with the actual molar ratio was varied from about 5.0 to 5.3 during the experiment.The results of the experiment are shown in Table 2.

Effluent analysis is expressed in weight percent for benzene and ethylbenzene and various other components including toluene, cumene, diethylbenzene, and in yield relative to ethylbenzene for ortho and varadiethylbenzene. The total xylene yield throughout the experiment was 0.

The reactor was equipped with four evenly spaced thermocouples from the inlet, TC#1, to the outlet, TC#4. From the exothermic profile shown by the thermocouple, it is clear that most of the alkylation reaction occurs in the lower part of the catalyst bed. Thus, the effective space velocity is substantially higher than the nominal value of 10 hours-' (LHSV).

Cold barley sample No. 1 1 4 5
6 7 8 Catalyst life, time
1,4 19. 27, 2 36.
44.0 61゜Pressure Psi
500 500 500 490 5
00 460 Outro TC4204205205205
204205TC32172182192172152
19TC2231229227227225220PopulationTCI 202 203
201 201 2o1 202
BZ weight% 89.90 75.74
76.22 76.39 81.44 87.4
7EB weight% 8.754 20.345
20.031 19.573 15.632
Yield N-AR weight % based on 9.786EB 0.482 0.367
0.310 0.347 0.279 0.3
57TOLPPM 1119 6
14 624 644 640 73
6CUMPPM 69 25
25 26 0 51M-D
EB weight% 8.971 10.818
10.574 10.836 10.459 1
5.0320+P-DEB weight% 6.461
7.584 7.643 7.955 7.7
98 10.638 Total xylene o, ooo
o, ooo o, ooo o, ooo
o, ooo o, oo.

Total DEB 15.832 18.7
o2 18.217 18.791 18.25
7 25.66986, 108. 1
32. 155. 179201
200 201 200 20+8
1.11 75.48 78.60 75
．． 40 80.1714.850 19.391
16.735 +9.412 45.4
730.403 0.391 0.298
0.436 0.46415.286 14.
749 15.728 14.398 15.
47] 11.205 11.046 11.58
6 11.637 1+, 9690.000
0.000 0.000 0.000
0.00026.492 25.795 27.3
14 26.035 27.440 Table ■ - Continued Sample No. l 14 15
16 17 18 Catalyst life, hours
210 257 279 300
306 Pressure PSI 525 5
05 475-545 510 500 Exit T
C4209206209208206TC323022
2222229220TC2226224220226
223 population TCI 201 2
01 202 202 201BZ weight% 76.76 78.17 73.
54 g3.29 85.21EB weight%
19.000 17.855 20.942
11.306 12.114 Yield N-AR weight % based on EB 0.348 0.225
0.240 0.475 0.430TOLPP
M 711 560 497
964 10321032CU
26 22 29 53
0M-DEB weight% 13.246 9
．． 997 12.593 23.973 10.
0450+P-DEB weight% 11.227 9
．． 235 12.322 23.034 9.8
36 total xylene o, ooo o, ooo
o, ooo o, ooo o, oo.

Total DEB 24.473 +9.2
32 24.915 47.007 19.88
1224 207 '224
224 222 22220+
201 201 201
200 20174.03 7
6.09 69.68 70.0+ 7
2.63 70.8820.961 19.
206 24.756 24.353 2
2.222 23.7080.280 0.
275 0.164 0.270 0.2
90. 33911.755 10.784
10.571 10°860 10.9
61 10.08811.695 11.55
3 11.573 11.830 11.
727 12.207 o, ooo o, o
oo o, ooo o, ooo
o, ooo o-oo.

23.451 22.337 22.144
22.690 22.688 22.3
From a review of the experimental data presented in Section 05, and considering that for the most part the ethylene charge to the reactor is slightly less than 20% of the benzene stoichiometry,
It can be seen that the zeolite beta catalyst is highly active and exhibits good selectivity for ethylbenzene production.

The activity of the catalyst remained substantially unreduced after the period of the experiment.

In carrying out this embodiment of the invention, the alkylation reaction is carried out at a reaction temperature well above the vapor pressure of the aromatic substrate to maintain the liquid phase in the reactor. To provide a complete liquid phase reaction, a spilled bed format is used where the catalyst bed is completely immersed in the liquid. This can be easily accomplished using upflow techniques, as used in experiments, and is generally preferred in practicing the invention. However, downflow control can be accomplished by controlling the outlet flow rate to ensure conversion of the catalyst bed with liquid benzene or other aromatic substrate.

Preferably, a stepwise reaction mode is used to ensure good solubility of ethylene (or other alkylating agent) in benzene (or other aromatic substrate) so that the entire reaction occurs in the liquid phase. In addition, the use of a multistage process provides the opportunity for intercooling where an adiabatic reactor is used or the use of several isothermal reaction stages is permitted.

Returning to FIG. 11, it includes multiple adiabatic reactors with intercooling and ethylene injection. A diagrammatic illustration of a stepwise reaction system used for the production of ethylbenzene by reaction of ethylene and benzene is presented.

More specifically, and as illustrated in the figures, ethylene and benzene are fed via lines 102 and 104 to an inlet line 105 of a dehydrator 1106 operated according to other embodiments as described below.

The dehydrator is operative to dewater the input to the alkylation reactor so that it is essentially dry, preferably containing no more than 100 ppm of water, more preferably no more than 50 ppm of water. By way of example, the dehydrator 106 may take the form of a packed column filled with a drying agent such as silica gel or other suitable hydrophilic medium.

The dehydrator effluent is fed to the first reactor 108 of a plurality of series-coupled alkylation reactors operated in upflow mode. Reactor 108 is operated at an average temperature of 3000C or less, preferably within the range of 200-250C. The pressure in reactor 108 is sufficient to maintain the benzene in the liquid phase and is preferably at least 50 psi below the vapor pressure of benzene at the reactor temperature.
It's expensive. Typically, the reactor pressure is about 500 to
It is within the range of 600 psia. The remaining downstream reactors are usually operated under approximately the same conditions as the first reactor. Effluent from the first reactor 108 is collected via line 109 and fed through heat exchanger 112 where it is cooled. Ethylene is fed via line 111 where it is mixed with the effluent from the first reactor 108. Preferably, the ethylene is fed to the reactor effluent prior to cooling in order to partition the ethylene into the fluid benzene. Desirably, the cooling step is performed to reduce the temperature of the raw material mixture fed to the second reactor 114 to approximately the same value as the temperature at which it is introduced into the first reactor 108. The average temperature in the second reactor is usually about the same as that in the first reactor. The pressure will be somewhat low to provide sufficient pressure gradients to aid system flow, if necessary. The effluent from the second reactor 114 is fed together with ethylene provided via line 117 to a second intercooler 119 where the charge mixture to the third reactor 120 is transferred to the first two reactions. Cool again to a temperature approximately equal to the temperature at which it was introduced into the vessel.

The product from reactor 120 is fed via line 122 to downstream separation and processing equipment 124 .

In unit 124, ethylbenzene is separated and recovered as a product of the alkylation plant. Typically, ethylbenzene will be used as a charge to the dehydrogenation system carried out in catalytic dehydrogenation in the production of styrene.

Typically, benzene and ethylene are separated in unit 124;
It is then recycled for use in the alkylation process. Heavy polyethylbenzene can be transalkylated with benzene to generate additional ethylbenzene as described above.

As usual, a stoichiometric excess of benzene relative to ethylene is fed to the alkylation reactor as a charge stock to increase selectivity for monoalkylation. Operating the reactor to provide liquid phase alkylation under relatively mild conditions not only minimizes xylenes produced during the alkylation reaction;
This allows the use of somewhat lower benzene/ethylene molar ratios than is normally the case. Usually the benzene/ethylene molar ratio will be 5:1 or less, more preferably 4:1 or less. Benzene/ethylene molar ratios as low as about 2=1 may be used. Ratios greater than 5:1 may also be used. However, very high ratios are rarely used, and in practice the benzene/ethylene molar ratio is 15:
It will rarely exceed 1. The benzene/ethylene molar ratios above refer to the entire system, and for a multi-stage reaction system such as that shown in the figure, the benzene/ethylene molar ratio fed to each stage is less than the total ratio.

The amount of ethylene dissolved in the benzene charged to each reactor stage depends in part on the number of reactor stages used. Preferably, at least three reactor stages are used as shown in the figure. Additional reactor stages may be provided, but the total number of stages usually does not exceed eight. Preferably, the pressure in each reaction stage and the amount of ethylene fed are at least 1
It dissolves mol% of ethylene in benzene.

Typically, at least 2 mole percent ethylene is dissolved in the charge to each reactor. Preferably, if many reactor stages are not used, the amount of ethylene dissolved in the liquid benzene phase of each reactor is usually at least 4 mole percent.

Table 7 below gives example conditions and reaction parameters for a multistage system of the type shown in the figure using five reaction stages. As discussed below, Table 7 lists preferred modes of operation when going from one reaction stage to the next, as well as alkylation conditions where the reaction pressure is above the vapor pressure of the aromatic substrate, but at reaction conditions. The advantages resulting from the use of multiple reaction stages in a liquid phase alkylation process that are below the vapor pressure of the agent are illustrated.

In Table 7, idealized reactor conditions for the ethylation of benzene with ethylene are described in columns 2-5. The benzene feed rate in moles per unit time for each reaction stage is shown in column 6. The benzene conversion for each reaction stage is shown in column 7, and the ethylene feed rate in moles per unit time for each reaction zone is shown in column 8. The last column represents the molar ratio of benzene to ethylene at the entrance of each subsequent reaction step. The data presented in Table 7 is based on an idealized case assuming that benzene conversion is approximately 90% of theoretical based on the feed rate of ethylene, which is of course the limiting reactant.

At the temperature and pressure conditions shown in Table 7, containing I
; the solubility of ethylene in liquid aromatic compounds is approximately 10 mol%. The ethylene feed to the first reaction stage is controlled to provide an amount of ethylene near the solubility limit. 1st
0.36 moles of benzene are converted in the reaction zone and, after cooling as described above, the effluent from the first reaction zone is fed to the second reaction zone. The aromatic feedstock to the second reaction zone is approximately 3.64 moles of benzene per unit time and approximately 0.36 moles of ethylbenzene and polyethylbenzene.
Consists of moles. Since the ethylated product can solubilize ethylene at the reaction conditions, the ethylene feed rate can be maintained at 0.4 moles per unit time, resulting in a reduced benzene conversion rate. Although the above relationship is general when going from one reaction step to the next, resulting in a reduced benzene to ethylene molar ratio and increased benzene conversion in each subsequent reaction step, 7th
In the idealized case represented in the table, the intermediate injection of ethylene is held constant.

This need not necessarily occur. For example, the ethylene feed rate may increase or decrease slightly from one stage to the next, or alternatively, as the overall progression through the multistage system increases, some of the benzene/ethylene ratios decrease as benzene conversion increases. increases and then decreases. As an example of a progressively decreasing feed rate, and with reference to the system represented in Table 7, the ethylene feed rate may change from one stage to the next without retaining the characteristics of a decreasing benzene/ethylene ratio as shown in the table. It may progressively decrease by 2-3% if you go for something. When the ethylene feed rate increases from one stage to the next, it is preferred to keep the ethylene below the solubility limit at the temperature and pressure conditions involved to avoid multiphase flow through the catalyst bed.

Multi-stage ethylation of benzene can also be carried out according to the present invention using an isothermal reaction zone. The isothermal reactor is
l) and can take the form of a tube-type heat exchanger with an alkylation catalyst deposited in the tube and a heat transport medium circulated through a shell surrounding the catalyst-filled tube. Of course, the heat exchange medium is fed through the reactor at a rate that maintains the temperature relatively constant throughout each reaction stage. In this case, intercooling is not necessary, but it is preferred to inject ethylene in front of each reaction stage.

As previously discussed, certain features of the present invention make it desirable to use a dehydration step. Aromatic conversion reactions such as alkylation or rearkyl transfer may be carried out in the vapor phase or in the liquid phase. An example of a zeolite with an intermediate pore size is ZSM-5 (approximately 6
(Angstrom pore size) are effective catalysts for vapor phase alkylation or transalkylation, in which the transfer of aromatic molecules in the gas phase through the molecular sieve network occurs by energetic vibrations. It is believed that a molecular sieve with a reasonably large pore size is necessary to provide an effective catalyst for processes such as liquid phase alkylation of benzene. Thus, benzene, which has a mechanical diameter of about 5.9 Angstroms, enters the network of an intermediate pore size molecular sieve such as ZSM-5. However, the resulting alkylated products, such as ethylbenzene or cumene, are not easily seeded through the molecular sieve channels by liquid phase displacement.

Zeolite molecular sieves used in the present invention and having pore sizes greater than 6.5 angstroms can be used under relatively mild conditions for liquid phase hydrocarbon to aromatic hydrocarbon conversion reactions such as benzene ethylation or polyethylbenzene transalkylation. is an effective catalyst for As mentioned above, the conversion occurs at relatively low temperature conditions below 300°C, about 275°C or less. In fact, effective ethylation or transalkylation reactions can occur on the large pore size zeolite molecular sieves used in accordance with the present invention in the liquid phase at temperatures within the range of about 200-250°C;
And such reactions can be accomplished without undesirable side reactions that occur under vapor phase reaction conditions. The pressure in the reaction zone in which the conversion reaction occurs does not necessarily need to be greater than or equal to the vapor pressure of the aromatic substrate involved. Preferably, the reaction zone pressure is at least 50 psi above the vapor pressure. Thus, in the ethylation of benzene at 225°C to produce ethylbenzene, the reactor pressure is preferably about 350 psig.
or more. Generally, the reactor pressure is about 250
It can be in the range of ~lOOopsig.

Ru.

As mentioned above, water can be tolerated in vapor phase reactions, but the high temperature conditions encountered in vapor phase reactions result in dealumination of the catalyst, which corresponds to a reduction in protonated sites and a reduction in acidic catalyst activity. It is expected that similar effects will not occur under the relatively mild conditions of liquid-phase aromatic conversion reactions;
And in fact, dealumination in the presence of water is not believed to occur under these conditions. However, by dewatering the feed stream to the liquid phase reaction zone, the aging quality of the catalyst is substantially increased. In fact, by reducing the water content to well below 300 ppm,
The aging quality of the catalyst in liquid phase conditions is specifically enhanced to values that are normally acceptable for vapor phase reactions without substantially adversely affecting the catalyst aging quality.

As mentioned above, the molecular sieve used in the present invention has a pore size greater than 6.5 angstroms which facilitates the movement of molecules within the molecular sieve network via a liquid phase displacement mechanism. The preferred zeolite molecular sieves, Zeolite Y and Beta, have pore sizes within the range of 7.0 to 7.5 Angstroms. The catalyst is not acid extracted to effect dealumination. In additional experiments conducted for the present invention, such large pore size zeolite molecular sieves were used as catalysts in liquid phase alkyl transfer of diethylbenzene. Two types of zeolite Y
The catalyst was used in this experiment. Zeolite Y is characterized by a three-dimensional channel system and has an average pore size of about 7.3. Zeolite Y catalysts are less than 10, usually about 5 to 69
It has a silica/alumina ratio.

In this experiment, a mixture of benzene and polyethylbenzene overrad fractions resulting from a vapor phase alkylation step was passed into a reactor containing a zeolite Y catalyst. The reactor was operated under an upflow mode configuration with effluent and a pressure of about 30 psig to keep the aromatics in the liquid phase. The flow rate was sufficient to give a space velocity (LH3V) of about 3 h-1 based on total feed. The weight ratio of benzene to polyethylbenzene overhead was approximately 4. Typical feed compositions used in the experiment are shown in Table ①.

Table ■ Non-aromatics 0. Ol benzene
78.87 toluene
0.00 ethylbenzene
3,40p-xylene 0. Ol
m-xylene 0.02 styrene 0.030-xylene
0.04 cumene
1.67n-propylbenzene 3.
30m-Ethyltoluene 0.15p-
Ethyltoluene 0.050-ethyltoluene 0.041.3.5-1-limethylbenzene 0,071.2.4-)limethylbenzene 0.205ec-butylbenzene
0.391. ．． 2.34-limethylbenzene
0.32m-diethylbenzene 7
．． 03n-Butylbenzene 0.29p
+ '-Diethylbenzene 3.90 Heavy substances 0.49 The water content of the raw material is approximately 3
00 ppm. The temperature was increased progressively during the run as necessary to maintain the alkylation reaction at 70% conversion of diethylbenzene. Over the first 11 days of the experiment, the wet feed was first passed through a dehydrator filled with molecular sieve desiccant. The product from the dehydrator was passed into the reaction zone. The dried feedstock was estimated to have a water content of approximately 30 ppm. Thereafter, and throughout the remainder of the experiment, the wet feed was fed directly to the reactor.

The results of an experiment using one type of zeolite Y are shown in FIG. In Figure 12, curves 126 and 127 are the temperature required to maintain 70% diethylbenzene conversion plotted on the vertical axis versus the lifetime of the catalyst in days plotted on the horizontal axis, A (duration of the experiment). , T. As shown in curve 126 for dry feedstock,
The catalyst showed an aging quality of about 1.8 °C per day (
average daily temperature rise required to maintain 70% conversion). Curve 127 in Figure 12 shows the raw material flow at 30
Figure 2 shows the aging quality of the catalyst when the wet feed containing 0 ppm is diverted from the dryer to feed directly to the alkylation reactor. As shown in curve 127, the aging characteristics for the catalyst were more than twice as high at about 3.9° C./day.

Similar experiments were conducted using other zeolite Y catalysts for liquid phase alkyl transfer of polyethylbenzene.

The raw materials used here were the same as those used in the experiments described above. In this case, the temperature was adjusted to the extent necessary to maintain the alkyl transfer reaction at 80% conversion of diethylbenzene. The space velocity is the one used in the previous zeolite Y experiment,
3 hours-' (LH5V). The alkyl transfer reaction is carried out in order to keep the aromatic hydrocarbons in the liquid phase.
It was carried out at a pressure of psig. In this test, approximately 300
A wet feed containing ppm was first fed to a reaction vessel containing zeolite Y. At the end of the 9th day, the feed stream was fed to a dehydrator containing a lilac gel that first extracted water from the feed stream to give a water content of about 30 ppm. Next, 11 more experiments
The reaction continued for several days, during which time the dehydrated raw material was fed to the reaction zone. The results of the experiments performed on the second zeolite Y are shown in Figure 13, where curves 129 and 130 are required for 80% diethylbenzene conversion of the wet and dry feedstocks, respectively, plotted against the catalyst life in days. It is a figure of temperature T1 degreeC considered to be. As shown in Figure 13, the initial wet feed resulted in very rapid catalyst deactivation.

However, at the end of wet feed injection, the introduction of dry feed not only abruptly reduces catalyst deactivation;
It actually increased the activity of the catalyst.

In addition to alkylation, this embodiment of the invention can be used in liquid phase alkylation of aromatic substrates. As shown before,
Particularly important liquid phase alkylation reactions involve mostly xylene or
Or ethylation of benzene under mild liquid phase conditions that does not produce any benzene.

Other liquid phase alkylation reactions can be used, particularly those involving the use of 02-C4 alkylating agents.

For example, this embodiment of the invention may be used in the reaction of propylene and benzene to produce cumene. Usually the alkylating agent is in the form of an olefin. however,
Other alkylating agents such as those disclosed in the above-mentioned patent by Politsauer may be used, such as alkynes, alkyl halides, alcohols, ethers, and esters. Also,
Aromatic substrates other than benzene, such as toluene or xylene, may also be subjected to liquid phase alkylation according to the present invention.

As mentioned above, the dehydration of aromatic feedstock according to the present invention is 7,0
This can be done in conjunction with the use of zeolite molecular sieves other than Zeolite Y having pore sizes in the range of ~7.5 angstroms. In particular, zeolite beta is an effective alkylation catalyst under mild temperature conditions involving liquid phase alkylation.

As previously mentioned, suitable zeolite beta alkylation catalysts contain up to 0.04% by weight expressed as Na2O;
Preferably of very low sodium content, below 0.02% by weight, and at least Boom2/g
has a high surface area. Zeolite beta is about 20-2
It has a silica/alumina ratio of 5.

The omega zeolite mentioned earlier with respect to its use in alkylation and transalkyl transfer, together with its X-ray diffraction pattern and its basic method of preparation,
No. 4,241,036 to Igan et al. Zeolite omega is synthesized by hydrothermal decomposition of a reaction mixture consisting of silica, alumina, alkali or alkaline earth metal oxides or hydroxides, in particular sodium hydroxide and an alkylammonium component, in particular tetramethylammonium hydroxide. .

The chemical composition of zeolite omega in its preferred state can be characterized by: [xR2+yM2
nO]:Al203:5-20SiO2:0-8
H2O, where X has a value ranging from O to 7, and the sum of X and y ranges from 0.5 to 1.5: R is hydrogen;
represents ammonium, alkylammonium or a mixture thereof: M is a metal compound, usually an alkali metal compound, such as sodium; and n is the valence of M.

Further, for a description of zeolite omega and its manufacture, see U.S. Pat. No. 4,241,036 to Lanigan et al.
No. 1, the entire disclosure of which is hereby incorporated by reference.

In benzene alkylation, both the benzene feedstock and ethylene (or other alkylating agent) may contain water. Therefore, it is preferable to pass it through a dehydrator together with benzene and ethylene. Separate dehydrators may be used for the two feed components, or typically ethylene and benzene are mixed in a combined feed stream and fed to the dehydrator and from there to the liquid phase reactor.

In applying this feature of the invention to the alkyl transfer of polyalkylbenzenes, all or part of the feed to the alkyl transfer reactor can be subjected to the dehydration step described above. Usually, the transalkylation of polyalkylbenzenes is carried out in combination with a previous alkylation step, in which the product from the alkylation reactor is subjected to one or more separation steps to remove the benzene and the combined polyalkylbenzene components. cause
It is then passed through a transalkylation reaction zone operated under liquid phase disproportionation conditions as previously discussed.

When the present invention includes an alkylation step carried out in conjunction with a liquid phase alkylation step carried out by the dehydration step, the polyalkylbenzene component fed to the alkyl transfer reactor should not substantially contain water. , and it is usually necessary to subject only the benzene component to a dehydration step. However, in other applications of the invention it may be necessary to subject the polyalkylbenzene component to a dehydration step before introducing it into the transalkylation reactor. For example, the alkylation step may be carried out in combination with a vapor phase alkylation step that allows water in the feed stream or in which water is additionally added, eg, as disclosed in the Berger et al. patent cited above. In this case, it may be necessary to dehydrate both the polyethylbenzene component and the benzene component before passing them through the alkyl transfer reactor.

Having described specific embodiments of the invention, modifications thereof may be suggested by those skilled in the art, and all such modifications are within the scope of the claims of the invention. It is understood that it is a thing.

The main features and aspects of the invention are as follows.

(2) a) feeding a feedstock containing an aromatic substrate into a reaction zone containing a molecular sieve aromatic alkylation catalyst; (b) feeding an alkylating agent into the reaction zone; C) feeding the reaction zone; operating at temperature and pressure conditions that maintain the aromatic substrate in the liquid phase and causing alkylation of the aromatic substrate by the alkylating agent in the presence of the catalyst, resulting in monoalkylated and polyalkylated producing an alkylated product consisting of a mixture of aromatic products: d) recovering the alkylated product from the reaction zone and collecting the product from the reaction zone for separation of the aromatic substrate; e) operating said separation zone to produce a low boiling fraction consisting of said aromatic substrate and a high boiling fraction consisting of a mixture of monoalkylated aromatic-polyalkylated aromatic mixture; f) feeding the high boiling fraction from the separation zone to a second separation zone; g) operating the second separation zone to separate a second low boiling fraction consisting of monoalkylated aromatic products and a second separation zone consisting of monoalkylated aromatic products; producing a high boiling fraction consisting of a quality polyalkylated aromatic product; h) said polyalkylated aromatic product comprising substantially all dialkylated and trialkylated aromatics in said polyalkylated product; i) supplying said aromatic substrate to said alkyl transfer zone; ``) supplying said aromatic substrate to said alkyl transfer zone; remaining in the liquid phase and achieving disproportionation of the polyalkylated aromatic fraction with a disproportionation product having a reduced polyalkylated aromatic content and an increased monoalkylated aromatic content; and operating under effective temperature and pressure conditions; k) feeding at least a portion of said disproportionated product to a first said separation zone.

2. The aromatic substrate consists of benzene, and the alkylating agent is an ethylating or propylating agent, and the polyalkylated aromatic content of the disproportionated product comprises dialkyl and trialkylbenzenes. , the method described in 1 above.

3. Further prior to step k) as described in point 1 above, the product from said transalkylation zone is fed to a third separation zone and said third separation zone is operated to produce a benzene-monoalkylbenzene component. 2 above, comprising producing a low boiling fraction and a high boiling fraction consisting of a polyalkylbenzene component and feeding said benzene-monoalkyl component to a first said separation zone according to step k) as described in 1 above. Method described.

4. The method according to 3 above, wherein the alkylating agent is an olefin.

5. The method according to 4 above, wherein the alkylating agent is ethylene.

6. The aromatic substrate consists of a benzene raw material, the alkylation catalyst consists of a molecular sieve selected from the group consisting of zeolite beta, zeolite omega and zeolite Y, and the alkyl transfer catalyst consists of zeolite Y, zeolite beta and zeolite omega. The method according to item 1 above, comprising a molecular sieve selected from the group consisting of:

7. The method according to 6 above, wherein the alkylation catalyst comprises zeolite beta.

8. The method according to 7 above, wherein the alkylating agent is ethylene.

9. The method according to 8 above, wherein the alkyl transfer catalyst is zeolite beta or zeolite Y.

10. a) feeding a benzene feedstock into an alkylation reaction zone containing a molecular sieve alkylation catalyst; b) feeding a C2-C, alkylating agent to the reaction zone; C) feeding the reaction zone to a operating at temperature and pressure conditions that effect the alkylation of the benzene by the alkylating agent in the presence of a catalyst; d) recovering the alkylated product from the reaction zone and removing the product from the reaction zone; e) operating the separation zone to produce a low-boiling fraction consisting of benzene and a high-boiling fraction consisting of a mixture of monoalkyl, polyalkylbenzenes; f) feeding the high-boiling fraction from the separation zone; feeding the fraction to a second separation zone;

g) operating a second said separation zone to produce a second lower boiling fraction consisting of a monoalkylbenzene product and a higher boiling fraction consisting of a heavier polyalkylbenzene fraction; h) at least a portion of said polyalkylbenzene fraction; to an alkyl transfer reaction zone containing a molecular sieve alkyl transfer catalyst; i
) supplying benzene to the alkyl transfer zone; k) operating under conditions of temperature and pressure effective to effect oxidation in a disproportionated product having a reduced polyalkylbenzene content and an increased monoalkylbenzene content; and k) at least one of the disproportionated products. An alkylation-alkylation process comprising the step of feeding a portion to a first said separation zone.

11. the alkylating agent is ethylene, the alkylation reaction zone is operated under temperature and pressure conditions that produce vapor phase ethylelation of the benzene, and the alkylation reaction zone is the average of the alkylation reaction zones. 10 above, operating at an average temperature of at least 100° C. below temperature.

12. a) feeding a benzene feedstock and an ethylating agent into a first reaction zone containing a zeolite beta alkylation catalyst; b) ethylating the benzene feedstock while maintaining the reaction zone in the liquid phase; operating under temperature and pressure conditions to produce an alkylated product consisting of ethylbenzene, a mixture of polyethylbenzenes; C) recovering said product from said reaction zone and feeding said product to a benzene separation zone; d) operating the benzene separation zone to produce a low-boiling fraction consisting of benzene and a high-boiling fraction consisting of an ethylbenzene-polyethylbenzene mixture; e) feeding the high-boiling fraction from the benzene separation zone to an ethylbenzene separation zone; f) operating said ethylbenzene separation zone to remove a second
producing a second high-boiling fraction consisting of a low-boiling fraction of and a heavy polyethylbenzene fraction containing up to 5% by weight of ethylbenzene; g) subjecting the polyethylbenzene fraction from the ethylbenzene column to an alkyl transfer comprising an alkyl transfer catalyst; h) supplying benzene to the transalkylation reaction zone; ]) supplying the transalkylation reaction zone with reduced liquid phase disproportionation of the polyethylbenzene fraction and increased ethylbenzene content; and j) operating at least a portion of the disproportionated product in a first
supplying said benzene separation zone to said benzene separation zone.
Method for producing ethylbenzene.

13. further feeding said disproportionated product to a separation zone, operating said zone to produce a low boiling fraction consisting of benzene and ethylbenzene and a high boiling polyethylbenzene fraction, and said low boiling fraction being subjected to step 1). 13. The method according to 12 above, comprising the step of feeding the benzene separation zone.

14. The method according to 12 above, wherein the alkyl transfer catalyst comprises a molecular sieve selected from the group consisting of zeolite Y and zeolite beta.

15. The method according to 14 above, wherein the alkyl transfer zone is operated at a benzene and alkylbenzene-based space velocity (L H S V ) that is lower than the benzene-based space velocity (L H V ) in the first reaction zone. Method.

16. The method of 15 above, wherein the alkylation zone space velocity is less than half the space velocity of the first alkylation zone.

17. Molecular sieve consisting of hydrogen zeolite beta having a surface area of at least 600 m2/g based on the crystal structure of zeolite beta.

18. The surface area of the molecular sieve based on the crystal structure of zeolite beta is at least 650 m2/
18. The molecular sieve according to 17 above, which is s.

19. The molecular zeolite beta is composed of hydrogen zeolite beta blended with a binder, and the surface area of the zeolite beta based on the complex of the molecular sieves containing the binder is at least 450 m2/g.
Molecular sieves described in.

20, 0.04% by weight Na 2 of the zeolite beta
18. The molecular sieve according to 17 above, having a sodium content of less than 0.

21.0.04% by weight in the crystal structure of zeolite beta
Molecular sieve consisting of hydrogen zeolite beta with a sodium content less than Na2O.

22. The catalyst according to 21 above, wherein the sodium content is less than 0.02% by weight Na2O.

(a ) treating the synthesized zeolite with an ion exchange medium to protonate a part of the active sites in the zeolite by exchanging the alkali metal; (b) treating the ion-exchanged zeolite at a temperature of 400 to 700°C; 2 to 1 at a temperature of
(C) treating the calcined heptaolide with an ion exchange medium to protonate an additional portion of the active sites in the zeolite by exchanging the alkali metal; (d) mixing the ion-exchanged zeolite from step (c) with a binder to produce a ground zeolite, binder mixture; (e) pelletizing the zeolite, binder mixture and producing A method for producing hydrogen zeolite beta, which comprises the step of drying pellets.

24. The zeolite beta synthesized by the treatment in step (a) is immersed in an ion-exchanged medium, the zeolite beta is separated from the ion-exchanged medium, and the separated zeolite beta is injected into a second ion-exchanged medium. 24. The method according to item 23 above, comprising immersion in an exchange medium.

25. The process of step (C) involves immersing the synthesized zeolite beta in an ion exchange medium, separating the zeolite beta from the ion exchange medium, and transferring the separated zeolite beta to a second ion exchange medium. 25. The method according to claim 24, comprising immersing in the liquid.

26. The method according to 23 above, wherein the ion exchange medium used in steps (a) and (C) is an aqueous solution of an ammonium salt.

27. The method according to 26 above, wherein the ammonium salt used in steps (a) and (C) is ammonium nitrate.

28. In producing hydrogen zeolite beta derived by modification of sodium zeolite beta synthesized by hydrothermal decomposition of a reaction mixture consisting of silica, alumina, sodium oxide and an organic templating agent, (a) the synthesized treating zeolite beta with an ion exchange medium consisting of an aqueous solution of ammonium salts to exchange a portion of the active sites in the zeolite beta by replacing sodium helium with ammonium ions; (b) the ion-exchanged zeolite; removing at least a portion of the beta templating agent from the zeolite and achieving a surface area based on the crystalline structure of the zeolite beta that is at least twice the surface area of the as-synthesized zeolite beta. (c) treating the calcined zeolite with an ion exchange medium consisting of an aqueous solution of ammonium salts to replace the sodium with ammonium ions to remove the active sites in the zeolite beta; (d) mixing the ion-exchanged zeolite from step (c) with a binder to produce a ground zeolite/binder mixture; (e) the zeolite/binder mixture; and drying the resulting pellets; (f) calcining the pellets at a temperature and for a time sufficient to decompose ammonium ions on the active sites of the zeolite to hydrogen. .

29. The method of claim 28, wherein the treatment step of step (a) is carried out by contacting the synthesized zeolite beta with the ion exchange medium for a period of at least 2 hours.

30. immersing the zeolite beta synthesized in process step (a) in the first portion of the ion exchange medium for a period of at least one hour; 30. The method of claim 29, comprising separating and immersing the separated zeolite beta in a second portion of the ion exchange medium for a period of at least 1 hour.

31. (a) Feeding a feedstock containing an aromatic substrate into a reaction zone and contacting it with an alkylation catalyst consisting of zeolite heta having a surface area of at least 600 m2/g concreting zeolite beta.

(b) supplying a C2-C, alkylating agent to the reaction zone; (c) maintaining the reaction zone with the aromatic substrate in the liquid phase;
operating at temperature and pressure conditions that cause alkylation of the aromatic substrate by the alkylating agent in the presence of the catalyst;
and (d) recovering an alkylated aromatic substrate from the reaction zone.

32, the zeolite beta has a sodium content of less than 0.04% by weight expressed as Na2O;
The method described in 31 above.

33. The method according to 3I above, wherein the aromatic substrate consists of benzene and the alkylating agent is an ethylating agent or a propylating agent.

34. The method according to 33 above, wherein the alkylating agent is ethylene.

35. (a) feeding a feedstock containing aromatic groups into a reaction zone and catalyzing it with an alkylation catalyst consisting of zeolite beta having a sodium content of less than 0.04% by weight, expressed as Na20; .

(b) supplying a C2-C, alkylating agent to the reaction zone; (c) maintaining the reaction zone with the aromatic substrate in the liquid phase;
and (d) recovering the alkylated aromatic substrate from the reaction zone. , a method for liquid phase alkylation of aromatic compounds.

36, when the zeolite beta is expressed as Na2O, it is 0.01! having a sodium content of less than %
The method described in 9t above.

37. The method of claim 35, wherein the alkylating agent is ethylene and the reaction mixture is operated under temperature and pressure conditions of 0.05% by weight or less based on the amount of ethylbenzene to produce xylene.

38, (a) feeding a feedstock containing an aromatic substrate to a first stage of a plurality of series-coupled reaction systems containing an alkylation catalyst consisting of zeolite beta; (b) an effluent of the first said reaction stage; (c) separately feeding a C2-C, alkylating agent to each of the reaction stages; (d) each of the reaction stages at an average temperature of less than 300°C. and maintaining the aromatic substrate in the liquid phase and operating at a pressure such that at least 1 mol % of the alkylating agent is dissolved in the aromatic substrate, with the temperature and pressure conditions in each reaction step in a multi-step reaction system comprising: causing alkylation of the aromatic substrate by the alkylating agent in the presence of the catalyst; and (e) recovering the alkylated aromatic substrate from the reaction system. Liquid phase alkylation method for aromatic compounds.

39. The method of claim 38, comprising at least three reaction steps comprising the zeolite beta catalyst.

40. The method of claim 38, further comprising the step of cooling the effluent from the first reaction stage before feeding the effluent to the second reaction stage.

41. The method of claim 40, wherein the alkylating agent fed to the second said reaction stage is mixed with the effluent from the first said reaction stage before said cooling step.

42. The method according to 38 above, wherein the alkylating agent is ethylene.

43. (a) feeding a benzene feedstock into a reaction zone and catalyzing it with an alkylation catalyst consisting of zeolite beta; (b) feeding an ethylating agent into the reaction zone; (c) introducing the reaction zone into the reaction zone. ethylbenzene, increasing the pressure in the zone by at least 50 psi above the vapor pressure of the benzene, causing monoethylation of the benzene in the liquid phase by the ethylating agent in the presence of the catalyst, and producing xylene under those conditions; and (d) recovering ethylbenzene from said reaction zone.

44. The reaction system comprises a plurality of series-coupled reaction stages containing the zeolite beta alkylation catalyst, wherein the benzene feedstock is fed to a first of the series-coupled reaction stages; The effluent from the reaction stage is
44. The method of claim 43, comprising passing the ethylating agent through each of the reaction steps and separately feeding the ethylating agent to each of the reaction steps.

45. The method according to 44 above, wherein the ethylating agent is ethylene.

46, further cooling the effluent from the first said reaction stage before feeding said effluent to said second said reaction stage, and cooling the ethylene fed to said second said reaction stage before said cooling step. a first step of mixing with the effluent from said reaction step;
The method described in 45 above.

47. (a) feeding a feedstock comprising at least one aromatic compound and having water entrained therein to a dehydration zone; (b) removing water from the feedstock in the dehydration zone; 10.
(C) providing a dehydrated raw material having a water content of 0 ppm or less; (C) treating the dehydrated raw material with a zeolite moleculum having a pore size greater than 6.5 angstroms and selected from the group consisting of zeolite Y and zeolite beta; (d) heating the reaction zone to a temperature sufficient to maintain the aromatic compound in the liquid phase and to allow the aromatic conversion reaction to proceed in the presence of the catalyst; and (e) recovering the converted product.

48. The method according to 1 above, wherein the dehydrated raw material has a water content of 50 ppm or less.

49. The method of claim 1, wherein the catalyst has a pore size within the range of 7.0 to 7.5 angstroms.

50. The method according to item 1 above, wherein the catalyst comprises zeolite beta.

51. The method of 1 above, wherein the reaction zone is operated at a pressure at least 50 psi above the vapor pressure of the aromatic compound.

52, (a) feeding a feedstock containing an aromatic substrate and having water entrained therein; (b) using the dehydration zone to remove water from the feedstock;
(c) recovering the dehydrated aromatic substrate from the dehydration zone and converting the substrate into a zeolite molecular having a pore size greater than 6.5 angstroms; (d) supplying an alkylating agent to the reaction zone; (e) subjecting the reaction zone to temperature and pressure conditions that maintain the aromatic substrate in the liquid phase; and (f) recovering the alkylated aromatic substrate from the reaction zone. A method for liquid phase alkylation of aromatic compounds, comprising the steps of:

53. The method according to 52 above, wherein the aromatic substrate consists of benzene, and the alkylating agent is an ethylating agent or a propylating agent.

54. The product from the reaction zone comprises a mixture of monoalkyl and polyalkylbenzenes, and the product from the reaction zone is further subjected to at least one separation step;
forming a polyalkylbenzene component, feeding the polyalkylbenzene component and benzene to a transalkylation reaction zone containing an alkyl transfer catalyst comprised of zeolite molecular soap having a pore size greater than 665 angstroms; carrying out liquid phase disproportionation of the polyalkylbenzene component in the presence of a transfer catalyst under temperature and pressure conditions that achieve a disproportionated product having a reduced polyalkylbenzene content and an increased t:monoalkylbenzene component; 53. The method according to item 52 above.

55. The method according to 52 above, wherein the catalyst has a pore size within the range of 7.0 to 765 angstroms.

56. The method according to 55 above, wherein the alkylating agent is an olefin.

57. The method according to 55 above, wherein the alkylating agent is ethylene.

58. The method according to 57 above, wherein the dehydrated raw material has a water content of 50 ppm or less.

59. The alkylation catalyst consists of zeolite beta;
57. The method described in 57 above.

60. In transalkylating a feedstock containing a mixture of polyalkylbenzene and benzene with entrained water to produce a disproportionated product consisting of monoalkylbenzene, (a) at least one portion of the feedstock is part was subjected to a dehydration process, water was extracted from this, and 100
providing a feedstock having a total water content of less than ppm; (b) converting the dehydrated feedstock into a zeolite molecular having a pore size greater than 6.5 angstroms and selected from the group consisting of zeolite beta and zeolite Y; (C) causing liquid phase disproportionation of the polyalkylbenzene component in the presence of the alkyl transfer catalyst to cause the reduced polyalkylbenzene to be dissolved in the polyalkyl benzene component; and (d) recovering said disproportionated product from said reaction zone. The alkyl transfer method.

61. The polyalkylbenzene component is produced in an alkylation reaction zone in which benzene is reacted with an alkylating agent to produce an effluent containing a mixture of monoalkyl and polyalkylbenzenes, and the feedstock is separated from the mixture. and benzene, the method according to 60 above.

62. The method of 6I above, wherein the alkylation reaction zone is operated under conditions that cause vapor phase alkylation of the benzene.

63. The method according to 6I above, wherein the alkylating agent is an ethylating agent or a propylating agent.

64. The method according to 61 above, wherein the alkyl rearrangement catalyst comprises zeolite beta.

65. The method according to 64 above, wherein the furkyl rearrangement catalyst comprises zeolite Y.

66, liquid-phase alkylation of an aromatic substrate using a C2-C alkylating agent, containing an alkylation catalyst, and in a multistage reaction system consisting of a plurality of reaction steps coupled in series, including an initial reaction step and a final reaction step. operating the reaction step under conditions of temperature and pressure that cause alkylation of the aromatic substrate by the alkylating agent in the presence of the catalyst;
At that time, the pressure is equal to or higher than the vapor pressure of the aromatic substrate and lower than the vapor pressure of the alkylating agent under the temperature conditions: the raw material consisting of the aromatic substrate and the alkylating agent is feeding a first reaction stage in relative amounts providing a first molar ratio of substrates; recovering an effluent consisting of a mixture of the aromatic substrate and alkylated product from each reaction stage before the final reaction stage; and feeding the effluent to the next successive reaction stage, feeding the alkylating agent together with the effluent to the next successive reaction stage, and feeding the alkylating agent together with the effluent to the first successive reaction stage. the multi-stage reaction system of a reduced molar ratio of the aromatic substrate to the alkylating agent in an amount that provides a final molar ratio of the aromatic substrate to the alkylating agent for the final reaction step that is less than the molar ratio; A process for the liquid phase alkylation of aromatic substrates, comprising the steps of: providing an overall proceeding through: and recovering an effluent from the final reaction stage consisting of a mixture of the aromatic substrate and the alkylated product.

67, the multistage reaction system comprises at least three reaction stages including an intermediate reaction stage between the initial and final reaction stages, and the effluent from the initial reaction stage is combined with the alkylating agent to contain the aromatic substrate and the alkylating agent. 67. The method of claim 66, wherein the intermediate reaction step is fed in a relative amount that provides an intermediate ratio of aromatic substrate to alkylating agent that is less than the initial molar ratio of agent and greater than the final molar ratio.

68, wherein the aromatic substrate consists of benzene and the alkylating agent is an ethylating or propylating agent;
The method described in 7.

69. The method according to 67 above, wherein the alkylating agent is ethylene.

70, carrying out the reaction step in an adiabatic reaction zone and further cooling the effluent from the subsequent reaction step before applying the effluent to the next subsequent reaction step. 69. The method according to 69 above.

71. The method of claim 70, wherein the ethylene fed to the next successive reaction stage is mixed with the effluent from the previous reaction stage prior to said cooling step.

[Brief explanation of the drawing]

Figures 1a-1C and 2a-2C are graphs illustrating alkyl transfer experiments performed using two different zeolite Y catalysts. Figures 3a-30 are graphs illustrating the results of experiments conducted on the alkyl rearrangement of diethylbenzene using other zeolite Y catalysts. Figures 4a-4C are a series of graphs illustrating experiments performed with rare earth zeolites. Figures 5a, 5b and 6 are graphs further illustrating experiments using zeolite Y catalysts. FIG. 7 is a simple flow diagram illustrating one embodiment of the present invention in which a polyethylbenzene fraction is subjected to a residue extraction step prior to alkyl rearrangement. FIG. 8 is an illustration of a modification of the process of FIG. 7 in which the product from the transalkylation reactor is subjected to a separation step prior to recycling. FIG. 9 is a brief illustration of another embodiment of the invention in which the bottoms fraction from an ethylbenzene column is fed directly to a transalkylation reactor, with the product of the transalkylation reactor being fed to a downstream separation zone. It is a diagram. FIG. 10 is a flow diagram showing an improvement to the specific example of FIG. FIG. 11 is an illustration of a special embodiment of carrying out the invention using multiple series-coupled reaction steps. FIG. 12 is a graph showing the results of an experiment involving dehydration of a feed fluid to a transfer alkyl reaction over a zeolite Y catalyst. FIG. 13 is a graph illustrating a combination of experiments involving dehydration of feed fluids to transalkyl reactions carried out over other zeolite Y catalysts. S (%) Ne Q Φ Shrine Φ ψ 0− υ ω Joyo□oo(
)ooooo. σ Engraving of drawings (no change in content) △ (Japanese) FIG, 12g - Procedural amendment (Radio) March 13, 1991 Commissioner of the Patent Office Toshi Ue Matsu 1, indication of case 1990 Patent Application No. 312965 No. 2. Name of the invention Aromatic conversion method and its catalyst 3. Person with amendment 5. Date of amendment order February 12, 1991 (dispatch mortar)
7. Contents of the amendment: Engraving of the drawing as attached (no changes to the content)

Claims (1)

[Claims] 1. a) feeding a feedstock containing an aromatic substrate into a reaction zone containing a molecular sieve aromatic alkylation catalyst; b) feeding a C_2 to C_4 alkylating agent to the reaction zone; c) operating the reaction zone at temperature and pressure conditions that maintain the aromatic substrate in the liquid phase and causing alkylation of the aromatic substrate by the alkylating agent in the presence of the catalyst to form a monoalkyl and a polyalkylated aromatic product; d) recovering the alkylated product from the reaction zone and collecting the alkylated product for separation of the aromatic substrate; feeding said product from a reaction zone to a separation zone; e) operating said separation zone to produce a low boiling fraction consisting of said aromatic substrate and a high boiling fraction consisting of a mixture of monoalkylated aromatic-polyalkylated aromatic mixture; producing a boiling point fraction; f) feeding the high boiling point fraction from the separation zone to a second separation zone; g) operating the second separation zone to produce a second separation zone comprising a monoalkylated aromatic product; producing a low-boiling fraction of and a high-boiling fraction of heavy polyalkylated aromatic products; supplying at least a portion of the polyalkylated aromatic product to an alkyl transfer reaction zone comprising a molecular sieve alkyl conversion catalyst; i) supplying the aromatic substrate to the alkyl transfer zone; j) the alkyl transfer reaction. a zone having a reduced polyalkylated aromatic content and an increased monoalkylated aromatic content while retaining the aromatic substrate in the liquid phase and averaging the polyalkylated aromatic fraction. k) supplying at least a portion of said disproportionation product to a first said separation zone; Method. 2. a) feeding a benzene feedstock into an alkylation reaction zone containing a molecular sieve alkylation catalyst; b) feeding a C_2-C_4 alkylating agent to the reaction zone; c) feeding the reaction zone to the catalyst. operating at temperature and pressure conditions that cause alkylation of the benzene by the alkylating agent in the presence of the alkylating agent; d) recovering the alkylated product from the reaction zone; e) operating said separation zone to produce a low-boiling fraction consisting of benzene and a high-boiling fraction consisting of a monoalkyl, polyalkylbenzene mixture; f) discharging said high-boiling fraction from said separation zone; g) operating a second said separation zone to produce a second low boiling fraction consisting of a monoalkylbenzene product and a high boiling fraction consisting of a heavy polyalkylbenzene fraction; h) feeding at least a portion of the polyalkylbenzene fraction to an alkyl transfer reaction zone comprising a molecular sieve alkyl transfer catalyst; i
) supplying benzene to the alkyl transfer zone; operating under temperature and pressure conditions effective to effect proportionation with a disproportionated product having a reduced polyalkylbenzene content and an increased monoalkylbenzene content; and k) of the disproportionated product. An alkylation-alkylation process comprising the step of feeding at least a portion to a first said separation zone. 3. a) feeding a benzene feedstock and an ethylating agent into a first reaction zone containing a zeolite beta alkylation catalyst; b) ethylating the benzene feedstock while maintaining the benzene feedstock in the liquid phase; c) recovering said product from said reaction zone and feeding said product to a benzene separation zone; d) operating the benzene separation zone to produce a low-boiling fraction consisting of benzene and a high-boiling fraction consisting of an ethylbenzene-polyethylbenzene mixture; e) feeding the high-boiling fraction from the benzene separation zone to an ethylbenzene separation zone; f) operating said ethylbenzene separation zone to remove a second
and a second high boiling fraction consisting of a heavy polyethylbenzene fraction containing up to 5% by weight of ethylbenzene; g) subjecting the polyethylbenzene fraction from the ethylbenzene column to alkyl transfer using an alkyl transfer catalyst h) supplying benzene to the transalkylation reaction zone; i) supplying the transalkylation reaction zone with reduced liquid phase disproportionation of the polyethylbenzene fraction and increased polyethylbenzene content; operating under temperature and pressure conditions to be achieved with a disproportionated product having an ethylbenzene content; and j) feeding at least a portion of said disproportionated product to a first said benzene separation zone. , a method for producing ethylbenzene. 4. A molecular sieve made of hydrogen zeolite beta having a surface area of at least 600 m^2/g based on the crystal structure of zeolite beta. 5. 0.04% by weight N in the crystal structure of zeolite beta
Molecular sieve consisting of hydrogen zeolite beta with sodium content less than a_2O. (a ) treating the synthesized zeolite with an ion exchange medium to protonate a part of the active sites in the zeolite by exchanging the alkali metal; (b) treating the ion-exchanged zeolite at a temperature of 400 to 700°C; 2-1 at a temperature of
(c) treating the calcined zeolite with an ion exchange medium to protonate an additional portion of the active sites in the zeolite by exchanging the alkali metal; (d) mixing the ion-exchanged zeolite from step (c) with a binder to produce a ground zeolite, binder mixture; (e) pelletizing the zeolite, binder mixture and resulting pellets. A method for producing the hydrogen zeolite beta, which comprises the step of drying the hydrogen zeolite beta. 7. In producing hydrogen zeolite beta derived by modification of sodium zeolite beta synthesized by hydrothermal decomposition of a reaction mixture consisting of silica, alumina, sodium oxide and an organic templating agent, (a) the synthesized treating zeolite beta with an ion exchange medium consisting of an aqueous solution of ammonium salts to exchange some of the active sites in the zeolite beta by replacing sodium with ammonium ions; (b) ion-exchanged the zeolite beta; sufficient to remove at least a portion of the templating agent from the zeolite and achieve a surface area based on the crystalline structure of the zeolite beta that is at least twice the surface area of the as-synthesized zeolite beta; (c) treating the calcined zeolite with an ion-exchange medium consisting of an aqueous solution of ammonium salts to replace the sodium with ammonium ions to remove other active sites in the zeolite beta; (d) mixing the ion-exchanged zeolite from step (c) with a binder to produce a ground zeolite/binder mixture; (e) pelletizing the zeolite/binder mixture; (f) calcining the pellet at a temperature and for a time sufficient to decompose ammonium ions on the active sites of the zeolite to hydrogen. 8. (a) feeding a feedstock containing an aromatic substrate into a reaction zone and contacting it with an alkylation catalyst consisting of zeolite beta having a surface area of at least 600 m^2/g crystalline zeolite beta; (b) C_2~ (c) supplying a C_4 alkylating agent to the reaction zone; (c) maintaining the reaction zone with the aromatic substrate in a liquid phase;
operating at temperature and pressure conditions that cause alkylation of the aromatic substrate by the alkylating agent in the presence of the catalyst;
and (d) recovering an alkylated aromatic substrate from the reaction zone. 9. (a) Feed a feedstock containing aromatic groups into the reaction zone and 0.04% by weight, expressed as Na_2O.
(b) supplying a C_2-C_4 alkylating agent to the reaction zone; (c) catalyzing the reaction zone with the aromatic substrate in the liquid phase; hold,
and (d) recovering the alkylated aromatic substrate from the reaction zone. , a method for liquid phase alkylation of aromatic compounds. 10. (a) feeding a raw material containing an aromatic substrate to the first stage of a plurality of series-coupled reaction systems containing an alkylation catalyst made of zeolite beta; (b) the effluent of the first reaction stage; (c) separately feeding a C_2-C_4 alkylating agent to each of said reaction stages; (d) supplying each of said reaction stages to at least a second one of said reaction stages; The aromatic substrate is maintained in the liquid phase and operated at a pressure such that at least 1 mol % of the alkylating agent is dissolved in the aromatic substrate, with the temperature and pressure conditions allowing the alkylating agent to be dissolved in each of the reaction steps. aromatic in a multi-step reaction system comprising: causing alkylation of the aromatic substrate by the alkylating agent in the presence of a catalyst; and (e) recovering the alkylated aromatic substrate from the reaction system. Liquid phase alkylation method for group compounds. 11. (a) feeding a benzene feedstock into the reaction zone and catalyzing it with an alkylation catalyst consisting of zeolite beta; (b) feeding an ethylating agent into the reaction zone; (c) introducing the reaction zone into the reaction zone. ethylbenzene, increasing the pressure in the zone by at least 50 psi above the vapor pressure of the benzene, causing monoethylation of the benzene in the liquid phase by the ethylating agent in the presence of the catalyst, and producing xylene under those conditions; and (d) recovering ethylbenzene from the reaction zone. 12. (a) feeding a feedstock comprising at least one aromatic compound and having water entrained therein to a dehydration zone; (b) removing water from the feedstock in the dehydration zone;
(c) providing a dehydrated raw material having a water content of ppm or less; (c) treating the dehydrated raw material with a zeolite moleculum having a pore size greater than 6.5 angstroms and selected from the group consisting of zeolite Y and zeolite beta; (d) heating the reaction zone to a temperature sufficient to maintain the aromatic compound in the liquid phase and to allow the aromatic conversion reaction to proceed in the presence of the catalyst; and (e) recovering the converted product. 13. (a) feeding a feedstock containing an aromatic substrate and having water entrained therein to a dehydration zone; (b) removing water from the feedstock using the dehydration zone;
(c) recovering the dehydrated aromatic substrate from the dehydration zone and converting the substrate into a zeolite molecular having a pore size greater than 6.5 angstroms; (d) supplying an alkylating agent to the reaction zone; (e) subjecting the reaction zone to temperature and pressure conditions that maintain the aromatic substrate in the liquid phase; and (f) recovering the alkylated aromatic substrate from the reaction zone. A liquid phase alkylation method for aromatic compounds. 14. In transalkylating a feedstock containing a mixture of polyalkylbenzene and benzene with entrained water to produce a disproportionated product consisting of monoalkylbenzene, (a) at least one of the feedstocks is (b) subjecting the dehydrated feedstock to a dehydration step to extract water therefrom and provide a feedstock having a total water content of less than 100 ppm; and passing through an alkyl transfer reaction zone comprising a zeolite molecular sieve alkyl transfer catalyst selected from the group consisting of zeolite beta and zeolite Y; (d) operating under temperature and pressure conditions that cause liquid phase disproportionation of the components and achieve a disproportionation product having a reduced polyalkylbenzene content and an increased monoalkylbenzene content; The transalkylation process comprises the step of recovering the disproportionated product from the reaction zone. 15. Liquid phase alkylation of an aromatic substrate using a C_2-C_4 alkylating agent in a multistage reaction system comprising an alkylation catalyst and a plurality of serially connected reaction stages including an initial reaction stage and a final reaction stage. wherein the reaction step is operated under conditions of temperature and pressure that cause alkylation of the aromatic substrate by the alkylating agent in the presence of the catalyst, wherein the pressure the aromatic substrate and the alkylating agent in relative amounts that provide a first molar ratio of the aromatic substrate to the alkylating agent; a first reaction stage; an effluent consisting of a mixture of the aromatic substrate and alkylated product is recovered from each reaction stage before the final reaction stage, and the effluent is fed to the next successive reaction stage; feeding the alkylating agent together with the effluent to the next successive reaction stage, and for the final reaction stage less than the molar proportion of the first fed to the first reaction stage; of the aromatic substrate to the alkylating agent in an amount that provides a final molar ratio of the aromatic substrate to the alkylating agent to provide an overall progression through the multi-stage reaction system of a decreasing molar ratio of the aromatic substrate to the alkylating agent; A process for the liquid phase alkylation of aromatic substrates, comprising the step of recovering an effluent from the final reaction stage consisting of a mixture of aromatic substrates and alkylated products.