JPS58105926A - Alkylation of aromatic compound using silica catalyst under presence of steam - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Alkyaromatized antiquities, such as ethylbenzene, ethyltoluene, isoprobylbenzene.

is highly valued as a precursor for the production of vinyl aromatic mononuclear compounds. The vinyl aromatic compounds produced are used to produce a variety of useful resin materials, such as styrenic resin. Typical commercial methods are produced by catalytic alkylation at elevated temperatures. So far,
There were two major drawbacks in the catalytic alkylation gas phase process.

A major drawback of this method is the production of undesirable by-products.

For example, ethyl-benzene! ! ! ! In the manufacturing process, a considerable amount of xylene isomers 41 are produced.

Even a small amount of xylene is undesirable since the separation of xylene isomers from ethylbenzene is extremely difficult due to the fact that the boiling points of ethylbenzene and xylene isomers are exactly .

Among others, it is the bonding of more alkyl groups than desired to the aromatic nucleus. Example - ethyltoluene>
In addition, trimethylbenzene from sweetfish is also produced. Separation of the desired product from the undesirable by-products is difficult to understand. This phenomenon, hereinafter referred to as polyalkylation, further reduces the yield of the ang4 product. Therefore, during the alkylation reaction, xylene isomers or other undesirable side organisms/j! This is a prudent thing to do in order to prevent the occurrence of similar events.

The second major drawback encountered with conventional catalytic alkylation methods is the rapid loss of catalyst activity. As the catalytic reaction progresses, the catalytic viscosity, expressed as R-cents (of the raw materials that are actually converted to the desired alkyl aromatic product compounds), continually decreases so that after a period of time, the alkylation is stopped. However, it is important to replace the catalyst or replace the catalyst. The associated bioavailability of the materials used and the cost of catalyst production or regeneration substantially determine the cost of the desired alkyl aromatic compound. As used herein, "stability" refers to the ability of a catalyst to convert feedstock to the desired product, measured as a function of the time during which the fertilization cycle is cruising.

Recently, sweet acid aluminosilicate catalysts have been recognized as useful in alkylation processes. In particular, z
Catalysts based on shi-s and -r have been shown to confer advantages in the alkylation process. Such aluminosilicates are completely degraded by caulking. Additionally, these products react rapidly when steam or water is present during the reaction. ·,sex? It is reported that there will be a loss. It is generally believed that the concentration of these catalysts in the bath is directly proportional to the aluminum concentration and that the water vapor gradually removes aluminum from the framework, thereby irreversibly deactivating the catalyst. It has also been shown that water interacts with the aluminum present in such compositions and imparts a repellent effect on the catalytically active sites of the catalysts 1 and 4.

An improved alkylation method and apparatus that can overcome these problems associated with pre-strike techniques is desirable.
There was medical treatment.

Accordingly, it is an object of the present invention to provide an improved method and apparatus for the alkylation of aromatic compounds.

Another object of the present invention is to provide an improved process and bottle making for the production of alkylaromatic compounds, such that the formation of by-products such as xylene, trimethylbenzene and polymers is reduced. It is.

4 of alkyl aromatic compounds such that the alkylated Wh b loses its alkylating activity more slowly.
It is also an object of the invention G) to provide an improved method and apparatus for manufacturing.

It is another object of the present invention to provide a method and apparatus for the production of alkyl aromatization adducts which convert relatively high sendage feedstocks into the desired argyl aromatic products. It is.

Another object of the invention is a method for producing alkyl aromatic compounds with extended cycle length and irz
and Jin, who provides k.

Yet another object of the present invention is to provide a method and apparatus that reduces the cost of producing the desired alkyl aromatic compounds.

Yet another object of the present invention is to provide an improved process for the production of alkylaromatic compounds, which increases the productivity of the equipment used.

Another object of the present invention is to provide a process and equipment for the alkylation of aromatic compounds which is particularly applicable to the production of ethylbenzene or ethyltoluene.

For these and other purposes, aromatic compounds.

A reactive alkene and an effective amount of water are passed through the silicalite alkylation catalyst bed at alkylation conditions.

This is achieved by providing a method for producing an alkyl aromatized adduct, which comprises recovering the produced alkyl aromatized adduct.

A further object of the invention is to.

reaction zone means; a flat membrane for adding and contacting a silicalite alkylation catalyst bed in said reaction zone means with a silicalite alkylation catalyst rich aromatic substrate enriched feedstock to said catalyst bed in said reaction zone means; means for adding to and contacting the catalyst bed in the reaction zone means; means for adding regulated starvation steam into the reaction zone means; and removing an alkyl aromatic compound-containing product stream from the reaction zone means. The alkyl aromatization adduct is the best way to do this! ! equipment for building
It? : Achieved by providing.

It is truly anticipated that the objects of the present invention can be successfully achieved using a combination of a silicalite alkylation catalyst and 41% water (which is in the form of steam under reaction a?!t'). 69. The reason is that most alkylation catalysts of the prior art are very moisture sensitive and the presence of ppm amounts of moisture during catalytic alkylation virtually destroys the catalyst activity and prevents useful reactions from occurring. It has been found to prevent from nine.

The method of the present invention can be applied to various aromatic raw materials.

Suitable raw materials include benzene, toluene, ethylbenzene, naphthalene and similar adducts. Moderately reactive alkenes can also be used. Suitable alkene sources include ethylene and propylene.

A silicalite alkylation catalyst is used in the present invention.

Silicalites are crystalline edged materials with a network of molecular-sized pores that act as catalytically active sites. Such catalysts are well known in the art; for example, U.S. Pat.
61.724, the entire disclosure of which is hereby incorporated by reference. These materials are polymorphs as opposed to aluminosilicates. As it is, their 5ilAL ratio is very high since the alumina present is only an impurity of the starting material used to make it.

Generally, the reaction is carried out with a substantial molar excess of aromatic groups* to further reduce the occurrence of polyalkylation. Desirably, the molar ratio of aromatic substrate to alkene feedstock is between about 2:1 and about 20:1.

Preferably it will be between about 7=1 and about 20°:1.

Water is usually added in the form of superheated steam.

It should be recognized that water is present in the aromatic feedstock in amounts per gram. For example, saturated benzene is approximately ? Contains OO'plum.

The use of a steam co-feed to add more water than would normally be present in the reaction along with the reactants themselves will be reflected by the percent red conversion to the desired formation. This effectively increases the safety of the catalyst and reduces the amount of undesirable by-products produced. Therefore, as used herein, the term "effective amount of steam" refers to improved stability under reaction conditions compared to the performance of the same catalyst in the absence of steam tea material under the same reaction conditions. Refers to the amount of water or moisture that is sent into the reactor along with the aromatic and alkene feed materials that will result in a time-saving silicalite catalyst that is used to exhibit properties and/or reduced by-product production.

Preferably from about 2 to about 100,000 pp
pm, most preferably about 20,000 ppm
Add water vapor between about 60,000 pptn 0.

The alkylation reaction takes place at elevated temperatures. □VC should use a minimum temperature of at least about 300C to maintain an appreciable reaction rate. Temperatures below about 600C are preferably avoided to prevent undesirable side reactions that would occur relatively easily at relatively cold temperatures. Suitably, the inlet temperature of the alkylation reaction is between about 350C and about 5
00C IjIJ* most preferably about 400C to about 460
It is kept between C. From the desired VC, the operating Ma can also be increased as the catalyst is gradually deactivated.

The operating pressure within the alkylation camber zone can be varied over a fire safety range. Typical VC5 pressures are between about atmospheric pressure and about 25 atmospheres. Preferably.

The pressure is maintained between about lθ and about 15 atmospheres.

Referring now to the drawings, the number 1 indicates the reactor '6 1 which defines the alkylation reaction zone.

Inside reactor 1 is a bed of silica, carlide alkylation catalyst 2. Although only one bed of catalyst is shown in the drawings, it will be understood that a multi-bed system comprising any desired number of catalyst beds may be used. Aromatic feedstock is added to the alkylation reaction mixture through inlet %3. The alkene feedstock is added to the aromatization stream via tube 4, which flows into tube 3. Similarly, a controlled proportion of superheated steam is added to the mixed aromatization adduct and alkene feed through VS't-, which is led into tube 3. Valve means 6 are provided above 5% in order to positively convert the water vapor added into the feed stream into the gunfire. One unit of the aromatic Aq-compound and alkene feedstock are contacted with the catalyst in the reaction zone in the presence of steam and at an anchorage sufficient to cause the alkylation. The alkyl aromatic product adduct formed is removed from reactor l through v7 and sent to fractionation zone 8.

The excess aromatic groups 4 are then separated from the alkyl aromatic product. ? The remaining i% aromatic groups are removed from the fractionation section 8 as the superheated fraction through the tube 9 and recycled to the tube 3. The crude alkyl monomer product 90% is discharged from fractionation section 8 as a bottom stream through tube IO. Futsuyo! 111. 7′j? produced as a by-product during the production of enalbenzene? Heavy materials such as methylbenzene can be recovered and recycled into the inlet pipe 3 for commercial operations.

In a preferred embodiment, the use of silicalite and steam tea raw materials in the alkylation reaction is combined to facilitate the use of silicalite and steam tea materials, thereby making it possible to extract a fraction of the xylene from the product contaminants. The present invention provides a particularly effective process for producing unaethylbenzene and hethyltoluene in which the amount of trimethylbenzene and other undesirable by-products is reduced. However, even more dramatically, the use of an effective amount of steam tea material yields a higher conversion rate than when no steam is used; Strengthen your sexuality. This makes it possible to avoid the V-length cycle Q) and response, which of course has a great commercial advantage. moreover.

The use of steam-based feedstocks and silicalite catalysts has little or no irreversible deactivation effect on the catalyst, and when scooped out, the same catalyst can be reused after regeneration with a substantial loss of activity. Can be used.

Ethylbenzene or ethyltoluene from benzene and hydrene aromatic radical N? When using the process of the present invention to make W, suitable silicalite catalysts are those having a crystalline size of less than about 8ξ croons and a silica to alumina ratio of at least about 200. Along with these catalysts,
About 20.000 to about 6o based on aromatic compound Oii
, oooppm is advantageously used. Most preferred is the use of about 40,000 ppm of steam-based feedstock. Approximately 350' to approximately 500C
Although 10% of the mixture can be used, it is particularly effective to operate within the range of about 410' to about 4750. The preferred reactant ratio (aromatics/alkenes) is about 7:1. to about 20:1 and preferred aromatic ratios range from about 100 to about 150. Operating pressures between about atmospheric pressure and about 25 atmospheres can be used, with a range of about 10 to about 13 suitable.

The present invention will be described in more detail with reference to the following non-limiting examples.

EXAMPLE 1 Benzene and ethylene were added into a reaction zone containing a bed of silicalite catalyst material having a particle size between 12 and 20 meshes and a S i /A 1 ratio greater than about 300. The depth of the floor was approximately &25 wounds. The molar feed ratio of benzene to ethylene was approximately 16=1. The operating conditions are approximately 410C at the inlet of the catalyst bed. a [and outlet pressure of about 11 atm, about 110 Ningzen WH8V
An all-encompassing friend.

For hours 7 to 14 of operation, approximately 20. Added QOO gas. Between the 16th hour and the 11th hour of the 241st operation, approximately 60,000 p) of poison flow was used. Between 26Bf and 34th hour of operation, ij:, 40,001) > Poisonous water vapor IJ1. fee was used. At the very least, from the 36th hour bJ] to the 43rd hour of the operation, about 100 ppm or less of steam-based raw material was used for one cycle. The product stream from the alkylation reaction zone was analyzed by gas chromatography. Catalytic activity was measured both at the start and end of the central heating according to the following formula: Number of moles of reactive alkene fed to the reactor x 100 The selectivity was measured according to the following formula: fc: total production One reaction was stopped after 100 hours of testing time. The initial catalyst activity was calculated to be 99.9% conversion.

The final catalyst activity was 89.7% conversion.

The initial selectivity was 98'% and at the end of the experiment the selectivity increased to virtually 995G. The results of each of these experiments using one catalyst sample are shown below: ? -00016-24 to 148699489±482
00026-34 to 69 99 369±326
73+68 99 375±61 40.00036
-43 76+51 99 1? ±vs <l
These experiments demonstrate that steam-based feedstocks significantly reduce the amount of xylene byproduct produced, even when compared between fresh and spent catalyst materials. It should be noted that during the first experiment, the xylene content was relatively high, but the conversion rate in the liquid was significantly higher than in the last experiment.

Example 2 Toluene and ethylene were added into a reaction zone containing a bed of 1.5 ml of silicalite catalyst having a particle size between 12 and 20 meshes and a 5tlAl ratio greater than about 300. The depth of the bed was approximately B, Ocm. The molar feed ratio line of toluene to ethylene was approximately 16=1. The operation conditions include an outlet pressure of approximately 11 atm and toluene W of 1 fJ130.
Non-SVs were included. Two separate experiments were conducted, one with a steam-based feed and one without a steam-based feed. The inlet temperature over the course of 6 increments was initially about 490C for the first 2463 hours, and then decreased to about 470C for about the next 24 hours. The results of these experiments are shown below: 0-24.5 98 92 3559±564
40.0000-24 98 88 5239±1
039 None 26-49 98 94 2702±
122 40.00024-48 98 94 29
88±122 None These experiments demonstrate that steam-based feedstocks significantly reduce the amount of trimethyl-benzene byproduct produced.

Example 3 At a molar ratio of toluene and ethylene'i7:1, a temperature in the range of about 450-490C at the catalyst bed inlet, about 1
The reaction was carried out at a pressure of 1 atmosphere and approximately 130 toluene WH8V. The catalyst used had a mesh size of between 12 and 20 mm and a bed depth of about 7.5 mm. The experiments were carried out using a new catalytic sound and without water vapor co-stimulation. Conversion rates Fi ranged from 9816 initially to 39 F after 100 hours of operation. A 20th experiment was conducted under the same reaction conditions but using a new catalyst of the same type and adding an additional 4 Q, 000 ppm of steam-based feed (based on toluene) into the reaction.

The initial conversion for this experiment was 9a8, and this was reduced to 57% after 258 hours of operation. This means that when an effective amount of water vapor is fed in the process, the conversion rate (catalyst activity measure) is 23% of the period of use of the catalyst.
This shows that it was maintained at a high level after A times.

Example 4 Inlet temperature between 450° and 480C in this experiment.

A pressure of about 11 atmospheres and an aromatic to alkene mole ratio of about 8:1 were used. Benzene was used as the aromatic feedstock and ethylene as the alkene. Benzene WH8V was 110.

Additionally, 40,000'119% water (based on benzene feed) was used. The catalyst had a mesh of between 12 and 20 and a bed depth of about 800. The first Zo.

The conversion rate during operation for hours was kept at a high level of about SS*. 1 selection rate for own machine is about 99'% after 100 hours of operation
Met.

The same catalyst used in the above experiment was then regenerated. The regeneration process used here is generally described below.

First, the catalyst material was heated to 480C in the presence of nitrogen gas. After 3 hours of wrinkle treatment, water vapor was added at a rate of 28WH8V. After 30 minutes, return the nitrogen to 12WIiSV,
And the water vapor was set to 5WH8V. After 10 hours, water vapor was increased again to a level of @f3WH8V, nitrogen to 24WH8V, and air flow was added at αs WHS V. Thereafter, water vapor and nitrogen were slowly removed from the system and air flow was increased stepwise over a period of 3 hours. Total playback time was approximately 18 hours.

With the regenerated catalyst used in the previous experiment.

The second experiment without steam co-feedstock was carried out from 450° to 500°.
A second experiment was conducted at an inlet temperature in the range of 2.5 C, a pressure of about 11 atmospheres, and a toluene to ethylene molar feed ratio of 16. Toluene WIiSVII'1130. Conversion was maintained above 98% during 160 hours of operation using regenerated catalyst. this is.

It is shown that the use of a steam co-feedstock does not substantially adversely affect the activity of the silicalite catalyst material.

However, the selectivity ranged from about 88 inches initially to a final 92 inches after 161 hours of cropping.

The cocoon weight embodiment is provided merely as an example of the invention and is not intended to be limiting. Since modifications may be made to the disclosed embodiments by those skilled in the art that encompass the spirit and nature of the invention, the scope of the invention should be construed in accordance with the following claims.

[Brief explanation of the drawing]

The drawing schematically represents an apparatus for producing alkyl aromatic compounds according to the invention. In the figure, 1 is a reactor, 2 is a catalyst bed, 6 is a welfare valve means, and 8 is a catalyst bed.
3.4, 5, 7.9 and 10 represent tubes, respectively. Patent applicant Kosden Technology Inc.

Claims (1)

[Claims] 1. Aromatic Compound 1 A reactive alkene and available water are passed through a bed of silicalite alkylation catalyst under alkylation conditions, and the resulting alkyl aromatization adduct is recovered. A method for producing an alkyl aromatic adduct. 2. The method according to claim 1, wherein the sample water is added in the form of superheated steam. 1. The method of claim 1, wherein the aromatic compound, the nuclear-reactive alkene, and the sample water are mixed before being added to the reaction zone containing the alkylation catalyst bed. 4. Add a molar excess of the aromatic compound into the reaction zone. How to place 8d in Tomb 1 of Tokuzu Chaogu. & The method of claim 4, wherein the molar ratio of aromatic compound to reactive alkene is within the range of about 2 to about 20. & The method of claim 1, "Mjlltl", wherein the reactive alkene is ethylene. 7. The aromatization adduct is benzene. fFfIt#
Scope of A request: Item 5146 Method of sushi listing. a The aromatic compound is toluene. A method according to claim 6. 9. The method of claim 1, wherein the temperature in the reaction zone is maintained between about 300p and about 600C. 10. The temperature in the reaction zone is about 400C to about 460C
is kept between. A method according to claim 9. 11. The pressure in the reaction zone is maintained between about 3 and about 25 atmospheres. A method according to claim 1. The pressure in the 1λ 16 zone is maintained between about 10 and about 15 atmospheres. A method according to claim 11. l & about 20,000 pp based on 11 of aromatic compounds
m ~ about 100. Add OOppm of water into the reaction zone. The method described in paragraph 1 of the range of % allowance start calculation. 14, about 40,000p based on the weight k of aromatic compounds
pm of water is added into the reaction zone. Claim 13
The method described in section. 1 & reaction zone means; means for adding and contacting a silicalite alkylation catalyst bed aromatic substrate compound feedstock in the reaction zone means to and contacting the catalyst bed in the nuclear reaction zone means; a reactive alkene feedstock in the nuclear reaction zone means; means for adding to and in contact with the skeleton catalyst bed in the means; means for adding an amount of water vapor kM into the reaction zone means; and an alkyl aromatate-containing product stream in the reaction zone means. An apparatus for producing an alkyl aromatized adduct, comprising means for removing it from the alkyl aromatization product. 16. Also included is a means for separating excess aromatic radicals from the alkyl aromatizing product stream. The device according to claim 15, paragraph 1. 17. It also includes means for +1) circulating the mono-branched aromatic group adduct to the aromatic substrate raw material means. An apparatus according to claim 16. 1 & A method for reducing the activity loss of silicalite catalysts used in the alkylation of aromatic 2r'r substances, characterized by adding effective steam to the reaction zone during the alkylation. 19. The method of claim 18, wherein the water vapor needle used is in the range of about 20,000 to about 60,000 ppm of the aromatic substrate. 20, about 40 based on 1- of the steam aromatic mud
,000 ppm pith. The method according to item 19, in which the range required is fff*. 21. A method for reducing undesirable gaseous harmonics during the alkylation of aromatic substrates using silicalite catalysts by adding an effective amount of steam to the reaction zone during the alkylation process. 2Z y Undesirable avian organisms are composed of xylene or trimethylbenzene. 23 The amount of water vapor used is about 20,000 to about 60,000, based on the loading of the aromatic substrate. 23. The method of claim 22, wherein the amount is within OOOppm. 24. The water vapor acupuncture needle used is 40,000'I)T)m based on the overlay of aromatic substrate,% 1j+
・The method described in item 23 of "i#Ice ζ, 1".