JPS58164527A - Isomerization of xylenes - Google Patents

Abstract

PURPOSE:In carrying out both the isomerization reaction of a xylene and the hydrogenation and dealkylation reaction of a specific alkyl-substituted aromatic hydrocarbon, to enable long-term operation, by reclaiming a catalyst having lowered activity through a combination of the combustion treatment of a carbonaceous substance and chlorine treatment. CONSTITUTION:In the presence of a catalyst composition containing crystalline aluminosilicate modified with platinum, a xylene isomer not reaching a thermodynamic equilibrium composition is isomerized, and simultaneously an alkyl- substituted aromatic hydrocarbon containing >=2C alkyl group linked to an aromatic group is hydrogenated and dealkylated. In the operation, the catalyst composition on which a carbonaceous substance is accumulated, having reduced activity, is at first brought into contact with O2-containing gas at <=600 deg.C, so that the carbonaceous substance is partially burned, it is brought into contact with a chlorine-containing substance and an O2-containing mixed gas at 200- 600 deg.C, the mixed gas is replaced with an inert gas, and the catalyst is reduced with H2-containing gas at 200-600 deg.C, so that the catalyst is reclaimed. The isomerization activity and de-ethylation reaction activity of the catalyst are recovered.

Description

[Detailed description of the invention] Unexploded is a l1K method in which xylenes are isomerized using a crystalline aluminosilicate catalyst containing metals such as platinum.
This relates to regenerating the catalyst with reduced fliability. More specifically, in addition to the isomerization reaction of the intermediate silenes, the present li- conducts a water bulking dealkylation reaction of an alkyl-substituted aromatic hydrocarbon containing at least one alkyl group having 2 or more carbon atoms bonded to an aromatic nucleus. This invention relates to regenerating mosquito catalysts with reduced IIK activity.

Industrially, the isomerization of xylenes is an isomerization reaction process of aromatic hydrocarbons mainly containing a mixture of xylene isomers, and isomerization of the isomerization reaction mixture of xylene isomers. This is carried out by appropriately combining the mono-process S1 separation of p-medium silene and the recycling and concentration process of the residual composition mixture after death. At that time, the xylene isomer mixture composition in the isomerization reaction product should be as close as possible to the thermodynamic equilibrium composition; suppressing reactions such as decomposition of xylenes (especially hydrogenation of benzene rings) and disproportionation reaction. This increases the efficiency of the isomerization reaction, reduces costs, and has a great impact on industrial value.

Many methods for isomerizing xylenes have been proposed in the past, and many of these methods use catalysts containing crystalline aluminosilicate zeolite and have a To9. Regarding the folding method, one point of research has been focused on the modification of the catalyst, -development and isomerization, and many proposals have been made regarding this.

- As an isomerization catalyst for silenes in MK,
Catalysts based on combinations of noble metals (such as nickel, platinum, palladium, etc.) and crystalline aluminosilicates are well known, and these catalysts have excellent activity.

For example, rice 11M? Specification No. 41523183 (4
1854-164s No. 3), a catalyst containing 0.1 to 11 crystalline aluminosilicate zeolite with a silica/alumina ratio of 12 or more is used, and the temperature is about 26℃ to about 53IC. (800”F~1oe
A method of isomerization at a temperature of (below) is described, and in the same specification, the wrinkled crystalline aluminosilicate zeolite is made of nickel and platinum.

It is also stated that it may contain iron, cobalt, palladium, etc.

Furthermore, the unexploded l1j1:iI et al. were previously proposed by Kil, and in the Publication No. 9 II #Tosho 66-14711g, a crystalline aluminosilicate-containing catalyst composition was prepared in the gas phase in the presence of a bulk of water at an elevated temperature of xylenes. In the contact isomerization method, the composition of the wrinkled crystalline aluminosilicate-containing catalyst is (1) platinum and (2) titanium, chromium, zinc, gallicum, germanium, stronticum, yttrium, zirconicum,
Molybdenum, Pazicum, Tin.

Pariu^, dragonium, sericum, tungsten, osmium, lead, cadmium, mercury, indium, tantanium,
It is described that the main catalyst component is preferably modified with at least two metals selected from the group consisting of perilicum, lithium, and rubidium.

All of these methods are suitable for the isomerization of xylenes containing ethylbenzene, and are characterized in that ethylbenzene is mainly converted into benzene and ethane through a water bulking and deethylation reaction as well as an essentialization reaction. There is.

According to these methods, in addition to reducing the transalcoholization reaction of xylene and ethylbenzene due to mold formation, the hydrogenation reaction and demethylation reaction of the benzene ring are significantly suppressed. This brings about great industrial advantages such as a significant reduction in xylene isomerization yield and an improvement in the xylene isomerization yield.

41Kmle4111Mis-xnysas Publication 5
In the method described above, a platinum-containing, crystalline aluminosilicate catalyst is superior, and while maintaining the xylene isomerization ability and selective hydrodeethylation ability, it eliminates the undesirable properties of platinum during the middle silene isomerization reaction. Feature 1: For example, hydrogenation reaction of benzene ring and parent methylation reaction are significantly suppressed, making it an improved layer isomerization method for nine-xylene steel.

However, when the isomerization method of medium silenes containing these platinum groups and using nine-grain is carried out over a long period of time,
A reduction in activity occurs, as is usually the case with reactions using solid acid catalysts. This is presumed to be due to the deposition and accumulation of vertical diathesis on the acidic points of the crystalline aluminosilicate or the activated night of platinum. Therefore, it is necessary to perform a catalyst regeneration operation for the purpose of removing vertical elemental substances at an appropriate time during long-term operation.

Methods for regenerating such crystalline aluminosilicate-containing catalysts that can be modified with platinum or other metals have been proposed so far.

However, if the combustion treatment of carbonaceous material on the catalyst in an oxygen-containing gas, which is commonly used in iron catalyst regeneration methods, is used, the xylene isomerization reaction activity of the catalyst can be recovered. However, it was observed that the activity of the deethyl reaction may further decrease, or that undesirable m-reactions such as hydrogenation of benzene nuclei may increase.

That is, when the deethyl reaction activity of the iron catalyst decreases, the ethylbenzene conversion rate decreases, and for example, in a para-xylene production process in which electric current is applied, the equipment efficiency decreases due to an increase in the amount of ethylbenzene recycled. On the other hand,
If the reaction is carried out under harsh conditions to ensure the conversion rate of ethylbenzene using an iron catalyst, the activity of the deethylation reaction may decrease. The reaction and demethylation reaction are accelerated, which reduces the yield of intermediate silene.Furthermore, the hydrogenation reaction to aromatic nuclei 4 also increases the loss of xylene.

Therefore, in the isomerization reaction process of xylenes containing ethylbenzene, reactivation of the isomerization activity of the catalyst and reactivation of the deethyl reaction activity are extremely redundant.

In general, platinum metal particles dispersed on catalysts containing silica/alumina, zeolite, etc. are exposed to local high temperatures during regeneration, etc. when combustion treatment is performed in the presence of elementary gas. It is thought that the movement and aggregation of the particles occur and the reaction mode changes based on the particles.

This J! Various proposals have been made so far as methods for preventing the movement and aggregation of platinum particles on a tactile carrier during production. For example, a method that avoids exposing platinum locally to high temperatures during regeneration, and starting the regeneration process from a low temperature region and increasing the temperature (see $l!I@411-16889), and a method that involves coexistence of steam during regeneration. There is a method in which the treatment temperature is gradually raised while the temperature is increased (see the specification of French Patent No. xsttxxs).

However, the isomerization activity of crystalline aluminum/silicate-containing catalysts modified with platinum, etc., which contain ethylbenzene and are used in the isomerization reaction of silane, cannot be improved by any regeneration treatment proposed so far. Although the line was activated, the deethyl reaction activity could not be reactivated.

An object of the present invention is to regenerate a catalyst whose activity has decreased during long-term operation of a xylenes isomerization reaction process, and to thereby provide an improved method that enables more reliable long-term operation of a xylene isomerization reaction process. Another object of the present invention is to provide a method for isomerizing silene l1IO, and to increase both the isomerization reaction activity and the deethyl reaction activity in the gas phase isomerization reaction process of the clene chain containing ethylbenzene or the like. An object of the present invention is to provide an improved xylene isomerization method that stably performs an ethylbenzene-based deethylation reaction as well as a xylene isomerization reaction by regenerating a platinum-modified crystalline aluminosilicate-containing catalyst. be.

Other objects of the invention will become apparent from the following description.

As a result of conducting various studies to achieve this objective, the present inventors have discovered that a regeneration method that combines the combustion treatment of carbonaceous materials on the catalyst and the salt treatment is extremely effective. Achieve invention.

That is, a raw material mixture mainly containing an unexploded IjllU% intermediate silene isomer that has not reached a thermodynamic equilibrium composition and an alkyl-substituted aromatic hydrocarbon bonded to an aromatic nucleus and having at least 41 alkyl groups with a prime number of 3 or more. , a method for isomerizing silene by contacting it in the gas phase in the presence of hydrogen with a crystalline aluminosilicate-containing catalyst composition which can be modified with platinum,
(1) At a temperature below 400° C., for at least sufficient time to burn at least 41 seconds of the carbonaceous material that can accumulate on the cough pad. (2) Contact with a gas mixture containing a chlorine-containing substance and molecular oxygen at a temperature of -7s o o°C (@2 treatment) ), (3) Substantially replacing atmospheric chlorine-containing substances and molecular oxygen with an inert gas [1).

(4) After regeneration by contacting with a hydrogen-containing gas to reduce the phlegm at a temperature of 1100 to 600°C (fourth stage), the isomerization is further carried out using the phthalate 5lIi composition. This is an improved method for isomerizing medium silenes, which is carried out in accordance with the 411 image.

A detailed description of the invention follows.

The raw material mixture to be isomerized by contacting with the tactile composition in the gas phase in the presence of a water volume in an unexploded WA is a mixture of medium silene isomers and an alkaline medium having at least one alkyl group having 2 or more carbon atoms bonded to an aromatic nucleus. It is sufficient that the xylene composition mainly contains a substituted aromatic hydrocarbon, and the composition of the xylenes used does not reach thermodynamic equilibrium.

As is well known, xylene is ortho-, meta- and para-
There are three types of isomers, and when a mixture of these three isomers in arbitrary proportions is subjected to an isomerization reaction, the isomerization reaction reaches a certain value of the proportion of these three isomers. When this is achieved, an equilibrium state is reached, and isomerization apparently does not proceed any further. The composition of the xylene isomer compound in this equilibrium state KsP is called the "thermodynamic equilibrium composition", and this thermodynamic equilibrium composition varies depending on the temperature, for example, the xylene isomer composition at the following temperature. The equilibrium composition of the body mixture is:

(1) In the case of a mixture of only 3m isomers of medium silene [427°C]; Body) In the case of a mixture of medium silene isomers containing ethylbenzene [427°C]; The intermediate silene isomers which have not reached the thermodynamic equilibrium composition are the intermediate silene isomers in which the am of at least one of the xylene osmo isomers deviates from # degrees in the thermodynamic equilibrium composition. Any mixing tube will do.

Furthermore, the alkyl-substituted aromatic hydrocarbon having at least 1 alkyl group having 9 or more carbon atoms bonded to the aromatic nucleus in the raw material mixture used in the present invention has a vertical prime number of 2 or more as a substituent, preferably 2 or more. It may have only 4 to 4 lower straight-chain or branched alkyl groups, or it may optionally have 9 methyl groups bonded to the aromatic nucleus in addition to such alkyl groups.

Examples of such alkyl substituents having 2 or more carbon atoms include.

Ethyl, n-propyl, iso-10, 0-butyl, isobutyl, 5ee-butyl, tert-butyl groups, etc. are included, and among them, the aromatic hydrocarbon containing an ethyl group as a substituent according to the method of the present invention On the other hand, it can be advantageously applied to 轡. There are no particular restrictions on the number of atomyl substituents having a longitudinal prime number of 2 or more, but -IIIK is 1 to 11, preferably 1 to 2. The number of methyl substituents that may be present is also not limited in percentage, but when present, it can be 1 to 5, particularly 1 to 4 per plate.

On the other hand, the aromatic nucleus to which these alkyl groups are bonded is an Ali benzene nucleus.

Therefore, examples of the alkyl-substituted aromatic hydrocarbon to which the method of the present invention can be advantageously applied include, for example, ethylbenzene,
Ethyltoluene, diethylbenzene, silene in ethyl,
Among them, the present invention is particularly effective for ethylbenzene.

Further, the volume of the alkyl-substituted aromatic hydrocarbon may be selected from the above-mentioned nine types and may be 21 m or more.

Furthermore, the raw material mixture used in the present invention may contain penne, toluene, and other components.

It is desirable that the raw material mixture used in the present invention accounts for at least the general KIO weight, preferably at least the SO type weight, based on the total weight of the xylene isomer thermometallic material. Those having an IQ weight upwind of 6 weight or more on a weight basis are advantageously used.

The crystalline aluminosilicate (hereinafter sometimes referred to as #iv offite), which is the base of the catalyst composition used in the present invention, mainly contains hydrogen ions such as water bulk ions or ammoecum ions in addition to cationite. Those containing precursors and having a silica/alumina molar ratio of at least 10, preferably in the range of 20-200, preferably in the range of 1% and 30-150 are used. That is, in the present invention, a high silica-containing zeolite, in which the content of silica is relatively large compared to alumina, is used as the catalyst base.

Representative examples of crystalline aluminosilicates that can be used in the present invention as a base for such catalyst compositions include wires, e.g.
Mobile 0or
pora meeting, New York, USA) 1
One shot was fired and the Z8M zeolite and Imperial Chemical Industries (Imp@rlal O
h@n+lcmaro I I+d+astry Ltd,
The zeta-based zeolite, which is more highly developed than the US (Japanese), is included, and the former ZgM-based zeolite is particularly preferred.

An example of the second ZaM type is 28M-5 (US FF).
lPatent No. 370! aJII specification), 28M-1
1 (see specification of US Patent No. 3701171e), 28
M-12 (see specification of US AI41 license No. 5ssz4asq), 28M-:4s (refer to specification of US license number 401 @ 245), 28M-311 (US license number 5ssz4as q specification), 28M-311 (US 1!i% license $I4046
Zeta-based zeolites include Zeta 1 (see %1I18it-stt** bulletin), Maesha Zeta S (41111161-s), etc.
yz@s4 public 11th grade MII) $JI is removed.

Previously, the present inventors discovered and already proposed TP-1 series ions as silica-based ionites (%1l18&
4-137500) can also be used.

In the present invention, it is possible to use at least one of the above-mentioned zeolites as the base of the catalyst composition, which is far from the reputation consisting of ZIM-1, ZaM-11, 28M-12 and 28M-3@. Preferably, excellent effects are achieved using 411Kzam-5.

Generally, industrially useful zeolites are produced by the substitution of their cationites by cations such as alkali metals such as Na, etc. under threat conditions, e.g. 28M-5
In the case of zeolite, most of the cation night is Na.
occupied by. The crystalline aluminosilicate according to the present invention is selected from ions that exhibit acidity under isomerization reaction conditions, such as hydrogen ions, anhydrous ions, alkaline earth metal cations, transition metal cations, and rare earth metal cations. It is desirable that the cation contains at least one type of cation.

When the metal cation is exchanged with a cation such as Na contained in the threat state, it may be carried out according to a known method. Recommended for contact treatment with media.

The crystalline aluminosilicate-containing catalyst composition used in the method of the invention includes platinum or platinum together with titanium, chromium, zinc, gallium, germanium, stronticum, yttrium.

Zirconicum, molybdenum, palladium, tin.

Varicum, Heptasium, Sericum, Tungsten.

At least 41 metals (the group consisting of osmicum, lead, cadmium, mercury, indium-12, beryllium, lithium, and rubidium) [hereinafter referred to as 1
It contains metal (sometimes referred to as Xun 1).

First, among the plating metals (a) mentioned above in the present invention, tin, paricum, titanium, indium, and cadmium have a particularly strong ability to suppress undesirable reactions such as hydrogenation of aromatic nuclei and demethylation of xylenes. suitable.

Regarding the content of the metal contained in the crystalline aluminosilicate-containing catalyst composition used in the present invention, platinum is 0.001% based on the weight of the crystalline aluminosilicate.
~2Ji [amount, preferably in the range of o, o @s ~ i, s weight - at least 2 of platinum and metal (a)
When containing a metal (a), the atomic ratio of metal (maro)/platinum is o, o i ~ to
, preferably in the range of Fio, oi to s. In this way, catalytic products modified with platinum or platinum and metals (Hata) and containing agglomerated aluminosilicate are generally known as round blades when zeolite is modified with metals.
It can be fully bloomed by law. KII containing platinum and metal (,), whichever is done first,
Although it may be difficult to do it all at once, the preferred method is to first denature with platinum and then denature with metal (heat).

As mentioned above, when molding axillary-modified zeolite containing the metal, it is possible to use a synthetic or natural refractory zeolite that is normally used as a binder for zeolite-based catalysts in accordance with conventional methods. The inorganic oxide 1 can be mixed with, for example, silica, alumina, silica-alumina, kaolin, silica-magnesia, etc., then formed into a desired shape, and then hardened by heating. The amount of modified zeolite in the catalyst composition obtained by such molding is generally about 1%, based on the weight of the cough catalyst composition.
Advantageously, it is 99% by weight, preferably 10 to 90% by weight.

Using the above-mentioned nine catalyst compositions, the isomerization reaction of xylenes in the precipitate compound can be carried out under conditions for the isomerization reaction of xylenes which are known per se.

Thus, the reaction temperature is generally from ZSO to 460°C, preferably from 270 to 400°C, preferably from 70 to 40°C.
0°C, particularly preferably within aS of 380 to 10°C, and the hydrogen partial pressure is generally 1 to 85 atm,
The pressure can be freely selected within the range of preferably 1 - 0 atm, particularly preferably 1 to 1 s atm.

In carrying out the method of the present invention, the feed ratio of the mixture is:
Although it can vary widely depending on the bulk hydrocarbon raw material and/or the type of catalyst used, it is generally about 1 to about soo, preferably 2
~100. More preferably, it is advantageous to supply in a weight unit time space range within the range of 1 to SOO.

In this specification, "weight unit time-space moderation" is a value calculated by the following formula: 69, and "catalyst weight" means the weight of the crystalline aluminosilicate that is the base of the catalyst product.

First, our dealkylation is carried out in the presence of hydrogen. The hydrogen supply ratio at this time can vary widely depending on the bulk hydrocarbon raw material and/or the type of catalyst used, but it is generally 0.1 to 15, preferably 0.1 to 15, expressed as a molar ratio of hydrogen/hydrocarbon raw material. It is appropriate to supply it at a ratio such that it is within 1-100fliH.

Under such reaction conditions, a crystalline aluminosilicate-containing catalyst composition modified with platinum or Hiroplatinum and the metal (a) is bonded to the aromatic nucleus as described above and has at least one alkyl group having a vertical prime number of 2 or more. When used in the isomerization reaction of intermediate silenes in the coexistence of bulk water with alkyl-substituted aromatic hydrocarbons, the next tIsK carbonaceous substances accumulate at the acidic points of the zeophyte or the active sites of platinum, leading to the isomerization reaction of xylene. Since the activity and the hydrogenation-dealing reaction activity for alkyl groups having 2 or more carbon atoms gradually decrease, if the reaction activity decreases to a certain level and at 9:00, the regeneration treatment using the 1# mold of the present invention is applied. good.

11 regenerating heat companies that meet the present invention, wrinkle catalyst composition (1)
- at a temperature below 00°C for at least sufficient time to burn at least 41 parts of the carbonaceous material that can accumulate on the catalyst;
Contact with a gas containing molecular oxygen (first treatment), (2) Contact with a large mixed gas containing a chlorine-containing substance and molecular oxygen at a temperature of 200 to 600°C (second treatment), (3 ) Substantially replaces the chlorine-containing gas and molecular oxygen in the air with an inert gas), (4)
! 11) in which the catalyst is reduced by contacting it with a water-volume-containing gas at a temperature of 0°C to 0°C.

lll [Details about the playback layer.

If the catalyst becomes inactive during the operation of the reaction, it is preferable to first perform the following procedure, that is, stop the supply of the raw material mixture as a pretreatment, and then continue supplying hydrogen for a certain period of time to cool the reaction system. Release most of the hydrocarbon mixture within. Further, by supplying an inert gas, water bulk gas in the system is substantially removed. These pretreatment operations are not particularly limited in terms of operating conditions as long as their purpose is achieved.

Next, the first process of reproduction is performed as described above. Cough happy lII &
The purpose of this method is to bring the gorge catalyst into contact with a molecular oxygen-containing gas, thereby substantially burning off the carbonaceous bulk materials, with the aim of removing the elemental materials accumulated on the wrinkle catalyst.

In addition, in this first treatment, it is preferable to minimize the S*% agglomeration force of the metals such as platinum contained in catalyst composition without destroying the crystal structure of the catalyst composition, and for that purpose. It is necessary to select the wrinkle treatment me item.

The treatment temperature when carrying out the tI611 is 600
℃ or less, preferably SSO ℃ or less, preferably i
If there is a fiK below o' o℃, there will be a storm.

The temperature for this treatment is relatively low, for example 150~!, in order to eliminate local temperature rises in the early stages of IIO in the axillary region where a large amount of carbonaceous substances and the like are present. It is preferable to maintain the temperature at sO°C, and monitor the combustion status of the carbonaceous material at that stage.

The amount of combustion is reduced and tkK*KJ is better! II is preferred. In a preferred embodiment of the present invention, the carbonaceous material is combusted at a certain level, maintained at that temperature until there is substantially no carbonaceous material that can be combusted, and then the bale is heated to the next temperature level. Substantially all of the vertically combustible material at this temperature is combusted. This stepwise combustion process continues up to the desired maximum temperature.

It is desirable that the above temperature is below SOO°C, preferably below sio°C, more preferably below SOO°C. When the maximum wrinkle temperature exceeds @OO℃ and Maruba metal has undesirable phenomena such as agglomeration of the metal contained in the catalyst, unreliable dynamic phenomena, and destruction of the crystal structure of the zeolite, etc. arise.

The oxygen concentration in the molecular oxygen-containing gas used in the first waterfall is 0.1 to 10011 amount-1, preferably 1-2
In addition to oxygen, at least one kind of inert gas such as nitrogen, helium, or argon is used at zero capacity. In addition, in the first half of #&Equipment 1, this oxygen concentration is set relatively, for example, 0.1-5 volume, to take into account the local temperature rise and the occurrence of the above-mentioned undesirable phenomenon. Keep it low, monitor the combustion situation, and increase the relative oxygen a level in the second half when the amount of combustion decreases.
It is convenient to make m high.

The pressure in the first treatment is 1 to 20 atmospheres,
In the first half of the wrinkle treatment process, it is desirable to maintain the pressure at a low level, such as 1 to 10 atm.

This #11 place 11KI! The time required for this depends on the amount of carbonaceous material deposited, its properties, J6JI temperature, pressure, oxygen concentration, etc., and is not constant. It is desirable to continue the carbon oxide treatment until the production of carbon dioxide gas or the consumption of oxygen decreases, preferably until they substantially stop, usually for 1 hour or more, preferably at a threshold of 5 to 100 hours. be.

The Hz treatment site for catalyst regeneration in this plant is where the platinum particles containing 1 mK are transferred during the combustion process of the above-mentioned No. 1 J6, etc.
In order to redisperse the agglomerated portions, the catalyst composition is brought into contact with a mixed gas containing a chlorine-containing substance and molecular oxygen and treated at a temperature of 200 to 600°C.

The i1*j1g treatment is performed using platinum or platinum and metals as described above, which have the activity of both the isomerization reaction of xylenes and the hydrogenation-dealing reaction of the alkali group having 2 or more carbon atoms.
The major 41 of the present invention is the regeneration treatment of a crystalline aluminosilicate catalyst composition modified by
It is one of 11.

Armpit J1g! The gas mixture used in the cooking process contains chlorine-containing substances and molecular oxygen. The chlorine-containing substances include at least one of the group consisting of chlorine gas, hydrogen chloride, and organic chlorine-containing substances. Chlorinated derivatives of hydrocarbons, such as tetrachloride, chloroform, and propylene dichloride. Chlorine-containing substances include the above-mentioned a@L friends, but the preferred ones are chlorine gas, hydrogen chloride, &! Preferred examples of carbon chloride and 41 include chlorine gas and hydrogen chloride.

The oxygen concentration in the mixed gas in Is2 treatment is 01 to 9
9.991Fti preferably range 8 from 1 to 20 volumes, and the amount of chlorine-containing substance added is from 0.01 to 0.01 as a molecule.
5 capacity - 1 preferably 0.02 to 11 Ft. (9) At least one of nitrogen, helium, argon, etc. is also used as an inert gas in the mixed gas.

In the present invention, as shown in the present invention, the contact heating method with a mixed gas in which Kll element is essential effectively redisperses platinum, etc. contained in the catalyst, and isomerization reaction of middle silenes. It has become clear that reactivation of the activity of the hydrogenation dealcolation reaction is effective.

The temperature when carrying out the 2nd II & tsu is 20 (1-600
℃, preferably in the range of 250 to sso'CtQ@.

If the shell temperature exceeds 600°C, phenomena such as assimilation of the crystal structure of the catalyst will occur, and if the temperature is below 200°C, redispersion of the platinum particles contained in the catalyst will be difficult to proceed. I like the evening.

The pressure at the third factory is 1 to 20 atm, preferably 1 to 10 atm, and the heating time is 1 to 10 hours, preferably 1 to 10 hours. Illll
The 13th place is s in order to move from the 2nd place to the 4th place JIK.
g" This is a step in which the oxygen-containing substances remaining in the gas in the system are substantially replaced with an inert gas after the treatment is completed.

Although the pressure and temperature are not particularly limited, it is advantageous for operation if the third processing plant and tl are in the same range.

The fourth process in the present invention includes the first process. In the catalyst composition in which the carbon-purchasing substance and the like were burned off and the contained platinum and the like were redispersed and escaped in the second stage 11, the catalyst composition was brought into contact with a bulk water-containing gas at a temperature of 4 for the purpose of reducing the plated platinum.
It is.

The treatment method uses a hydrogen-containing gas at 200 to 600C under normal pressure, preferably so-o-s.
Platinum in the oxidized state is reduced and converted to metallic platinum at a temperature of 0°C. A must on this occasion! The amount of hydrogen is preferably 10 moles or more of the theoretical amount required to convert platinum oxide into metallic platinum. The time required for such water volume reduction is determined by the reduction temperature.

Although it is influenced by the amount of catalyst, reducing pressure, water volume of 111 degrees, weight, etc., it is usually more than so minute, preferably F1.
The range of 1 to 10 hours is wide range.

In this way, the present invention provides a catalyst that can be used in the isomerization reaction of intermediate silenes in the raw material mixture by applying the above-described regeneration treatment to the composition of the catalyst. This method is characterized by regenerating the activities of both the isomerization reaction of xylenes and the hydrodealkylation reaction of xylenes.

Thus, according to the present invention, the above-mentioned aromatic hydrocarbon raw material is supplied again after being activated by the above-mentioned #Il~4th regeneration process 11, and the above-mentioned aromatic hydrocarbon raw material is supplied again to the above-mentioned Nakasire/! The isomerization reaction of I can be continued for 11 times.

Furthermore, by carrying out the isomerization reaction of medium filtrate/a according to the present invention, it is possible to maintain high isomerization reaction activity as well as the above-mentioned hydrodealkylation reaction activity, especially water volumizing dealkylation reaction activity, and aromatic nucleus The loss of xylene due to hydrogenation and demethylation reactions is small, and the cough isomerization reaction can be advantageously carried out over a long period of time due to industrial KLI.

Moreover, the activity after catalyst regeneration can be completely restored to the activity before regeneration by employing the regeneration treatment method of the present invention. In particular, the isomerization reaction of xylenes with high hydrodeethyl activity is one of the main objectives of the present invention, but the reduction in deethyl activity due to regeneration due to the drawbacks of platinum-containing zeolite catalysts can be avoided by the method according to the IPJK of the present invention. Completely original activity level K
Being able to recover up to that point is a huge advantage.

As described above, the isomerization reaction of H+silenes according to the present invention can be carried out industrially very advantageously, and it can be said that the economic effect thereof is very large.

The method of the present invention will be described in further detail below with reference to Examples. However, the present invention is not limited to the following examples.

Incidentally, various ratios (*) and abbreviations appearing in the examples have the following meanings, respectively.

Deethylation rate -- Para 1? Silene at (weight-) [PX]m: Degree of equilibrium balance of xylene in xylene isomers at reaction temperature (weight-) (IB)y: 1189 degrees (weight-) in the feed liquid
) (IB)F: 184 degrees in product liquid (weight -
) (x)F; Medium silene 3 isomer in the feed liquid - degree (weight -) [x)p;
Weight -] Example 1 Synthesize 28M-5 according to the method disclosed in US wAIf #31-201. During the synthesis, tri-n-propylamine and n-propyl bromide were added as organic nitrogen cation sources. The compound was identified as 28M-5 from the X-ray diffraction pattern. Obtained nine Z
After passing through 8M-S and washing thoroughly with water, 10
It was dried at 0° C. for 8 hours, then at 200° C. for 16 hours, and then calcined for 16 hours at 450° C. under air circulation in an electric Matsufuru furnace. Then 5hot 11-ammonium chloride water #
l liquid 1. Ion exchange was performed at st and 80°C for 24 hours. Repeat this operation two more times. After that, it was thoroughly washed with water and dried with IIISil at 100°C in an electric dryer, followed by 3.
(by drying for 16 hours at 0°C and further constituting for 16 hours at 450°C under air circulation in an electric Matsufuru oven)
Get Z8M-5. This thing has O sodium content of O,
The amount of os31 is 71, and the silica/alumina molar ratio is 71.

Then, using the ``kHz PT'' (silica/alumina molar ratio 71) obtained as above, the following (pt-an/alumina) was prepared.
Z 8 M&t synthesis nine.

That is, HIpI 01@Tei 6H, 01511q was dissolved in 2-1 water, dissolved in 26-hydrochloric acid, and tin chloride (
8n04) Add 1 ``7'' I. 1Fc3.
@114 Constant sulfuric acid 15- was added to KH'MIZ in the solution.
8M-530t was immersed. The mixture was then kept under reflux for 6 hours using a rotary evaporator.

The capping medium was distilled off at 100°C, and the PT- Obtain 8a/Z 8 M-5. The resulting catalyst contained 0.2% platinum and 0.23% tin based on total weight.

lI! Example 8 Nine H shoes Z8M-5 (
'Silica/alumina molar ratio 2) is used as follows (p
tan/Z 8 M 5 was synthesized. That is, p
Dissolve +(NH3)4011-NH00,162f in 90-kg water and immerse Hg78M-530t in this. This was subjected to ion exchange treatment at 50° C. at 8 o'clock while being shaken occasionally, and then filtered and thoroughly washed with water at room temperature. Then 8 hours at 101°C in an electric dryer, then 1 hour at 200°C.
After drying for one hour and baking at 450C in an electric Matsufuru furnace in the summer, pt/Z8M-5 was obtained.
! The pt/Z8M-530t obtained as above was immersed in the o, 5- and go-water solution. After leaving this overnight at SO℃, water was distilled off using a rotary evaporator, and then 10
By drying at 0°C for 8 hours and at goo°C for 11 hours, and then firing in an electric Matsufuru furnace at 450°C with an opening time of 8 o'clock, the p.
Obtain t-8n/Z8M-5. The resulting nine catalysts may contain 0.3% platinum and 0.1% tin based on total weight.

Example 3 HjllZ8M-! obtained in Example 1 Synthesize K p t/Z 8 M S as follows using a. That is, H, p t OLm −@HI04 G ”f is 26
- and immersed it in water. After death, the solvent was distilled off at 40°C using a rotary evaporator, and then at 100°C for 1 hour and at 200°C for 1 hour in an electric drying state.
Dry for 1 hour, then put in an electric Matsufuru oven under air circulation for 45 minutes.
p t / Z 8 by incubating for 8 h at 0 °C.
Get MS.

The nine catalysts obtained contained 0.05% platinum based on the total weight.

Yi-Example 4 Powdered pI-8n/Z8 obtained in Example 1
Add 1/1 weight ratio of alumina gel for talomadograph (200 mesh) to M-6 and mix thoroughly.
It was majestic because of its size of 20 meters. The obtained Kyusei footwear was baked in an electric Matsufuru furnace at 450° C. under an atmosphere of “II” air for 8 hours, and then charged into a pressurized fixed bed reactor.

Thereafter, a bulk treatment was carried out at 400° C. for 2 hours in a hydrogen stream, and then a middle silene isomerization reaction was carried out using the mixed silene having the composition shown in Table 1 as a raw material. Reaction condition line Reaction temperature: SSO℃, weight unit hourly space velocity (WH
8V): 20, OHR = (based on zeolite weight), hydrogen/aromatic hydrocarbon volume (molar ratio): 2/1% Total pressure:
■ The product composition at 48 hours after starting ToI and raw material feed in P81A is as shown in RUN-1 in Table-1. The composition of Purilide after passing through the oil for 1140 hours under the same conditions is also shown in RUN-IK in Table 1.

After this, the cylinder feed was stopped during mixing, and the temperature was 150°C.
In OP8IA, only hydrogen was supplied for 1 hour, and then the inside of the system was purged with nitrogen. After that, the next Mr. O plays Ij &
I performed Mu. First, aso℃, 14.7 P8
Air was introduced into the catalyst bed at a rate of 1005 g/m using IAK, and the combustion of the vertical substance was also started.

That is, the body was maintained at SSO°C for 4 hours while passing air through it, and after death, it was further maintained at 400°C for 4 hours and at 41t0°C for 6 hours, and then the pressure was increased to 43P8Im at this temperature and held for 2 hours to make it into charcoal. 9. Burn quality. After that, 5
Replace the system with IlIA (third treatment), in a hydrogen stream 4
The bulk treatment was carried out at 00° C. for 2 hours (III4 treatment station), and mixed xylene was fed again under the control conditions. The product composition 48 hours after starting the feed is RUN- in Table 1.
As shown in 3.

Oil was passed through the system for XXO hours under the same conditions, after which the cylinder feed was stopped during mixing, the system was kept at 360℃ and 150P8I, and water was supplied for 1 hour, and then the system was replaced with nitrogen. Perform the recycled tin layer (B). That is, first, mso℃, 14.7 P8IAK and 1O to the catalyst bed.
Air was introduced at a rate of O-/slI, maintained under these conditions for 4 hours, and then further maintained at 400°C for 4 hours and at 450°C for 6 hours. 9.

Then nitrogen, air, &! &l using carbon chloride, 7vo
l % water volume and o, s voItso chlorine containing trx
The round mixed gas prepared in c was heated at a rate of 46
Platinum redispersion treatment (second treatment) was carried out by supplying platinum at 0° C. and 147 PII for 1 hour at 480° C. After that, the remaining chlorine and oxygen were purged with a nitrogen stream (third heat treatment), and after reaching 4oo'cK, a reduction treatment of 11L (1114L) was carried out for 2 hours in a hydrogen stream.
treatment) and perform a third mixing cycle under the above conditions again. The product composition of the 48th hour after starting the feed was 6 times 9 as shown in RUN-4 in Table 1.

After passing through the oil for an hour in ssO, 714MII & 1% of 7mass in a nitrogen stream at 1m (mixed food containing Dta element and 1% of chlorine)
Except for using
), the silene isomerization reaction in the 4i-th Q was carried out under the above-mentioned dispute, and the product composition at 48 o'clock after the start of the feed was 8υN- in Table 1! Described in i.

From the results in Table 1, it can be seen that a comparison between BUN-1 and RUN-2 shows a tendency for the PX equilibrium achievement rate and deethylation rate to decrease with long-term operation of the xylene isomerization reaction.

Furthermore, from the results in Table 1, ll 1. J RU where platinum redispersion processing (second processing) has not been performed in the 4th processing
In N-3, the de-ethyl activity decreases significantly and the loss rate of medium silane increases, but in I11~$s, which includes platinum redispersion treatment,
It is clear that the deethylation rate can be activated without using the ILUN-4.

Table-1 Example 5 Nine powdered pt/Z8M obtained in Example 3
First, the xylene isomerization reaction was carried out using 1+11 in the same manner as in Example 4KIe except that K was used.
1ALi. The reaction conditions were: reaction source t, *s o ℃ 1 weight unit hourly space velocity (WH8V): 1. OHR-”
(based on the weight of the second compound), hydrogen/aromatic hydrocarbon (mole ratio): 1/3. Total pressure: 120 P8 summer,
Feed starting value 4S hours Bo product composition is shown in RUN-1 in your opinion, it was put in a steamer, passed through oil for 1-0 hours under the same conditions, and after death, the mixed kijilene tweed was stopped, and then Example 4 Similarly to the 9th regeneration process (B) described in 9.
Treatment was performed. After that, the zth O under the above reaction conditions
Perform the xylene ^ sexualization reaction, and check the product composition at 40 o'clock after starting the feed! RUIN-zKl11 in I-s
69.

As is clear from the results, due to the effect of platinum redispersion treatment (#I2 processing ring 1), 8ON-4's RLIN
-1 and the same 〇 level KToru.

Table-2 Comparative Example Nine powdered pt-am/Z8 obtained in Example 2
First, a middle silane isomerization reaction was carried out in exactly the same manner as described in Example 4 and in Example 90, except that M-@ was used. The reaction conditions are: reaction temperature: 1S (1°C, 1 weight unit, hourly space velocity (WH8V): s, o (based on zeophyte weight)
, hydrogen/aromatic hydrocarbon volume (molar ratio): s/*, To at a total pressure of 120P8Im), The product composition at 48 o'clock after the start of Tweed is as shown in RUN-IK in Table 3)
And nine. After passing through the oil for an ISO time, combustion of carbonaceous materials was carried out using the nine regenerated convicts described in Example 4.
), N, substitution (third process) and reduction process 11 (JII4
4 ml), a second xylene isomerization reaction was carried out under the above conditions, and the product composition 48 hours after the start of feeding is shown in RUN-2 in Table 3.

After 160 hours of oiling, exactly the same procedure as above.

(depending on the method) After carrying out the process, a third xylene isomerization reaction is carried out under the above conditions. 411 hours after feed start 41 The product composition is RUN in Table 3.
-It happened as shown in 3.

From the results in Table-No., after the first regeneration (RUN-8), the sylene loss rate increased due to a decrease in the deethylation rate, and after the second regeneration (RUN-3), the hydrohydrogenation reaction increased. It is clear that the KdP silene loss rate further increases due to the development of the hydrogenolysis reaction.

Table 3 Procedures Amendment Book Showa Sy., Fl/Japan Mr. L. Commissioner of the Japan Patent Office Case display case it-4Sms9 No. 1 1m911#) 4th name xylene isomerization method Intermediary: Applicant: Higashi*Sakashi, 5-1 Yuki-chome, Uchisaiwai-cho, Chiyoda-ku, Toyojin Yuka Co., Ltd. Representative: Tomo Tokusue, 1st generation Ruito, 1-111 Uchisaiwai-cho, Chiyoda-ku, Tokyo
No. 1 (Josho Building) Teijin Ltd. In-house (7736) Patent attorney Hiroshi IlliiIM Contact information
(so・) 4481 Gourd Correction target ``Hosei'') 1 required 15-r, 6.1 (1
3m188@page, line 7, "precious metals" is corrected to "metal."

(3) “Al Z/Silike F” with 11 purchases and 11 lines of Meisho
is corrected to "Al-Z nosilicate".

(3) "Rinen-like" in the meaning line on page 1 of the specification is corrected to "other ■-like."

(4) - rMobll Cor in 4 lines from the bottom of 1m page of a book
pora-ttomJ rMobll Oll Cor
Correct it as por+atiom J.

(5) Delete "Particularly preferably 10 to 400 degrees Celsius" on page 23, lines 13 to 14 of the specification (6) Specification 11
Page 13 line, same page line 14, S Hatake page 1 line, same page meeting line 0M page 1
Line 0, 3 lines from the bottom of Oka, 1 line from as, same page/line, pNi
Page I, line 11, page 11, line 1 from the bottom of page Oka, page 4, line 4.

rptJ of 41j line 1 and 4 page bird line respectively r Pt
Correct it with J.

that's all

Claims (1)

[Scope of Claims] L Mainly contains an alkali-substituted aromatic hydrocarbon having a medium silene isomer and an aromatic nucleus K111 which have not reached a thermodynamic equilibrium composition and at least one alkyl group having a large carbon number of 2 or more. The silene is isomerized by contacting the heated material with a crystalline aluminosilicate compound that can be modified with platinum in the presence of a large volume of water at elevated temperatures. In a method in which carbonaceous substances accumulate and the activity decreases, the catalyst substance accumulates in the scissors catalyst at temperatures below 011111°C and at least 1 part of the 9 noble substances accumulates in the catalyst. φ(
Contact with a gas mixture containing a chlorine-containing substance and molecular oxygen at ~5oIc01LjIF
VX snow treatment), -) Substantially replace O#1-containing substances and molecular oxygen in the atmosphere with an inert gas (3rd place), (a) SO...00℃ After regeneration by reducing the catalyst by contacting it with a hydrogen-containing gas (1 m4), the catalyst composition was further regenerated using scissor isomerization. Method for isomerizing Marunaka sauce type 7. i The degree of bulk chain in the wrinkled gas is 0.1
~1009 Quantity method #11. 2. The method according to item 1 or 2, wherein the pressure at the 8WC is 1 to 30 atm. Table: The chlorine-containing substance in Rattaninozokoro 11 is chlorine gas. A method for recording any one of the following terms, which is at least 1 m depending on the volume of chloride water and the details of the organic chlorine-containing substance. If the oxygen content in the gas mixture at the i gs treatment plant is 0.
The method according to any one of Items 1 to 4, which is a meeting capacity whisper. Tortoise $11 MIIK #1 - where the concentration of chlorine-containing substances in the mixed gas is 0.01 to capacity - as chlorine molecules
7j method according to any of Section 5. 7. The pressure at iris 3 location 11 is 1-10 atmospheres $
11. The method according to any one of items 1 to 6. Turtle: The wrinkle-tactile composition contains platinum, titanium, black A, m*
, #lJium, germanium, strontium, yttrium, zirconium, molybdenum, palladium, tin, barium, cesium, sericum, tungsten, os1um, lead, cadmium, water #l, indium, lanthanum, beryllium, lithium and Contains at least one metal selected from the group consisting of Rubidium! s1 Method of injection. t. The method of claim 1, wherein the crystalline aluminosilicate O silica/alumina molar ratio is at least 10. lα Alchemized crystalline aluminosilicate becomes Zeolite Light ZIM-13,'! The method according to item 1, in which the group consisting of t9ite 18 M-u and (Otite zIM-38) is one type.
$11111 or 07F method containing 0.001-1 weight of platinum based on 0 weight. 1z Wrought alkyl-substituted aromatic JIi vertical hydrogen is bonded to the aromatic nucleus and has 1 to 3 linear or branched chain alkyl groups of vertical lines 92-4 in ', and optionally 2. The method according to claim 1, wherein the aromatic hydrocarbon is an aromatic hydrocarbon which may have 1 to 2 9-methyl groups attached thereto.