TW552254B - Gas phase alkylation method and catalyst - Google Patents

Abstract

Ethylbenzene is produced by alkylation over monoclinic silicalite catalysts having a weak acid site concentration of less than 50 micromoles per gram. A feedstock containing benzene and ethylene is applied to an alkylation reaction zone having at least one catalyst bed containing a monoclinic silicalite catalyst having a weak acid site concentration of less than 50 micromoles per gram. The alkylation reaction zone is operated at temperature and pressure conditions in which the benzene is in a gaseous phase to cause gas-phase alkylation of the aromatic substrate in the presence of the silicalite catalysts to produce an alkylation product. The alkylation product is then withdrawn from the reaction zone for separation and recovery.

Description

552254 A7 B7 V. Description of the invention (1)

The present invention relates to an aromatic alkylation method and catalyst ', which includes gas phase alkylation of an aromatic matrix using a modified silica ore aromatic alkylation catalyst. The improved catalyst and method provide an alkylation product with fewer impurities and unwanted reaction by-products. Aromatic conversion methods using molecular sieve catalysts are well known in the chemical processing industry. The aromatic conversion reaction system includes the alkylation of an aromatic substrate such as benzene to an alkyl aromatic such as ethylbenzene, ethyltoluene, cumene, or a higher aromatic, and the alkylation of a polyalkylbenzene to a monoalkylbenzene. . Alkylation reactors that produce mixtures of mono- and poly-alkylbenzenes can be linked to downstream alkyl transfer reactors through various separation steps. The alkylation and transalkylation conversion method can be performed in a liquid phase, a gas phase, or a condition in which both a liquid phase and a gas phase are present. In order to improve the industrial alkylation operation, not only the conversion efficiency of the catalyst is emphasized, but also the by-products generated. For example, in the production of ethylbenzene, ethylene and benzene are introduced into an alkylation reactor in the presence of various catalysts. Some of the by-products measured include diethylbenzene, xylene, propylbenzene, cumene, butylbenzene, and other components collectively referred to as heavy substances. These by-products have a negative impact on the purification of the desired product. In addition, even by separation ' these by-products need to be removed from the system. Cost of product required for proper waste addition. An example of gas-phase academy is found in U.S. Patent No. 4,107,224 to Dwyer. In this case, gas phase ethylation of benzene using a zeolite catalyst is performed in a downflow reactor having four catalyst beds in series. The output from the reactor reaches the separation system 'where ethylbenzene is recovered, and polyethylbenzene is recovered into the alkylation reactor, where benzene is mixed (please read the precautions on the back before filling this page) Γ — Printed by the Intellectual Property of the Ministry of Economic Affairs and Employees' Cooperatives. The paper size is applicable to the Chinese National Standard String (CNS) A4 specification (210X297 mm) -4-552254 A7 B7 5. Description of the invention (2) The transalkylation reaction is performed. The Dwyer catalyst system includes ZSM-5, ZSM-11, ZSM-12, ZSM-35, ZSM-38, and similar materials. Molecular sieve silica is a well-known alkylation catalyst. For example, U.S. Patent No. 4,520,220 to Watson et al. Discloses the use of silicalite catalysts, which have an average crystal size of less than 8 microns, and a silica / alumina ratio of at least about 200, which is used Ethylation of aromatic substrates such as benzene or toluene yields ethylbenzene or ethyl toluene individually. As disclosed by Wat sn et al., The alkylation process can be performed in a multi-bed type alkylation reactor at a temperature range of about 350 ° -475 ° with or without a common feed stream. Watson et al. Reactor conditions are such as those provided for general gas phase alkylation conditions. Another method that uses silica ore and includes ethylating benzene under gas-phase reaction conditions and refluxing the product-containing polyethylbenzene back to the alkylation reactor is disclosed in U.S. Patent No. 4, Waguespack, No. 922, 053. In this case, the alkylation is performed using a catalyst such as silica ore or ZSM-5 at a temperature generally between 370 ° C to about 470 ° C and a pressure up to about 25 atmospheres. The catalyst is described as humidity sensitive, and care is taken to prevent the presence of moisture in the reaction zone. The alkylation / transalkylation reactor includes four catalyst beds in series. Benzene and ethylene were introduced into the top of the reactor to reach the first catalyst bed, while polyethylbenzene was partially refluxed to the top of the first catalyst bed, and polyethylbenzene and benzene were injected into the reactor between the stages. The difference. Another method involving the use of silica ore as an alkylation catalyst involves the alkylation of alkyl phenyl substances to produce di-americyl benzene with a suppressed ortho isomer content. Therefore, such as US Patent No. 4 of Butler et al., This paper size applies Chinese National Standard (CNS) A4 specification (210X297 mm) III # .— (Please read the precautions on the back before filling this page) Printed by the property ^ employee consumer cooperative -5- 552254 A7 B7 V. Description of the invention (3) No. 4 8 9, 2 1 4 Uncovered, using gravel ore as a single-basis substrate, toluene or ethylbenzene alkane The catalyst is basicized to produce a corresponding dialkylbenzene such as ethyltoluene or diethylbenzene. Butler et al. Disclose in detail the ethylation of toluene under the gas phase conditions at a temperature range of 350 ° -500 ° to produce ethylbenzene. As revealed by Butler, the ortho ethylbenzene present in the reaction product is substantially lower than the kinetic equilibrium amount under the gas phase reaction conditions used.

U.S. Patent No. 4,185,040 to Ward et al. Discloses an alkylation method using a low sodium content molecular sieve catalyst, which is said to be particularly useful for producing ethylbenzene from benzene and ethylene, and from benzene and propylene. Cumene. The Na2O content of the zeolite should be less than 0.5 weight percent. Examples of suitable zeolites include molecular sieves of the X, Y, L, B, ZSM-5 and Ω crystal forms, and preferably hydrogenated Y zeolites that are steam stabilized. Revealed in detail are steam-stabilized ammonium Y zeolites containing about 0.2 percent Na2O. A variety of catalyst shapes are disclosed in the Ward et al. Patent. Although a cylindrical extrudate can be used, the shape of the catalyst is particularly so-called "trefoil" and its structure is similar to that of three leaf clover. The surface area / volume ratio of the extrudate should be between 85-1 60 inch η range. The alkylation method can be carried out using upward or downward flow, the latter is preferred, preferably under the conditions of temperature and pressure in which at least part of the liquid phase is stored, at least until the substantial All olefin alkylating agents are depleted. Ward et al. State that rapid catalyst inactivation occurs under most alkylating conditions when no liquid phase is present.

U.S. Patent No. 4,169,111 to Wight discloses an alkylation / transalkylation process using crystalline aluminosilicates to produce ethylbenzene in alkylation and transalkylation reactors. The catalyst in this alkylation and transalkylation reactor — IΙΦΙ (Please read the precautions on the back before filling this page) Order-Line Economy Department Intellectual Property ^ Printed by the employee consumer cooperative Cooperative standards of Chinese paper ( CNS) A4 specification (210X297 mm) -6- 552254 A7 B7 _ V. Description of invention (4) II — Dance — (Please read the notes on the back before filling this page) Line-can be the same or different, including low Sodium zeolite has a silica / alumina molar ratio between 2 and 80, preferably between 4 and 2. Exemplary zeolites are molecular sieves including X, Y, L, B, ZSM-5 and Ω crystal forms, and steam stabilized gamma zeolites containing approximately 0.2% Na2◦ are preferred. The alkylation reactor is operated in a downflow mode under the temperature and pressure conditions in which a portion of the liquid phase is stored. The output from the alkylation reactor is cooled in a heat exchanger, supplied to a benzene separation distillation column, and the overheads are recovered there, and refluxed to the alkylation reactor. The original high melting point bottoms from the benzene distillation column containing ethylbenzene and polyethylbenzene were supplied to the original ethylbenzene distillation column, from which the ethylbenzene process product was recovered. The bottom product from the ethylbenzene distillation column is supplied to a third distillation column to provide a diethylbenzene overhead fraction of substantial purity, which contains 10 to 90 percent, preferably 20 to 60 percent of diethylbenzene. . The diethylbenzene overhead fraction was refluxed to the alkylation reactor, while the side fraction contained the remaining diethylbenzene and triethylbenzene, and the high molecular weight compound was supplied to the reactor together with benzene. The effluent from the reactor was returned to the benzene distillation column via a heat exchanger. Intellectual Property of the Ministry of Economy ^ 7 Printed by Employee Consumer Cooperatives

U.S. Patent No. 4,774,377 to Barger et al. Discloses an alkylation / transalkylation process that includes the use of individual alkylation and transalkylation reaction zones. The transalkylated product is refluxed to the middle. In the separation zone. In the Barger method, temperature and pressure conditions are adjusted to carry out the alkylation and transalkylation reactions in the basic liquid phase. The transalkylation catalyst system is an aluminosilicate molecular sieve, including X-type, Y-type, ultra-stable-Y, L-type, omega-type and mordenite-type zeolites, the latter being preferred. The catalyst used in the alkylation reaction zone is a solid material containing phosphoric acid. Aluminosilicate can also be used for alkylation. The size of this paper is applicable to Chinese National Standard (CNS) A4 specification (210X297 mm) 552254 A7 B7 V. Description of the invention (5) Catalyst, providing 0.01 to 6 volume percent of water in The alkylation reaction zone. The output from the alkylation reaction zone is provided to the first and second separation zones. Water is recovered in the first separation zone. In the second separation zone, the intermediate aromatic product and the trialkyl aromatic and better products are separated to produce an input of a transalkylation reaction zone having only a dialkyl aromatic component. If it is an ethylbenzene manufacturing method, it is Ethylbenzene is diisopropylbenzene if it is cumene. The phenylene is also provided in the transalkylation zone for use in the transalkylation reaction, and the output from the transalkylation zone is refluxed to the first separation zone. The alkylation and transalkylation zone can be operated in a downstream, upstream, or horizontal flow configuration. For this reason, this technique provides a variety of transalkylation methods to handle partially alkylated by-products such as diethylbenzene. It is desirable to have a catalyst that reduces the content of by-products that are difficult to handle during the alkylation / alkyl transfer process. It is desirable to provide a catalyst that reduces the xylene and propylbenzene content during the ethylene / benzene alkylation process. Summary of the Invention According to the present invention, a method for gas phase alkylation of an aromatic substrate is proposed. This is achieved by contacting a gas phase feed containing an aromatic matrix and an alkylating agent with a molecular sieve aromatic alkylation catalyst to produce a reaction product containing a monoalkylated aromatic product and reduced by-products. . The catalyst is characterized by a bimodal acidity with a concentration of less than 50 micromoles (50 micromoles / g) of weak acid sites per gram of catalyst. The alkylation reaction can be carried out in a reaction zone having a single or multiple catalyst beds in series. The monoclinic silicalite catalyst can also be characterized by crystal sizes smaller than one micron, preferably about 0.5 microns. Aromatic substrates such as benzene and alkyl groups .-- 丨 _ | (Please read the precautions on the back before filling out this page.) _ _ Printed by the Ministry of Economic Affairs, Intellectual Property, Employee Consumer Cooperatives. ) A4 specification (210X297 mm) -8-552254 A7 B7 V. Description of the invention (6) A chemical agent such as ethylene, propylene or α-olefin is introduced into the reaction zone, and the alkylation reaction zone is located in the aromatic zone. The group substance is operated under the temperature and pressure conditions of the gas phase, so that the aromatic substance is subjected to gas phase alkylation in the presence of a monoclinic silicalite catalyst having a bimodal acidity to produce an alkylated product. The alkylation product is then polymerized from the reaction zone. The aromatic matrix / alkylating agent weight ratio of the raw materials used is between about 10 and 25. When ethylbenzene or other alkylated aromatics are produced, the alkylation products from the reaction zone can be provided to an intermediate recovery zone to separate and recover ethylbenzene from the alkylation products, and separate and recover the Polyalkylated aromatic component. At least a portion of the polyalkylated aromatic component is provided to a transalkylation reaction zone of the intermediate recovery zone. Benzene is provided to the transalkylation reaction zone, and the transalkylation reaction zone is operated under conditions of temperature and pressure that cause the polyalkylated aromatic portion to undergo disproportionation to produce ethylbenzene with increased Content and disproportionation products with reduced polyalkylated aromatic component content. When the transalkylation reaction is carried out, the transalkylation zone may contain a zeolite gamma transalkylation catalyst, and it is under a temperature and pressure condition that allows the feed to maintain a liquid phase in the transalkylation zone. Brief description of the figure Figure 1 shows the bimodal acidity of the catalyst. Figure 2 shows the unwinding of the bimodal acidity curve of Catalyst C. Fig. 3 is a graph showing the formation of xylene in an ethylbenzene amination method, with respect to the concentration of a weak acid site in the catalyst. Figure 4 is a diagram showing the formation of propylbenzene in the ethylphenylalkyl method. The paper size is applicable to the Chinese National Standard (CNS) A4 specification (210 × 297 mm) 丨 Dance 丨 (Please read the precautions on the back before filling (This page), 11 Printed by Intellectual Property of the Ministry of Economic Affairs ^ Printed by the Employee Consumption Cooperative -9-552254 A7 B7 V. Description of the invention (7) Relative to the concentration of weak acid sites in the catalyst. DETAILED DESCRIPTION OF THE INVENTION The present invention relates to gas phase alkylation of benzene using a compatible silicalite alkylation catalyst having a weak acid site concentration of less than 50 micromoles per gram of catalyst. This method improves product quality and reaction efficiency. In the gas phase alkylation, when ethylbenzene is formed from ethylene and benzene raw materials, in addition to the required ethylbenzene, other impurities and undesired by-products can also be formed. These undesirable products include compounds such as xylene, cumene, n-propylbenzene and butylbenzene, and polyethylbenzene, and high-boiling alkyl aromatic components ... sometimes referred to as "heavy substances", Has a boiling point of 1 85 ° C or higher. As is well known, the reduction of these impurities and by-products is extremely important. This is especially the case for xylene. The o-xylene (0-xylene) is a styrene contamination that cannot be removed by distillation. The meta-para-xylene has a distillation point that is very close to that of ethylbenzene or styrene, and makes the product difficult to isolate and purify. The presence of these isomers, meta and para-xylene requires high reflux and many distillation stages. The propylbenzene needs additional reflux, or more styrene remains in the residue, reducing the yield of the desired product and increasing the volume of the residue. It should be noted that although the present invention is particularly useful for alkylating benzene with ethylene to form ethylbenzene, the method can also be used to produce other alkylated aromatics, such as forming propylbenzene, using propylene as the alkyl group化 剂。 Chemical agent. Other olefins can also be used as alkylating agents. Zeolite catalysts are widely used in acid-catalyzed reactions such as alkylation, cracking, isomerization, disproportionation, and so on. The number of acid sites, their strength, and their ability to reach the reactant molecules are all in the process of catalyst activity, selectivity, and catalyst inactivation. The paper size applies the Chinese National Standard (CNS) A4 specification (210X29? Mm). I —1 #; (Please read the notes on the back before filling this page)

, TT Intellectual Property of the Ministry of Economics ¾ Printed by Employee Consumer Cooperatives 552254

A B Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 5. The invention description (8) plays an important role. It is generally accepted that only a fraction of the total number of sites is used in the catalytic process. Unwanted reactions often occur due to the presence of acid sites with different strengths. Three different catalyst samples were tested. The properties of these catalysts are shown in Table I below. Table I: Catalyst AB AB Type CDS or smooth extrudate Same 4 Same size 1/10 " CDS Same Same 1/16 " Smooth composition Pentasil 'Zeolite Pentasil Zeolite Pentasil Zeolite Alumina Alumina Alumina% L〇I 1000 T < 5.0 wt. ≪ 2.0 wt. Bulk density (CBD), Lds / ft3 CDS 27 ± 3 CDS: 26.4 smooth = 32 ± 3 surface area, m2 / g 275 275 porosity cc / g > 29.2 angstroms 0.50 (minimum 値) 0.59 crushing strength Lbs / mm > 0.9 1.1 The size of all catalyst samples is 20-40 mesh. Approximately 0.45 grams of catalyst sample was placed in a test tube. The thermocouple was placed at the middle height of the catalyst bed. The test tube is mounted on a TPD / TPR device and fixed. The TPD (temperature programmed desorption) equipment I ......-· 1-!-!---I taxi-------- „1--I-! 11 (please first Read the notes on the back and fill in this page.) This paper size is in accordance with Chinese National Standard (CNS) A4 (210X297mm) -11-552254 A7 B7 V. Description of the invention (9) Measure the amount of ammonia needed to remove ammonia from the catalyst Temperature. The higher the temperature, the stronger the acid. The leak is detected by passing inert gas through the tube and blocking the outlet of the exhaust pipe. If there is no gas leak, blocking the end of the outlet pipe will completely stop the gas flow. The temperature of the sample was increased to 650 ° C at 5 ° C (5 ° C / min) under an inert gas flow (50 ml / min), and the catalyst was dried at this temperature for 4 hours. The sample was cooled To 100 ° C. The catalyst sample is saturated with ammonia (NH3) by flowing NH3 gas at 100 ° C. NH3, which is physically adsorbed or weakly fixed, is passed through the test tube at 150 ° C by inert gas. (Catalyst bed) Desorption after 2 hours. NH3 is desorbed at a temperature increase rate of 5 ° C / minute, up to 650 ° C. The flow rate of the sweep gas is 50 ml / minute. NH3 Adjust the absorption rate from 5 ° C / min to 10 ° C / min, and repeat the experiment. Let us see the effect of the temperature increase rate on the shape and position of the peak. Known catalysts-especially zeolite catalysts The pore geometry controls the "transportation" of reactants and product molecules, and controls the characteristics of the products formed. The main catalyst is a silica-based catalyst. Silica has the same type of ZSM-5 zeolite Frame structure with a five-membered ring of Si-0 or A1-0 tetrahedron in a tetrahedral frame. This frame depicts a three-dimensional system of intersecting channels defined by 10 oxygen rings in all three directions, with a width of about 6 in diameter A. The catalyst sample is described in Table 2. These catalysts are prepared from silica powder and have the same porosity distribution. I ------. 丨 丨 丨 舞 丨 (Please read the precautions on the back first (Fill in this page again) Order # 1 Printed by the Ministry of Economic Affairs, Intellectual Property, Employees' Cooperatives, and Paper Standards Applicable to China National Standard (CNS) A4 (210X297 mm) _ 12 _

552254

Catalyst Na ppm Si〇2 / A12〇3 ratio A < 100 225 B 140 320 C 130 320 The acidity of various alkylated catalyst samples is 650 t: after drying, it is determined by NH3-TPD. The acid site is saturated by flowing NH3 at 100 ° C (please read the notes on the back before filling in this I) to NH3. Physical adsorption and weak chemical adsorption of NH3 were desorbed at 150 ° C for 2 hours. Desorption at 150 ° C was completed within 2 hours as indicated by the TCD signal. NH3 is then desorbed by passing an inert gas through the catalyst at a temperature adjustment rate of 5 ° C / minute or 10 ° C / minute, up to 65CTC. Unless otherwise stated, the acidity results obtained at 5 ° C / min desorption temperature adjustment are compared or the relationship between the acidity and catalyst activity and selectivity is examined. The TCD (Thermal Conductivity Detector) signal (milliamp) printed by the Intellectual Property of the Ministry of Economic Affairs ^ employee consumer cooperative is converted to NH3 millimoles per gram of catalyst sample, as shown by the concentration of the acid site. The results are shown in Table 3. Figure 1 shows the NH3-TPD properties of the catalyst samples. All three catalyst samples did not have NH3-desorption spikes, one with a peak maximum 値 at about 240 ° C and the other with a peak maximum 値 at about 350 ° C. These systems are those with a temperature adjustment rate of 5 ° C / min. A slight change in the spike temperature can cause a change in the catalyst bed position in the test tube. The peak temperature of the three samples shown in Table 3 was obtained using a sample weight of 0.43 6 = 0.005 grams. The number of parts recorded in Table 3 is printed by the three national silk (CNS) A4 specifications (21GX297 mm) -13 _552254. Printed by the Intellectual Property of the Ministry of Economic Affairs and the Employee Consumer Cooperative A7 B7. Within percentages. The acid sites where peaks occur at < 3 OOt and > 300 ° C are classified as weak and strong acid sites. This classification is arbitrarily and relatively classified to distinguish the bimodal spikes of the three catalysts. It is not compared with catalysts with different types of catalyst compounds. NH3-desorption spikes are separated using spike-nested unwinding techniques. The number of weak and strong acid sites is calculated from the integrated area of the spikes after the unwinding of the spikes. For example, The untwisting spikes of NH3-TPD of catalyst sample C are shown in Figure 2. Therefore, the term weak acid is used to define the acidity of the first spike that can produce a bimodal acidity curve. The lower temperature 値 〇 in the bimodal acidity curve shown in Figure 2 increases the desorption and increases the temperature rate (10 ° C / min) to shift the maximum peak to a higher temperature. It has been found that the total number of acid sites is very consistent (± 0.001 Moore / g) 0 Catalysts B and C compared to Catalyst A have lower total acid sites. The lower acid sites of Catalysts B and C result in the silicon used to make these catalysts. Stone powder has a lower aluminum content (or a higher Si02 / A1203 ratio). In addition, Catalyst B and C powder samples have a slightly higher sodium (Na) content than Catalyst A. It is known that sodium ions decrease Zeolite acidity. It is important to note that the three catalyst samples 'show smaller changes in weak acid sites compared with strong acid sites. The results show that the reduction of the framework aluminum helps reduce strong acid sites' and has a smaller effect on weak acid sites. This paper size applies the Chinese National Standard (CNS) Α4 specification (21〇'297 mm) -14- ---------.——---- ^ —— order -----— line · Γ (Please read the precautions on the back before filling out this page) 552254 A7 B7 V. Description of the invention (Θ Table 3. Catalyst acidity measured by NH3-TPD Intellectual property of the Ministry of Economic Affairs Intellectual Property Co., Ltd. Printed catalyst acid Parts, millimoles / gram weak (T ma X, .C) Strong (T max,. C) Total NH3-Des Temperature increase rate A 0.050 ((237) 0.143 (356) 0.193 5 ° C / mi η 0.045 (252) 0.149 (377) 0.194 1 0 ° C / min B 0.046 (235) 0.109 (346) 0.155 5 ° C / min 0.040 (251) 0.113 (365) 0.153 10 〇C / min C 0.045 (241) 0.119 (351) 0.158 5 ° C / min 0.032 (245) 0.124 (347) 0.156 10 ° C / min Table 4 lists the use of ethylene in gas phase conditions (one way, τ person □ = 400 ° C ,: LHS V 70 hours -1) Part of the formation of by-products of the tested catalyst undergoing benzene alkylation. The product selectivity series for overall diphenylbenzene, propylbenzene, butylbenzene, and heavies is shown in Table 4. Figures 3 and 4 are graphs showing the selectivity of the catalyst to xylene and propylbenzene as a function of the weak acid site of the catalyst. Draw a straight line, and Table 5 lists R2 値. As shown in the foregoing, the three catalyst samples showed a small difference in the number of weak acid sites. However, it was found that the small acid sites in the weak acid sites increased to increase the formation of xylene and propylbenzene. This paper size applies Chinese National Standard (CNS) A4 specification (21〇 > < 297mm) -15- (Please read the precautions on the back before filling this page)

Line 552254 B7 V. Description of the invention (Table 4. Catalyst deactivation and phenylalkyl by-product selectivity Catalyst PPM selectivity, relative to EB xylyl propyl BZ butyl BZ A 85 345 335 B 56 237 322 C 48 207 266 Table 5. R2 値 (Please read the precautions on the back before filling in this page) R2 The relationship between the weak acid site and the strong acid site xylene 0.9997 0.7726 The weak acid site propyl BZ 0.9997 0.7715 The weak acid site butyl BZ 0.6057 0.1601 The Ministry of Economic Affairs does not have a good relationship with the intellectual property of the employee. In a specific example of the invention printed by a consumer cooperative, a multi-stage alkylation reactor with multiple alkylation catalyst beds is used. One or more catalyst beds contain the invention The silica mineral alkylation catalyst has a concentration of weak acid sites of less than fifteen micromoles per gram (< 50 micromoles / g). The catalyst of the present invention preferably has weak acid sites of less than 48 micromoles per gram. Concentration. Although the catalyst of the present invention can be used alone, one or more of the catalyst beds may also contain other alkylated catalysts. The composition of the catalyst is used to optimize the catalyst life and yield. The well-known silica ore system ZSM-5 zeolite molecular sieve-16- This paper size applies to Chinese National Standard (CNS) A4 specification (210X297 mm) Intellectual property of the Ministry of Economy ¾ Printed by employee consumer cooperatives 552254 A7 B7 V. Description of the invention (14) Catalyst, but Generally has the characteristics of a higher silica / alumina ratio 'to provide an aluminum / unit cell ratio of less than 1, in addition, the general characteristics are to have an average crystal size slightly larger than that of a ZSM zeolite. As is well known in the art world' Silica ore ... its primary synthesis form has orthorhombic symmetry 'can be transformed into monoclinic symmetry by calcination as disclosed in US Patent No. 4'599'473 to DeBras et al. Such as DeBras Et al. &Quot; Physico-chemical characterization of pentasil type materials, I. precursors and calcined zeolites, and II. Thermal analysis of the precursors, "Zeolites, 1 985, Volume 5, pages 369-383, detailed Stone ore generally has a relatively large crystal size. Therefore, at an average of less than one aluminum atom per unit cell (silicon dioxide / alumina ratio of about 200), silica ore generally has about 5-10 microns or Larger average crystal size. The aforementioned Butler et al. Patent No. 4, 4 8 9, 2 1 4 discloses experiments on ethylation of toluene using silica ore with a larger crystal size, from 1-2 microns up to 8 microns . Another characteristic of the silica ore is the variable gradient of the gradient ', such that the aluminum gradient is positive when the molecular sieve crystal is internal to the surface. That is, the silica ore may have the characteristics that the core portion is relatively lacking in aluminum and the shell portion is relatively rich in aluminum. It is known that "aluminum-rich" is a relative term, and in the case of silica ore, even the shell portion of the crystal has a low bromine content. In another specific example, the silica ore described in the present invention is used The gas phase alkylation of the catalyst uses a gas phase transalkylation method, in which the alkylation and transalkylation reactor is integrated with the intermediate recovery zone, preferably including a plurality of separation zones, to effectively provide a feed Method for flowing to the reactor and returning the output from the transalkylation reactor to a benzene recovery zone located downstream of the alkylation reactor, --1 ---- ^ --- II ----- 1 ^ . ^ 1 (Please read the notes on the back before filling out this page) This paper size applies to Chinese National Standards (CNS) A4 specifications (210X 297 mm) -17- 552254 Intellectual Property of the Ministry of Economic Affairs 笱 Printed by employee consumer cooperatives A7 B7 V. Description of the invention (1 cold operation. In this integrated operation mode, the transalkylation product is applied to the original stage of the benzene recovery zone. The subsequent separation step is performed by applying a split feed to the transalkylation reactor. The preferred catalyst used in the transalkylation reactor is Molecular sieves larger than the porosity of the silica ore catalyst. The transalkylation catalyst is preferably zeolite Y. The hospitalized reactor is preferably operated at a temperature substantially higher than the temperature of the transalkylation reactor. In a specific example of the invention, the reflux output from the transalkylation reactor is passed to the original separation zone in a case where it has a heat exchange relationship with the product feed of the alkylation reactor. A good system includes at least four of the aforementioned catalyst beds. More catalyst beds may be available, and sometimes it is preferable to have at least five or six catalyst beds in the alkylation reactor. The reactor is operated Alkylation in a gas phase at a temperature range of about 630 ° F -800 ° F inlet temperature to about 700 ° F -850 ° F outlet temperature (both aromatic and alkylating agents are gas phase The pressure may be in the range of about 250 to 450 pounds per square inch absolute pressure, which gradually decreases from a catalyst bed to subsequent beds as the temperature increases. For example, benzene and ethylene provided at the top of the reactor Available at temperatures of about 740 ° F and about 430 psi absolute pressure Enter the reactor. The alkylation reaction is a heat-recovery reaction, so the temperature gradually increases from, for example, the first to the last catalyst bed. The interstage temperature can be increased from 750 ° F to the first catalyst bed. 765 ° F after the two catalyst beds, 820 ° F after the third catalyst bed, and about 840 ° F after the last catalyst bed. In the operation of the multi-stage reaction zone, the benzene-ethylene mixture is generally In the initial stage of the reaction zone, it was introduced into the first catalyst bed, and several continuous catalyst beds were also introduced -------, --- IΦ ---- r--, 玎 ----- (Please read the precautions on the back before filling this page) This paper size is applicable to the Chinese National Standard (CNS) A4 specification (210X297 mm) -18- Printed by the Intellectual Property of the Ministry of Economic Affairs and the Consumer Cooperatives 552254 A7 B7 V. Description of the invention (16) Between stages. In the example shown, vinyl is supplied with benzene to the first catalyst bed chaotically at the top or upper end of the reactor. In addition, an interstage injection of ethylene and benzene was provided between the subsequent catalyst beds. The weight ratio of the benzene-p-ethylene feedstock injected into the top of the alkylation reactor may be between about 18 and 22. The silicalite alkylation catalyst according to the present invention is a boron-carbon courtyard ketone family (peen t a s i 1) from a high silica molecular sieve. This Boron Carbon Academy Ketone Molecular Sieve System is described in, for example, " Pentasil Family of High Silica Crystalline Materials " by Kokotailo et al., Chem. Soc. Special Publ. 33, 133-139 (1 980). The silicalite molecular sieve alkylation catalyst has a porosity slightly less than the preferred zeolite-Y used in the transalkylation reactor. The silicalite catalyst has an effective porosity or window in the range of 5-6 Angstroms. Zeolite Y has a porosity of about 7 Angstroms. The preferred silica ore of the catalyst used in the present invention is extruded into a "three-leaf" shape using an alumina binder, having a general diameter of about 1/16 ", and an extrusion of about 1 / 6-1 / 4 " The "three-leaf" cross-sectional shape increases the surface area of the extruded catalyst beyond what would be expected from a generally cylindrical extruded material. The silicalite catalyst used is characterized by monoclinic silicalite. The monoclinic silica ore can be disclosed in Cahen et al., U.S. Patent No. 4,781,906 and DeClippeleir et al., U.S. Patent No. 4,772,456. The gravel ore generally contains a small amount of sodium and iron. As mentioned above, the silicalite alkylation catalyst has a crystalline structure, which is characterized by an aluminum-rich shell and an interior lacking aluminum compared to the shell. The silicalite catalyst system does not contain water And does not have a detectable or required water content. In detail, the silica ore catalyst preferably contains not more than about one millionth of this paper. The paper size is applicable to the Chinese National Standard (CNS) A4 specification (210X 297). %) -19- — IK——iI — ^ · ---- ΊII, 玎 ----- 1 ^ 0— (Please read the precautions on the back first (Fill in this page) Intellectual property of the Ministry of Economics ¾ Printed by employee consumer cooperatives 552254 Α7 _ Β7 V. Description of invention (17) No. 200 sodium, preferably no more than about 100 parts per million sodium, and no More than 500 parts per million of iron is preferred to not more than about 300 parts per million of iron. The alumina medium is a high-purity alumina such as "catapal alumina". The preferred alumina binder is characterized by an abnormally high porosity 'and an abnormally low sodium content. As mentioned earlier, the crystalline structure of the silicalite itself has a low sodium content. By maintaining a low sodium content in alumina, a very high portion of the catalyst site in the silicalite structure is maintained in the active hydrogen form. That is, the low sodium content of the adhesive is susceptible to the sodium and sodium in the adhesive. The ion exchange between the acid sites in the catalyst minimizes the neutralization in the crystalline catalyst. Another feature of the alumina adhesive is the relatively high average porosity after the catalyst is extruded and cut into particles. In particular, the average porosity of the adhesive can be called " maximum " porosity &Quot; to avoid confusion with the porosity of the silica ore itself ... about 1,000 angstroms or more, preferably in the range of 1000 to 4000 angstroms. A preferred porosity range is in the range of about 1,000 to about 1,800 angstroms. When the relatively high rhenium porosity adhesive is applied to the catalyst particle itself, it can promote the extent to which the silica zeolite molecular sieve reaches the catalyst particle by avoiding the alumina diffusion mechanism, or at least minimizing it. Media efficiency. The porosity of the molecular sieve structure itself is generally predicted to be about 5-6 angstroms. The silica ore preferably contains only a small amount of sodium, about 70-200 parts per million of sodium, and only a small amount of iron, about 200-500 parts per million. The catalyst need not contain any additional '' promoter π metal incorporated in the catalyst's synthesis process. After describing specific examples of the present invention, modifications will become apparent to those skilled in the art, and the present invention covers all modifications included in the scope of the patent application. —IK -----—---- ^ —— Order ----- Ί Line-Hr (Please read the precautions on the back before filling this page) This paper size applies to China National Standard (CNS) A4 (210X297 mm) 20-

Claims (1)

552254 Α8 Β8 C8 D8 Date printed by the employee's consumer cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs ^ iL 1M fu 附件, Appendix A of the scope of patent application: No. 9 0 1 0 8 8 1 5 Chinese Patent Application Amendment Amended November 14, 1991. 1. A method for gas-phase courtyard basalization of a family of substrates, including: providing an alkylation reaction zone with at least one catalyst bed containing monoclinic silica ore contact Medium, having a concentration of weak acid sites of less than 50 micromoles per gram; and at least one other catalyst bed containing a second monoclinic crystal, introducing raw materials of an aromatic matrix and an alkylating agent into the multi-stage reaction zone ; Operating the alkylation reaction zone under a temperature and pressure condition, wherein the aromatic matrix is in a gas phase, so that the aromatic matrix undergoes gas phase alkylation in the presence of the monoclinic silicalite catalyst; To produce an alkylation product; and removing the alkylation product from the reaction zone. 2. The method according to item 1 of the application, wherein: the aromatic matrix is benzene, and the alkylating agent is an ethylating or propylating agent. 3. The method according to item 1 of the patent application range, wherein: the raw material has an aromatic matrix / alkylating agent weight ratio in the range of 10 to 25. 4. The method according to item 丨 in the scope of patent application, wherein: the catalyst has a weak acid site concentration of less than 48 micromoles per gram. 5. The method according to item 1 of the patent application range, wherein: The alkylating agent is an α-olefin. (Please read the notes on the back before filling this page) 552254, A8 B8 C8 D8 6. Scope of patent application 6. A method for gas phase ethylation of benzene, which includes: providing an alkylation reaction zone with at least one catalyst bed containing monoclinic silica ore Catalyst: having a concentration of weak acid sites lower than 50 micromoles per gram; introducing raw materials of benzene and ethylene into the multi-stage reaction zone; operating the alkylation reaction zone under a temperature and pressure condition, wherein the benzene system is Being in a gas phase to perform gas phase ethylation to produce an alkylated product comprising ethylbenzene; and taking the alkylated product from the reaction zone, separating and recovering ethylbenzene from the alkylated product. 7. The method according to item 6 of the patent application, wherein: the alkylation product from the reaction zone contains a reduced concentration of xylene 08. The method according to item 6 of the patent application, wherein the alkylation The product system contains reduced concentrations of propylbenzene. 9. The method of claim 6 in the scope of patent application, wherein: the alkylation product includes reduced concentration of butylbenzene. 10. The method according to item 6 of the patent application range, wherein: the raw material has a benzene / ethylene weight ratio in the range of 10 to 25. 1 1. The method according to item 6 of the patent application, wherein: the reaction zone includes between 4 and 8 catalyst beds. 1 2. A silica ore catalyst with a bimodal acidity called a weak acid site and a strong acid site, wherein the catalyst has a paper size of less than 50 micromoles per gram, using Chinese national standards ( CNS) Α4 specification (210 × 297 mm) (Please read the precautions on the back before filling this page) Printed by the Employees 'Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs -2- Printed by the Employees' Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 552254 A8 B8 C8 D8 6. Scope of Patent Application Concentration of weak acid parts. 13. The catalyst according to item 12 of the scope of patent application, wherein the concentration of the weak acid site is lower than 48 micromoles per gram. 14. The catalyst according to item 12 of the scope of patent application, wherein the total concentration of the weak acid site ′ and the strong acid site is less than 1 75 micromoles per gram. This paper size is applicable to China National Standard (CNS) A4 (210X297 cm) (Please read the precautions on the back before filling this page) -3-