TW574200B - Alkylaromatic process using a solid alkylation catalyst - Google Patents

Description

A7 B7

574200 V. Description of the invention (1) Scope of the invention The present invention relates to an alkylation reaction of aromatic humans with olefins using a solid catalyst. BACKGROUND OF THE INVENTION About 30 years ago, branched-chain alkylbenzenesulfonate-based household laundry detergents were found to gradually contaminate rivers and lakes. The solution is to use straight-bonded benzene sulfonate (LABS) to make cleaners. It has been known that the latter is more easily biodegradable than the former. LABS is made from linear alkylbenzene (LAB). The petrochemical industry produces lAB by dehydrogenating straight-chain burned hydrocarbons into linear-associated hydrocarbons in the presence of hf. This is the industry standard method. In recent decades, environmental issues related to HF have been valued. Therefore, alternative methods that use catalysts other than HF and have effects comparable to or better than the standard method have been studied. Solid alkylation catalysts (for example) are the focus of active research. The solid alkylation catalyst process operates at a higher benzene / olefin mole ratio than HF. The benzene / olefin mole ratio when operating with a cleaner alkylation method using HF is from 12: 1 to 6: 1. The solid firing catalyst method operates at higher benzene / olefin ratios (basically 30: 1 to 20: 1). One reason is that solid alkylation catalysts have a lower selectivity for the production of monoalkylbenzenes, so the benzene / olefin mole ratio must be increased to meet stringent selectivity requirements. Selectivity is defined as the weight ratio of the monoalkylbenzene product to all products. The solid catalyst is passivated by use. The alkylation process using a solid alkylation catalyst basically involves regenerating the catalyst periodically by removing the gelled polymer that accumulates on the catalyst surface and hinders the reaction site. Therefore, the paper size of the solid catalyst is applicable to the Chinese National Standard (CNS) A4 specification (210 X 297 mm) II I I I I I ---- install i 丨!丨 丨 丨 Order -------- (Please read the notes on the back before filling this page) Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs 574200

Description of the Invention (The "f" printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs refers to the time that can be continuously converted between two regeneration treatments. Fang Niao * 's continuous material towel is designed to obtain effective catalyst regeneration. And low-cost devices, so solid catalysts are the best. Du Fang, solid catalysts used in the hydration reaction of compounds ㈣ hydrocarbons can be J 疋 /, 6 to 20 carbon atoms, which are usually adsorbed by the catalyst Such by-products include the formation of polynuclear hydrocarbons with 1G to 2Q carbon atoms in the delicetic reaction of € 6 to C2Q hydrocarbons, and also include alkylbenzenes with a molecular weight greater than the desired alkylbenzene. High products (such as di- and tri-alkylbenzenes) and fuming oligomers. Such catalyst passivation agents are appendages to the alkylation of aromatics: these purifying agents or poisons can be used by aromatic The family reactants can be easily desorbed by cleaning the catalyst. Therefore, the catalyst can be easily reactivated or regenerated by removing the accumulated passivation from the catalyst surface through the aromatic reactants through the catalyst. Effect, the degree of recovery of catalyst activity is usually 100%. Therefore, it is desirable to have a device to regenerate these catalysts repeatedly, that is, to restore their activity to use their catalytic effect for a long time. It is also desirable to minimize the additional equipment required for regeneration. According to this, an integrated continuous alkylation is sought Method and method for removing catalyst blunt frame or reducing catalyst purification. SUMMARY OF THE INVENTION In one embodiment, the present invention is a monolithic method for producing sintered aromatics from alkanes and aromatics. Regenerate passivated solid alkylation catalysts, and optionally avoid by-products that will passivate the catalysts from contacting the solid alkylation catalysts. In the present invention, alkyl aromatics (eg, detergent grade alkyl aromatics) are separated and manufactured. This paper size is in accordance with Chinese National Standard (CNS) A4 (210 X 297 mm) (Please read the precautions on the back before filling this page). «1_1 · ϋ ΛΜΜΚΜ tmmmm I an emmmmm if Hua574200 A7 B7 V. Invention Note (3) (Please read the precautions on the back before filling this page). The effluent from the solid catalyst alkylation reactor to produce a relatively low purity aromatic-containing (such as benzene) fluid. Fluid is suitable for Ring-to-production solid catalyst reactors, and relatively high-purity aromatics-containing (eg, benzene-containing) fluids, which are suitable for passing into deactivated alkylation reactors containing passivated catalysts for regeneration treatment The rectifier provides an economical way to manufacture relatively low purity aromatics-containing fluids and maintain a solid catalyst bed in operation that maintains a relatively high purity aromatics (eg, benzene) / fluorene mole ratio. In order to delay the passivation and extend the life of the solid alkylation catalyst. The fluid at the bottom of the rectifier can be passed to the aromatics fractionation tube to obtain a fluid containing relatively high purity aromatics. Although the production of this relatively high purity fluid requires some capital And operating costs, but the aromatics column does not have to be recycled only when the relatively high-purity fluid reaches the commissioned alkylation reactor. Therefore, relatively low-purity fluids (such as those obtained from rectifiers) replace relatively high-purity fluids. The overhead fluid from the fractionation column column is circulated to the alkylation reactor which is put into production. In another feature, the present invention can be further integrated with the absorption and removal unit to remove aromatic by-products formed during the alkane dehydrogenation reaction, because the high-purity fluid here is also suitable for regeneration in the absorption and removal unit. Disable the absorption bed. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economics One device of the present invention is that a single column can be used to provide a low-purity and high-purity aromatics-containing fluid and an underflow containing aromatics feed and alkyl aromatics. In addition, a single column typically uses a high-purity fluid containing aromatics. In most cases, this fluid contains benzene from a single column as a clean overhead stream. This relatively low-purity aromatic or benzene-containing fluid is usually a side stream from a tray at the middle height of a single fractionation tube. This side cut is usually obtained at the middle height of the rectification unit in the fractionation tube. Distillate bottom stream from a single column contains -6-This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs 574200 A7 ------ B7 5 2. Description of the invention (4) There are alkyl aromatic products from the firing process and any heavy alkylate by-products formed in the chemical zone in any alkane cycle unit. When used in a detergent alkylation process, the present invention can use a rectifier to reduce the cost of benzene cycle to an alkylation reactor used to make a detergent alkylate. The higher the benzene / olefin mole ratio in the cleaner alkylation reactor that is put into production, the better the invention is. Its advantages come from ... not only because the “refined process is a more economical method for separating alkylation reactor fluids” compared to the previous method using fractionation tube columns, but also because the circulating fluid produced by the residual process is sufficiently pure Benzene-containing fluid circulated to the t-cleaner burning reactor that was put into production. Therefore, when a relatively low-purity overhead flow is sufficient, less relatively high-purity fluid can be used, and the present invention can reduce the cost of recycling benzene to an alkylation reactor. In a special form, the bottom of the benzene distillation zone flows into a fractionation tube (commonly referred to as a benzene column), and most of the remaining benzene in the alkylation reactor fluid is removed to obtain a purer than benzene rectifier. The resulting column top flowed with a high benzene column top fluid. Of course, in the scope of the present invention, some of the top stream of benzene column column can be recycled to the cleaning agent alkylation reactor that is put into production, but in order to minimize the relatively high purity benzene stream from the top column hall of benzene column into the put into production and burn When the reactor is converted, the present invention can achieve the greatest advantages. An obvious way for the present invention to reduce the costs associated with recycling benzene to a commercialized alkylation reactor is to significantly reduce the size of the benzene column. By passing the remainder of the reactor fluid into the benzene column, the alkylation reactor fluid from production can be neutralized to remove some winters. Because the amount of benzene output from the benzene column is reduced, the benzene column can be reduced. Diameter, height and energy required for reboiling. Although the new solid catalyst firing unit can benefit from this advantage, this advantage is due to the fact that the paper size of the solid catalyst applies to the Chinese National Standard (CNS) A4 specification (21 × X 297 mm). I- ^ · I-- ---- t ----- 1 --- (Please read the notes on the back before filling out this page) Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 574200 A7 ----- B7 V. Description of the invention ( 5) The alkylation method is accomplished by converting the existing HF cleaning agent alkylation method into a solid alkylation catalyst, which is not easy to obtain. This is because the benzene content of benzene that can be removed from the fluidization reactor fluid by using a benzene refiner is not as high as the benzene content in the bottom fluid of the HF stripper in the HF alkylation process. Therefore, when using a benzene rectifier located between the fluidization reactor and the benzene column, when the catalyst is changed from HF to a solid alkylation catalyst, all the existing fractions in the existing HF alkylation method can be reused and can be greatly used. Save the investment cost of converting into a solid catalyst alkylation unit. Because the HF stripper present in the HF alkylation process is easily modified and can be used as a benzene rectifier in a solid alkylation process, it can save most of the cost of a new benzene rectifier, which can further save costs. Accordingly, in one embodiment, the present invention is a method for making alkyl aromatics. Under alkylation conditions, in the presence of solid alkylation catalysts, olefin and aromatics feeds form alkylaromatics in the alkylation zone in operation. This alkylation condition is sufficient to purify at least a portion of the solid-state calcination catalyst in the aerating zone in operation. The commissioned fluid containing the fluorenyl aromatics and the aromatics feed is discharged from the commissioned alkylation zone. At least a portion of the production fluid is separated into a relatively low-purity fluid containing an aromatics feed but no alkyl aromatics and an aromatics-containing feed having a higher purity than that contained in a relatively low-purity fluid and no alkyl aromatics Relatively pure fluids and a distillate bottoms stream containing an aromatics feed and rich in alkyl aromatics. At least a portion of the relatively pure fluid is circulated to the commissioned alkylation zone. Burned aromatics were recovered from the bottom of the library. At least a portion of the relatively low purity fluid contains an aromatic feed to a k-zone for V containing at least partially passivated solid alkylation catalyst. This relatively low-purity fluid is in contact with a partially purified solid alkylation catalyst in a deactivated alkylation zone to partially regenerate this solid alkylation. This paper is sized to Chinese National Standard (CNS) A4 (210 X 297 mm) ) ---- I ------ install -------- order --- I ----- (Please read the precautions on the back before filling this page) 5742〇〇

c's δΛ 佳 'C1Q _ (: 14 is better. The feed hydrocarbons in the feed are reacted with the aromatic derivatives in this method. Appropriate benzene calcined derivatives (including fluorenyl m, but not limited to, toluene, di Toluene and high carbon methylation: monoethylbenzene and diethylbenzene; cumene (cumene), n-propylbenzene, and cumene; butylbenzene; and pentylbenzene. Therefore, the alkylation of benzene is derived The substance may have-or more alkyl groups, and each alkyl group may have ii 5 or more carbon atoms. The most commonly used alkyl aromatic method that can be used in the present invention is the production of linear alkylbenzene (LAB). Lab The process usually introduces n-alkanes into a dehydrogenation reactor. Usually the branched fluorenes formed during the dehydrogenation reaction are not removed. The monofluorenes in the feed are usually present at low concentrations. As for the Monoolefins, because the position of the double bond is not required, any point on the fluorene chain may be unsaturated. The monoolefin in the feed reacts with benzene, and the product obtained by alkylating the monoolefin with an alkylated derivative of benzene may not be A suitable detergent precursor like alkylated benzene. Although the alkylation reaction requires only 1 mole of benzene per mole Monofluorene, but the use of 1: 1 mole ratio will cause excessive polymerization of fluorene, and the polyalkylation reaction will form a large amount of di- and tri-carbon benzenes, and higher-carbon poly-phenylated benzene and cotton · hydrocarbons Polymers, trimers, etc., and unreacted benzene. This alkylation reaction is carried out according to the required conversion, selectivity, and degree of linearity. It is recommended that the total molar ratio of benzene: monoolefin is from 5: 1 to 3 0: 1, preferably between about 8: 1 and about 20: 1. Benzene and linear monoolefins react under alkylation conditions in the presence of a solid alkylation reaction catalyst. These alkylation conditions include The temperature is between about 80 ° C (176 T) and about 14 (TC (284 T)), and the temperature is usually not higher than 135 ° C (275 T). Alkan-10- This paper size applies to Chinese National Standards (CNS) A4 specification (210 X 297 mm) ------------ ^ -------- ^ --------- (Please read the note on the back? Matters before (Fill in this page) Printed by the Employees' Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 574200 A7 B7 V. Description of the invention () The chemical reaction is carried out by the liquid phase method, and the pressure must be sufficient to keep the reactants in a liquid state. The required pressure must depend on the feed and temperature. Fixed, but usually at 1480-7 000 (Please read the precautions on the back before filling out this page) kPa (200- 1000 pSi (g)) absolute pressure range, most often 2170-3550 kPa (g) (300-500 psi (g)) ° solid Alkylation catalysts basically have acid functional groups, so they are more commonly called solid acid catalysts. Such solid acid catalysts include, for example, amorphous stone phosgene-oxidized ingot material, crystalline ingot salt material (Such as zeolites and molecular sieves), naturally occurring and artificial clays (including columnar clays), sulfated oxides (such as: condensed hafnium oxide), traditional Friedel-Crafts catalysts (such as: aluminum chloride and chlorine Zinc) and general solid Lewis acid. A solid alkylation catalyst can extrude the catalyst, including clay and at least one polyvalent metal; US Patent No. 5,034,564 to J. A. Kocal proposes a catalyst containing columnar clay and a binder; ^ A Kocal U.S. Patent Nos. 5,196,574 and 5,344,997 propose fluorinated hard monoxide-oxide catalysts; U.S. Patent No. 5,302,732 by K.Z. Steigleder et al. Describes an ultra-low alumina-silica-oxide oxide; and U.S. Patent No. Marinangeli et al. Propose a clay comprising delaminated or columnar charged four sides. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs, the effluent from the alkylation reaction zone is preferably passed into the rectifier. The rectifier is significantly different from the stripper. Considering the distillation procedure in general, the difference between the rectifier and the stripper can be seen. Distillation method is based on the fact that when the liquid is in contact with the vapor phase, the components which are more volatile in the south are more easily concentrated in the vapor phase than in the liquid phase. In a multi-stage operation, the 'liquid goes down a vertical distillation tube and passes through multiple stages, in which these phases are contacted by convection with upward vapor. The column is divided into two zones at the point where the feed is directed into the distillation tube. The stripping zone is located below the feed point and rectified -11-This paper size is in accordance with Chinese National Standard (CNS) A4 (210 X 297 cm) 574200 A7 B7 V. Description of the invention The Γ zone is located above the feed point. Steam shaker F extracts the more volatile components from the downward moving liquid in E. In the rectification zone, the concentration of fluff is reduced. In practice, the stage where the liquid P and the portion, Yexin and the breastmilk are in contact with each other may be a tray or a filling material. Therefore, in the refiner, the feed is located in several stages; compared to the stripper, the feed enters the stripper from above the stages. In addition, the 'rectifier' reduces the concentration of the less volatile components in the vapor, and the stripper extracts the more volatile components from the liquid vapor flowing downward. The finisher typically has from about 10 to about 20 separation stages and typically uses trays with an efficiency of about 60%. Therefore, the refiner usually has about 15 to about h trays, and basically has 20 trays. Less than two trays can be used, and some or all of the i-plates can be used in vapor-liquid contact medium (such as: irregularly shaped regular shape @ Bed Saddle-shaped & regularly arranged structured elements) instead . This benzene rectifier typically uses a reboiler (located outside or inside the benzene rectifier), a feed preheater, or both. A benzene rectifier also basically uses a condenser, which condenses the vapor or vapor mixture, condensing usually more than 95% by weight (more often more than 995% by weight) of the vapor. A portion of the condensed overhead stream is substantially back to the higher part of the benzene rectifier. The remaining condensed overhead effluent is recycled to the commissioned alkylation reactor. Unless specifically stated otherwise, the "part of a fluid" as used herein refers to a portion of the liquid stream that has a composition substantially the same as the liquid stream. The operating conditions of the benzene refiner include pressures from about 50 to about 70 psi ( g) (345 to 483 kPa (g)), but it is also possible to use specific pressures as high as the container design limit. The top and bottom temperature of the benzene refiner is usually about 300 ° C (149 ° C), so that The temperature difference between the top and bottom of the benzene rectifier is very small. Benzene-12- This paper size applies to China National Standard (CNS) A4 (210 X 297 public love) (Please read the precautions on the back before filling This page) -------- Ordered by! Printed by the Employees 'Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs Printed by the Employees' Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs Printed by 574200 A7 _ B7 V. Invention Description The rectified product usually produces a bottoms stream, which contains sufficient benzene, so that the bottoms stream has a boiling point quite close to the overhead stream. Usually, about 50% to about 70% of the benzene entering the rectifier is along with the pure overhead stream. Discharge .. Compared to relatively high-purity fluid (recoverable from the top of the benzene column column) Relatively low purity benzene-containing fluids (such as those recovered from the net overhead of the benzene rectifier) have a relatively low purity. The relatively low-purity benzene-containing liquid stream from the overhead of the benzene rectifier The concentration of benzene is from about 80 to about 98 mole%. In terms of the outflow of the top of the palate, the hydrocarbon burning concentration is usually 2 to 20 mole%, preferably 2 to 5 mole%. The concentration of alkylated benzene (alkyl aromatics) is usually less than 100 wppm. The presence of tiger hydrocarbons in contact with the catalyst at the normal alkylation temperature has a significant adverse effect on the solid alkylation catalyst and will also occupy the reaction. The volume of alkylated benzene can be produced in the reactor. According to this, in addition to the alkane content, relatively low-purity liquid streams (such as benzene rectifier fluids) are a suitable source of benzene that is partially recycled into the alkylation reactor. The presence of benzene essence The chain-view hydrocarbons in the net overhead fluid of the stiller usually have 5 to 22 carbon atoms. The first source of alkanes in the overhead stream of the benzene rectifier is the alkanes accompanying the mono-olefin-containing feed. Such Alkanes have essentially the same number of carbon atoms as the monoolefins in the feed. Alkanes are also included with the benzene-containing introduction fluid Into the benzene refining column overhead distillation stream. The alkane boiling point of this benzene introduction stream is usually close to the boiling point of benzene. In the net bottom stream of the benzene rectifier, the molar ratio of benzene / alkyl aromatics is about 7: i, which can be passed into a benzene column. This benzene column can be used to remove the remaining benzene using basically 45 to 55 (usually about 50) trays. The overhead stream of this benzene rectifier enters or approaches from benzene. The 30th tray from the top of the column. Benzene-13 for replenishment. This paper size is in accordance with China National Standard (CNS) A4 (210 X 297 mm). • I,! ΚίΜίν aaw I η ···· α ··· · n · n ϋ nnn 「丨 · * · ϋ« ϋ nt— MmMm9 · 1 I (Please read the note on the back? (Fill in this page again) 574200

Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs 1 (without drying first) can also be introduced to the benzene column. This benzene column typically uses a reboiler and an overhead condenser of the overhead stream, which returns the liquid to the top of the benzene column. The operating conditions of the benzene column include a pressure of about 170 kPa (10 psi (g)), a top distillation temperature of about 93 ° C (200 T), and a bottom temperature of about 232 ° C (45 ° T). The benzene official column produces a net overhead distillate stream, the benzene concentration of which usually exceeds 95 mole%, preferably more than 99.9 mole%, and more preferably 99 99 mole%. The benzene column column overhead distillation stream may contain low-concentration alkanes, the concentration of which is usually lower than 5 moles, preferably lower than 0.1 mole%, more preferably lower than 100 wppm, and lower than 10 wppm. Better. The concentration of alkylated benzene (alkylated aromatics) present in the net overhead stream of the benzene column is usually lower than the concentration of alkanes. Therefore, the purity of the benzene stream recovered from the overhead of the benzene column according to the present invention is generally higher than that of the overhead from the benzene rectifier. The net overhead stream of the benzene column may contain an alkane te having 5 to 22 carbon atoms. The particular alkane present in the net overhead stream of the benzene column depends primarily on the stripping stream from the alkane in the monoene smoke feed, the benzene-containing introduction, and any aromatic by-product removal zones used. According to the present invention, a portion of the net overhead of the benzene column is passed into a deactivated alkylation reactor containing an alkylation catalyst to be reactivated or regenerated. The benzene purity of the solid state calcined catalyst is an important parameter. It is combined with the regeneration temperature to ensure that the regenerated catalyst restores the acceptable degree of activity of the alkylation reaction. Without wishing to be limited to a particular theory, the presence of alkanes in the relatively high temperature contact with the alkylating catalyst used during regeneration can adversely affect the catalyst. Therefore, it is believed that relatively pure fluids (such as the overhead stream from a benzene column) are relatively clean compared to relatively low-purity fluids (such as the net overhead of a benzene rectifier). This paper applies Chinese national standards (CNS). A4 specifications (210 X 297 mm) ------------------ ^ --------- CPlease read the legal notices on the back and fill in This 574200 A7 V. Description of the invention (12 The residual effluent printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs) The lower alkane concentration is a suitable fluid suitable for regenerating passivated solid alkylating catalysts. Therefore, it is better to implement In the example, the distillate from the top of the benzene column flows into the solid catalyst bed for regeneration treatment. The effluent from the reactor containing regeneration, hydrocarbon burning, benzene burning and self-catalyst desorption ( des〇rbed). Although, during normal operation, this effluent from the deactivated alkylation reactor can be passed into the benzene refiner in the same way as the effluent from the calcination reactor, it is still desirable This regeneration effluent is passed to the benzene column. Therefore, the benzene column can have benzene from the bottom of the benzene rectifier and make-up And benzene from an alkylation reactor undergoing regeneration treatment. In a commonly used device, the distillate from the benzene column is passed to a hydrocarbon burning column to form an overhead distillate stream containing unreacted alkanes (which is generally recycled back to the To the dehydrogenation zone) and a distillate stream containing the burnt product and any higher molecular weight by-product hydrocarbons (formed in the selective alkylation zone). This distillate is passed into a reactivated column to produce a detergent-containing alkane The overhead product of the compound is an alkylate product stream and a residual bottom stream containing polymerized olefins and benzene (heavy tiger compound). In another embodiment, the present invention is a monolithic aromatic compound This method involves the dehydrogenation of linear chain hydrocarbons to linear olefins, and then in the presence of a solid pitting catalyst, benzene is kneelized with straight chain smoke to regenerate a passivated solid alkylation catalyst. And avoid contacting by-products that passivate the catalyst with the solid alkylation catalyst. The structure of this dehydrogenation zone is preferably substantially the same as that shown in the drawing of US-A-5,276,231. Feed containing burned hydrocarbons Unreacted combustion with circulating hydrogen and circulation from the alkylation zone Merging. This forms a reaction stream, heats this stream and makes -15- This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) (Please read the precautions on the back before filling this page) Decoration- Printed by the Employees' Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs 574200 A7 _ B7 V. Description of the invention (13) The appropriate catalyst bed is maintained at an appropriate dehydrogenation temperature, pressure, etc. The dehydrogenation catalyst is used in dehydrogenation technology. The learners, such as those shown in US-A-3,274,287, US-A-3,315,007, US-A_3,315,008, US_A-3,745,112 and still-eight-4,43,517, need not be further detailed. It is usually cooled, the catalyst bed effluent or reactor effluent is partially condensed, and the effluent entering the surface area is separated. A common variation of this example includes the selective hydrogenation of diolefins typically present in the dehydrogenation product stream. Selective diene hydrogenation is formed during the catalytic dehydrogenation of alkanes. The selective diene dehydrogenation reaction converts the diolefin to a monoolefin, which is the desired product in the dehydrogenation zone, and produces a selective diene hydrogenation product stream. Selective diene hydrogenation reactions are described in us_A_ 4,520,214 and US-A-5,012,021. In this embodiment for the production of alkylated aromatics, the aromatics removal zone eliminates or significantly reduces aromatic by-products from the feed into the selective alkylation zone. Removal of aromatic by-products reduces the passivation rate of the solid alkylation catalyst and thereby significantly increases the product of linear alkylated aromatic compounds. It is known that aromatic by-products are formed during the catalytic dehydrogenation of alkanes. It is believed that these aromatic by-products include alkylated benzene, fluorene or other polynuclear aromatics, alkylated polynuclear hydrocarbons in the range of ChtCb, indene and tetralin, and can be considered as aromatic primary paraffins. Basically, from about 0.2 to about 0.7 weight percent of the alkane compound feed into the dehydrogenation reaction zone. Usually, no more than 1% by weight forms aromatic by-products. It is believed that when most, if not all, commercially available dehydrogenation catalysts are present, at least some of these by-products will form under appropriate dehydrogenation conditions. In the method that does not remove the aromatic by-products, the aromatic by-products are removed at -16- This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) I .-------- -^ -------- 1 --------- (Please read the notes on the back before filling out this page) 574200 A7 B7 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs Explanation (The concentration in the gaseous effluent is basically 4 -1 0 Cw / I / 0, which makes solid urethane

The catalyst is quickly passivated. t U This embodiment of the present invention uses at least one aromatics removal zone to selectively remove at least a portion of the aromatic by-products in the dehydrogenation product stream. This aromatic removal zone is preferably located between the dehydrogenation zone and the selective alkylation zone, as it is preferred to selectively remove the aromatic products before the aromatic byproducts enter the selective alkylation zone. This embodiment or a suitable aromatics removal zone of the present invention includes an L absorption separation zone. When the aromatics removal zone is an absorption separation zone, the present invention is carried out in a fixed bed or a moving absorbent bed system, but a fixed bed system is preferred. The aromatic by-product-containing fluid is preferably passed through the absorption and separation zone in the same direction. Because one of the absorption bed or the chamber is consumed by the aromatic by-product accumulated on it, a bypass can be added to the consumption zone. And continuous uninterrupted operations pass through the same direction area. A suitable absorbent may be selected from materials which meet the main requirements for selectivity of aromatic by-products and are easy to use. Suitable absorbents include, for example, molecular sieves, silica, activated carbon activated carbon, activated alumina, silica-alumina, clay, cellulose acetate, synthetic magnesium silicate, macroporous magnesium silicate, and / Or macroporous polystyrene gel. It should be understood that the effectiveness of the aforementioned absorbents is not necessarily equal. The choice of absorbent depends on several considerations, including the ability of the absorbent to retain aromatic by-products, the% selectivity of the aromatic field J product that the absorbent retains and the solid alkylation catalyst, and the cost of the absorbent . A preferred absorbent is a molecular sieve, and a preferred molecular sieve is 1 3 X zeolite (sodium zeolite X). The artisan knows how to choose the proper conditions to operate the absorbent without undue experimentation. For example, fixed bed separation zone containing J 3 x zeolite-17- This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) -----------^ ---- ---- Order ------- (Please read the note on the back? Matters before filling out this page) 574200

Description of the Invention (Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economy can be maintained at about 20X to 30 (rc (6 "F to about 572 T), preferably about 100 C to 200 C (212Tm 392 T). The aromatic by-product fluid maintains the liquid phase at a temperature of 敎, and the liquid space velocity per hour is from about 1 hour to about 10 hours-1, and from about i hours -i to about 3 hours_ t Ma Jia. Aromatic By-product fluids can flow up, down, or radially through the absorption separation zone. Although liquid and vapor phase operations can be used in many absorption separation processes, they are due to lower temperature requirements and because of aromatics in liquid phase operations The absorption yield of by-products is relatively high, so in terms of the absorption and separation zone, it is better to operate in liquid phase. Therefore, during the absorption of aromatic by-products, the temperature and pressure of the absorption and separation zone are selected so that the fluid can maintain the liquid. It is better to be able to selectively remove aromatic by-products. However, those skilled in the art know how to absorb the separation zone to achieve the most suitable operating conditions, which includes the reaction zone conditions of the present invention and its variants. Therefore , This implementation of the invention Including the absorption and separation zone contained in a general reaction tank 'This reaction tank contains a dehydrogenation zone, a selective diene hydrogenation zone, a selective alkylation zone, or a selective monoolefin hydrogenation zone. After an appropriate processing time, the absorbent passes through Regeneration by removing the aromatic byproducts absorbed in the absorbent. There are many ways to regenerate this absorbent. Any suitable regeneration method can be used, including changing the temperature and pressure of the absorbent and using a relatively pure fluid (such as: The benzene column overhead distillate stream) replaces or releases the absorbed aromatic by-products. The flow direction of the benzene column overhead distillate stream through the absorption and separation zone can be upward or radial, but it flows downward The phase of the benzene column overhead distillation mixture passing through the absorption and separation zone may be a liquid phase and / or a vapor phase. -18- This paper size is applicable to China National Standard (CNS) A4 (210 X 297 mm) ------------- Installation -------- Order --------- (Please read the notes on the back before filling this page) 574200 A7 B7 16 5 2. Description of the invention (The effluent fluid is discharged from the aromatic removal zone, which contains benzene and stripped hydrocarbons. Such as pentane), this zone is stripped with hydrocarbons and then contacted with a benzene-containing fluid to produce aromatic by-products during the dehydrogenation period. The effluent fluid basically passes into a money column that releases the absorbent, This produces a heavy hall bottom stream containing aromatic byproducts. If the effluent from the top of the benzene column containing any burned material enters the aromatics removal zone, these alkane feeds will be present in the effluent and It will end up in the heavy bottoms of the column that releases the absorbent. This is because the aromatic byproducts and alkanes usually have the same carbon number, so the aromatic byproducts and alkanes boil together at about the same temperature. Therefore the alkanes (Which may be converted into the desired alkylated aromatics) and aromatic by-products (which are not easily converted into the desired alkyl aromatics) are recovered in the same liquid stream, and the column that releases the absorbent exhausts the aromatics The by-products are also exhausted. The higher the concentration of alkanes in the overhead stream of the benzene column from the aromatics recovery zone, the higher the consumption of these alkanes from the desorption column with aromatic by-products. . Accordingly, in the best case, because of its higher purity, the regeneration fluid in the aromatics removal zone is a relatively pure fluid (net overhead from the benzene column) rather than a relatively low purity fluid ( Such as: benzene rectifier's net overhead distillation liquid). Therefore, the alkane content of relatively pure fluids (such as benzene column overheads) is preferably less than 0.1 mole%, more preferably less than 100 wppm, and even more preferably less than 10 wppm alkanes. . This desorption column also produces a net overhead stream, which contains lighter components (ie, benzene) and a stripping mixture (eg, pentane). This clean overhead distillate is passed into a fractionation tube which separates the stripping compounds from benzene. When the stripping compound is pentane, the separation zone is a pentane-removing fractionation tube which produces a net overhead stream comprising pentane and a net bottom stream comprising benzene. This net overhead distillation Z-stream recovery -19- This paper size applies to China National Standard (CNS) A4 specifications (210 X 297 mm) J ---------- 0 ^ ------- ---------- (Please read the notes on the back before filling in this page) Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs

Claims (1)

574200 A B c D Patent Application No. 089110371 Chinese Patent Application for Replacement of the Patent Scope (September 1992) u | j 1 · A method for producing alkyl aromatics, comprising: (a) under firing conditions, in the presence of a solid alkylation catalyst, the feedstocks of aromatic hydrocarbons and aromatics are in production; The alkylation zone forms alkyl aromatics, and the firing conditions are sufficient to at least partially passivate at least a portion of the drying catalyst in the alkylation zone that is put into production, and to include the aromatics and aromatics containing the alkyl radicals. The production fluid of the feedstock is discharged from the production of the alkylation zone; (b) at least one fraction of the production effluent is separated into a relatively low-purity fluid containing an aromatics feed but no fluorenyl aromatics and an aromatics-containing The feed has a higher purity than the relatively low-purity fluid and a relatively high-purity fluid without alkyl aromatics, and a distillate bottoms stream containing an aromatics feed and rich in fluorenyl aromatics; (0 will at least a portion of the relatively low-purity fluid Recycle back to the production of alkylation zone; (d) Recovery of alkyl aromatics from the distillate underflow; (e) Contacting at least a portion of the solid alkylation catalyst in the deactivated alkylation zone with at least a portion of a relatively high purity fluid To at least partially regenerate this solid alkylation catalyst and in the deactivated alkylation zone Create at least a partially regenerated solid alkylation catalyst, and discharge the bale aromatics from the decommissioned alkylation zone; decommission effluent from the family feed; (f) circulate at least part of the decommissioned effluent fluid for step (b) ) Is separated in (g) by periodically deactivating the alkylation zone as a step and operating the alkylation zone in (0) and operating the alkylation zone as a step ...) The exchange is put into operation and the alkylation zone is stopped. 574200 Patent application scope 2. The method according to item 丨 of the patent application scope, in which a single column provides a relatively tritium-purity fluid as an overhead distillate stream and a relatively low-purity fluid as a side stream and a residual bottom stream, among which are from decommissioning and commissioning The effluent from the tritium zone is returned to a single column. The method according to the scope of application for patent application, wherein at least a part of the produced fluid is put into the rectifier, the relatively low-purity fluid is the overhead from the rectifier, and the rectifier provides the rectifier bottom stream, At least a portion of the rectifier bottom flows into the fractionation zone, and a relatively high-purity fluid produced in the fractionation zone becomes the overhead of the fractionation tower and the bottom stream becomes the fraction of the distillation. The method according to item 3 of the scope of patent application, further characterized in that at least a portion of the rectifier column overhead comprises a portion of the fractional column overhead stream, and wherein at least a portion of the column fraction Fractionation overhead stream. 6. The method according to the scope of patent application No. 2, 2, 3 or 4, further characterized in that the aromatics feed concentration of the relatively low-purity fluid is from 80 to 98 mol%, and the aromatics of the relatively high-purity fluid The substance concentration exceeds 95 mole%. The method according to item i, 2, 3, or 4 of the scope of the patent application, wherein the zero hydrocarbon contains an olefin having 6 to 22 carbon atoms, and the aromatics feed contains benzene and a pit-based derivative of benzene. 7. The method according to item 2, 2, 3 or 4 of the scope of the patent application, further characterized in that the alkylation conditions include an aromatics / fluorene feed molar ratio of $ to 30: 1. * 8 · Method according to item 4 of the scope of patent application, in which & > Kai T, rectifier and fractionation -2- This paper size applies Chinese National Standard (CNS) A4 specification (21〇χ 297 mm) A BCD 574200 Zones are contained in different slots. 9. The method according to item i, 2 or 3 of the scope of patent application, which is further characterized by a concentration of fluorenyl aromatics of a relatively low-purity fluid below 100 wppm. The method of item 3 or 4, further comprising the steps of: performing a dehydrogenation treatment and recovering an alkane-containing, mono-olefin, <; Dehydrogenation product stream of Cg hydrocarbons, dihydrocarbons and aromatic by-products; passing at least a portion of the dehydrogenation products to the commissioned alkylation zone to supply olefins; in at least one commissioned aromatic by-product removal zone containing absorbents Under the conditions that can effectively and selectively absorb aromatic by-products and reduce the concentration of aromatic by-products, at least a portion of the aromatic by-products are selectively removed from at least a portion of the dehydrogenation product stream to no more than 2 % By weight; passing in a portion of relatively pure fluid into at least one deactivated aromatic by-product removal zone containing an absorbent which contains the absorbed aromatic by-products' until removed from the deactivated aromatic by-products Zone removal at least partially absorbed Aromatic by-products; and recovering the aromatic by-product-containing exhaust fluid and aromatic compound-containing absorbent fluid from one of the deactivated aromatic by-product recovery areas, and periodically changing at least one of the aromatic by-products in operation The function of a removal zone and at least one deactivation zone for aromatic byproducts. -3-This paper size applies to China National Standard (CNS) A4 specifications (210X297 public copy)