MXPA99011156A - Olefin skeletal isomerization process - Google Patents

Abstract

An isomerization process for C4 to C15 olefins carried out by the reaction of C4 to C15 olefins, having a first skeletal distribution, with aromatic compounds under alkylation conditions to produce an alkylated aromatic product, dealkylation of the alkylated aromatic product under dealkylation conditions to produce a dealkylated product comprising said aromatic compounds and olefins corresponding to the olefins in the alkylation and having a second skeletal distribution different than said first skeletal distribution. Acidic catalysts such as molecular sieves are used in both alkylation and dealkylation. The reactions may be carried out in either straight pass fixed beds or in catalytic distillation reactors.

Description

PROCESS D? ISOM? RIZACSON D? OLEFIN STRUCTURE DESCRIPTION D? THE INVENTION The present invention relates to a process for the isomerization of olefin structures. More particularly, the process involves aromatic alkylation / dealkylation to convert linear olefins to branched olefins (also referred to herein as isoolefins or tertiary olefins) and to remove olefins from paraffins. The isomerization of olefin structure is an important reaction for the fuel and chemical industries. For example, the isomerization of n-butene to isobutylene and n-pentenes to isoamilenes has been practiced to produce isoolefins. Since n-pentenes have octane numbers lower than isopentenes, isomerization of n-pentene is useful for the production of motor fuel. The isomerization of n-butenes and n-pentenes to isoolefins used to produce oxygenates such as tertiary methylbutyl ether (MTBE) and __ter-amylmethyl ether (TAME) is enormously important for the "formulation" of reformulated gasoline (RFG). Ethers are used as octane improvers in gasoline and to reduce unwanted emissions. Currently, there is no simple technology for separating olefins from paraffins and converting linear olefins to branched olefins. So far, mainly high purity isoolefins (mainly tertiary olefins) have been produced through the separation of tertiary olefins from the olefin mixtures using the "cold acid" process, ie extraction of sulfuric acid, however, the Sulfuric acid in general environmental processes is not desirable nor is this process particularly cost efficient. The patent of the same number 3,121,124 (Shell) describes the removal of tertiary olefins from mixed streams through etherification and ether decomposition to recover the tertiary olefin substantially in pure form. Subsequently, other processes have been described employing the decomposition of ethers in patents of the same number 4, 447, 668"(CR & L); 4, 551, 567 '(CR & L); and" 4,691,073"(Exxon). "However, in these processes, the linear olefins are substantially unaffected and the main result is to separate isoolefins from paraffins and linear olefins. The recovery of linear olefins, such as isoolefins, is limited, since they are usually present in a too dilute amount for which there is no available technology to convert them economically to isoolefins. The straight-pitch isomerizations of the conventional fixed olefin bed are of limited equilibrium, thus practically limiting the yield of obtainable isoolefins. Isomerizations are performed using acid catalysts such as molecular catalysts, and the like. The structure isomerization has been carried out with acid catalysts such as fluorinated alumina, SAPO (silicoaluminophosphates), ALPO (aluminophosphates), ferrierite, aluminosilicates, zeolites, clays, etc. It has been known that ferrierite and ZSM-35 are form-selective zeolite catalysts for the isomerization of n-butene to isobutylene structure. The most preferred to carry out isomerization is the operation of the fixed bed of vapor phase, wherein a tubular reactor is packed with heterogeneous acid catalysts and the vapors of the olefinic hydrocarbon feed supplies are passed through the bed of catalyst at temperatures that are effective for the isomerization of structures. Usually, the double bond isomerization of olefins is much easier than the isomerization of structure and therefore the temperatures required for the double bond isomerization are much lower than the isomerization temperatures of structures. The altered structure of the alkyl groups of aromatic compounds such as the butyl group of butylbenzene is another type of isomerization which is different from the olefin isomerization. R.M. Roberts et al. (JACS Vol 81, 640, 1959) "have explained the structural isomerization between the sec-butyl and isobutyl groups without breaking the butyl group of the benzene ring.The interconversion between sec-butylbenzene, isobutylbenzene and tert-butylbenzene is demonstrated through" the reaction catalyzed by acid. The composition of the equilibrium mixture contains only a small amount of tert-butylbenzene, probably due to the high instability of the carbonium ion of tert-butylbenzene. The isomerization of butyl groups proceeds through the formation of an intermediate coupling, or "a complex intermediate, s-linked formed first through the network of interaction of aromatic alkyl compounds with an acid site in a catalyst and After converting to a methyl-bridge-p-complex intermediate, the catalyst used in the conventional process for isomerization of olefin structure generally exhibits a relatively rapid catalyst deactivation caused by the deposition of heavy carbonaceous materials (coke) on the surface and pores of the catalyst Therefore, there has always been a rapid initial catalytic deactivation without consideration of the catalysts Due to "this rapid initial catalyst deactivation and other competitive reactions the isomerization of structure has become impractical at temperatures below about 350 ° C. Since olefinic hydrocarbon feedings usually contain a small amount of dienes and alkynes in addition to olefins, deactivation of the catalyst becomes much faster. Therefore, frequent regeneration of the catalyst is necessary. To overcome the slower isomerization reaction rates, the reaction temperatures had to be high. This can lead to a much faster catalyst deactivation and usually increases the coke formation reactions, producing products lighter than intended. Therefore, catalyst regeneration or replacement of the deactivated catalyst with a fresh catalyst becomes necessary. In fact, generally the duration of the catalyst generation cycle is one of the main determining factors if a process becomes commercially successful or not. Aromatic alkylation with olefins is widely practiced to produce various alkylated products and can be carried out with various acid catalysts. The zeolite catalysts are known among the best for this purpose, see, for example, US Patents 4,169,111 (Unocal); 4,301,310 (Mobile); 4,798,816 (Unocal); and 4,876,408 (Unocal); 4,891,458 (Chevron); 4,849,569 (CR & L); and 5,446,223 (CR &L).

The dealkylation is well documented. T. Takahashi et al (Kinetics &Catalysis (IV 291) performed vapor phase dealkylation of the tert-butyl aromatic compounds such as tert-butylbenzene, tertiary p-butyl-loubuene and tertiary p-butylethylbenzene on a silica-alumina catalyst The tert-butyltoluene was dealkylated on a Y-zeolite catalyst The reactivities of the dealkylation of the three isomers of butylbenzene on silica-alumina catalysts were investigated by P. Andreu et al (J of Catalysis, Vol. 21, 225,1971) .The reactivity was reduced in the order of ter-sec- and n-butylbenzene. The dealkylation of tert-butylbenzene from 180 to 360 ° C produced only isobutylene as the olefin product. Two different mechanisms were proposed for the dealkylation of sec-butylbenzene; one for temperatures lower than 400 ° C and the other for temperatures higher than 400 ° C. The dealkylation olefin products at temperatures below 400 ° C contain little isobutylene. D. Farcasiu (J Org. Chem., Vol 44, No. 13, 1979) investigated the catalyzed dealkylation of alkylbenzene compounds such as toluene, ethylbenzene, isopropylbenzene and tert-butylbenzene. The dealkylation of alkylaromatic compounds was suggested to occur through the sequential formation of two intermediates. The first intermediate phenyl cation (delocalized charge) was formed through the protonation of the benzene ring of alkylaromatic compounds. This intermediate is broken down into benzene, and the alkylcarbonium ion (the second intermediate). This second intermediate is broken down to the olefin product with or without the structure isomerization. The -first intermediary is identical to the intermediary proposed by R.M. Roberts for the interconvention of butyl groups of sec-butylbenzene and isobultylbenzene. Therefore, the work of R.M. Roberts and D. Farcasiu, presented previously, can explain the reaction mechanisms involved in the conversion of linear olefins to isoolefins through the consecutive alkylation-clesalkylation reactions described in this invention. U.S. Patent 4,499,321 has described a selective process of dealkylation of 1,4-dialkylbenzene from mixtures of dialkylbenzene using molecular sieve catalysts. This process is useful for preparing m- and p-cresols. A mixture of m- and p-cresol is alkylated with isobutylene to a mixture of isomers of tert-butylcresol, which are separated by distillation. The separated isomers are dealkylated to produce m- and p-cresols. M. Miranda in Hydrocarbon Processing, pages 51-52, August "1987 describes a process for the recovery of pure isobutylene from mixtures of C4 through selective alkylation of phenol with isobutylene and dealkylation to recover isobutylene. The types of the processes described above are described as being suitable for catalytic distillation reactions In catalytic distillation or reactive distillation, the components of the reaction system are concurrently separated through distillation, using the catalyst structures such as the distillation structures. Such systems are described variously in US Patents 4,215,011 (CR & L); 4,232,177 (CR & L); 4,242,530 (CR & L); 4,250,052 (CR & L); 4,302,356 (CR & L); and 4,307,254 (CR & L); The present invention provides a method for separating defines from paraffins, an advantage of the present process is that the dealkylation of the Alkylated aromatic product provides a desired mixture of define isomers which are easily separated from the aromatic compounds. This advantage arises from the substantial difference in the boiling point between olefins and aromatics. No technique is known that describes the isomerization of efin structure through the alkylation and dealkylation of aromatic compounds therewith. The reaction of olefins with aromatic compounds in the presence of paraffins, the separation of the alkylated material, the dealkylation of the alkylated material and the recovery of structurally-isomerized olefins is not described in the art.The invention is broadly an isomerization process of olefin structure for olefin C4 to "Cj.5 a through the reaction of at least one C4 to C5 olefin, having a first structure distribution, with aromatic compounds under alkylation conditions to produce an alkylated aromatic product, the dealkylation of the alkylated aromatic product under dealkylation conditions to produce a unalkylated product comprising the aromatic and olefin compounds: corresponding to the olefins in the alkylation and having a second distribution of different structure "from the first distribution of structure The olefins fed to the alkylation are isomerized during the alkylation / dealkylation. "structure distribution" means ca the relative composition of the linear branched isomers of a given olefin. For example, a feed of C4 to the alkylation reaction may contain butene-1 and butene-2, so its structure distribution is 0% branched olefins and 100% linear olefins and after dealkylation there is a 50 % of tert-butylene and the rest butene-1 and butene-2, in this way the structure distribution of the dealkylated olefins is 50% branched and 50% linear.The alkylation reaction is preferably carried out under conditions to achieve substantially a 100% conversion of the olefins present Since "the olefins are usually present as part of an aliphatic stream, containing paraffins and olefins, the alkylation also serves to separate the alkenes from the rest of the stream. During the alkylation step, the alkylated aromatic compounds may contain both branched and linear alkyl groups due to the rearrangement of the structure of the alkyl groups depending on the alkylation temperature even if only linear olefins are present in the feed. Acid catalysts are used in both alkylation and dealkylation steps. Molecular sieves are the preferred catalysts for both reactions and zeolites are more preferred. The aromatics of the dealkylation can be recovered and recirculated to the alkylation unit to repeat the process. Similarly, linear olefins can be recovered and recirculated either to the alkylation reaction or "dealkylation reaction" A method for recovering the ter-olefins, which comprise a part of isoolefins and for separating said ter-olefins from the mixture of olefin is to contact the mixture of defines with a C 1 to C 1 alcohol to selectively react the ter-olefins to form ethers as described above.The unreacted olefins of this reaction are easily separated from the ethers for recirculation towards the alkylation reaction or otherwise used The alkylation and dealkylation reactions can be either or both carried out in fixed beds of straight through or in catalytic distillation reactors using suitable acidic catalysts such as Al-containing materials, for example, alumina and molecular sieves including zeolites. using the same catalyst or a catalyst similar to that of alkylation, that is, an acid catalyst, such as a zeolite. The alkylation conditions are more severe than the alkylation conditions, but in both reactions there is some reverse reaction. Otherwise, the reactions carried out by catalytic distillation are advantageous since the reaction products are concurrently separated from the inerts and the distillation can be operated to maintain the reagent feed inside the bed of the catalytic distillation structure (in the case of the alkylation, the aromatic is maintained in the catalyst zone and the alkylated product removed, and in the case of dealkylation, the alkylate product is maintained in the catalyst zone and the aromatic and olefitas are removed). In one embodiment, the aromatic alkylation reaction is performed in a catalytic distillation reactor using a feed containing paraffins, linear olefins and / or branched olefins using a zeolite catalyst, wherein a portion of the olefins, up to about a conversion of the 100% aromatic alkyl olefins whereby the paraffins and a portion of the excess aromatics are separated from the alkylated products by distillation within the distillation reactor. The separate mixture composed of the alkylated aromatics and a portion of aromatics is passed through a catalytic dealkylation reactor of the fixed bed to produce branched olefins. The content of branched olefin in the olefin product has been found to be equal to or greater than a conventional olefin isomerization. In another embodiment, the dealkylation of a ter-alkyl aromatic compound is carried out in a catalytic fixed-bed reactor. When the dealkylation temperature is relatively low, the olefin product for the most part is composed of branched olefin, indicating that there is little isomerization of the branched olefin to linear olefin or rearrangement of the structure of the ter-alkyl group of the starting alkylaromatic compound to the linear alkyl group. However, as the dealkylation temperature rises, the linear olefin content in the olefin product increased uniformly, indicating the increased structure isomerization of ter-olefin to olefin, as well as the isomerization of structure of the ter-group. alkyl to the linear alkyl group. The unalkylated material preferably separated from the olefins and returned to the dealkylation zone and the aromatics separated from the olefins and returned to the alkylation zone. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic representation of an embodiment of olefin alkylation, dealkylation and recovery. Figure 2 is a schematic representation of a modality of a selective reaction for ter-olefins followed by alkylation / dealkylation. Figure 3 is a schematic representation of an embodiment of the alkylation, dealkylation and recovery of isoolefin through selective etherification of the isoolefin. Figure 4 is a flow diagram of the present invention for the separation of isoolefins.

REAGENTS Olefins are preferably C 4 to C 4 olefins, more preferably C 4 to C 1 olefins including their normal and iso forms. For example, suitable olefins are butenes, isobutene, 1-pentene, 1-hexene, 2-hexene, 2,3-dimethyl-1-pentene, 1-octene, 1-nonene and 1-decene, dodecene and the like. As described above, a special case uses a feed, with a high content of linear olefins which are isomerized during the process to the corresponding iso forms. The aromatic compounds are preferably organic aromatic compounds under the pressure conditions of the distillation column reactor. Organic aromatic compounds include hydrocarbons of one or more rings and from 6 to 20 carbon atoms, which may contain substituents that do not interfere with alkylation including halogen (Cl, Br, F and I) OH and alkyl, cycloalkyl, aralkyl groups and alkaryl of 1 to 10 carbon atoms. Suitable organic aromatic compounds include benzene, xylene, toluene, phenol, cresol, ethylbenzene, diethylbenzene, naphthalene, "indene, phenyl bromide, 1,2-dihydronaphthalene, and the like, a preferred group of compounds for use in the process of present is benzene, xylene, toluene, phenol and cresol A preferred group of compounds for use in the process of the present benzene, xylene and toluene mixtures of aromatic compounds and olefin mixtures can be used as feeds for the process of The present, as well as relatively pure streams of either or both. RENT In alkylation, the molar ratio of the organic aromatic compound to olefin may be in the range of 1: 1 to 100: 1, preferably 2: 1 to 50. 1 and most preferably from 2: 1 to 10: 1 The alkylation reaction is carried out in the presence of acid catalysts The preferred catalysts are zeolite, Beta, Y-zeo lita, "ferrierite, mordenite, ZSM-5, ZSM-11, supported phosphoric acid (SPA), acid resin, etc. DEALAKING The dealkylation of the alkylated products can be carried out in the presence of acid catalysts. The preferred catalysts are molecular sieves, purified organic acidic clays and amorphous aluminosilicates. The preferred sieve catalysts are of a pore size of one, two or three medium to large (from 3.50 to 7.6A °, preferably from 3.5 to 7.5A °) which are sieves such as ferrierite, SAPO-11, SAPO-35, ZSM-5, ZSM-22, ZSM-23, ZSM-57, zeolite beta, pentacil zeolite and zeolite Y.

The dealkylation can be carried out in the vapor phase or in the presence of both vapor and liquid using both fixed-bed catalysts and catalytic distillation columns. The feeds to the "dealkylation" reactor can be pure alkylates or mixtures of alkylates and aromatics. such as benzene, toluene and xylene or paraffins. Since the dealkylation reaction is an endothermic reaction, it is desired to obtain dilute alkylate as a high conversion unless a multiple reactor system with intermittent reheating or more complex reactors such as tube heat exchangers or sheet plate reactors is employed. . The dealkylation products are olefins and aromatics. The olefin products of the dealkylation are composed of the olefin isomers from which ter-olefins can be selectively reacted with alcohols, water, carboxylic acids or aromatics. The remaining linear olefins are returned to either the alkylation reactor or the dealkylation reactor to be converted to ter-alefins. The temperature scale for the dealkylation is from 180 to 550 ° C, preferably from 200 to 450 ° C. In general, the "lowest pressure is favored for the desalkylation reaction." The pressure scale is sub-environmental to 24,605 kg / cm ~ m (350 psig), preferably from environment to 10,545 kg / cm-m (150 psig). ) The alkyl aromatic compound can be pure or mixtures with various aromatic or paraffinic compounds Depending on the components in the mixtures of the alkyl aromatic compounds, the catalyst selection and the operating conditions, the olefin products are pure or substantially pure ter-olefins, linear substantially pure olefins or olefin isomer mixture. The alkylation reaction of the present can be carried out at ambient pressure under high pressure, for example from 1 to 40 atmosphere. In the reactor distillation column, the temperature will vary depending on the local composition, i.e. the composition at any given point along the column. In addition, the temperature along the temperature will be as in any distillation column, the highest temperature is at the bottom and the temperature along the column will be the boiling point of the compositions at that point in the low column particular conditions of pressure. In addition, the isothermal heat of the reaction does not change the temperature in the column, but rather "merely causes a higher boiling." However, the temperatures within the column with the above considerations in mind are generally on the 50 ° C scale. the critical temperature of the mixture, preferably from 70 ° C to 300 ° C at pressures from 1 to 20 atmospheres.If the feed for the dealkylation is composed of several alkylaromatic compounds whose alkyl groups are composed of ter, sec, iso and n -alkyl ", the dealkylation can be carried out selectively or non-selectively, depending on the purpose of the alkylafon or the application of the olefin products. For a given catalyst, lower temperatures are employed for the selective dealkylation of ele-alkyl-alkyl aromatic compounds to ter-olefin. On the other hand, higher temperatures are used for the "non-selective dealkylation to produce the mixed olefin products containing various olefin isomers, for example, if a part of the alkylaromatic compounds is composed of compounds containing a ter-alkyl group. , pure or substantially pure ter-olefins can be produced by carrying out the dealkylation at a lower temperature It is important that deasalkylation is not carried out at too high temperatures, since the olefin product will contain linear olefins due to the rearrangement of structure of some ter-olefin products or the ter-alkyl group of alkylaromatic compounds The dealkylation of the remaining unconverted alkylaromatic compounds at higher temperatures yields a mixed-definition product of olefin isomers whose composition is of an absolute distribution of The optimum temperatures for dealkylation depend on of the alkyl group in the alkylate and the catalyst used. For example, when a terrierite molecular sieve is used as a catalyst for the dealkylation of tert-butyltoluene, it is desired to dealkylate at temperatures less than about 298.8 ° C (570 ° F). For a given acid catalyst, the ter-arylaromatic compound can be dealkylated at lower temperatures than the corresponding sec-alkylaromatic compounds. The ter-alkylaromatic compounds can be dealkylated on moderately acidic catalysts. The works of R.M. Roberts and D. Farcasiu discussed above, may suggest a reaction mechanism involved in the conversion of linear olefins to isoolefins through consecutive alkylation-dealkylation reactions described in this invention. These consecutive reactions can be carried out in one step or in two steps. If the alkylation is carried out at higher temperatures and lower pressures, both the alkylation and deasalkylation as well as the olefin isomerization can occur simultaneously in the catalytic reaction zone, resulting in the olefin isomers in the reaction products in one step. However, if the alkylation reaction is carried out at a temperature 2 lower and high pressure, and dealkylation is performed at a lower temperature and at a lower pressure, the same result can be obtained in two steps. The dealkylation step products are mixtures of linear isoolefins and olefins from which the isoolefins (branched olefins) can be separated from the linear defines by existing technologies such as distillation, extraction or selective reaction such as etherification. In the selective reaction technique, the separation of isoolefins in the mixtures is achieved by reacting isoolefins with a number of reagents. Since the isoolefins are much more reactive than the linear olefins, the isoolefins in the mixtures can be reacted selectively with alcohols, water, carboxylic and aromatic acids, and then unreacted linear olefins are separated from the reaction products of boil higher through a simple distillation technique. The recovered linear olefins are recirculated to the alkylation reactor. When an alcohol such as methanol or ethanol is employed for the selective reaction, the agent for the isoolefins, ether such as methyl tert-butyl ether or ethyl tert-butyl ether is the reaction product. These esters are valuable products, for these ethers they have been used for the mixing components such as oxygenates and the 2 octane component for reformulated gasoline. If the isoolefins are desired products, these ethers are dealkylated to isoolefins and alcohols, and the isoolefins are "separated from the alcohols by simple distillation." Thus, this invention provides a means to convert olefin components with a low content of RON in mixtures with a high RON content as well as lower high vapor pressure components in gasoline. " It is desirable to reduce olefin and aromatic components in gasoline due to environmental reasons and other reasons. Ethers are replacement components for this purpose. Therefore, this invention provides a useful technology for the production of MTBE or TAME from mixed mixed streams, when they use aromatic compounds such as benzene, toluene, xylene or phenols for the selective reaction agents with isoolefins, the "ter-alkylaromatic compounds are reaction products. When the isoolefins are desired products, these ter-alkylaromatic compounds are dealkylated in the presence. of acid catalysts. It is important that the dealkylation is not carried out at "too high temperatures." If the dealkylation temperature is "too high, the olefin product will contain linear olefins.

If the alkyl groups or alkylaromatic compounds are composed of linear alkyl groups and the linear olefins are desired products, the dealkylation is carried out at the lowest possible temperature using less acidic catalysts. STRAIGHT STEP REACTOR For straight bed alkylation of fixed bed, olefin and aromatic feeds are premixed before entering the catalytic reaction zone. Another technique performed by this fixed bed alkylation is that of the olefin feed which is divided into several portions and then each portion is fed to the alkylation reactor at different sites as the aromatic feed flows through the fixed bed reactor. For this fixed-bed operation, the reactor effluent stream can be recirculated to improve the selectivity and dilute the heat of the reaction, since the alkylation reaction is isothermal. The preferred scale for alkylations of 50 to 500 ° C, preferably 80 to 300 ° C. The pressure for the alkylation reactor must be high enough that a portion of the aromatics could exist as a liquid form. Therefore, the pressure for the alkylation reactor depends on the temperature and composition of the feed to the reactor.

DISTILLATION COLUMN REACTOR When the alkylation is carried out by cooling the catalytic distillation reactor, a distillation column is charged with catalysts, and light olefins such as C, or C5 olefins can be introduced to the distillation tower in the section lower of the tower and aromatics such as toluene or xylene may be introduced into the distillation tower in the upper section of the tower, or both olefins and aromatics are introduced into the lower section of the tower depending on the operating condition such as the temperature and pressure required for the alkylation and effective separation of aromatic or aromatic paraffins from the alkylated products. The unreacted paraffins in the olefin-containing feed are separated from the reaction mixture as a product of leaving vapors, and the alkylates (alkylated products) and possibly some of the aromatics are removed at the bottom of the tower as the product. Bottom residue: If desired, remove some of the aromatics as the product of leaving vapors together with paraffins After carrying out the dealkylation of the alkylate, the products, olefins and aromatics are removed from the column as outgoing vapors , and the unreacted alkylates are recovered as the bottom residue product to be recirculated to the top of the catalyst The desired conversion per step is from 10 to 100%, preferably from 30 to 80%. When using the catalytic distillation column reactor, the column pressure should be high enough, so that at least a part of the Food can exist in liquid form. The product olefins are removed from the catalytic reaction zone as the product of leaving vapors. The unconverted alkylates are removed from the bottom of the column and recirculated to the top of the catalyst. When the alkylation is carried out in the catalytic distillation mode, the exact location of the olefin feed in the distillation column reactor will depend on the particular feeds and the desired product. In one embodiment, the olefin feed to the reactor is preferably made below the catalyst bed thus allowing the mixing of the reactants before contact with the catalyst bed. In another embodiment, the olefin feed to the reactor is preferably made above the catalyst bed. The aromatic feed can be added at any point in the distillation column reactor, however, it is preferred to add below the fixed bed or at the reflux as a cover, depending on its boiling point. Preferably, there is a large excess of the aromatic to the olefin in the reactor in the range of 2 to 100 moles of aromatic per mole of olefin, ie the net molar feed reaction of the aromatic compound to olefin can be close to 1: 1, although the catalytic distillation system is operated in order to maintain a substantial molar excess of aromatic compound to olefin in the reaction zone. The alkylated product is the highest boiling material and is separated in the lower portion of the column usually as bottom residue. The organic aromatic compound may be the second highest boiling component or the third highest boiling component. Very large molar excesses of aromatic compounds require a very high reflux ratio in the column, and a low unit productivity. In this way, the correct ratio of the aromatic compound to olefin should be determined for each reagent combination, as well as the acceptable olefin content either in the leaving vapors or the alkylation product. The catalyst bed length in the column particularly is the portion where the reagents are in contact in and the reaction occurs, depends on the reagents, olefin feed location and the unreacted olefin acceptable in the streams leaving the stream. . 2 Some degree of proof will be required for each group of reagents and current purity parameters after the descriptions herein. The advantages of the alkylation herein carried out in the catalytic distillation mode are derived from the continuous washing of the coke or coke precursors on the catalyst surface, resulting in a much longer catalyst fouling, the natural separation of products in the catalytic reaction zone, the more stable flow of the reactants towards the catalytic reaction zone, a better transport of materials between the bulk phase and the reaction zone, and a better temperature control caused by the dynamic vapor-liquid equilibrium and steam traffic after the traditional fixed-bed process. The alkylate products are composed of a number of different alkyl groups. For example, n-butenes are olefins for alkylation, alkyl groups in alkylated aromatic compounds are mostly sec-butyl and tert-butyl groups. The degree of isomerization of the alkyl group depends on the temperature. For example, if the alkylation is performed at temperatures less than about 204.4 ° C (400 ° F) with molecular sieve catalysts, then the alkylation products contain a small amount of ter-butylaromatic compounds.

When n-pentene is used, the alkyl groups are C5 isomers such as sec-pentyl, 3-methyl-butyl, ter-amyl, etc. If a mixed C5 stream such as TAME raffinate is used for the alkylation, the paraffin components in the mixed feed can easily be separated from the alkylate and can serve as feed material for the steam pyrolyzer for the production of ethylene or the isomerization of paraffin structure, since it contains little or no olefins. In some reactions in the distillation column reactor, the olefin will be a higher boiling material than the aromatic hydrocarbon, for example, Ce + olefins. In such cases in a catalytic distillation reaction, any unreacted olefin will appear in the bottom residues of the alkylation product, although a lateral extraction may be used to reduce the material in the product to a negligible level. However, the operation of the reaction with less than a stoichiometric amount of olefin in the reaction zone, as described, will normally maintain the level of olefin in the bottom residues at a low or completely eliminated level. CATALYSTS "Molecular sieves are porous crystalline alumina-silicate materials." Zeolites are one of the 2 Typical examples are composed of silicon and aluminum atoms each surrounded by four oxygen atoms to form a small pyramid or tetrahedron (tetrahedral coordination). The term molecular sieve can be applied to both natural existence zeolites and synthetic zeolites. Naturally occurring zeolites have an irregular pore size and are generally not considered as equivalents of synthetic zeolites. However, in the present invention, natural existence zeolites are acceptable as long as they are substantially pure. The remainder of the present invention will be directed to synthetic zeolites with the understanding that natural zeolites are considered equivalent thereto as indicated above, ie, since natural zeolites are the functional equivalents of synthetic zeolites. Molecular sieves _ in particular or other catalysts can be employed by enclosing them in a porous container such as cloth, screen wire or polymer mesh for use in catalytic distillation. The material used to make the container must be inert to the reactants and conditions in the reaction system. The fabric can be any material that meets this requirement, such as cotton, fiberglass, polyester, nylon and the like. The screen wire can be aluminum, steel, stainless steel, and the like. The polymer mesh can be nylon, Teflon or the like. The mesh or centimeter of the material used to make the container is such that the catalyst is retained therein and will not pass through the openings in the material. Particles up to approximately 0.15 mm in size or powder can be used and particles with a diameter up to approximately 0.635 cm (1/4 inch) can be used in the containers. The container used to maintain the catalyst particles can have any configuration, such as the cavities described in the above commonly followed patents or the container can be a single cylinder, sphere, donut-shaped, bucket, tube or the like. Each container containing a solid catalytic material comprises a catalyst component. Each catalyst component is intimately associated with a separation component, which is composed of at least 70% by volume of open space to about 95% by volume of open space. This component may be rigid, elastic or a combination thereof. The combination of catalyst component and separation component form the catalytic distillation structure. The total volume of the open space for the catalytic distillation structure should be at least 10% by volume and preferably from at least 20% by volume to approximately 65% by volume. Thus, desirably the separation component or material should comprise approximately 30% by volume of the catalytic distillation structure, preferably approximately 30% by volume to 70% by volume.A suitable separation material is wire "of open mesh woven stainless steel, generally known as particle separator wire or expanded aluminum. Other elastic components may be nylon open woven polymeric filaments similar to Teflon and the like. Other materials such as foam material of highly open structures, for example, ceramic or monolithic structures of metal foam (rigid or elastic) can be formed instead of or applied around the catalyst component. In the case of larger catalyst components such as pellets of about 0.635 cm (1/4 inch) to 1.27 cm (1/2 inch), spheres, pills and the like, each component, larger can be individually and intimately associated with or surrounded by the separation component as described above. It is not essential that the separation component be completely covered by the catalyst component. It is only necessary that the separation component be intimately associated with the catalyst component which will act to separate the various catalyst components away from one another as described above. In this way, the separation component in effect provides a substantially open matrix of space in which the catalyst components are randomly but substantially evenly distributed. A catalytic distillation structure for use herein comprises placing molecular sieve particles in a plurality of cavities in a cloth web, which is supported in the distillation column reactor by stainless steel wire and open mesh fabric by twisting the two together in a helical form. This allows the requirement to flow and prevents the loss of catalysts. The fabric can be of any material that is inert in the reaction. It is useful in cotton or linen, but fiberglass cloth is preferred. "_" Figure 4 illustrates one embodiment of the present invention. That is, the production of isobutene of high purity through alkylation of benzene with isobutene from a stream of C4 containing predominantly n-butene, "C4 isobutene and alkenes." Referring to the drawing, the distillation column reactor 10 is divided into three sections.In the middle section, the catalyst packing (catalytic distillation structures) is placed as described, using a Y-zeolite ferrierite deposited in the glass fiber band cavities and formed into a helix with a stainless steel mesh as described.The inner portion of the column is a conventional distillation column configuration. Benzene is conveniently added through line 14. The olefin-containing feed 8 is mixed with the benzene and fed to the column through 9 just below the catalyst packing 12 for better mixing.The reaction is exothermic and It starts by contacting the two reagents in the catalyst package, the alkylated products are boiling higher than benzene and the feed C4, and are recovered through 18 as a bottom residue product. The feed of the C4 is adjusted so that there is a molar excess of benzene in the reactor. In addition to the C 4 alkanes and benzene, other light residues may come out as protruding vapors 20. The outgoing vapor is passed to the condenser 22, which is operated to substantially condense all of the benzene passing through 24 into the accumulator 16 and , therefore, through reflux through 26 to column 10. The benzene used in the reaction and the loss with the light waste, mainly C4 alkanes (which leave the accumulator 16 through 28) are assumed through of fresh benzene feed 14.

The bottom "residues contain a mixture of alkylated benzene with primary and secondary isobutene and butylbenzene which passes through 18 to the dealkylation unit 30, which is a catalytic distillation column operated to concurrently dealkylate fractionated alkylate and benzene. and butenes "as outgoing vapors 32 and heavy vapors as a product of bottom residues 33. In this embodiment, benzene is separated from olefin in column 35 and returns through 34 to supply 14 to column 10. olefins are recovered as salient vapors 36. Figure 1 is a flow diagram showing graphically the trajectory of reagents, products and by-products through each of the various possible reactions in the system, including the separation and recovery of isoolefins from the primary olefins Figure 2 is a flow chart showing the treatment of unreacted olefins from a tertiary olefin reaction according to the alkylation / dealkylation of the present. Figure 3 illustrates an embodiment of the present invention, that is, the production of high purity isobutene through alkylation of toluene with isobutene from a stream of C4 or C5 containing mainly n-butene, isobutene and C4 alkanes or the corresponding primary C5 isoolefins. Referring to the drawing, the distillation column reactor 110 with the middle section containing the catalyst package (catalytic distillation structures) 112 positioned as described, using beta zeolite deposited in the cavities of the glass fiber bands and formed in a propeller with stainless steel mesh as described. The lower portion of the column is a conventional distillation column configuration. The development of toluene is conveniently added through line 114. Feed 108 containing olefin is mixed with recirculation of toluene 154 and recirculation without isoolefin 162 and fed to the column through 109 below catalyst packing 112 for better mixing. The exothermic reactions started by contacting the two reagents in catalyst packaging. The alkylated products are boiling higher than toluene and feeding C or C5 and are recovered through 118 as a bottom waste product. The feed of C4 or C is adjusted so that there is a molar excess of toluene to olefin in the reactor. In addition to the C 4 or C 5 alkanes, other light residues or some toluene escapes as leaving vapor 120. The leaving steam 120 is passed to a condenser (not shown) 3 to substantially condense all of the toluene that is returned to column 110 as reflux. The bottom residues in column 110 contain a mixture of alkylated toluene (the defines are substantially 100% converted) which pass through 118 to the dealkylation unit 130, which is a fixed straight-through reactor operated to dealkylate concurrently toluene alkylate. The total dealkylation product is passed through line 132 to distillation column 140, where the unalkylated material is separated and recirculated under line "144 to desalker 130. Toluene and olefins are recovered as vapors passing through line 142 to distillation column 150, where the aromatics are recovered as bottom residues through line 154 and recirculated to alkylation column 110. In this embodiment, olefins are passed to a plant of 160, wherein the isoolefins are preferentially reacted with alcohol, such as methanol to form MTBE or TAME.The development of the olefin feed can be added through line 156. The ether plant can be any of Those known in the art, the system of the present has a double benefit when used together with an ether plant., since there is a conversion of linear olefins to isoolefins, the efficiency of the ether unit is increased, in two ways, first through "the conversion of the linear defines in the feed of development and the conversion of the linear olefins , recirculated from the ether plant to the present system The second benefit is the removal of potential poisons for the etherification catalyst, for example, propionitrile, which is a cumulative poison for resin catalysts. used in the etherification, and dimethyl sulfide, they will either pass through the alkylation zone and leave with the alkenes or react in the alkylation catalyst and will be removed during regeneration.The unreacted olefins from the ether plant can be recirculated to the mixed olefin through line 162. Items such as valves, kettles, slipstreams, etc., n or they are shown, but they could be obvious aspects for those who fix such equipment. EXAMPLES "" EXAMPLE 1 CONTROL A 1816 kg (4 lbs) of commercial 1/4"extrusion catalyst ferrierite (Pl) was packed into" a tube with a diameter of 6.35 cm ". (2.5" ) The length of the catalyst bed was 10.16 cm (4 '). The isomerization of n-pentenes structure in mixed C5 hydrocarbons (raffinate of TAME) was performed in the operation of the traditional fixed bed by passing the hydrocarbon vapor over the downward flow of catalyst. The raffinate of TAME was composed of 4.56% by weight of C3-C4S, 32.14 by weight of n-pentenes, 4.36% by weight of isoamylene (2-methyl-2-butene and 2-methyl-1-butene), 0.94% by weight of 3-methyl-1-butene, 50.27% by weight of isopentane, 6.45% by weight of n-pentane, 1.28% by weight of + C6 and others. The isomerization results at 41 hours in the stream are listed in Table 1. CONTROL B An experiment similar to a different condition is performed with a different feed. Power supply C5 mixed was composed of 1.29% by weight of C3-C4S, 66.04% by weight of n-pentenes, 9.86% by weight of isoamylene (2-methyl-2-butene and 2-methyl-1-butene), 2.87% by weight weight of 3-methyl-1-butene, 3.51% by weight of isopentanes, 14.63% by weight n-pentane, 1.80% by weight of + C6 and others. The results of isomerization at 31 hours in the stream are listed in Table 1. EXAMPLE 2 CONTROL 1.86 kg (4.1 lbs) of 0.158 cm (1/16") extrusion catalyst of commercial ferrierite (pl) was packed in a tube with a diameter of 6.35cm (2.5"). The length of the catalyst bed was 10.16 cm (4 ') - The isomerization of n-butene structures in mixed C4 hydrocarbons (raffinates 2) was performed in the traditional fixed bed operation by passing the hydrocarbon vapor over the flow descending catalyst. The raffinate feed of MTBE was composed of 0.03% by weight of C3, 4.64% by weight of isobutane, 22.85% by weight of n-butane, 1.35% by weight of isobutylene, 70.95% by weight of n-butenes, 0.18% in weight of + C5 and others. The isomerization results at about 49 hours in the stream are listed in Table 3. EXAMPLE 3 M-xylene was re-alkylated with TAME C5 raffinate on a commercial Beta zeolite catalyst (6 g, 10-20 mesh in a steel tube) stainless with a diameter of 1.27cm (0.5") for a length of 25.4cm (10")) at 215.5 ° C (420 ° F) under a pressure of 7.03kg / cm2m (100 psig). The feed was prepared by mixing m-xylene with a raffinate of TAME of C-, to have a xylene / olefin ratio of 4.90. The raffinate composition of TAME was 0.07% by weight of C3s, 2.92% by weight of butenes, 0.54% by weight of butanes, 33.33% by weight of m-pentenes, 4.64% by weight of isomilenes (2-methyl-2). -butene and 2-methyl-1-butene), 0.92% by weight of 3-methyl-1-butene, 0.72% by weight of cyclopentene, 48.25% by weight of isopentane, 7.56% by weight of n-pentane and 1.05% in weight of Cg + / unknown. The alkylation was performed at 148.8-176.6 ° C (300-350 ° F) and at a pressure of 7.03 kg / cm2m (100 psig) with a feed rate of 12 WHSV. The conversion of total olefins in the diet was on the scale of 97.7 to 100%. The mixed product of the xylene alkylation reaction; with defines of 'C5 mixed was concentrated through the distillation of non-aromatics and some excess of xylene to prepare the feed for dealkylation. The feed composition for the dealkylation was 28.53% by weight of alkylate and 71.47% by weight of xylene. Five different commercial catalysts (6 g and 10 to 20 mesh) were loaded into "a stainless steel reactor with a diameter of 1.27 cm (0.5") by a length of 25.4 cm (10") for the dealkylation reaction of the feed The results of the dealkylation are listed in Table 1. EXAMPLE 4 The alkylation of toluene with a mixed C4 stream was carried out using a catalytic distillation reactor The composition of the mixed C4 stream was 0.98% isobutane, 0.42% isobutylene, 45.33% n-butane, 31.98% trans-2-butene, 16.10% cis-2-butene and 5.19% + C5. The height of the catalytic distillation column was "63.5 cm (25 ') and the internal diameter of the column was 2.54 cm (1"). Beta commercial zeolite (0.208 kg (0.46 lb) and excluded products of 40.64 (16")) were packaged in specially designed permeable containers and loaded in the middle section of the distillation column. 25.4 cm (10 ') The top and bottom options (each of 19.05 cm) (7.5') of the catalyst were packed with ceramic supports The scale in the operating condition of the catalytic distillation was 231.1-248.3 ° C (448-479 ° F) of • column temperature, upper pressure of 17.22- 18.98kg / cm2m (245-270 psig) and a feed rate of 13-24 WHSV. The molar ratio of toluene to olefin in the feed was varied from 4.5 to 6.2. The paraffin components in the feed, a very small amount of unreacted olefins and approximately 60-80% unreacted toluene were removed from the top of the column as the product of leaving vapors. The alkylate products and approximately 20-40% remaining unreacted toluene were removed from the kettle at the bottom of the column as bottom residue products The results of the alkylation are listed in Table 2. A composite product, whose composition was 0.97% by weight of non-aromatics, 36.93% of aromatics (benzene, toluene and xylenes), 61.86% by weight of various butyl toluene isomers (mono, di and tri-butyltoluene), and 0.42% by weight of heavy products, was dealkylated on various molecular sieve catalysts. The alkyl group on butyltoluene was composed of linear and branched butyl groups, but mostly of a sec-butyl group. The results are listed in Table 3. EXAMPLE 5 The dealkylation of tert-butyl toluene was carried out using a feed composed of 64.5% tert-butyl toluene and 35.41% toluene. A commercial ferrierite catalyst (4.78 g and 10 to 20 mesh) was charged to a stainless steel reactor (diameter 0.5") for a length of 25.4 cm (10") for the dealkylation reaction. of the previous feed. The results are listed in Table 4.

TABLE 1 Isomerization of d-olefípa structure n-C5 Desalkylation of pentllx-l-alkylates EXAMPLE Control 1A Contro l I B Catalyst P1 Pl P1 PA ez UP P3 Temperature "C 398.8 354.4 343.3 287.7 31S.S 315.5 287.

Pressure, psig 10 15 25 30 30 30 30 Flow Rate, WHSV 7 7 7 10 6.5 7 7 Conversion) X 7 \ .7 ** 30.5 ** 52.9 37.9 43.4 53.4 42.8. { -C5 = * / n-penyenos 2.56 0.79S 3.04 4.04 1.06 2.93 2.33 i -Cj * * X in Cj ~ 68.0 43.1 70.9 75.1 49.2 72.4 68.2 Product i - C ^ *% in C? * 40.7 3 .a 41 .8 42.2 17.5 20.8 24.2 Product Product Distribution% by weight 1 .2 0.1 3.9 2.1 0.9 2.1 1.5 5.3 1.3 11.7 1S .0 15.3 22.3 22.9 90, 98.0 78.9 70.1 83.8 59.3 69.3 + C * 2. 0.6 5.5 12.7 tr 16.3 6.3 % Product in C4 86. 79.8 93.5 83.2 79.2 63.4 59.7 X Product in Ce 37.1 80.8 80.2 98.7 85.7 77.8 75.7 • i - Cg = 2-M-B-2 * 2-M-8- 1 Pl = \ Ferrierite (Gl>, EZ = Zeolite-Y, UP = Beta Zeolite <EU), P3 = Beta Zeolite (QQ) P4 a Ferrierita (G2) ** Conversion of n-Cs * TABLE 2 Alkylation of Toluene with Mixed C4 Feeding (Catalytic Catalytic Mode) Column temperature'C 231.1 - 238.3 237.2 - 245.5 235- 250.5- 235-248.3 Distillation temperature ° C 315.5 312.7 319.4 320. 5 OVHD prßss, ps ig 270 245 255 255 Column pd , psig 2.5 2.5 2.5 2.5 Free ratio, WHSV 13 13 13 24.1 Molar ratio toluene / butene 6.21 5.07 4.47 6.19 Hours in current 276 456 612 804 Conversion of butane, X 99.5 99.3 99.2 95.4 Monoalkylate in alkylate 98.1 95.3 96.5 98.4% by weight TABLE 3 Isomers of Structure of Olefin of 11-C4 Desalkylation of Butyl Toluene Example 2 S Catalyst Pl P1 P2 Ul? I P3 UP UC PM Temperature "C 426.6 398.8 398.8 398.8 343.3 371.1 315.5 343.3 354.4 Pressure, psig 10 10 10 10 10 10 10 10 10 Flow Rate, WHSV 12 4 7 4 4 7 7 20 16 Conversion, X 49.7 ** 49.7 40.7 64.2 51.5 81 .2 73.9 S9.1 47.1 I-C4 * X in C4 = 45.4 44.0 44.1 45.2 47.6 20.3 48. 1 44.8 7.83 Product i -c5 = * X in c5 = 7.94 2.75 2.70 2.72 3.32 2.96 3.64 3.24 1 .41 Product Distribution Product. wr.% c1 = c3 0.5 7 10.6 21 .7 15.7 8. J 16.4 T4.2 2.4 c4 93.5 83.3 76. t 41 .4 39.3 63.2 40.8 40.7 85.8 C5 1 .2 5.2 6.6 17.6 21 .2 17.5 22.7 22.a 11.0 * c6 4.8 4.5 6.7 19.3 23.8 11 .2 20. 1 22.1 0.8 C = Product in C4 69.9 90.3 85.9 29.8 20.6 73.7 13.5 41 .1 88.8 c * Product in cs 81 .0 97 97.7 35.7 25.0 73.7 16.3 50.9 51 .7 * Isoamylene ß2-tt-s-l * 2-M-8-2 PI »Ferrite (Gl), PZ- Fyrrrite (N), Ul = * 2SM-5, P3 = Beta Zeolite (OQ), UP * Beta Zeolite (EU), UC - Peptas il Zeolita, P »< = Beta Zeol? Ta < S > ** Conversion of nC = TABLE 4 Desalting of 4-tert.-butyl toluene alkylate Temperature "C 232.2 260 287.7 315.5 343.3 371.1 Pressure, psig 40 40 40 40 50 50 Flow rate, WHSV 10 10 10 10 10 10 Conversion,% 23.5 26.2 28.8 33.4 59.8 71.6% i-Butene in c ~ 3.9 94.8 94.7 84.8 74.4 67.2 Comp, Thermal Eq, 2 61.8 59.3 57.4 55.8 53.8 52.3 The control experiments were performed for the linear olefin structure isomerization in control example 1 and 2. When the isomerization of the linear olefins of C and C5 was performed in a vapor phase using a commercial ferrierite catalyst in the operation of traditional fixed bed, there were dramatic changes in activity and selectivity at the beginning of the reaction as others established in the published documents and patents, due to the formation of coke in strong active sites. The structure isomerization of linear olefins of C4 and C5 became effective at a relatively high temperature, > 398.8 ° C (> 750 ° F).

When the conversion of the linear olefins to isoolefins was performed according to this invention, there were marked differences in the reaction temperatures from the olefin structure isomerization of the fixed bed of traditional vapor phase, allowing a broader scale of temperature of operation for this invention. This translates to a longer catalyst cycle time. Due to the invention of cleaning by the high-boiling aromatic compounds in the feeds during the alkylation or dealkylation, it was possible to keep the catalyst surface and the pores cleaner for a longer time. The active sites and pores in the catalysts were kept cleaner from the deposition of coke. Therefore, the catalysts were able to sustain high activities for a longer time. Surprisingly, the dealkylation reaction of the lquilates was effective at temperatures much lower than the temperature > 398.8 ° C (> 750 ° F) required for the isomerization of olefin structure in the operation of the fixed bed. The fact that the dealkylation reaction can be carried out at a lower temperature than the olefin structure isomerization for a given catalyst has a very important implication for the production of isolefins and isolefin derivatives. Since the equilibrium concentration of the isolefins is reduced with temperature, the conversion of linear olefins to isolefins was performed in accordance with this invention and resulted in higher yields of isolefins in Tables 1 and 3. The advantage of this invention on the process of isomerization of conventional olefin structure can be clearly understood. Not only the isolefin components in the product streams in this invention are higher than the conventional olefin structure isomerization, but also the product streams of this invention have higher concentrations of olefins, resulting in isolefin currents desirable for downstream processing. For example, in the production of ethers such as MTBE or TAME, higher yields of ethers can be obtained for a unit of given size. The linear olefins in the products can be converted to isolefins after the removal of isolefins by the selective reaction of isoolefins and recirculation towards the alkylation reactor, due to the paraffin components in product streams that are sufficiently low. However, this is not true for the conventional olefin structure isomerization processes, since the concentration of olefin in the refining stream of the recovery reactor of Isolefin (the selective reactor) is too dilute. Higher boiling alkylated products can easily be dealkylated to olefins and aromatics. The unconverted alkylates can be recovered by the conventional method such as simple distillation and recirculation and the separated aromatics of C4 and C5 hydrocarbon through conventional distillation or separation technique and recycled back to the alkylation reactor. When the ter-alkylbenzene such as tert-butyltoluene is dealkylated using the ferrierite (Pl) catalyst at lower temperatures, the olefin products are substantially pure isobutylene as shown in TABLE 4. However, when the dealkylation was carried out at a higher temperature, the ter-olefin products were diluted in an increased manner with other olefin isomers. This invention can also be used to improve the octane of gasoline FCC and gasoline naphtha slightly reformed in one step. Instead of performing the alkylation and dealkylation separately, the alkylation, dealkylation and olefin isomerization can be simultaneously performed in a catalytic distillation column where an acid catalyst is charged. The C4-C8 olefins in the gasoline can effectively be converted to mixtures of olefin isomers. The gasoline feed is fed to the middle section of the catalytic distillation tower. The exact position of the feeding position in the tower can be varied by the composition of the gasoline to obtain the best improvement of _ ROM. The products of the outgoing vapors and bottom residues of the distillation tower combine to produce improved gasoline.

Claims (33)

1. CLAIMS 1. A process for the isomerization of olefin structure from C4 to C5 through the reaction of at least one olefin of C4 to C15, having a first structure distribution, with aromatic compounds under alkylation conditions to produce an alkylated aromatic product, the dealkylation of the alkylated product under dealkylation conditions to produce a dealkylated product comprising aromatics and olefins corresponding to the olefins in the alkylation and having a second structure distribution different from the first structure distribution.
2. 2. The process according to claim 1, characterized in that the olefin is at least one C4-C8 olefin.
3. 3. The process according to claim 1, characterized in that the olefin of C4 is present.
4. 4. The process according to claim 1, characterized in that the C5 olefin is present.
5. 5. The process in accordance with the claim 1, characterized in that the alkylation is carried out under conditions to obtain a conversion of 10-100% of the olefin present.
6. 6. The process according to claim 5, characterized in that the alkylation is carried out under conditions to obtain a conversion of 30-100% of the olefin present.
7. 7. The process according to claim 1, characterized in that the alkylation is carried out in the presence of an acid catalyst.
8. 8. The process according to claim 7, characterized in that the catalyst comprises a molecular sieve.
9. 9. The process according to claim 7, characterized in that the acid catalyst comprises a zeolite.
10. 10. The process according to claim 1, characterized in that the dealkylation is carried out in the presence of an acid catalyst.
11. 11. The process in accordance with the claim 10, characterized in that an acid catalyst comprises a molecular sieve.
12. 12. The process according to claim 10, characterized in that an acid catalyst comprises a zeolite.
13. 13. The process according to claim 1, characterized in that the alkylation is carried out in the presence of an acid catalyst and the dealkylation is carried out in the presence of an acid catalyst.
14. 14. A process for the isomerization of linear olefin structure in the scale of C4 olefins a. Cg, characterized in that it comprises: (a) feeding an organic aromatic compound and an olefin of C4 to C15 in an alkylation zone containing an acid catalyst to maintain a molar ratio of organic aromatic compound: "olefin on the scale of 2 to 100: 1 in the reaction zone under alkylation conditions to catalytically react a portion of the organic aromatic compound and the olefin to form an alkylation product comprising an alkylated organic aromatic compound, an alkylated organic aromatic compound, an unreacted organic aromatic compound and a unreacted olefin, (b) separating the alkylated organic aromatic compound from the other components of the alkylation product, (c) feeding the alkylated organic aromatic compound to a dealkylation zone containing an acid catalyst under dealkylation conditions to dealkylate an portion of the organic aromatic compound uilated to form a dealkylation product comprising an organic aromatic compound, olefin and an alkylated aromatic compound.
15. 15. The process according to claim 14, characterized in that the alkylation zone comprises a distillation column reactor containing an acid catalytic distillation structure of the fixed bed in a distillation reaction zone, wherein: (i) such organic aromatic compound and the olefin catalytically react to form an alkylation product and (ii) the alkylation product is fractionally distilled to separate its components, and the organic aromatic compound is removed from the distillation column reactor.
16. 16. The process according to claim 14, characterized in that the dealkylation zone comprises a distillation column reactor containing an acid catalytic distillation structure of the fixed bed in a distillation reaction zone, wherein: (i) the compound Alkylated organic aromatic is catalytically dissociated to the dealkylation product and ~~ (ü) the olefin is separated from the dealkylation product and removed from the distillation column reactor.
17. 17. The process according to claim 14, characterized in that the alkylation zone comprises a distillation column reactor containing a fixed-bed acid catalytic distillation structure in a distillation reaction zone wherein: (i) the compound aromatic and the olefin catalytically reacts to form the alkylation product and (ii) the alkylation product is fractionally distilled to separate its components, and the alkylated organic aromatic compound is removed from the distillation column reactor, and the distillation zone comprises a distillation column reactor containing a fixed bed acid catalytic distillation structure in a distillation reaction zone wherein: (i) the alkylated aromatic compound is catalytically dissociated to the dealkylation product (? i) the olefin is separated from the product of dealkylation and is removed from the distillation column reactor.
18. 18. The process according to claim 14, characterized in that the alkylation reaction zone comprises a fixed-bed straight-through reactor.
19. 19. The process according to claim 14, characterized in that the dealkylation reaction zone comprises a fixed-bed straight-through reactor.
20. 20. The process in accordance with the claim 14, characterized in that the alkylation reaction zone comprises a fixed-bed straight-through reactor and the dealkylation reaction zone comprises a fixed-bed straight-through reactor.
21. 21. The process in accordance with the claim 15, characterized in that the dealkylation reaction zone comprises a fixed-bed straight-through reactor.
22. 22. The process in accordance with the claim 16, characterized in that the alkylation reaction zone comprises a fixed-bed straight-through reactor.
23. 23. The process according to claim 14, characterized in that the dealkylation is carried out under conditions to selectively dealkylate branched olefins.
24. 24. The process according to claim 23, characterized in that the branched olefins are separated from the dealkylation product.
25. 25. The process in accordance with the claim 14, characterized in that the olefin in the dealkylation product comprises a mixture of branched olefins and linear olefins.
26. 26. The process according to claim 25, characterized in that the mixture of branched olefins and linear olefins is separated from the dealkylation product.
27. 27. The process according to claim 26, characterized in that the mixture of branched olefins and linear olefins is contacted with a Cx to Cu alcohol in the presence of an acid catalyst under verification conditions to selectively react a portion of the branched olefins.
28. 28. The process in accordance with the claim 27, characterized in that the olefin comprises C olefin and the branched olefins comprise tert-butylene
29. 29. The process according to claim 27, characterized in that the olefin comprises C5 olefin and the branched olefins comprise isoamylene.
30. 30. The process according to claim 14, characterized in that the organic aromatic compound comprises hydrocarbons.
31. 31. The process according to claim 14, characterized in that the organic aromatic compound comprises benzene.
32. 32. The process according to claim 14, characterized in that the organic aromatic compound comprises toluene.
33. 33. The process according to claim 14, characterized in that the organic aromatic compound comprises xylenes.