RU2075467C1 - Process for preparing ethylbenzene or cumene - Google Patents

Abstract

FIELD: petrochemical industry. SUBSTANCE: process for preparing ethyl benzene or cumos by alkylation and/or transalkylation with alkylating agent such as ethylene and/or diethyl benzene, propylene and/or diisopropyl benzene at 100-250 C at benzene to alkylating agent ratio of 3-10:1. The catalyst is acid mordenite catalyst having SiO₂/Al₂O₃ molar ratio of more than 30:1 and crystalline structure determined by diffraction of X-rays having index of symmetry of greater than 1 and viable under reaction conditions without activation for 500 hours. Catalyst is prepared by calcination of original acid mordenite catalyst having certain characteristics and treating with aqueous acid solution. EFFECT: more efficient preparation process. 8 cl, 3 tbl

Description

 This invention relates to the use of mordenite zeolites as catalysts in the alkylation or transalkylation of aromatic compounds for the production of cumene, ethylbenzene or other alkylated benzenes.

 Cumene, also known as isopropylbenzene, is used to produce phenol, acetone and alpha-methylstyrene. Ethylbenzene is used to produce styrene. Various methods of these industries are known.

 The various process schemes are alkylation and / or transalkylation reactions known to produce high yields of monoalkyl aromatic compounds such as cumene or ethylbenzene. However, existing methods are not without problems, including the production of unwanted by-products. Examples of such by-products formed together with cumene include oligomer alkylating agents, heavy polyaromatic compounds and undesired monoalkylated and dialkylated compounds, for example n-propylbenzene, butylbenzenes and ethylbenzene. The production of undesired xylenes is a separate problem in the production of ethylbenzene. Another problem related to existing methods relates to the use of Friedel-Crafts catalysts, for example, solid phosphoric acid or aluminum chloride. Phosphoric acid catalysts generally require the use of water for co-feed, resulting in a corrosive slurry by-product. The problems of concentrating by-product slurry product can be eliminated by using zeolite catalysts.

 It is known that aromatic hydrocarbons can be alkylated in the presence of an acid-treated zeolite. US Pat. No. 4,393,262 (1983) teaches that cumene is prepared by alkylation of benzene with propylene in the presence of a special zeolite catalyst. US patent N 3140253 (1964) and US patent N 3367884 (1968) widely describe the use of acid-treated mordenite for the alkylation of aromatic compounds. However, such alkylations are generally not selective with respect to the location and amount of substitutions. In addition, the catalysts are often quickly deactivated, which requires a lengthy and expensive replacement or reactivation.

 Thus, there remains a need for an efficient method for producing alkylated benzenes having minimal levels of impurities when using catalysts having a low negative environmental impact and a long service life.

 One of the objectives of this invention is a method for the alkylation of benzene or substituted benzene to obtain alkylated products having low levels of impurities. The invention is also directed to transalkylation of polyalkylated aromatic compounds. The method includes reacting benzene with an alkylating agent having from two to eighteen carbon atoms in the presence of a catalyst under such conditions that an alkyl benzene is obtained having a low content of impurities. The catalyst has a long service life and is easily reactivated by washing with hot benzene, if necessary during the alkylation process. If desired, the reaction can also be carried out by burning carbon-containing precipitates. The catalyst is an acid mordenite zeolite having a silica / alumina molar ratio of at least 30: 1. In addition, the mordenite zeolite catalyst has a crystalline structure, which is determined by X-ray diffraction as having a symmetry index of at least 1.

 Another objective of the invention is a method for producing alkylated benzene, including cumene and ethylbenzene, using transalkylation, which involves contacting benzene and a mixture of dialkylated benzenes in the presence of a catalyst, said catalyst is an acid mordenite zeolite having a silica / alumina ratio, equal to at least 30: 1, and a crystalline structure, which is determined by x-ray diffraction, having a symmetry index equal to at at least 1 under such reaction conditions that basically an unpainted alkyl benzene is obtained, and the catalyst does not show a substantial deactivation after at least 500 hours of use.

 A still further object of this invention is a method for producing cumene by alkylation / transalkylation, which is contacting benzene with diisopropyl benzene and propylene in the presence of a catalyst, said catalyst being an acid mordenite zeolite having a silica / alumina ratio of at least 30 : 1 and a crystalline structure, which is determined by x-ray diffraction, having a symmetry index equal to at least 1, in such reaction conditions, which basically results in unpainted cumene, and the catalyst does not show substantially deactivation of at least 500 hours of use.

 Another additional objective of the invention is a method for producing ethylbenzene by alkylation / transalkylation, which is the contacting of benzene with diethylbenzene and ethylene in the presence of a catalyst, said catalyst is an acid mordenite zeolite having a silica / alumina ratio of at least 30 1 , and a crystalline structure that is determined by x-ray diffraction, having a symmetry index of at least 1, under such conditions x reaction, which basically results in unpainted alkylated ethylbenzene, and the catalyst does not show substantially deactivation after at least 500 hours of use.

 Another objective of this invention is the composition of the catalyst, which is an acid mordenite zeolite having a molar ratio of silica / alumina of at least 30 1, and a crystalline structure that is determined by x-ray diffraction, having a symmetry index of at least 1 and an inert binder of silica.

 Under the conditions of this method, cumene is obtained having an unexpectedly low bromine number and low levels of impurities such as n-propylbenzene, butylenebenzene and ethylbenzene. Ethylbenzene is obtained with low levels of impurities, such as xylenes. Unexpectedly, the catalyst is not easily deactivated.

 Using the practice of this invention, cumene suitable for the production of phenol is obtained. The resulting ethylbenzene is suitable for the production of styrene.

 Any monocyclic aromatic compound may be alkylated or transalkylated using the method of this invention. The aromatic compound is preferably benzene or substituted benzene. Non-limiting examples of substituted benzenes that can be alkylated using the method of the present invention include phenol and aniline. In the production of cumene and ethylbenzene, the aromatic compound is a substituted benzene or a mixture of benzene and alkyl benzenes and other by-products obtained from the alkylation of benzene with propylene or ethylene.

 In a preferred embodiment, benzene is an aromatic compound that is alkylated using propylene as an alkylating agent to form cumene. In another preferred embodiment, the mixture of benzene and diisopropyl benzene is transalkylated as a separate reaction or simultaneously with the alkylation of propylene. Diisopropyl benzenes can be obtained using the method of this invention or can be formed by other alkylation methods. In a third preferred embodiment, benzene is alkylated with ethylene or transalkylated with polyethylene benzenes to form ethylbenzene.

 The aromatic compound may be used undiluted in a liquid state or dissolved in a suitable solvent. If a solvent is used, any inert solvent that dissolves the aromatic compound and does not interfere with the alkylation reaction can be used. The preferred solvent is 1,3,5-triisopropylbenzene or decamine.

 In the alkylation of benzene to form ethylbenzene, the preferred alkylating agent is ethylene or a mixture of polyethylbenzenes. In the alkylation of benzene to produce cumene, ethylene or a mixture of the m-, o- and p-isomers of diisopropyl benzene is the preferred alkylating agent. Isomers can be formed as by-products in the alkylation of benzene with propylene to produce cumene or the method of this invention or in a completely different way. When the alkylating agent is a mixture of isomers that are formed as by-products during the alkylation of benzene with propylene to produce cumene, the cumene can be distilled or otherwise removed from the by-products of the mixture. The mixture is then returned for transalkylation to the same reactor where the benzene with propylene was alkylated. In another embodiment, cumene is formed by some other alkylation methods, for example, a method using a solid phosphoric acid catalyst, and by-products are used as a transalkylating agent with benzene in the method of this invention. By transalkylation, ethylbenzene can also be obtained.

 In a practically preferred embodiment of the production of cumene, benzene is alkylated by the method of this invention using propylene as an alkylating agent. As mentioned above, in this method diisopropyl benzene is also formed as a by-product. The diisopropyl benzene obtained in the practice of this invention is a mixture of m-, o- and p-isomers enriched with p-isomers. Cumene is separated from by-products using technologies known in the industry, such as distillation. The remaining mixture, including diisopropyl benzene, is re-sent to transalkylation with benzene to form more cumene. The catalyst of this invention also shows reaction selectivity in the transalkylation of a pair of isomers to a greater extent than the ortho and meto isomers.

 The catalyst used in the practice of this invention is an acid mordenite zeolite and a silicon-based binder. Mordenite zeolite has a silica / alumina molar ratio of at least 30 1, a symmetry index (S1), as defined hereinafter, of at least 1.0.

 The zeolite of the invention should be an acid-modified zeolite with interconnected twelve-ring and eight-ring channels. Zeolites have structural lattices, which are formally formed by silicon oxide and alumina tetrahedra, which are joined by vertices. Tetrahedra can be associated with the formation of pores or channels. The pore size is determined by the number of tetrahedrons in the ring. Twelve-ring zeolites contain rings formed from twelve tetrahedra. Eight-ring zeolites contain rings formed from eight tetrahedra. The zeolites of this invention contain interconnected twelve-ring and eight-ring channels. Examples of zeolites suitable for use in this invention are mordenites, offset, and gmelinites. Mordenite-like zeolites, for example, ECR-1, which is described in US Pat. No. 4,657,748, and mordenite aggregates with other zeolites are also suitable for the catalyst, as are zeolites having twelve-ring channels, for example, L, ZSH-12, Beta and other zeolites. A preferred catalyst is an acid mordenite zeolite.

 The catalyst used in this invention is made using a process that involves contacting a strong acid with an acid mordenite zeolite having a molar silica / alumina ratio of less than 30 1 and a crystalline structure that is determined by x-ray diffraction as having a symmetry index (S1) of from 0.6 to 1.0 under conditions suitable for removing an amount of alumina sufficient to provide a molar ratio of silica / alumina equal to in cr yney least 30 January.

 The composition of the catalyst, even if mordenite zeolite itself can be used for the purposes of the present invention, in practice mainly includes mordenite in the composition of the catalyst, including zeolite and a binder of inert silicon oxide.

 The weight ratio of mordenite binder is 1/3. The composition of the catalyst is made in the form of extruded materials having high compressive strength and improved porosity. High compressive strength is required to work in this way in the form of a fixed bed. High porosity in the composition is necessary to accelerate mass transfer to / from the active zones of the catalyst. An inert binder is necessary to prevent side reactions and to control catalyst deactivation through reactions with active zones in the binder.

, размеры восьмикольцовых пор составляют

Структура и свойства морденитового цеолита описаны в Zeolite Molecular Sieves Donald W. Breck (John Wiley Sons, 1974) на страницах 122 124 и 162 163.Mordenite is an aluminosilicate, a typical unit cell of which is described by the formula Na ₈ [(AlO ₂ ) ₈ (SiO ₂ ) ₄₀ • 24H ₂ O] Mordenite is the most saturated silicon natural zeolite with a molar ratio of silicon / aluminum (Si / Al) equal to 5/1. The dimensions of the twelve-ring pores are

, the size of the eight-ring pores is

The structure and properties of mordenite zeolite are described in Zeolite Molecular Sieves Donald W. Breck (John Wiley Sons, 1974) on pages 122 124 and 162 163.

The catalyst of this invention is prepared from mordenite zeolite, typically containing alkali or alkaline earth metal cations or aluminum ions. Preferably, the catalyst of the invention is made from sodium mordenite zeolite, and most preferably from sodium mordenite zeolite having a symmetry index less than 1.0. The symmetry index is a dimensionless quantity obtained from the X-ray diffraction pattern obtained for the hydrated form of sodium mordenite. To obtain x-ray data, a standard technique is used. The radiation of the Ka ₁ line _of copper and a Philips Electronics spectrometer are used. Mordenite zeolites give an X-ray diffraction pattern, the diffraction peaks of which have d distances corresponding to the distances for mordenite crystals described by JD Shermeen and JM Bennett, "Framework Inductures Related to the Zeolite Tordenok", Molecular Sieves, JW Weier and JW Uytterhoeven, ensistry Evances in Chevrolet , 121, 1973, pp 52 65. The symmetry index is defined as the sum of the heights of the peaks of reflexes [III] (13.45, 2 0) and [241] (23.17, 2 0). Preferably, the symmetry index of sodium mordenite is in the range of 0.5 to 1.0. More preferably, the symmetry index of sodium mordenite is in the range of 0.60 to 1.0.

. Предпочтительно размер кристалла находится в интервале

. более предпочтительно

. В общем кристаллы могут образовывать агрегаты, которые можно использовать в таком виде или связанные с большие частицы для способа этого изобретения. Например, выдавленный материал может быть использован для изготовления уплотненного слоя реактора путем сжатия агрегатов в неимеющие связующего частицы подходящего размера. С другой стороны выдавленный материал может быть изготовлен путем использования связующих, хорошо известных в этой промышленности. Предпочтительный размер частиц находится в интервале от 1 микрометра (ρм) до 20 микрометров (μм).Four ordered crystalline structures are assumed to be possible for natural and synthetic mordenite zeolites from an analysis of X-ray diffraction data (JD Sherman and JM Bennett, cited reference, p. 53). The symmetries of these four figures are Cmcm, Cmmm. 1 mcm and 1mmm, as defined by NFM Henry and K. Jonsdale, International Tables of X-ray Crystallograpzy, 3ed. Ed Volume 1, Kynch Press (1969). X-ray diffraction data show that mordenites are either physical mixtures or seedlings of the Cmmm, Imcm and mmm structures with the Cmcm structure. Thus, mordenites can be generally described as having a crystalline structure representing a Cmcm symmetry matrix, having the Cmcm, Imcm or Immm symmetry domains defined therein, or mixtures thereof. Preferably, the mordenite of this invention has a crystalline structure, which is a Cmcm symmetry matrix, having Cmmm symmetry domains distributed therein. Symmetry Index refers to the symmetries of crystals present in a mordenite sample. A symmetry index in the range of 0.60 to 1.0 provides optimal sodium mordenite as the starting material for the process of this invention. The crystal size of primary sodium mordenite can be any that makes the catalyst effective for producing cumene having a low bromine number and low levels of impurities. Typically, the crystal size may be in the range

. Preferably, the crystal size is in the range

. more preferably

. In general, crystals can form aggregates that can be used in this form or associated with large particles for the method of this invention. For example, extruded material can be used to make a packed reactor bed by compressing aggregates into non-sized binder particles of a suitable size. On the other hand, extruded material can be made using binders well known in the industry. The preferred particle size is in the range from 1 micrometer (ρm) to 20 micrometers (μm).

 The primary sodium mordenite zeolite described above or its equivalent is processed to produce a catalyst of the invention for use in an alkylation process. Treatment involves contacting mordenite with an acid. In one preferred embodiment, the treatment comprises contacting mordenite with an acid, calcining the treated mordenite with a strong acid. In another preferred embodiment, the catalyst is prepared without calcination.

 The initial acid treatment removes most of the sodium ions or their equivalents from primary mordenite. Processing may also remove part of the aluminum ions. Organic acids and inorganic acids, which give hydrogen ions for acid treatment, have a suitable composition. Examples of such acids are hydrochloric acid, hydrobromic acid, sulfuric acid, phosphoric acid, nitric acid, acetic acid, oxalic acid and the like. Inorganic acids are the preferred source of hydrogen ions, hydrochloric, nitric and phosphoric acids are more preferred and hydrochloric acid is most preferred. Another suitable primary treatment includes ion exchange with ammonium salts, for example with ammonium chloride. In this method, sodium ions or their equivalents are removed, but aluminum ions are not replaced. When heated, ammonium substituted mordenite removes ammonia and mordenite turns into an acid form.

Usually, during the initial acid treatment, the primary sodium mordenite forms a suspension with an aqueous acid solution. The acid solution may have any concentration that provides a catalyst having the properties and activity of the catalyst of this invention, described hereinafter. Preferably, the concentration of the aqueous acid solution is in the range of 0.01H to 6H; more preferably in the range of 0.5H to 3.0H. The relative amounts of an aqueous acid solution to the solid mordenite used may vary. Typically, the ratio is less than 15 cm ^{3 of} an acid solution per gram of solid mordenite. Preferably, the ratio is in the range from 5 cm ^{3 of} an acid solution per gram of solid mordenite to 10 cm ^{3 of} an acid solution per gram of solid mordenite. The temperature and duration of contact of mordenite with an acid solution may also vary. Preferably, the mordenite is contacted with the acid at a temperature of from 10 to 100 ^° C. Typically, the contact time between the acid solution and mordenite can vary from 5 minutes to several hours. It is important that there is enough time to contact the acid solution with all particles of mordenite. Preferably, the contact time is from 5 minutes to 60 minutes. The removal of acid, as described here, can be repeated if necessary. After that, mordenite is washed with water one or more times in order to wash soluble substances from mordenite. Preferably, washing with water is carried out at ambient temperature. It is possible after washing with water to subject mordenite to air drying at a temperature in the range from 20 to 150 ^o C.

In one embodiment, the treatment after exchange with acid and drying in air, the acid mordenite zeolite is calcined in air or heated in an inert atmosphere, for example, in hydrogen. It is believed that such heat treatment moves part of the aluminum from the zeolite lattice; however, such a theory should not be construed as limiting the scope of the invention. Typically, the calcination or heating temperature may be in the range of 250 to 950 ^° C. Preferably, the calcination or heating temperature is in the range of 300 to 800 ^° C. More preferably, the temperature is in the range of 400 to 750 ^° C. Most preferably, the temperature is from 500 to 700 ^o C.

After calcination, the acid-treated mordenite described above is subjected to further acid treatment to further dealumination. The second acid treatment is contacting the calcined mordenite with a strong acid under conditions sufficient to produce the acid mordenite catalyst of this invention. For the purposes of this invention, a “strong” acid is defined as an acid that reacts sufficiently fully with a solvent to form an acid conjugated with the solvent. For example, if gaseous hydrogen chloride is dissolved in water, then the acid / base reaction proceeds with the formation of the conjugate acid H ₃ O ⁺ and Cl ^- . Preferably, the strong acid is an inorganic acid. More preferably, the strong acid is nitric acid, hydrochloric acid or sulfuric acid. Most preferably, the strong acid is nitric acid. The concentration of strong acid will vary depending on the selected acid. In general, acid is used in the form of an aqueous solution of any concentration that provides for the extraction of aluminum from calcined acid mordenite, as described hereinafter. For example, for nitric acid, the concentration of acid in an aqueous solution is preferably in the range of 2H to 15H. An acid concentration in the range of 4H to 12H is more preferred. The most preferred acid concentration is in the range of 6H to 8H. An aqueous solution of acid and calcined mordenite are contacted in the ratio that the catalyst of the invention provides. Preferably, the ratio of the aqueous acid to mordenite solution is in the range from 3 cm ³ of the acid solution per gram of mordenite to 10 cm ³ of the acid solution per gram of mordenite. More preferably, the ratio is 5 cm ^{3 of} an acid solution per gram of mordenite. The temperature and contact time may vary depending on the selected acid. Preferably, mordenite is contacted with an acid solution at a temperature in the range from an ambient temperature of 22 ^° C. to 220 ^° C. More preferably, mordenite and acid are contacted at a temperature that allows an aqueous acid solution to boil under atmospheric conditions. Preferably, the contact time is from 1 hour to 6 hours, more preferably from 1 hour to 3 hours, most preferably 2 hours. After completion of contacting with strong acid, mordenite is filtered and re-washed with water until the wastewater is free of acid. Preferably, the washed mordenite is subjected to heat treatment and contact with a strong acid more than once. Finally, the washed acid mordenite zeolite is dried for several hours at a temperature in the range of 100 to 150 ^° C. to remove physically adsorbed water. Dried acid mordenite is activated, heated for 2 hours at a temperature in the range from 300 to 700 ^o C. This activation can remove more strongly bound water and residual absorbed substances.

 In another preferred embodiment, primary sodium mordenite is treated with a strong acid without an intermediate calcination step. The catalysts used in the method of this invention may also contain a binder. For this purpose, binders known for use with a mordenite zeolite catalyst are used. Non-limiting examples of binders are preferred, including alumina and silica with silica.

 After treating primary sodium mordenite with an acid, optionally calcining and re-treating with strong acid in accordance with the method of this invention, obtaining an acid mordenite catalyst that can convert high conversion benzene to cumene having a low bromine number and low levels of impurities. This catalyst has particular characteristics by which it can be identified, especially the molar ratio silica / alumina and the symmetry index and porosity, as defined hereinafter.

 An additional characteristic of the catalyst is its minimal deactivation during the alkylation of benzene or substituted benzenes. In the method of the present invention, the catalyst remains active for a long period of time. By retention of activity is meant that the catalyst retains at least 60, more preferably 75 and most preferably 90 percent of its activity for at least 500 hours of use, more preferably for at least 750 hours of use and most preferably at least 900 hours use. The catalyst preferably remains active for significantly longer than 900 hours of use.

In the alkylation reaction of the present invention, a catalyst that detects any deactivation can be regenerated by a stream of benzene at a temperature of 250 ^o C.

As a result of acid extraction, the molar ratio of silica / alumina (SiO ₂ / Al ₂ O ₃ ) of the acid mordenite catalyst rises above the ratio of the initial sodium mordenite. The acid-treated mordenite catalyst has a silica / alumina molar ratio of at least 30: 1. Preferably, the silica / alumina molar ratio is in the range of 40: 1 to 300: 1.

(1 нм). Подобным образом мезопоры определяются как имеющие радиус в интервале от

(1 нм) до

(19 нм), тогда как макропоры определяются имеющими радиус от

(10 нм) до

(100 нм). После кальцинирования и обработки сильной кислотой кислотный морденитовый катализатор этого изобретения имеет микро-, мезо- и макропоры. Пористость катализатора может характеризоваться общим объемом пор, определяемым как сумма объемов микро-, мезо- и макропор на грамм катализатора.As an additional result of acid removal and optional calcination, the symmetry index of the mordenite catalyst is increased compared to the original mordenite. The symmetry index is determined as described above. Although the symmetry index is found from x-ray data, the index determines the ratio of the symmetries Cmem and Cmmm, Imcm or Immn available in the catalyst. An increase in the symmetry index indicates the enrichment of the catalyst component Cmcm. For alkylations, the symmetry index in the catalysts of at least 1 demonstrates the minimum deactivation that is possible when high benzene alkylation performance is achieved. Preferably, the symmetry index is in the range from 1 to 2. A third property of the acid mordenite catalyst by which it is identified is porosity. All zeolites have pores that are formed as a natural consequence of the growth of a zeolite crystal. New pores or changes in existing pores can occur during the processing of zeolites, for example, using heat or acid as in the method of this invention. Typically, pores are divided into micropores, mesopores and macropores. For the purposes of this invention, micropores are defined as having a radius of 3A (0.3 nm) to

(1 nm). Similarly, mesopores are defined as having a radius in the range of

(1 nm) to

(19 nm), while macropores are determined to have a radius of

(10 nm) to

(100 nm). After calcination and treatment with strong acid, the acid mordenite catalyst of this invention has micro-, meso- and macropores. The porosity of the catalyst can be characterized by the total pore volume, defined as the sum of the volumes of micro-, meso- and macropores per gram of catalyst.

The catalyst of this invention has a total pore volume sufficient to provide a high yield of the required alkylated benzene with low levels of impurities. Preferably, the total weight of the pore volume is in the range of 0.18 cm ³ / g to 0.45 cm ³ / g. Porosity can be additionally estimated by the relative distribution of meso- and macropores, which can be expressed in the ratio of the combined volume of meso- and macropores to the total pore volume. The catalyst of this invention has a combined meso and macropore volume ratio to total pore volume sufficient to provide a high yield of the desired alkylated aromatic compounds with low levels of impurities. Preferably, the ratio of the combined volume of the meso- and macropores to the total pore volume is in the range of 0.25 to 0.75.

(100 нм). Как говорилось ранее, для целей этого изобретения поры с радиусом

(1 нм) или менее называют микропорами. Поры с радиусом от

(1 нм) до

(10 нм) называются мезопорами и поры с радиусом от

(10 нм) до

(100 нм) называются макропорами. Поры с радиусом в интервале от

(1 нм) до

(100 нм) известны в литературе как "переменные поры". Объем микропор (Vm) получают при помощи t-способа. Различие между общим объемом микропор представляет собой объем переменных пор (V_t=V_т-V_m. Общее распределение пор в интервале переменных пор используют для расчета относительных объемных вкладов мезопор и макропор. Например, объем мезопор рассчитывают, умножая объем переменных пор на долю общего объема пор от

(1 нм) до

(10 нм), (V_me=V_tfme). Тогда объем макропор получают просто вычитанием объема мезопор из переменного объема (_ma=V_t-V_me). Такой метод дает гарантию, что уравнение V_t= V_m+V_me+V_ma - справедливо. Изотермы адсорбции, полученные для морденитовых катализаторов этого изображения, представляют собой тип. 1, который описывается уравнением Лангмюра. Из этого уравнения получается область поверхности Лангмюра. Способы, используемые для получения областей поверхности и объемов пор, описаны S.Lowell Sntroduction to Power Sorfase Area (John Wiley Json's 1979) или в руководствах к оборудованию Digisorb-6, изготовленному Quantachrome Corporation.The porosity measurement described above is carried out taking into account measurements of the surface area and pore volume of mordenite powders obtained using any suitable instruments, for example Quantachrome Didisorb-6, using nitrogen as an adsorbed substance, at a boiling point of nitrogen of 77 K (-196 ^o C). The total pore volume (Vt) is determined by the amount of nitrogen adsorbed at a relative pressure close to unity. It is accepted that pores with a radius of less than

(100 nm). As mentioned earlier, for the purposes of this invention, pores with a radius

(1 nm) or less are called micropores. Pores with a radius of

(1 nm) to

(10 nm) are called mesopores and pores with a radius of

(10 nm) to

(100 nm) are called macropores. Pores with a radius in the range of

(1 nm) to

(100 nm) are known in the literature as "variable pores." Micropore volume (Vm) is obtained using the t-method. The difference between the total micropore volume is the volume of variable pores (V _t = V _t -V _m . The total pore distribution in the interval of variable pores is used to calculate the relative volume contributions of mesopores and macropores. For example, the volume of mesopores is calculated by multiplying the volume of variable pores by the fraction of the total pore volume from

(1 nm) to

(10 nm), (V _me = V _tfme ). Then the volume of macropores is obtained simply by subtracting the volume of mesopores from a variable volume ( _ma = V _t -V _me ). This method ensures that the equation V _t = V _m + V _me + V _ma - is valid. Adsorption isotherms obtained for mordenite catalysts of this image are of type. 1, which is described by the Langmuir equation. From this equation we obtain the region of the Langmuir surface. Methods used to obtain surface areas and pore volumes are described by S. Lowell Sntroduction to Power Sorfase Area (John Wiley Json's 1979) or in the Digisorb-6 equipment manuals manufactured by Quantachrome Corporation.

The acid mordenite catalyst identified here above is capable of adsorbing diphenyl into a system of intracrystalline pores, and vice versa, desorbing diphenyl. The adsorption of diphenyl is carried out by holding acid mordenite in diphenyl vapor at 100 ^o C for a time sufficient to obtain an almost constant weight. Preferably, the adsorption capacity of acid mordenite to diphenyl is 5 weight percent. More preferably, this ability is 10 weight percent. Diphenyl desorption is carried out by heating the mordenite of the diphenyl sample in a dynamic helium atmosphere from 285 to 1000 ^o C with a heating rate of 10 ^o C / min. Biphenyl desorption can be investigated using thermal gravimetric analysis in combination with gas phase chromatography and mass spectrometry (TgA-gC-MS). It was found that weakly adsorbed diphenyl exhibits a weight loss at a temperature below 300 ^o C; whereas strongly adsorbed diphenyl shows a weight loss at temperatures from 300 up to 1000 ^° C. The amount of strongly adsorbed diphenyl is estimated by subtracting the amount of weakly adsorbed diphenyl from the total amount of diphenyl adsorbed by the sample. The fully processed mordenite catalyst of this invention shows a sharp weight loss at temperatures below 300 ^° C. and little or no weight loss from 300 to 1000 ^° C. In contrast, acid-substituted mordenite shows a sharp weight loss at temperatures below 300 ^° C. and a second weight loss starting at 300 ^o C and lasting up to 1000 ^{o C. It is} obvious that weakly adsorbed diphenyl is located in places from which it is relatively easy to get out, while strongly adsorbed diphenyl is located in places from which It is relatively difficult to get out. Thus, the acid mordenite catalyst of this invention readily provides access and yield of adsorbed diphenyl. However, this theory should not be aimed at linking or limiting the scope of the invention.

 The ratio of benzene or substituted benzene to catalyst may be any weight ratio that produces the desired alkyl benzene with relatively high selectivity and low levels of impurities. Preferred ratios will also depend on the configuration of the reactor. For example, in a bath type reactor, the weight ratio of benzene or substituted benzene to catalyst is preferably in the range from 0.1: 1 to 2000: 1. More preferably, the weight ratio in the range from 10: 1 to 500: 1. Most preferably, the ratio is in the range from 50: 1 to 100: 1. Below the preferred lower limit of 0.1: 1, productivity will be very low. Above the preferred upper limit of 2000: 1, the conversion of the aromatic compound may be low.

 The ratio of benzene or substituted benzene to alkylating agent may vary depending on the type of alkylating agent, type of reaction, for example, batch or continuous, and reaction conditions, for example, temperature, pressure, weight hourly space velocity (WHSV). When the alkylating agent is propylene, the ratio of benzene to propylene in the continuous reactor is preferably from 10: 1 to 3: 1. The preferred ratio may be lower in the reactor type with the supply of propylene as it is consumed. When diisopropylene benzene is used in the transalkylation reaction, the ratio of benzene to diisopropylene benzene is also preferably from 10: 1 to 3: 1. When the alkylation and transalkylation reactions occur simultaneously, the ratios of benzene to propylene and diisopropylene benzene are 10: 1. In detail, when the alkylating agent is ethylene, the ratio of benzene to ethylene in the continuous reactor is preferably from 10: 1 to 3: 1. As is known to those skilled in the art, when using reactors of various configurations, different ratios of reactants may be preferred.

 The alkylating agent can be reacted all at once, for example in the case of a liquid alkylating agent. Alternatively, the alkylating agent may be reacted as it is consumed until the desired conversion is achieved, for example, in the case of a gaseous alkylating agent, which is fed continuously to the reactor.

 When the alkylating / transalkylating agents are a mixture, for example a mixture including both propylene and diisopropyl benzene, the components can be added independently of each other.

 The contacting of benzene or substituted benzene with an alkylating agent in the presence of a catalyst can be carried out in a reactor of any configuration. Reactors of the bath type or continuous, for example, with a fixed bed, a slurry bed, a fluidized bed, catalytic distillation or counterflow reactors, are suitably configured for contact. Preferably, the reactor should be equipped with a device for monitoring and controlling the reaction temperature, a device for monitoring and measuring the reaction pressure, and optionally a device for mixing the reacting substances. Benzene or substituted benzene may be in molten, liquid form or in the form of a solution. The alkylating agent can be introduced in a liquid or gaseous state and can be added all at once at the beginning of the reaction or introduced continuously as it is consumed during the reaction. The catalyst can be used in various forms, for example, in the form of a fixed bed, a moving bed, a fluidized bed, in the form of a suspension in a liquid reaction mixture or in a reaction distillation column.

Contacting of the reacting substances in the presence of a catalyst can be carried out at any temperature and pressure at which alkylated products are formed having a low content of impurities. In the production of cumene, the temperature is preferably in the range from 100 to 250 ^° C., more preferably from 130 to 200 ^° C. In the production of ethylbenzene, the temperature is preferably in the range from 100 to 250 ^° C., more preferably from 180 to 250 ^° C. Below the lower limit 100 ^o C the reaction proceeds slowly. Above the preferred upper limit of 250 ^° C., the level of impurities rises.

 The pressure in the reactor for the bath type reactions is preferably in the range from 10 psig (170 kPa) to 200 psig (1478 kPa). More preferably, a pressure in the range of 10 psig (170 kPa) to 1000 psig (790 kPa). Below preferably a lower limit of 10 psig (170 kPa), the alkylation rate is very low. Above the preferred upper limit of 200 psig (1478 kPa), the preferred propylene alkylating agent will be difficult to polymerize. Reactions of a different configuration will have other preferred conditions.

Benzene, an alkylating agent and / or a transalkylating agent must be contacted for a time sufficient to convert benzene to alkylated products and sufficient to produce the required amount of cumene. In general, the contact time will depend on other reaction conditions, such as temperature, pressure, and reagent / catalyst ratios. In the production of cumene in a typical bath type reactor with a stirrer with a benzene-catalyst ratio of 50 1 at 150 ^° C, a propylene pressure of 100 psig (790 kPa) and a stirring speed of 2000 rpm, for example, the reaction time is preferably in the range of 0, 1 to 10 hours. More preferably, the reaction time is in the range of 1 to 4 hours.

 After alkylation / transalkylation of benzene or substituted benzene, the product mixture can be separated using standard techniques. For the purposes of this invention, the term "conversion" refers to the molar percentage of benzene or substituted benzene, which reacts to form an alkylated product. Typically, in a bath type reaction to produce cumene from benzene and propylene, the conversion achieved in the practice of this invention is in the range of 10 to 40 molar percent. When converting below 10 percent, cumene recovery is not practical, since a large amount of benzene is supplied for reprocessing. With a conversion of over 40 percent, the amount of by-products, for example diisopropyl benzene, becomes large, necessitating a large transalkylation step. In the same way, the term “benzene selectivity” refers to the molar percentage of the reacted benzene, which is converted into the desired product, for example, cumene or ethylbenzene. Smaller amounts of various by-products are also formed, for example, the o-, p- and m-isomers of diisopropyl benzene and other alkylated benzenes, for example, n-propylbenzene, butylbenzenes and xylenes. Typically, the benzene selectivity for cumene or ethylbenzene is in the range of 70 to 95 molar percent.

 Another measurement of selectivity is “propylene selectivity” or “ethylene selectivity”, which refers to the molar percent of propylene or ethylene, which are converted to cumene or ethylbenzene, respectively. Preferably, the propylene selectivity or ethylene selectivity is at least 55 molar percent to 90 molar percent.

 The concept of simultaneously a high degree of conversion and high selectivity in relation to the desired product can be conveniently expressed in terms of productivity. For these purposes of the present invention, the term "productivity" refers to the product of conversion numbers and selectivity. For example, the cumene production method of the present invention, giving 15% benzene conversion and 85% cumene selectivity, will have a cumene productivity of 12.75 percent, which is a product of 15 percent and 85 percent. Typically, the productivity of cumene or ethylbenzene achieved by the method of the invention without considering any reprocessing or reaction is at least 10 molar percent.

 An additional important factor is the presence of various impurities in the product. Even very small amounts of certain impurities, for example, n-propyl benzene or propylene oligomers in the case of cumene or xylene in the case of benzene, cause significant problems for various uses. Processes carried out under various conditions result in different levels of impurities. Thus, a particular advantage of the method of the present invention is low levels of impurities. In the case of cumene production, low levels of oligomers are also important, which is indicated by a low bromine number. In the production of cumene, the bromine number is preferably not more than 100, more preferably not higher than 50, and most preferably not more than 20. The cumene obtained by the method of this invention contains less than 1000 ppm impurities, more preferably less than 200 ppm (ppm) ) The ethylbenzene obtained by the process of this invention has xylene impurities of less than 1000 ppm (ppm), more preferably less than 500 ppm (ppm).

 An additional characteristic of the cumene obtained by the method of this invention is the amount of paint in the product. Cumene obtained in accordance with the practice of this invention is essentially colorless.

 The following examples are provided to illustrate the catalyst and method of this invention and are not intended to limit its scope. All percentages in the examples are molar percentages, unless otherwise indicated.

 To compare the catalysts in the processes of alkylation or transalkylation of benzene obtained in accordance with the invention, with catalysts obtained in accordance with US Pat. US N 3763260, conducted comparative experiments.

1. Obtaining catalysts
1.1 Catalysts in accordance with the invention.

Sodium mordenite (TOSOH TSZ-620; 200 g), having a molar ratio of SiO ₂ / Al ₂ O _{3 of} 14.9 and a symmetry index of 0.61, was added to 2 L of 6 M hydrochloric acid. The resulting mixture was stirred at room temperature for 30 minutes and then filtered. The filter cake was washed three times by dispersing it in 2 L of deionized water, stirring for 30 minutes at room temperature and filtering between washes. The washed filtered precipitate was then calcined by placing the sample in a furnace preheated at 400 ^° C and keeping it at this temperature for 2 hours.

The calcined mordenite sample obtained in accordance with the method described above was cooled and added to 2 L of 6 M nitric acid. The mixture was boiled at atmospheric pressure for 2 hours. After boiling, the mixture was cooled and filtered. The filtered precipitate was washed three times for 30 minutes using 2 L of deionized water each time. After a third washing and filtering, the filtered precipitate was dried at 100 ^° C. overnight and calcined a second time at 700 ^° C. for two hours to obtain the acid mordenite catalyst of the invention, which was designated “3DDM-1/620/400 ^° C”. The molar ratio of SiO ₂ / Al ₂ O ₃ and the symmetry index, the total pore volume and the established pore volume of the prepared catalyst are presented in table 1.

Acid mordenite catalyst "Dow 3 DDM-1/620/500 ^o C" illustrating the claimed invention, obtained by the method described above, except that the temperature of the first calcination was 500 ^o C and not 400 ^{o The} properties of the catalyst are presented in the table 1.

The acid mordenite catalyst "Dow 3DDM-2/620/700 ^o C" illustrating the claimed invention was obtained by the method described above, except that the temperature of the first calcination was 700 ^o C, not 400 ^o C and with one more exception consisting in the fact that boiling with strong acid and the first calcination at 700 ^o C was repeated once. The properties of the catalyst are presented in table 1.

 1.2 The catalyst in accordance with US Pat. U.S. Pat. No. 3,763,260.

Acid mordenite catalyst was obtained in accordance with the method of US Pat. USA N 3763260. Mordenite was designated according to the starting mordenite used as "620 / Pollizr / 700 ^o C. In Example 1 of US Pat. No. 3763260, the starting mordenite is sodium mordenite with a silica / alumina molar ratio of 17. Therefore, for this comparative As an example, the closest commercially available mordenite was selected with a silica / alumina molar ratio of 14.7 and was designated TOSOH-620. Sodium mordenite was converted to acid mordenite by the acid treatment described above.

The above industrial mordenite was treated with acid according to the method of example 2 US Pat. USA N 3,763,260. Accordingly, mordenite (100 g, TOSOH-620) was subjected to acid extraction with 1 L of 12 M hydrochloric acid under reflux for 12 hours at normal pressure. The acid-extracted solid was filtered off. Then, to remove chloride, the filtered product was washed three times by dispersing it at room temperature in 1 L of deionized water for 30 min and filtering between washes. The washed material was dried at 100 ^° C and calcined at 700 ^° C to obtain a comparative acidic mordenite catalyst designated "620 / Pollizer / 700 ^° C, the properties of which are also presented in Table 1.

 2. Alkylation of benzene with ethylene to ethylbenzene.

Used the installation of two reactors, in which the catalyst layer was separated and placed in two separate reactors connected in a cascade. All benzene was charged into the first reactor, while half of the ethylene was added to the first reactor, and the second half to the second reactor. The experimental conditions were as follows:
Temperature 200 ^o C
Hourly space-weight velocity (ChOVS) 2 h ^-1
Pressure 50 bar
Total epsilon (moles of ethylene / moles of benzene) 0.36
In all experiments, the total amount of loaded catalyst was 30 g (15 g / reactor). In the experiment with the catalyst "620 / Pollitzer / 700 ^o C" after the observed some deactivation of the catalyst, the temperature was raised to 220 ^o and the pressure to 52 bar (to maintain the liquid phase). Ethylene conversions and relative concentrations of ethylbenzene in the products are presented in table 2. The increase in the concentration of ethylbenzene in the case of the catalyst "620 / Pollitzer / 700 ^o C" after 45 hours of experience was achieved by increasing the temperature to 22 ^o
3. Transalkylation of benzene with diethylbenzene to ethylbenzene.

Catalyst samples were loaded into a conventional closed loop reactor with one catalyst bed. In each experiment, 6.7 g of catalyst was used. Benzene and diethylbenzene were mixed and the mixture was fed to the catalyst bed. The mixture benzene / diethylbenzene contained 37 wt. diethylbenzene. Experiment Conditions:
Temperature 240 ^o C
Hourly space-weight velocity (CHOVS) 1 h ^-1
Sufficient pressure to maintain the liquid phase
Total epsilon (moles of ethylene in diethylbenzene / moles of benzene) 0.521
The results of each experiment are presented in table 3. Digital points indicate the molar percentage of the starting diethylbenzene converted to ethylbenzene. The first point presented from this data was taken after 20 hours of flow. It is known that when transalkylation is carried out with an epsilon value of more than 0.5, the catalyst deactivates faster. Therefore, the data presented in table 3 relate to a process with faster decontamination than can be observed in industrial operations, where the epsilon value is less than 0.5.

 4. Discussion of the results.

From table 2 it is seen that in the alkylation reaction, the catalyst obtained in accordance with the invention, compared with the catalyst obtained in accordance with US Pat. US N 3763260, gives the following results:
significantly higher ethylene conversion;
a significantly higher percentage of ethylbenzene in the reaction product; and
a significantly smaller decrease in activity during the reaction.

Similarly, from table 3 it can be seen that in the transalkylation reaction, the catalyst obtained according to the invention, compared with the catalyst according to US Pat. US N 3763260, gives the following results:
significantly higher diethylenebenzene conversion rate; and
a significantly smaller decrease in activity during the reaction.

Claims (8)

1. A method of producing ethylbenzene or cumene by reacting benzene with an alkylating agent selected from the group consisting of ethylene, diethylbenzene or a mixture thereof, propylene, diisopropylbenzene or a mixture thereof at a temperature of 100 - 250 ^o C and a molar ratio of benzene alkylating agent (3 10) 1 in the presence of an acid mordenite catalyst having a molar ratio of silica of alumina of more than 30 1, obtained using an acid treatment, characterized in that an acid mordenite catalyst having a determination of a crystalline structure separated by X-ray diffraction having a symmetry index of more than 1 and operating under a reaction condition of at least 500 hours without deactivation, obtained by calcining a starting acid mordenite having a molar ratio of silica of alumina of less than 30 1, and a symmetry index 0.5 1.0 at a temperature of 250 950 ^o C, contacting the calcined mordenite with an aqueous solution of a strong acid under conditions allowing obtaining an acidic mordenite having a molar e ratio of aluminum oxide, silicon oxide is more than 30 1, and a symmetry index of more than 1, optionally followed by calcination steps and repeating the contacting with an aqueous solution of a strong acid.  2. A method according to claim 1, characterized in that ethylene or propylene is used as the alkylating agent.  3. The method according to p. 1, characterized in that they use a catalyst having a molar ratio of silica: alumina (40,300) 1.  4. The method according to claim 1, characterized in that the benzene is subjected to transalkylation with diethylbenzene or diisopropylbenzene.  5. The method according to p. 1, characterized in that they use the original acid mordenite catalyst obtained by treating the sodium form of mordenite with an acid having a concentration in the range of 0.5 N 3.0 N.  6. The method according to p. 1, characterized in that they use an acid mordenite catalyst containing silicon oxide as an inert binder. 7. The method of producing cumene according to claim 1, characterized in that the benzene is subjected to alkylation and / or transalkylation by reacting it with propylene and / or diisopropylbenzene at a temperature of 130,200 ^° C and a molar ratio of benzene to propylene and / or diisopropylbenzene (3 10) 1 and other conditions for obtaining unpainted cumene. 8. The method of producing ethylbenzene according to claim 1, characterized in that the benzene is subjected to alkylation and / or transalkylation by its interaction with ethylene and / or diethylbenzene at a temperature of 180-250 ^° C and a molar ratio of benzene ethylene and / or diethylbenzene (3 10) 1 and other conditions providing unpainted ethylbenzene.

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