CS212946B1 - Method of transalkylation of aromatic hydrocarbons - Google Patents

Description

BACKGROUND OF THE INVENTION The present invention relates to a transalkylene of aromatic hydrocarbons in a liquid or gas phase on a catalyst comprising aa zeolite component, a matrix and a contact component.

The main source of aromatic hydrocarbons is the catalytic referrovanie recently replaced by pyrolysis, in addition to coking coal, which contributes to total production! maximum 10%. The benzene: toluene: xylenes ratio is about 10:40:40 in the aromatic fractions for reforming, 10: 6: 2 for pyrolysis and 10: 1: 4: 0.5 for cocaine, suggesting that pyrolysis produces mainly benzene, while referring mainly to toluene and xylenes.

When comparing the production of individual boronates with the demand as raw materials for the production of synthetic yellow fibers, masses, resins and other petrochemicals, there is an excess of toluene produced and great demand for benzene and xylenes. Increased demand for benzene and is improved by utilizing excess toluene in the process of hydrodealkylating toluene to benzene, especially when pyrolysis is the predominant source of aromatics.

These drawbacks are overcome by the process according to the invention, which consists in a process for the transalkylation of aromatic hydrocarbons such as toluene, individually ^C 8 ^-C 9 aromatics or

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212 946, a mixture of toluene with aromatics Cg and higher, an aromatic cut at bv above 78 ° C, or a mixture of benzene with a frequency of polyalkylbenzenes, the essence of which is to treat benzene and xylenes with disproporolone and transalkylaryl. . the polyalkylbenzenes are processed to cumene and to the like; Ethylbenzene by passing in a hydrogen or hydrogen-containing gas environment at a temperature of 200 to 600 ° C, a pressure of 0.1 to 6.0 MPa, a spatial rate of 0.5 to 10 h ¹ and a ratio of H ₂ : hydrocarbon = 1 to 25! 1 mol / mol through a catalyst consisting of:

(a) from 10 to 90% by weight of the active acidic component consisting of synthetic aluminosilicate or a mixture of 1 to 95 parts synthetic and up to 100 parts supplemented with natural aluminosilicate, with a ratio of Sio ₂ : AlgO 4 = 4 to 100: 1 mol / mol, with an internal pore diameter of 0.3 to 1.2 nm and with an alkali metal content, expressed as light oxides of less than 5% by weight, and a sale of other metal cations Ib as well as

II.b, Vl.b, or VIII. groups;

b) from 10 to 90% of the matrix, which may consist of <, β, β-alumina, SiOg. Emorphous natural or synthetic alumosilicate, natural clays containing bentonite, kaolinite, halloyzlt either untreated or treated with solutions of mineral acids, bases of salts or organic reagents, at a concentration of 0,01 to 10 M at a temperature of 5 to 130 ° C for 0.5 to 240 hours;

c) from 0.01 to 30% by weight of at least one of the metals I.b, II.b, Vl.b, VHI. groups or lanthanides in the form of elemental metal, physiologists or sulphides.

The disproportionation of the alkyl aromatics takes place as a reverse reaction of two molecules of the alkyl aromatics to form two new aromatics and a different number of alkyl groups on the nucleus. E.g. breast monoalkylbenzene will react disproportionately:

wherein R-methyl, ethyl, propyl, etc.

Tranaalkylation of aromatic hydrocarbons proceeds as a reaction of two aromatic molecules with a diverse number of alkyls per meal (or even without alkyl), producing two molecules of novel aromatics, which may also be the same. For example, for the transelkylaol of trielkylbenzene with monoalkylbenzene (where alkyl is the same everywhere), the equations are:

R

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The modified zeolites offer the high concentration of catalytically active acid centers required for the course of these reactions, on a large surface that aa has regular pores of molecular dimensions.

The present invention resides in the possibility of toluene in the process of disproportioning toluene to benzene and xylenes, and in the toluene trisalkylation and trimethylbenzene to the main product - xylenes. In addition to the advantage that not only benzene but also valuable xylenes are produced from excess toluene, the process is characterized by the possibility of treating less commonly used or generally unused trimethylbenzenes and / or non-used trimethylbenzenes, respectively. the entire ^C 9+ aromatic fraction for xylenes. Similar is removed by ^C9 ₊ aromatics with benzene and transalkylovaí. The field of application of transalkylation catalysts is the utilization of polyalkylbenzene fractions from the production of cumene, respectively. ethylbenzene by alkylation. These polyalkylbenzenes can be trans-alkylated with benzene to cumene, respectively. ethylbenzene, thereby utilizing them to increase the production of the desired aromatics.

For example, from the disproportionation of pure toluene to benzene and xylenes, the addition of trimethylbenzenes to the feed can lead to transalkylation of toluene with trimethylbenzene to the main product - xylenes, and the feed of pure trimethylbenzenes will mainly be xylene and tetramethylbenzenes. Similarly, trans-alkylation of otyltoluenes and benzene to ethylbenzene and toluene, trimethylbenzenes β benzene to toluene and xylenes and the like can be similar. Also preferred is the use of polyalkylbenzene fractions from the production of cumene or ethylbenzene by alkylation. These polyalkylbenzenes can be transalkylated with benzene to ethylbenzene or cumene, utilizing the waste aromatic fractions to increase the production of the desired aromatics. This great flexibility in the possibilities of exchange of the feed components is one of the great advantages of transalkylation.

The process of transalkylating alkylaromates on zeolite catalysts is described in the following examples without the ropes being covered.

Example 1

100 weight diols of Na Y-type (NaY) type Y sacrifice were mixed with 1000 parts by weight of a 1 M aqueous ammonium nitrate solution and the mixture was refluxed with stirring for 3 hours at boiling point. After the zeolite had settled and the solution was aspirated, the zeolite was washed with distilled water and the ion exchange was repeated 9 more times. The resulting NH ₄ form of zeolite Y was washed with distilled water until neutral to NO ₃ and, after drying, was calcined at 450 ° C for three hours, predominating in the H-form. Composition and surface properties of NaY and HY eu in Table 1.

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Table 1

Composition (wt.%) h ₂ o Si0 ₂ ^A1 ° 2 At ₂ 0 CaO NaY 26.50 48.04 15.75 9.41 0.15 HY 28.86 53.50 16.96 9.34 0.11 about Surface m / g / 7. Volume of cm / g NaY 754 0.34 HY 783 0.39

Example 2

3Q of the weight parts of zeolite HY of Example no. 1 was mixed with 20 parts by weight of acid-treated bentonl and 50 parts by weight of alumina. The mixture was impregnated with an aqueous nickel nitrate solution such that the resulting catalyst contained 3% (w / w) Ni. After drying and calcining at 450 ° C for 3 hours, the catalyst was reduced directly in the reactor in a stream of hydrogen at 180 ml / min. at a pressure of 0.1 MPa and a temperature of 420 ° C for 2 hours. At a toluene disproportionate of about 0.01% halogen-hydrocarbons on the catalyst at 440 ° C, at a pressure of 2.5 MPa, at a reactor speed of 1 and mol. · toluene ratio = 10: 1, the liquid reaction products of the following composition (in mol%): 1% of light products, the products of unsaturated%, 13.0% benzene, 73.5% toluene, 8.6% _Cg aromatics, and 0, 8%

Cg aromatics.

Example 3 by weight parts of zeolite HY of Example no. 1 was mixed with 70 parts by weight of alumina, and the mixture was impregnated with an aqueous solution of HgPtClg so that the resulting catalyst contained 0.5% by weight. Pt. After drying and calcining at 450 ° C for 3 hours, the catalyst was reduced in the reactor for 2 hours under a stream of 180 ml / min hydrogen. at a temperature of 420 ° C, a pressure of 0.1 MPa. With disproportionation of m-xylene on this catalyst at a temperature of 450 ° C, a pressure of 1.6 MPa, a flow rate of 1 h ^-1 and molar. the ratio H ₂ : m-xylene = 10: 1 had the liquid reaction products as follows (in mol%): 0.9% light products, 1.9% saturated products, 0.4% benzene, 8.7% toluene, 1.7% ethylbenzene, 16.0% p-xylene, 43.8% m-xylene, 18.1% o-xylene, 0.5% ethyltoluenes, 7.2% trimethylbenzenes, and 0.8% aromatics.

EXAMPLE 4 by weight of zeolite HY of Example no. 1 e was mixed with about 70 parts by weight of alumina, and the mixture was impregnated with a palladium chloride solution such that the resulting catalyst contained 0.5% Pd by weight. After drying, the catalyst was calcined at 450 ° C

212 948 hours and reduced directly in the reactor for 2 hours under a stream of 180 ml / min of hydrogen. at a temperature of 420 ° C and a pressure of 0.1 MPa. At a temperature of 420 ° C, a pressure of 2.5 MPa, a space velocity of 1 h ^-1 and mol. ratio H ₂ : toluene = 10: 1 had the liquid reaction products as follows (in mol%): 4.1% light products, 1.9% saturated products, 18.7% benzene, 57.1% toluene, 4% aromatics, 2.3% aromatics and 0.3% aromatics.

Example 5

On the 0.5% Pd / 30% ΗΪ + 70% alumina catalyst prepared in Example 4, aa a transalkylation of a diisopropylbenzene (polyalkylbenzene fraction from the production of cumene by alkylation of benzene propylene) with benzene was performed. At a temperature of 340 ° C, a pressure of 2.4 MPa, a space velocity of 1 and a mol ratio of H ₂ : hydrocarbons = 10: 1, the composition of the liquid reaction products was as follows (in mol%):

readily apparent saturated benzene toluene raw material - - 57.0 - products __ 0.5 2.6 57.5 1.1

Οθ arom. cumene diisopropylbenzene more difficult raw material - 1.4 29.6 12.0 s products 0.5 19.3 6.0 3.0 " -

Example 6

100 parts by weight of synthetic mordente in Na-form (NaM) was mixed with * 1000 parts by weight. of aqueous 2N hydrochloric acid and refluxed at the boiling point of the mixture with stirring for 3 hours. After the zeolite had settled, the solution was aspirated, the zeolite was passed through distilled water and the dealumination with 2N NC1 solution was repeated 4 more times. The zeolite was then exchanged 5 times with an aqueous solution of 1 M ammonium nitrate in a similar manner. The resulting dealuminated mordenite in the NH4 form was washed with distilled water until neutral to NO3. After drying, it was calcined at 450 ° C for 3 hours to convert to the H-form (HM). The composition and surface properties of NaM and HM zeolites are given in the table below:

Composition (wt.%)

h ₂ o sieve ₂ ai ₂ o ₃ At ₂ 0 CaO U.S 13.06 89.24 10.52 5.25 0.28 HM 6.56 87.97 3.77 0.04 0.21

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SiOg / AlgO 4 mol / mol about surface m / g pore volume cnP / g U.S 11.19 364 0,137 HM 39.73 435 0,289

Example 7 The weight parts of HM prepared in Example 6 were mixed with 65 weights. parts - alumina and with 5 parts by weight of kaolinite. The mixture was impregnated with a palladium chloride solution such that the resulting catalyst contained 0.5% Pd by weight. After drying, the catalyst was calcined at 450 ° C for 3 hours, and reduced in a reactor with 180 ml / ml hydrogen gas. at a pressure of 0.1 MPa, a temperature of 420 ° C for two hours. On this catalyst, toluene was disproportionated at 400 ° C, 1.6 MPa, 2 M ^-1 and mol. ratio H ₂ : toluene = 10: 1 as follows the composition of the liquid reaction products (in mol%): 3.6% of light products, 1.0% of saturated products, 20.8% of benzene, 48.8% of toluene,

21.5% aromθ of aromatics, 4.2% Cg of arachnates and 0.2% C C- q of aromatics.

Example 8

A mixture of toluene and 1,2,4-trimethylbenzene was transalkylated on the catalyst prepared in Example 7. The composition of the liquid reaction products at a temperature of 400 ° C, a pressure of 1.6 MPa, a flow rate of 2 ti ^-1 and mol. ratio H ₂ : hydrocarbon = 10: 1 is given in the table:

readily apparent saturated benzene toluene raw material - - - 83.1 products 1.8 0.3 13.3 42.3.

Cg arom. Cg arom. θιο ^erom · raw material - 16.9 - products 32.4 9.1 0.8

Example 9 parts by weight of synthetic alumina in the H-form (HM) prepared according to Example 6 was mixed with 20 parts by weight of acid-activated natural mordenite and with 60 parts by weight of alumina. The mixture was impregnated with a palladium chloride solution such that the catalyst contained 0.5% Bd. After drying at 105 [deg.] C. and a calender at 450 [deg.] C., the catalyst was reduced with a flow of hydrogen at a flow rate of 180 ml / mln. at a pressure of 0.1 MPa and 420 ° C for 3 hours. At 400 ° C, a pressure of 2.5 MPa, a flow rate of 2.5 h ^-1 and a molar ratio of H ₂ : toluene = 10: 1, the composition of the liquid products of the reaction was as follows (wt%):

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0.12% light hydrocarbons; 0,1 saturated hydrocarbons; 18.7% benzene; 56.5% toluene;

20.4% C8 aromatics; 3.1% of _Cg aromatics; 0.1% C ₁₀ aromatics;

Example 10

The catalyst prepared in Example 9 was transalkylated with benzene with a C8 aromatic fraction. The composition of the raw material and the liquid reaction products of the transalkylation run at 400 pressures of 1.5 MPa and a space velocity of 1.5 h ^-1 and a molar ratio Hg ^: hydrocarbon in the table:

readily apparent saturated benzene toluene ethylbenzene xylene raw materials - ... 66.4 - - products 2.2 3.4 54.7 21.3 7.9 6.4

propylbenzene ethyltoluene trlmetylbenzén Aromatic raw materials 5.3 24.2 4.1 - products 0.1 3.1 0.5 0.4

OBJECT OF THE INVENTION

Claims (1)

OBJECT OF THE INVENTION A process for the transalkylation of aromatic hydrocarbons, which may be toluene, individually ^C 8 → 9 aromatics or mixtures thereof, a mixture of toluene with aromatics C 8 and above, an aromatic slice boiling above 78 ° C, a mixture of benzene with a polyalkylbenzene fraction are reacted in a hydrogen or hydrogen-containing gas environment at a temperature of 200 to 600 ° C, a pressure of 0.1 to 6.0 MPa, a space velocity of 0.5 to 10 h ^-1 and a Hg: fraction to be treated! = 1 to 25: 1 mol / mol through the catalyst that is composed (a) from 10 to 90% by weight of an acidic component consisting of a synthetic crystalline aluminosilicate or a mixture of 1 to 95 parts synthetic and up to 100 parts supplemented with natural aluminosilicate and a SiOg: ^A1 ratio of 2 ° 3 ^{9 4: 1 with an} internal pore diameter of 0 , 3 to 1.2 nm with an alkali metal content, expressed as oxides of up to 5% by weight, and below that of other cations Ib as well as II.b, VI.b, or VIII. groups (b) from 10 to 90% of the matrix, which may consist of?, 3'-alumina, SiOg, amorphous natural or synthetic aluminosilicate, naturally clay containing bentonite, kaolinite, halloyzite, untreated or 0.01 to 10 M solutions of mineral acids, bases, salts or organic reagents1 treated, one or more times, at a temperature of 5 to 130 ° C for 0,5 to 240 hours, (c) from 0.01 to 30% by weight of at least one of the metals I.b, II.b, VI.b, VIII. groups or lanthanum in the form of elemental metal, oxides or sulphides.