FI76005C - ALUMINUM-BOR-SILICATE CATALYST, FREQUENCY FOR FRAMSTAELLNING AV DENNA OCH ALKYLERINGSPROCESS. - Google Patents

Description

76005 1 Aluminum-borosilicate catalyst, process for its preparation and alkylation process

Aluminium-bor-siiikatkatalysator, förfarande för framställnlng av denna ocl alkylerlngsprocess 5

The invention relates to an aluminum-borosilicate catalyst in which the molar ratio of S104 / Al2O2 is between 10 and 150 and the molar ratio of AlO2 / Al2O2 is between 2 and 200 and a process for the preparation of the catalyst.

The invention also relates to a process for the alkylation of aromatic hydrocarbons using these catalysts.

The use of crystalline silicate compounds in the alkylation of aromatic hydrocarbons has long been known. For example, U.S. Patent 4,283,306 describes a crystalline silicate for methylating toluene to paraxylene.

Crystalline alkylation mixtures of aromatic hydrocarbons from aluminosilicate catalysts are also known in the art. U.S. Patent 2,904,697 relates to an alkylol process using a metal aluminum bridge bridge.

U.S. Pat. No. 3,251,897 describes x- and y-type aluminosilicates, and in particular those in which the cation is hydrogen or a rare earth metal. 11. Many other patents describe aluminosilicates which have high selectivity for the formation of parasubstituted aromatics, for example U.S. Patents 3,702,886. , 3,965,207, 4,100,217 and 4,117,024.

U.S. Patent 4,117,024 has modified crystalline aluminosilicates using solutions of sparingly reducing oxides such as antimony, phosphorus or boron.

Alkylolntl processes have been described in many patents. Alkylation in the vapor phase with high silicon aluminosilicate catalysts generally gives high conversion. The life of the silicate catalyst is quite long and in many cases the pressure required is low, which makes these processes economically attractive. Examples of vapor phase alkylation-35 are e.g. U.S. Patents 3,751,504 and 3,751,506.

The present invention relates to novel zeolite catalysts containing silicon, aluminum and boron in which the catalyst pores and channels are not blocked by atoms, molecules or ions, for example sulphate or chlorine ions. In this case, the movement of the reagents within the silicate is undisturbed, which produces a high degree of conversion in the alkylation process and a high selectivity.

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The aluminum-borosilicate catalyst according to the invention is characterized in that the catalyst is prepared by modifying the catalyst with boric acid, boron oxide or a mixture thereof.

The invention relates to a process for the preparation of aluminum-borosilicate catalysts which are particularly well suited for use in the alkylation of aromatic hydrocarbons, giving a high degree of conversion and / or high selectivity for the production of para-substituted hydrocarbons. The invention also relates to a process for the alkylation of aromatic hydrocarbons using these catalysts.

Thus, according to the invention, there is provided a process for the preparation of aluminum-borosilicate catalysts in which the molar ratio of SK 2 / Al 2 O 2 is between 10-150, preferably between 10-60 and the molar ratio Al 2 O 2 / B 2 O 2 between 2-200 , preferably between 19-200. The molecular formula of these catalysts can be limited as follows: 0.8-1.2 M 2 / n O: Al 2 O 3: 0.005-0.1: 10-150 SiO 2: x H 2 O 25 where M is at least one cation with a valence between n and x 0-60. The process is characterized in that a reaction mixture of an organic nitrogen-containing cation, one or more alkali metal oxides, aluminum, boron and silicon oxides and water is heated in a closed reaction space first at a higher temperature and then at a lower reaction temperature for a sufficiently long time. time to form a crystalline aluminum-borosilicate catalyst.

In the above formula, M is at least one cation having a valence of n.

M may also be a mixture of alkali metal cations, preferably sodium and potassium cations. The nitrogen-containing organic cation may be an ammonium cation such as tetraethyl, tetrapropyl or tetrabutylammonium cation. The nitrogen-containing organic cation may also be a pyrrolidine-derived cation.

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3 76005 1 In preparing the zeolite catalyst according to the invention, a reaction mixture containing a cation containing organic nitrogen, alkaloids, oxides of aluminum, boron and silicon and water is first heated in a reaction vessel. The pressure required in the reaction varies between 1 and 15 bar, depending on the conditions. The higher tempering temperature is selected between 165-220 ° C and preferably between 190-200 ° C. By using a higher annealing temperature, a homogeneous reaction mixture is obtained in a shorter time and the formation of crystals begins more rapidly. The heating time at the initial temperature is between 30 minutes and 6 hours. Heating is continued at a lower reaction temperature between 100-190 ° C, preferably between 130-170 ° C.

The heating time at a lower temperature is selected to be at least 8 hours and preferably between 1-6 days.

In the catalyst according to the invention, it is possible to exchange Kati ions for other cations using a known ion exchange technique. The preferred procedure is to exchange the alkali metal cation for a hydrogen ion, which increases the activity of the catalyst in the alkylation of the aromatics.

According to one embodiment of the invention, the catalyst obtained in the above manner can be further modified with boron-containing compounds to provide a catalyst which, in alkylation, produces parasubstituted aromatics in high yield. The modification can be carried out by mixing the catalyst prepared as described above and boric acid, boron oxide or a mixture thereof in a dry state. The mixture is then heated to 300-700 ° C, preferably 550-600 ° C with stirring. Heating time el not critical. When a catalyst thus modified is used, para-substituted aromatics are obtained in high yield by alkylation.

The catalysts according to the invention can, of course, be used either as such or in combination with conventional supports and binders.

The invention also relates to an alkylation process utilizing Al-B-Si catalysts prepared by the process of the invention. The process can alkylate various hydrocarbons such as benzenes, naphthalenes, anthracenes and substituted derivatives such as toluene and ethylbenzene.

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Numerous compounds having at least one reactive alkyl radical, such as ethylene, propylene, formaldehyde, alkyl halides and alcohols, can be used as the alkylating agent in the process of the invention.

5 The process conditions in the alkylation, such as temperature, pressure and flow rate, are generally critical depending on the starting materials and are described in more detail below.

The alkylation process according to the invention is carried out in the vapor phase. As the reactor, either a fluidized bed reactor or a fixed bed reactor is used. The aluminum-borosilicate used as a catalyst is in the hydrogen form. Depending on the type of reactor, the amount of catalyst, the particle size of the catalyst and other factors, the reactor pressure can vary from atmospheric pressure to 10 bar. The temperature may range from 200 to 700 ° C, preferably from 300 to 600 ° C. Before the feedstocks are contacted with the catalyst, they are heated to the desired reaction temperature. The flow rate used depends on the reactants, the reactor and generally ranges from 1 to 100 hr * (WHSV). The molar ratio of aromatic hydrocarbon to alkylating agent can range from 0.5 to 20. In monoalkylation, the preferred molar ratio of 20 is 1-4. In addition, a diluent gas, for example nitrogen and / or coke scavengers, for example hydrogen, can be used.

The hot product stream leaving the reactor is cooled to room temperature or below, after which the liquid and gas phases are separated. Unreacted gases can be stored and reused. Unreacted liquid components such as toluene are separated from the product mixture, for example by distillation, and reused.

The following examples further describe the preparation of the catalyst 30 of the invention.

Example 1 In this example, an aluminum-35 boron silicate catalyst labeled BOA-1 is prepared.

4.05 g of NaOH was dissolved in 165 ml of water. To the solution was added

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87.85 g in tetrapropylammonium bromide to give solution A.

Solution B was prepared by dissolving 4.2 g of NaAlO 2 (containing 28.4 wt%

Na 2 O, 46.8 pZ Al 2 O 3> and 24.8 pZ H 2 O) and 0.19 g Na 2 O 3 x 10 H 2 O (containing 16.3 pZ Na 2 O, 36.5 pZ 2 H 2 O) 405.5 g H 2 O . Solutions A and B were then mixed together and added to an autoclave, which was additionally charged with 34.2 g of SiO 2 (bridge gel) and 82.8 g of water. The composition of this mixture was as follows: 0.02 mol Na 2 O, 0.02 mol Al 2 O 3, 0.001 mol Na 2 S 2 O 3, 1 O 3, CH 3 CH 2 CH 2 O 3 and 36.3 mol water.

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The mixture was heated at 200 ° C for 2 hours and then at 160 ° C for 3 days. After cooling to room temperature, the crystalline product was filtered and washed with 2 L of water. The crystals were dried at 100 ° C and then at 530 ° C for 18 hours.

The catalyst thus obtained was contacted with a 5 p-Z solution of ammonium chloride at 80 ° C for 1.5 hours. This procedure was repeated three times and 15 ml of solution per gram of catalyst was used each time. The product was filtered and washed with water until free of chlorides. Drying was performed at 100 ° C and after drying, it was calcined in air at 530 ° C overnight to give the hydrogen form of the catalyst BOA-1.

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The surface area of the catalyst was 345 m / g.

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Example 2 This example relates to the synthesis of BOA-2 of an aluminum 1-boron bridged catalyst.

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The following ingredients were mixed with water (265 g): 6.5 g Na 2 O 2 (containing 28.4 p 2 Na 2 O, 46.8 p 2 Al 2 O and 24.8 p 2 H 2 O) and 0.29 g Na 2 O 2 (containing 16.3 pZ Na 2 O, 36.5 pZ B 2 O 3 and 47.2 pZ H 2 O). To the mixture was added 2.78 g of NaOH and stirred well. The mixture was placed in an autoclave and 35,900 g of H 2 O, 395 g of SiO 2 and 141 g of pyrrolidine were added. The mixture was heated to 200 ° C

at 3 ° C and then at 165 ° C for 3 days, after which it was cooled to room temperature over 15 hours. Crystals suo-, 76005

O

dated and washed with water (3 L). Further preparation of the BOA-2 catalyst was performed as in Example 1 except that a nitrogen atmosphere was used instead of air at temperatures above 100 ° C.

Example 3 In this example, the modification of the catalysts BOA-1 and BOA-2 is carried out with boron compounds.

The catalysts (5 g) prepared in Examples 1 and 2 were mixed with 0.5 g of ^ 2 ^ 3 and heated in air at 550 ° C for 1 hour. During heating, the components were mixed 5 times. After this treatment, the modified catalysts were ready for use.

Toluene ethylation experiments were performed using the unmodified and modified catalysts BOA-1 and BOA-2 prepared in Examples 1-3.

Examples 4-8 In these examples, a fluidized bed reactor charged with 5 g of the unmodified catalyst BOA-1 of Example 1 was used. In all examples, the reaction temperature was 600 ° C and the feed rate and toluene / ethylene molar ratio were varied. The results are shown in Table I below.

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Table I

Examples Temp, tol.reth. WHSV tol.conv. p-ethyltol. per ethyltol.

total ethytol per aro-5 ° C moles hr ^%% matics% 4 600 0,8 24 25 26 67 5 600 1,1 22 26 24 85 10 6 600 1,9 20 30 27 91 7 600 1,4 38 13 45 90 8 600 1.9 50 9 58 96 15 Examples 9-13

In the following examples, 5 g of the catalyst BOA-1 modified according to Example 3 was added to the fluidized bed reactor. The results are shown in Table II.

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Table II

Examples Temp. tol.:eth. WHSV tol.conv. p-ethyltol. per ethyltol. 25 total ethytol. per aro- ° C moles hr ^%% matics% 9 520 1.9 61 12 90 91 30 10 520 2.3 59 13 90 100 11 520 1.4 32 22 84 95 12 520 1.4 37 22 90 97 13 470 1.2 33 17 93 100 35 No O-ethyltoluene was formed.

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Examples 14-15 In these examples, the catalyst of Example 1 BOA-1 (5 g) was used as a catalyst in a fixed bed reactor. The results are shown in Table III.

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Table III

Examples Temp. tol.:eth. WHSV tol.conv. p-ethyltol. per ethyltol.

10 total ethytol. per aro- ° C moles hr *%% matics% 14,500 2.1 25 6 74 92 15 15 600 2.1 25 7 72 98

Examples 16-18 In the following examples, 5 g of the unmodified catalyst BOA-2 of Example 2 was added to the fluidized bed reactor. The reaction temperature used was 600 ° C. The results are shown in Table IV.

Table IV

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Examples Temp. tol.:eth. WHSV tol.conv. p-ethyltol. per ethyltol.

total ethytol. per aro- ° C moles hr ^%% matics% 30_______ 16 600 1.1 22 28 27 84 17 600 1.5 42 22 39 87 18 600 1.9 50 17 53 78 35_______ 11 76005

Examples 19-2 ^ 5 g of the catalyst BOA-2 according to Example 2 were modified according to Example 3, and a fluidized bed reactor and a reaction temperature of 600 ° C were used in the alkylation experiments. The results are shown in Table V.

Table V

10 Examples Temp. tol.:eth. WHSV tol.conv. p-ethyltol. per ethyltol.

total ethytol. per aro- ° C moles hr *%% matics% 15 19 600 2.3 15 2 92 70 20 600 1.9 20 2 92 65 21 600 1.5 42 2 89 30 20 Example 22

Methylation of toluene with methanol was performed using a toluene / methanol molar ratio of 2: 1. The catalyst was BOA-2 from Example 2 modified according to Example 3. The reaction was carried out in a fixed bed reactor at 500 ° C. The yield was 1% pure isomer-free p-xylene.

Claims (10)

1. The aluminum boron silicate catalyst, the mM SiO 2 / Al 2 O 2 * molar ratio is between 10 and 150 and the Al 2 O 2 / lO 2 molar ratio is between 2 and 200, characterized in that the catalyst is prepared by modeling the catalyst with boric acid, boron oxide or a mixture thereof. 1 Patent claim Catalyst according to claim 1, characterized in that the amount of boron compound used in the modification is 0.1-30 v-Z, heist 0.5-10 v-Z. 3. A process for the preparation of a catalyst according to claim 1 or 2, characterized in that a reaction mixture is heated which comprises organic nitrogen containing cation, alkali metal oxide or a mixture of such, aluminum, boron and silica, and water for the preparation of an aluminum boron sieve catalyst and by modeling the catalyst thus obtained by contacting it with boric acid, boron oxide or a mixture thereof without using any kind of water or other solvent. Method according to claim 3, characterized in that the modification is carried out at a temperature of 300-700 ° C. 25 5. Alkylation process for the alkylation of aromatic hydrocarbons, characterized in that a modified Al-B-S1 catalyst according to claim 11 is a hydrogen form or a modified catalyst according to claims 3-4. 30 An alkylation process according to claim 5, characterized in that it is carried out either in a floating-bed or a fixed-bed reactor. An alkylation process according to claim 5, characterized in that the hydrocarbons are benzenes, naphthalenes, anthracenes or substituted derivatives such as toluene, xylene, ethylbenzene and phenols. Il