NL8420257A - METHOD FOR PRODUCING ZEOLITE CATALYSTS AND ALKYLATION PROCESS - Google Patents

Description

- 1 - 8420257

Process for producing zeolite catalysts, as well as alkylation process.

The invention relates to a process for producing zeolite catalysts. In particular, the invention relates to Al-B-Si catalysts which are suitable for the alkylation of aromatic hydrocarbons. 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 is known in the art. For example, U.S. Patent 4,283,306 describes a crystalline silicate for methylating toluene to paraxylene.

Furthermore, crystalline aluminum silicate-15 catalysts are known in the art for the alkylation of aromatic hydrocarbons. U.S. Patent 2,904,697 relates to an alkylation process using metallic aluminum silicate. US Patent 3,251,897 20 describes X and Y type aluminum silicates and in particular those which have as cation or hydrogen or a rare earth metal. Several other patents disclose aluminum silicates which have a high selectivity to form para-substituted aromatics: for example, U.S. Pat. Nos. 3,702,886, 3,965,207, 4,100,217, and 4,117,024.

In U.S. Patent 4,117,024, crystalline aluminum silicates are modified using solutions of difficultly reducible oxides such as antimony, phosphorus or boron.

Alkylation processes have been described in numerous patents. Vapor phase alkylation with aluminum silicate catalysts, which are rich in silicon, generally provides a high conversion. The useful life of silicate catalysts is quite long, 8420257-2 and in many cases the required pressure is low, which makes the process economically attractive. Examples of vapor phase alkylation are described, inter alia, in U.S. Patents 3,751,504 and 3,751,506.

The invention relates to new zeolite catalysts, which contain silicon, aluminum and boron, and in which the pores and passageways are not blocked by the influence of atoms, molecules or ions, for example of sulphate or chlorine ions. Therefore, the movement of reagents within the silicate is unobstructed, resulting in a high degree of conversion in the alkylation process and high selectivity.

The invention relates to a process for producing such aluminum boron-silicate catalysts which are particularly well suited for use in the alkylation of aromatic hydrocarbons and which provide a high degree of conversion and / or high selectivity for the production of para, substituted hydrocarbons, the invention also relates to a process for alkylating aromatic hydrocarbons using said catalysts.

Thus, the invention provides a process for producing aluminum boron-silicate catalysts, wherein the S'IQg / Al-Q2 mol ratio is in the range of 10-150, preferably in the range of 10-60, and the A12Q3 / B203 mol ratio is in the range of 2-200, preferably in the range of 19-200. The molecular formula of said catalysts can be expressed as follows: 0.8-1.2 M2 / n 0: Al2C> 3: 0.005-0.1 B203: 10150 SiC> 2: x H2 O, where M is at least one cation with valence n, and x is in the range 0-60. The process is characterized in that a reaction mixture is heated, which contains a cation with organic nitrogen, one or more alkali metal oxides, oxides of aluminum, boron and silicon and water, in a closed reaction volume first at a temperature which is a higher temperature, and then at a lower reaction temperature for a time sufficient to allow the formation of crystalline aluminum borosilicate catalyst take place, 8420257 - 3 τ

In the above formula, M is at least one cation with the valency η. M can also be a mixture of alkali metal cations, preferably of sodium and potassium cations. The organic cation containing nitrogen can be an ammonium cation, for example a tetraethyl, tetrapropyl or tetrabutyl ammonium cation. The organic cation, which contains nitrogen, can also be a cation derived from pyrrolidine.

When producing a zeolite catalyst 10 according to the invention, a reaction mixture is first heated in a reaction vessel, which contains a cation with organic nitrogen, alkoxide, oxide of aluminum, boron and silicon, and water. Depending on the circumstances, the pressure varies, as required. for the reaction, in the range of 1-15 bar. A higher starting temperature is selected in the range of 175-220 ° C, preferably 190-200 ° C. When a higher starting temperature is used, a homogeneous reaction mixture is obtained in a shorter time and the formation of crystals occurs more quickly.

The heating time at the starting temperature is preferably between 30 min and 6 hours. The heating is continued at a lower reaction temperature in the range of 100-190 ° C. The heating time at the lower temperature is preferably chosen in the range of 1-6 days. It is possible with a catalyst according to the invention to remove ions. exchange against other cations using the known ion exchange technique.

A commendable practice is to exchange an alkali metal ion for a hydrogen ion, which increases the activity of the catalyst in aromatic alkylation.

As can be seen from one embodiment of the invention, the catalyst produced in the manner described above can be further modified using compounds containing boron 35 to produce a catalyst which produces high yield para-substituted aromatics in alkylation. The modification can be accomplished by mixing a catalyst produced as described above and boric acid, boron oxide or a mixture thereof 40 in the dry state. Thereafter, the mixture 8420257-4 is heated to 300-700 ° C, preferably 550-600 ° C, mixing from time to time. The heating time is not critical. When a catalyst modified in this way is used, para-substituted aromatics are obtained with a high yield in the alkylation.

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

The invention always relates to an alkylation process, in which Al-B-Si catalysts produced by the process according to the invention are used. With this process various hydrocarbons such as benzenes, naphthalenes, anthracenes and substituted derivatives such as toluene and ethylbenzene can be alkylated .

As the alkylating agent in the process of the invention, many compounds can be used which have at least one reactive alkyl radical, for example ethylene, propylene, formaldehyde, alkyl halides and alcohols,

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

The alkylation process of the invention takes place in the vapor phase. The reactor used is a fluidized bed reactor or a fixed bed reactor. The aluminum silicate, which is used as a catalyst, is present in the hydrogen form. The reactor pressure can vary from atmospheric pressure to 10 bar depending on the type of reactor, amount of catalyst, catalyst particle size and other factors. The temperature may vary in the range of 200-700 ° C, preferably in the range of 300-600 ° C. Before contacting the input materials with the catalyst, they are heated to the desired reaction temperature. The flow rate used depends on the reactants, the reactor, and generally varies in the range of 1-100 hours -140 (WHSV1, The molar ratio of aromatic hydrocarbon 8420257-5 and alkylating agent can vary in the range of 0 / 5-20 The molar ratio recommended in monoalkylation is 1- 4. In addition, a diluent gas may be used, for example, nitrogen and / or coking agents, for example, hydrogen.

The hot product stream leaving the reactor is cooled to room temperature or to a lower temperature, after which the liquid and gas phases are separated. The unreacted gases can be stored and reused. The liquid components, which have not participated in the reaction, for example toluene, are separated from the product mixture, for example, by distillation and reused.

15 The following example shows how to prepare

the catalyst of the invention described in more detail, EXAMPLE I

In this example, the aluminum borosilicate 20 catalyst bearing the identification BOA-1 is produced.

4.05 g of NaOH was dissolved in 165 ml. To the solution, 87.85 g of tetrapropylammonium bromide were added at room temperature, whereby solution A was obtained.

Solution B was prepared by 4.2 g of NaA102 (containing 28.4 wt.% Na2 O, 46.8 wt.% Al2 O2, and 24.8 wt.% H2 O and 0.19 g Na2B4. that 16.3 wt%

Na2O, 36.5 wt. % B- ^ O ^ and 47.2 wt. % H2G contained 405.5 g H 2 O in 30. Solutions A and B were then mixed

together and introduced into an autoclave, further adding 34.2 g SiO 2 (silica gel) and 82.8 g water.

The composition of the mixture was as follows: 0.02 mole Na 2 O, 0.02 mole Al 2 O 2, 0.001 mole B 2 O 2, 0.57 mole SiO 2, 35 0.33 mole N (CH 2 CH 3 CIL 3) 3 and 36, 3 moles of water.

The mixture was heated at 200 ° C for 2 hours and then at 160 ° C for three days. Then it was cooled to room temperature, the crystalline product was filtered off and washed with 2 liters of water.

40 The crystals were dried at 100 ° C and then 8420257-6 - calcined at 530 ° C for 18 hours,

The catalyst thus obtained was contacted with a 5 wt. % solution of ammonium chloride at 80 ° C for 1.5 hours. This procedure was repeated three times, using 15 mm of solution per 1 g of catalyst each time. The product was filtered and washed with water until the chloride was free.

Drying was performed at 100 ° C and after drying, the calcination was performed in air at 530 ° C overnight for 10 h to obtain the hydrogen form of the catalyst BOA-1.

The surface area of the catalyst was 345 m2 / g.

EXAMPLE 2 This example relates to the synthesis of the aluminum borosilicate catalyst BOA-2.

The following ingredients were mixed in water (265 g): 6.5 g NaAK> 2 (containing 28.4 wt% Na 2,, 46.8 wt% Al 2 O 2 and 24.8 wt% H 2 O) and 0, 29 g Ma2B2 Oy 20 (containing 16.3 wt% Na2O, 36.5 wt% B2®3 and 47.2 wt% H2 O). 2.78 g of NaOH were added to the mixture and mixed well. The mixture was placed in an autoclave, and 900 g H 2 O, 395 g SiO 2 and 141 g pyrrolidine were added. The mixture was heated at 200 ° C for 3 hours and then at 165 ° C for three days, after which it was cooled to room temperature for 15 hours.

The crystals were filtered off and washed with water (3 liters). The further preparation of the catalyst BOA-2 took place as in example 1 with the difference that a nitrogen atmosphere was used instead of air at temperatures higher than 100 ° C.

- EXAMPLE ^ 3

In this example, drilling compound modification of the catalysts BOA-1 and BOA-2 is performed.

To the catalysts prepared in Examples 1 and 2 (5 g thereof) were added 0.5 g of B 2 O 3, followed by heating in air at 550 ° C for 1 hour. The components were mixed five times during heating.

After this treatment, the modified catalysts 40 were ready for use.

8420257 - 7 -

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

5 EXAMPLES 4 * -8

In these examples, a fluidized bed reactor was used, into which 5 g of the unmodified catalyst BOA-1 of Example 1 was introduced. In all examples, the reaction temperature was 600 ° C and the feed rate and the toluene / ethylene mole ratios were varied. The lesson results are shown in Table I below.

^ Table v

Pre-Temp. tol .: eth, ViHSV tol.conv. ethyl ether toll. per 15 images o 'mill -1% tol.per aromatics total% eth.tol, g.

"O

4 6ÖÖ ÏÏJ8 24 25 26 67 20 5 600 1,1 22 26 24 85 6 600 1,9 20 30 27 91 7 600 1,4 38 13 45 90 8 600 1,9 50 9 58 96 EXAMPLES 9-13 25 In the following examples, 5 g of the modified catalyst BOA-1 of Example 3 was placed in a fluidized bed reactor. The results are shown in Table II.

Table II

30 Pre-Temp. toll. : eth. WHSV tol.conv. p-ethyl-eth.tol. per images o mill -1% tol. per aromatics C hour total% eth.tol.

% 35 “~~ 9 520 Γ79 61 Ï2 9Ö 91 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 40 Er o-ethyltoluene did not form.

8420257 - 8 - EXAMPLES 14 * 15

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

Table III

Pre-Temp. toll. : eth. VJHSV tol.conv. p-ethyl-eth.tol.per images on mill -1% tol.per aromatics hour total% 10 eth.tol.

% R-5O0 I! 6 6 74 92 15 600 2.1 25 7 72 98 EXAMPLE 16-18 In the following examples, 5 g of the unmodified catalyst BOA-2 of Example 2 was introduced into a fluidized bed reactor. The reaction temperature used therein was 600 ° C. The results are shown in Table IV.

Table IV

Pre-Temp. toll. : eth, VJHSV tol.conv, p-ethyl-eth.tol.per images o 'mill -1% tol.per aromatics total% eth.tol.

25% 16 600 1.1 22 28 27 84 17 600 1.5 42 22 39 87 18 600 1.9 50 17 53 78 v EXAMPLES 19-21 30 5 g of the catalyst BOA-2 of Example 3 was modified as in Example 3, and in the alkylation runs, a fluidized bed reactor and a reaction temperature of 600 ° C were used. The results are shown in Table V.

- table V - 8420257

- 9 -Table V

Pre-Temp. tol .: eth. WHSV tol.conv, p-ethyl-eth.tol. per images o_ mill -1% tol.per araraten hours total eth.tol.

5% 19 600 2.3 15 2 92 70 20 600 1.9 20 2 92 65 21 600 1.5 42 2 89 30 EXAMPLE 22 10 The methylation of toluene was carried out with methanol using a toluene / methanol molar ratio of 2: 1. The catalyst was BOA-2 from Example 2, modified as in Example 3. The reaction was run in a fixed bed reactor at 500 ° C. The yield was 1% of pure isomer-free p-xylene.

- conclusions - 8420257

Claims (15)

1. Process for preparing an aluminum borosilicate catalyst with the configuration: 0.8-1.2 M2 / n O: Al2 O3: 0.005-0.1 B2C> 3: 10150 Si02: x H20 with the characteristic that a reaction mixture containing a cation containing organic nitrogen, an alkali metal oxide or a mixture thereof, aluminum oxide, boron oxide and silicon dioxide and water, is heated in a closed reaction vessel first at a higher starting temperature, and then at a lower reaction temperature to form the aluminum borosilicate catalyst. 2. A method according to claim 1, characterized in that the starting temperature is at least 165 ° C and not higher than 220 ° C and that the heating time at the starting temperature is in the range of 30 min. 15 to 6 hours. 3. Process according to claim 1 or 2, characterized in that the lower reaction temperature is in the range of 100-190 ° C, preferably in the range of 130-170 ° C and that the heating time at this temperature is at least 8 hours and preferably 1-6 days. 4. A process according to any one of claims 1 to 3, characterized in that the cation containing organic nitrogen is derived from pyrrolidine or from tetraethyl, tetrapropyl or tetrabutyl ammonium chloride, or a mixture thereof. 5. A process according to any one of claims 1 to 4, characterized in that the cation containing organic nitrogen is wholly or partly substituted with hydrogen to form an acid catalyst. 6. AluminumHorosilicate catalyst, wherein the SiC> 2 / Al2C> 3 mole ratio is in the range of 10-150 and the Al 2 O 2 / B 2 Oq mole ratio is in the range of 8420257 ^ 11 * 2-200, characterized in that the catalyst is produced by modifying a catalyst produced by the method of claims 1-4 with boric acid, boron oxide or a mixture thereof. Catalyst according to claim 6, characterized in that the amount of boron compound used for the modification is 0.1-30 wt. %, preferably 0.5-10 wt. %. 8. Process for producing a catalyst according to claim 6 or 7, characterized in that a reaction mixture is heated which contains a cation with organic nitrogen, an alkali metal oxide or a mixture thereof, aluminum oxide, boron oxide and silicon dioxide and water, for producing an aluminum-borosilicate catalyst, and modifying the catalyst thus obtained by contacting it with boric acid, boron oxide or a mixture thereof, using no water or other solvent. 9. A method according to claim 8, characterized in that the modification is carried out at 300-700 ° C, 10. Alkylation process for the alkylation of aromatic hydrocarbons, characterized in that an Al-B-Si catalyst is used as the catalyst, produced by the process according to claims 1-5, or an unmodified Al-B-Si catalyst according to claim 6 in its hydrogen modification, or a catalyst modified according to claims 8-9. 11. Alkylation process according to claim 10, characterized in that it is carried out in a fluidized bed reactor or in a fixed bed reactor. Alkylation process according to claim 10, characterized in that the hydrocarbons are benzenes, naphthalenes, anthracenes or substituted derivatives such as 8420257 - 12 - toluene, xylene, ethylbenzene and phenols. Alkylation process according to claim 10, characterized in that the alkylating agent contains at least one reactive alkyl radical, for example ethylene, propylene, alcohol, formaldehyde or alkyl halide. Alkylation process according to claim 10, characterized in that the reaction temperature is in the range of 200-700 ° C, the flow rate (WHSV) in the range of 1-100 hours and the reaction pressure is atmospheric pressure or higher. Alkylation process according to claim 10, characterized in that an inert diluent gas is used, for example nitrogen and / or substances, which reduce the formation of coke, for example hydrogen. - * r * · ———— ——— 8420257