RU2505357C2 - Elaboration of technology of production of alkylation catalysts - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: claimed is method of obtaining catalyst of isobutene alkylation with olefins on the basis of NaNH₄Y zeolite with residual sodium content not more than 0.8 wt %, in which zeolite is impregnated in mixing with water solution of lanthanum nitrate, taken in amount which ensures lanthanum content in final catalyst 0.5-6.0 wt %, with obtaining suspension; powder of aluminium hydroxide of boehmite structure is peptised with acid solution to pH 1-3 with obtaining another suspension. After that, both suspensions are mixed, evaporated to the state of formability and granules are formed. After that, obtained granules are dry-cured at room temperature, dried at 50-120°C for not less than 5 hours and at 150-500°C for not less than 4 hours. In a particular case after calcinations palladium chloride is applied on catalyst. Also claimed is method of isobutene alkylation in presence of claimed catalyst.

EFFECT: simplification and cheapening of catalyst obtaining process.

4 cl, 1 tbl, 4 ex

Description

The invention relates to a technology for the production of catalysts and can be used for the alkylation of isoparaffin hydrocarbons with olefins in the oil refining and petrochemical industries.

A known method of producing a catalyst for the alkylation of isoparaffin hydrocarbons with olefins by ion exchange of zeolite granules of the type of faujasite, molded with 30% aluminum oxide to calcium cations, rare earth elements, ammonium. The degree of exchange for rare-earth elements of the obtained sample is 47-50%, for the ammonium group - 14% [1].

The disadvantage of this method of preparation of the catalyst is the preparation of a catalyst with low activity and selectivity in the alkylation reaction of isoparaffin hydrocarbons with butylenes and propylene. The yield of alkylate does not exceed 60-70% of the mass. from missed butylenes, and the content of saturated hydrocarbons in the alkylate is 75-80%.

A known method of producing a catalyst for the alkylation of isoparaffin hydrocarbons with olefins by ion exchange of a faujasite type zeolite with aqueous solutions of calcium salts, rare earth elements, ammonium at a temperature of 150-220 ° C and saturated vapor pressure. The yield of alkylate in the presence of such a catalyst increases to 85%, with the conversion of olefins - 88-93%. [2].

The disadvantage of this method is the high consumption of rare earth elements for ion exchange of the initial sodium form of faujasite.

A known catalyst for the alkylation of isobutane with butylenes, representing zeolite Y with a molar ratio of SiO ₂ / Al ₂ O ₃ = 4.5-5, in which sodium cations are replaced by NH ₄ ⁺ cations to a degree of exchange of 95% and rare earth ions up to 60% from the exchange capacity [3]. During the alkylation of isobutane with butene-1 with a ratio in the reaction mixture of 20: 1, a weight feed rate of the mixture with an olefin of 0.05 h ^{-1, a} temperature of 38 ° C and a pressure of 34 atm. After 6 hours of operation, an alkylate is obtained with a relatively high yield of 185%, counting on butene-1. The content of the C ₈ fraction is about 70%, and the content of trimethylpernans in it is about 80%.

The disadvantage of this catalyst is an unacceptably low olefin load and at the same time low stability of its operation: after 5-6 hours of operation, the content of unsaturated compounds in the alkylate is 10-20% and the relatively high consumption of rare-earth elements for conducting zeolite ion exchange.

There is a known method of producing a catalyst described in [4], according to which the initial HNaY zeolite with molar ratios of Na ₂ O / Al ₂ O ₃ = 0.31 and SiO ₂ / Al ₂ O ₃ = 5.5 in order to remove residual sodium initially subjected to ion exchange for ammonium cations from a 2M solution of ammonium nitrate at a temperature of 100 ° C for 2 hours. Then a 3-fold ion exchange was carried out for lanthanum cations at a temperature of 100 ° C for 2 hours, the result was a zeolite with the formula: H _26.4 La _8.4 Na _0.95 Al _52.6 Si _139.4 O ₃₈₄ , for which the physicochemical properties were studied and tested in the alkylation reaction of isobutane with butylenes.

There is also known a method of producing a catalyst in which a polycation-decationized form of zeolite Y, modified with metals of group VIII of the elements was obtained by ion exchange of a NaY zeolite with a molar ratio of SiO ₂ / Al ₂ O ₃ = 4.0 to ammonium cations to a residual content of Na ₂ O = 2 0% of the mass. [5]. The obtained ultra-stable form of zeolite Y was subjected to ion exchange for calcium cations, then to ion exchange for rare-earth cations, then modified in a solution of nickel or cobalt salts. The zeolite thus obtained was tested in an isobutane alkylation reaction with butenes at a temperature of 50-90 ° C, a pressure of 1.3-2.0 MPa, a paraffin / olefin ratio of 10/1, a feed rate of 0.8-1.2 h-1 . The selectivity for hydrocarbons C ₈ reached 83% of the mass.

The closest in technical essence and the achieved result is a catalyst based on a faujasite zeolite for the alkylation of isobutane with C ₂ ÷ C ₄ olefins, described in [6]. According to the known technical solution, the catalyst has the following composition,% mass .: sodium oxide 0.26 ÷ 0.8; rare earth oxide 12.0 ÷ 20.0; calcium oxide 0.8 ÷ 4.2; platinum or palladium oxide 0.02 ÷ 1.2; aluminum oxide and silicon dioxide - the rest. Testing of the catalyst for the alkylation of isobutane with olefins at 90 ° C, a feed rate of 1.3 h ^-1 and a duration of 7 hours shows an alkylate yield of 180 ÷ 210% by weight.

The disadvantage of the catalyst is the low selectivity for the target product Σiso-C ₈ (total isooctanes) - 67.4% of the mass. during the alkylation of isobutane with olefins, in particular butenes.

A common drawback of technologies for the preparation of heterogeneous catalysts according to the techniques described in [4-6] is the complexity and high cost of the described technologies, associated with:

- with the use of significant amounts of rare earth elements (up to 10-15% per catalyst), the cost of which has recently increased (by an order of magnitude).

- with the need to use the apparatus under pressure up to 1.5 MPa (autoclave) with heating to temperatures of 220 ° C;

- with the presence of large numbers of operations with solutions.

The objective of the present invention is to develop a technology for the preparation of a catalyst with activity, selectivity for hydrocarbons iso-C ₈ and the stability of the work is not inferior, and in some cases exceeding the corresponding parameters for the prototype in a simpler and cheaper way.

The problem is solved in that a method for producing an isobutane alkylation catalyst by olefins based on a NaNH ₄ Y type zeolite with a residual sodium oxide content of not more than 0.8 wt%, including treating the zeolite with an aqueous lanthanum salt solution, drying and calcining the obtained catalyst, in which the zeolite with stirring is first impregnated with an aqueous solution of lanthanum nitrate, taken in an amount providing the lanthanum content in the final catalyst of 0.5% -6.0% of the mass. - get a suspension; the boehmite structure aluminum hydroxide powder is peptized to pH 1-3 and another suspension is obtained, then both suspensions are mixed, evaporated to formability and formed into granules, after which the obtained granules are dried at room temperature, dried at 50-120 ° C for at least 5 hours and calcined at a temperature of 150-550 ° C for at least 4 hours.

After calcination, palladium chloride can be applied to the catalyst, taken in an amount providing a palladium content in the finished catalyst of 0.2 wt%. and dissolved by heating in a 25% ammonia solution, after which the catalyst is again dried at room temperature, dried at 120 ° C and calcined at 500 ° C for 3 hours.

A method is also proposed for the alkylation of isobutane with olefins in the presence of a catalyst based on a zeolite of the NaNH ₄ Y type with a residual sodium oxide content of not more than 0.8 wt%, in which the alkylation is carried out in the presence of the catalyst described above, wherein the isobutane is alkylated with olefins at a temperature of 80 ° C , a pressure of 12.3 MPa, the ratio of isobutane: olefins in the feed 10: 1, the volumetric feed rate of the olefins 0.15 h ^-1 and the duration of the feed 8 hours.

The technical result consists in simplifying and cheapening the technology for producing a catalyst with its high activity and selectivity for iso-C ₈ hydrocarbons.

The following examples illustrate the proposed technical solution, but in no way limit it.

Example 1

0.46 g of La (NO ₃ ) ₃ * 6H2O salt is dissolved in 50 ml of distilled water, 55.1 g of NaNH ₄ Y pressed on the filter impregnated on the filter is impregnated with the resulting solution with a residual Na ₂ O content of up to 0.8-0.9% mass. described in [5] at room temperature, with thorough stirring for 10 min - (suspension 1).

7.6 g of boehmite structure aluminum hydroxide powder was peptized with an oxalic acid solution to pH 2. (suspension 2).

Slurries 1 and 2 are thoroughly mixed, evaporated to formability and molded into granules. The granules are dried at room temperature, dried at 120 ° C for 5 hours and calcined at 300 ° C for 1.5 hours and at 500 ° C for 2.5 hours.

Get a catalyst with a content of 0.5% lanthanum.

The obtained catalyst sample was tested in the alkylation reaction of isobutane with olefins in a laboratory micropilot installation, at a temperature of 80 ° C, a pressure of 12.3 MPa, the ratio of isobutane: olefins in the feedstock 10: 1, the volumetric feed rate of the feedstock for olefins 0.15 h ^-1 , duration feedstock 8 hours. A mixture of butylenes is used as olefins.

The test results are presented in table 1.

Example 2

2.8 g of La (NO ₃ ) ₃ * 6H ₂ O salt are dissolved in 50 ml of distilled water, 53.5 g of NaNH ₄ Y pressed on the filter zeolite filtered with a residual Na ₂ O content of up to 0.8-0.9 are soaked in the resulting solution. % of the mass. described in [5] at room temperature, with thorough stirring for 10 min - (suspension 1).

7.5 g of boehmite structure aluminum hydroxide powder was peptized with an acetic acid solution to pH 3 (suspension 2).

Slurries 1 and 2 are thoroughly mixed, evaporated to formability and molded into granules. The granules are dried at room temperature, dried at 120 ° C for 5 hours and calcined at 300 ° C for 1.5 hours and at 500 ° C for 2.5 hours.

Get a catalyst with a content of 3.0% lanthanum.

The obtained catalyst sample was tested in the alkylation reaction of isobutane with olefins in a laboratory micropilot plant, at a temperature of 80 ° C, a pressure of 12.3 MPa, the ratio of isobutane: olefins in the feedstock 10: 1, the volumetric feed rate of the feedstock over olefins 0.15 h ^-1 feed time raw materials 8 hours. A mixture of butylenes is used as olefins.

The test results are presented in table 1.

Example 3

5.6 g of La (NO ₃ ) ₃ * 6H ₂ O salt is dissolved in 50 ml of distilled water, 53.5 g of NaNH ₄ Y pressed on the filter zeolite filtered with a residual Na ₂ O content of up to 0.8-0.9 are soaked in the resulting solution. % of the mass. described in [6] at room temperature, with thorough stirring for 10 min - (suspension 1).

7.5 g of boehmite structure aluminum hydroxide powder was peptized with an acetic acid solution to pH 3 (suspension 2).

Slurries 1 and 2 are thoroughly mixed, evaporated to formability and molded into granules. The granules are dried at room temperature, dried at 120 ° C for 5 hours and calcined at 300 ° C for 1.5 hours and at 500 ° C for 2.5 hours.

Get a catalyst with a content of 6.0% lanthanum.

The obtained catalyst sample was tested in the alkylation reaction of isobutane with olefins in a laboratory micropilot installation, at a temperature of 80 ° C, a pressure of 12.3 MPa, the ratio of isobutane: olefins in the feedstock 10: 1, the volumetric feed rate of the feedstock for olefins 0.15 h ^-1 , duration feedstock 8 hours.

The test results are presented in table 1.

Example 4

0.93 g of La (NO ₃ ) ₃ * 6H ₂ O salt are dissolved in 50 ml of distilled water, 54.6 g of NaNH ₄ Y pressed on the filter zeolite with a residual Na ₂ O content of up to 0.8-0 are impregnated with the resulting solution, 9% of the mass., Obtained by the method described in [5], at room temperature, with thorough stirring for 10 minutes, and suspension 1 is obtained.

7.6 g of boehmite structure aluminum hydroxide powder was peptized with a solution of nitric acid to pH 1, thereby obtaining a suspension of 2.

Then suspensions 1 and 2 are thoroughly mixed, evaporated to formability and formed into granules. The granules are dried at room temperature, dried at 50 ° C for 5 hours and calcined at 300 ° C for 1.5 hours and at 500 ° C for 2.5 hours. 30 ml of a solution containing 0.1 g of palladium chloride dissolved in 7 ml of 25% ammonia is applied to a calcined catalyst base, the catalyst is dried at room temperature, dried at 120 ° C, calcined at 550 ° C for 3 hours .

Get a catalyst with a content of 1% lanthanum and 0.2% Pd.

The obtained catalyst sample was tested in the alkylation reaction of isobutane with olefins in a laboratory micropilot installation, at a temperature of 80 ° C, a pressure of 12.3 MPa, the ratio of isobutane: olefins in the feedstock 10: 1, the volumetric feed rate of the feedstock for olefins 0.15 h ^-1 , duration feedstock 8 hours. A mixture of butylenes is used as olefins.

The test results are presented in table 1.

From the test results of the catalysts prepared according to examples 1-4, shown in table 1, it is obvious that in the main parameters: conversion, alkylate yield, iso-C ₈ hydrocarbon selectivity, the obtained catalysts are not inferior, and in some cases, exceed the corresponding parameters for the prototype .

Information sources

1. USSR author's certificate No. 507350, cl. 01J 21/16, 1972.

2. USSR Copyright Certificate No. 936991, cl. B01J 37/30, B01J 29/08, 1982

3. US patent No. 3549557, CL. 252-455, publ. 1970 year

4. C. Flego, I. Kiricsi, W.O. Parker Ir., M.G. Clerisi, "Applied Catalysis A: General", 124 (1995) 107-119.

5. P.P. Shiriazdanov, U.S. Rysaev, S.A. Akhmetov, A.P. Turanov, Yu.V. Morozov, E.A. Nikolaev "Petrochemistry", 2009, vol. 49 No. 1, pp. 90-93.

6. SU 1309383, B01J 29/12, С07В 37/00, 10.20.1996.

Table 1: Test results of catalyst samples in the alkylation reaction of isobutane with olefins. Example for example Butylene conversion, wt.% The yield of alkylate, wt.% C ₅ -C ₇ , wt.% isoC ₈ , wt.% the sum of C ₉ , wt.% C ₅ , wt.% C ₆ , wt.% C ₇ , wt.% TMP *, wt.% DMG **, wt.% C ₈ not / id., Wt.% one 99 190 13.8 81.8 4.4 2,8 3.9 6.1 69.7 8.5 3.6 2 99 185 16.3 78.7 5,0 4,5 4.9 6.9 63.6 8.5 6.6 3 99 153 16.8 77.9 5.3 4,5 5.2 7.1 63.1 8.5 6.7 four one hundred 200 12.6 82.3 5.1 2.7 3.9 6.0 71.2 7.9 3.4 prototype one hundred 184 there is no data 67.4 5.1 56.2 11,2 * - trimethylpentanes
** - dimethylhexanes

Claims (4)

1. A method of producing an isobutane alkylation catalyst with olefins based on a NaNH ₄ Y type zeolite with a residual sodium oxide content of not more than 0.8 wt.%, Comprising treating the zeolite with an aqueous lanthanum salt solution, drying and calcining the resulting catalyst, characterized in that the zeolite is first while stirring, they are impregnated with an aqueous solution of lanthanum nitrate, taken in an amount providing a lanthanum content in the final catalyst of 0.5% -6.0 wt.% - a suspension is obtained; boehmite structure aluminum hydroxide powder is peptized to pH 1-3 and another suspension is obtained, then both suspensions are mixed, evaporated to formability and formed into granules, after which the obtained granules are dried at room temperature, dried at 50-120 ° C for at least 5 hours and calcined at a temperature of 150-550 ° C for at least 4 hours 2. The method of producing a catalyst according to claim 1, characterized in that after calcination, palladium chloride is applied to the catalyst, taken in an amount providing a palladium content in the finished catalyst of 0.2 wt.%, And dissolved by heating in a 25% ammonia solution , the catalyst was again dried at room temperature, dried at 120 ° C and calcined at 500 ° C for 3 hours 3. The method of alkylation of isobutane with olefins in the presence of a catalyst based on a zeolite of the NaNH ₄ Y type with a residual content of sodium oxide of not more than 0.8 wt.%, Characterized in that the alkylation is carried out in the presence of a catalyst obtained according to claim 1 or 2. 4. The alkylation method according to claim 3, characterized in that the alkylation of isobutane with olefins is carried out at a temperature of 80 ° C, a pressure of 12.3 MPa, the ratio of isobutane: olefins in the feedstock 10: 1, the volumetric feed rate of the feedstock for olefins 0.15 h ^{- 1} and the duration of the feed 8 hours