RU2302898C1 - Trimetallic reforming catalyst preparation process - Google Patents

Abstract

FIELD: petroleum processing catalysts.

SUBSTANCE: catalyst containing platinum, rhenium, antimony, and chlorine on alumina are prepared by impregnation of carrier with aqueous solution of compounds of indicated elements, antimony being deposited as first or second component. Once antimony or platinum-antimony combination, or rhenium-antimony combination deposited, catalyst is dried at 130°C and then calcined in air flow at 500°C. Reduction of catalyst is performed at 300-600°C and pressure 0.1-4.0 MPa for 4 to 49 h. After deposition of antimony or two elements (platinum-antimony or rhenium-antimony) and drying-calcination procedures, second and third or only third element are deposited followed by drying and calcination. Final reduction of catalyst is accomplished in pilot plant reactor within circulating hydrogen medium at pressure 0.3-4.0 MPa and temperature up to 600°C for a period of time 12 to 48 h.

EFFECT: enhanced aromatization and isomerization activities of catalyst and also its stability.

2 cl, 1 tbl, 8 ex

Description

The invention relates to the field of preparation of reforming catalysts.

Known methods for the preparation of alumina-platinum reforming catalysts by impregnating alumina with aqueous solutions containing compounds of the active components, followed by drying and calcination at temperatures up to 650 ° C, followed by reduction with hydrogen or a hydrogen-containing gas at a temperature of 250-500 ° C [a.c. USSR No. 666703, B01J 23 / 42.1979; A.S. USSR No. 161694, B01J 11/08, 1963; US Pat. US No. 4485188, B01J 27/02, 1984].

A disadvantage of the known methods for the preparation of reforming catalysts is that these methods do not provide a sufficient degree of stability of catalytic activity.

The closest in technical essence to the method of producing a metal catalyst on a carrier containing platinum, rhenium and antimony is the method [US Pat. VNR No. 177860, B01J 27/24, 1983], which consists in impregnating the carrier with a solution of the corresponding metals in the presence of one or more Quaternary ammonium compounds and subsequent reduction of the catalyst.

The disadvantage of this method is the insufficiently high aromatic and isomerizing activity and stability of the reforming catalysts.

The aim of the present invention is to develop a method of preparing an alumina-platinum reforming catalyst containing rhenium and antimony, which has increased aromatic and isomerizing activity and stability.

This goal is achieved by the proposed method for the preparation of alumina-platinum reforming catalyst, containing, along with platinum, rhenium and antimony.

An essential distinguishing feature of the proposed method is that antimony is introduced as the first or second element in an amount of 0.02-1.0 wt.% And catalyst recovery is carried out at a temperature of 300-600 ° C and a pressure of 0.1-4.0 MPa for 4-48 hours after injection antimony and after the final introduction of all metals. This method allows to increase the aromatic and isomerizing activity of the catalyst, as well as the stability of its catalytic properties.

The proposed method for the preparation of alumina-platinum reforming catalyst is as follows.

A catalyst containing platinum, rhenium, antimony and chlorine on alumina is prepared by impregnating the support with aqueous solutions of the compounds of these elements. In this case, antimony is applied as the first or second component. After applying antimony or a combination of platinum-antimony or rhenium-antimony, the catalyst is dried at a temperature of 130 ° C and calcined in a stream of air at a temperature of 500 ° C. The catalyst recovery is carried out at a temperature of 300-600 ° C and a pressure of 0.1-4.0 MPa for 4-48 hours. After applying antimony or two elements of platinum-antimony or rhenium-antimony and performing the drying, calcining and recovery operation, the second and third element or only the third element are applied and the drying, calcining operations are repeated. The final recovery of the catalyst is carried out in the reactor of the pilot plant in a circulating hydrogen medium at a pressure of 0.3-4.0 MPa, temperature up to 600 ° C for 12-48 hours.

On the catalyst, upon completion of reduction, n-heptane is reformed. The process is carried out under the following conditions: pressure 1.0 MPa; temperature 475 ° C; the volumetric feed rate of n-heptane 2.5 h ^-1 ; the molar ratio of hydrogen: n-heptane 5. The composition of the reaction products and the stability of the catalyst are determined, which is understood as the rate of decrease in the activity of the catalyst (the rate of decrease in the concentration of iso-heptanes and toluene in the reaction products).

The present invention is illustrated by the following examples.

Example 1

200 g of alumina (γ-Al ₂ O ₃ ) are impregnated with 100 ml of an aqueous solution of antimony chloride, the concentration of antimony in the impregnating solution is 5.0 g / l. The excess solution is evaporated at a temperature of 75-80 ° C. The catalyst is dried at a temperature of 130 ° C and calcined in a stream of air at 500 ° C. The recovery of the catalyst is carried out in a stream of hydrogen at a temperature of 500 ° C for 12 hours and a pressure of 1.0 MPa. Next, the catalyst is impregnated with 140 ml of an aqueous solution of platinum chloride and 1.5% hydrochloric acid solution. The concentration of platinum in the impregnating solution is 5.0 g / l. For a more uniform distribution of the active components over the carrier granule, a 1.5% solution of acetic acid is added to the solution. The excess solution is evaporated at a temperature of 75-80 ° C. The catalyst is dried at a temperature of 130 ° C. Next, the catalyst is impregnated with 140 ml of an aqueous solution of rhenium and 1.5% hydrochloric acid solution. The concentration of rhenium in the impregnating solution is 2.86 g / l. The excess solution is evaporated at a temperature of 75-80 ° C. The catalyst is dried at a temperature of 130 ° C. For a more uniform distribution of the active components over the carrier granule, 1.5% acetic acid solution is added to the solution. At the end of all impregnation and drying, the catalyst is calcined in a stream of air with an admixture of 1.5 g / m ^{3 of} carbon tetrachloride at 500 ° C for 6 hours and a pressure of 0.1 MPa.

The catalyst contains, wt.%:

platinum 0.35

rhenium 0.20

antimony 0.25

chlorine 1.1

the rest is γ-Al ₂ About ₃

The catalyst is loaded into the reactor of the pilot reforming unit and reduced in a stream of circulating hydrogen at a temperature of 500 ° C for 12 hours and a pressure of 1.0 MPa.

After completion of the catalyst recovery, n-heptane is reformed at a pressure of 1.0 MPa; temperature 475 ° C; volumetric feed rate of heptane 2.5 h ^-1 ; the molar ratio of hydrogen: n-heptane 5.

As a result of n-heptane reforming, a catalysis is obtained which contains 18.4% by weight of iso-heptanes; 28.2 wt.% Toluene; the total conversion of n-heptane is 91.2%, the rate of decrease in the content of isohexanes and toluene in the catalyst is 0.5 wt / h.%.

Example 2

The application of antimony and the restoration of the catalyst is carried out, as in example 1. The second applied element is rhenium, the third element is platinum. The application of these elements and further preparation of the catalyst is carried out, as in example 1. The catalyst contains, wt.%:

platinum 0.35

rhenium 0.20

antimony 0.25

chlorine 1.1

the rest is γ-Al ₂ About ₃

Upon completion of the catalyst recovery, n-heptane is reformed as described in Example 1.

As a result of the reforming of n-heptane, catalysis is obtained, which contains 19.5% by weight of iso-heptanes; 27.0 wt.% Toluene; the total conversion of n-heptane is 91.0%, the rate of decrease in the content of isohexanes and toluene in the catalyst is 0.5 wt / h.%.

Example 3

The first element to be applied is platinum, which is applied as in Example 1. The catalyst is dried at a temperature of 130 ° C. Next, the catalyst is impregnated with 100 ml of an aqueous solution of antimony chloride, the concentration of antimony in the impregnating solution is 5.0 g / l. The excess solution is evaporated at a temperature of 75-80 ° C. The catalyst is dried at a temperature of 130 ° C and calcined in a stream of air at 500 ° C. The catalyst recovery is carried out in a stream of hydrogen at a temperature of 500 ° C for 12 hours and a pressure of 0.1 MPa. The third element applied is rhenium, which is applied, as in example 1. The catalyst is dried, calcined and reduced, as in example 1.

Upon completion of the catalyst recovery, n-heptane is reformed as described in Example 1.

As a result of the reforming of n-heptane, catalysis is obtained, which contains 17.5% by weight of iso-heptanes; 27.5 wt.% Toluene; the total conversion of n-heptane is 90.5%, the rate of decrease in the content of isohexanes and toluene in the catalyst is 0.6 wt / h.%.

Example 4

The first element to be applied is rhenium, which is applied as in Example 1. The catalyst is dried at a temperature of 130 ° C. Next, the catalyst is impregnated with 100 ml of an aqueous solution of antimony chloride, the concentration of antimony in the impregnating solution is 5.0 g / l. The excess solution is evaporated at a temperature of 75-80 ° C. The catalyst is dried at a temperature of 130 ° C and calcined in a stream of air at 500 ° C. The catalyst recovery is carried out in a stream of hydrogen at a temperature of 500 ° C for 24 hours and a pressure of 4.0 MPa. The third application element is platinum, which is applied as in Example 1. The catalyst is dried, calcined and reduced, as in Example 1.

Upon completion of the catalyst recovery, n-heptane is reformed as described in Example 1.

As a result of n-heptane reforming, a catalysis is obtained which contains 17.0% by weight of iso-heptanes; 28.0 wt.% Toluene; the total conversion of n-heptane is 90.1%, the rate of decrease in the content of isohexanes and toluene in the catalyst is 0.6 wt / h.%.

Example 5

200 g of alumina (γ-Al ₂ O ₃ ) are impregnated with 100 ml of an aqueous solution of antimony chloride, the concentration of antimony in the impregnating solution is 0.4 g / l. The excess solution is evaporated at a temperature of 75-80 ° C. The catalyst is dried at a temperature of 130 ° C and calcined in a stream of air at 500 ° C. The recovery of the catalyst is carried out in a stream of hydrogen at a temperature of 300 ° C for 48 hours and a pressure of 1.0 MPa. Further preparation of the catalyst is carried out as described in example 1.

The catalyst contains, wt.%:

platinum 0.35

rhenium 0.20

antimony 0.02

chlorine 1.1

the rest is γ-Al ₂ About ₃

Upon completion of the catalyst recovery, n-heptane is reformed as described in Example 1.

As a result of n-heptane reforming, a catalysis is obtained which contains 16.5% by weight of iso-heptanes; 26.0 wt.% Toluene; the total conversion of n-heptane is 88.1%, the rate of decrease in the content of isohexanes and toluene in the catalyst is 0.7 wt / h.%.

Example 6

200 g of alumina (γ-Al ₂ O ₃ ) are impregnated with 100 ml of an aqueous solution of antimony chloride, the concentration of antimony in the impregnation solution is 20.0 g / l. The excess solution is evaporated at a temperature of 75-80 ° C. The catalyst is dried at a temperature of 130 ° C and calcined in a stream of air at 500 ° C. The recovery of the catalyst is carried out in a stream of hydrogen at a temperature of 600 ° C for 4 hours and a pressure of 1.0 MPa. Further preparation of the catalyst is carried out as described in example 1.

The catalyst contains, wt.%:

platinum 0.35

rhenium 0.20

antimony 1.0

chlorine 1.1

the rest is γ-Al ₂ About ₃

Upon completion of the catalyst recovery, n-heptane is reformed as described in Example 1.

As a result of n-heptane reforming, a catalysis is obtained which contains 20.0% by weight of iso-heptanes; 25.5 wt.% Toluene; the total conversion of n-heptane is 89.3%, the rate of decrease in the content of isohexanes and toluene in the catalyst is 0.5 wt / h.%.

Example 7

200 g of alumina (γ-Al ₂ O ₃ ) are impregnated with 100 ml of an aqueous solution of antimony chloride, the concentration of antimony in the impregnating solution is 5.0 g / l. The excess solution is evaporated at a temperature of 75-80 ° C. The catalyst is dried at a temperature of 130 ° C. Next, the catalyst is impregnated with 140 ml of an aqueous solution of platinum chloride and hydrochloric acid.

The concentration of platinum in the impregnating solution is 5.0 g / l. For a more uniform distribution of the active components over the carrier granule, a 1.5% solution of acetic acid is added to the solution. The excess solution is evaporated at a temperature of 75-80 ° C. The catalyst is dried at a temperature of 130 ° C. Next, the catalyst is impregnated with 140 ml of an aqueous solution of rhenium and 1.5% hydrochloric acid solution. The concentration of rhenium in the impregnating solution is 2.86 g / l. The excess solution is evaporated at a temperature of 75-80 ° C. The catalyst is dried at a temperature of 130 ° C. For a more uniform distribution of the active components over the carrier granule, a 1.5% solution of acetic acid is added to the solution. At the end of all impregnation and drying, the catalyst is calcined in a stream of air with an admixture of 1.5 g / m ³ carbon tetrachloride at 500 ° C for 6 hours and a pressure of 0.1 MPa.

The catalyst contains, wt.%:

platinum 0.35

rhenium 0.20

antimony 0.25

chlorine 1.1

the rest is γ-Al ₂ About ₃

The catalyst is loaded into the reactor of the pilot reforming unit and reduced in a stream of circulating hydrogen at a temperature of 500 ° C for 12 hours and a pressure of 1.0 MPa.

Upon completion of the catalyst recovery, n-heptane is reformed as described in Example 1.

As a result of n-heptane reforming, a catalysis is obtained which contains 15.5% by weight of iso-heptanes; 25.1 wt.% Toluene; the total conversion of n-heptane is 89.3%, the rate of decrease in the content of isohexanes and toluene in the catalyst is 0.9 wt / h.%.

Example 8. (for comparison)

200 g of alumina (γ-Al ₂ O ₃ ) are impregnated with 200 ml of an aqueous solution of antimony chloride of platinum chloride, rhenium and hydrochloric acids. The concentration of antimony in the impregnating solution is 2.5 g / l, platinum 3.5 g / l and rhenium 2.0 g / l, hydrochloric acid 1.5 wt.%. The application of active elements is carried out in the presence of quaternary ammonium compounds. The excess solution is evaporated at a temperature of 75-80 ° C. The catalyst is dried at a temperature of 130 ° C. The catalyst is calcined in a stream of air with an admixture of 1.5 g / m ³ carbon tetrachloride at 500 ° C for 6 hours and a pressure of 0.1 MPa.

The catalyst contains, wt.%:

platinum 0.35

rhenium 0.20

antimony 0.25

chlorine 1.1

the rest is γ-Al ₂ About ₃

The recovery of the catalyst is carried out in a stream of hydrogen at a temperature of 500 ° C for 12 hours and a pressure of 1.0 MPa.

Upon completion of the catalyst recovery, n-heptane is reformed as described in Example 1.

As a result of the reforming of n-heptane, a catalysis is obtained which contains 10.7% by weight of iso-heptanes; 22.7 wt.% Toluene; the total conversion of n-heptane is 81.2%, the rate of decrease in the content of isohexanes and toluene in the catalyst is 1.2 wt / h.%.

Thus, it is shown that the preparation of the catalyst according to the proposed method allows to increase its isomerizing and aromatizing activity, as well as to increase the stability of its operation. The results obtained in examples 1-7 are presented in the table.

No. p / p Order of application of elements The content of antimony, wt.% First Recovery Terms Catalyst Test Results Temperature, OS Pressure, MPa Time h The content of iso-heptanes in the catalyst, wt.% The toluene content in the catalyst, wt.% The total conversion of n-heptane, wt.% The rate of decrease in the content in the catalyst Σ of iso-heptanes and toluene, wt./h% one. Sb-pt-re 0.25 500 1.0 12 18.4 28.2 91.2 0.5 2. Sb-re-pt 0.25 500 1.0 12 19.5 27.0 91.0 0.5 3. Pt-sb-re 0.25 500 0.1 12 17.5 27.5 90.5 0.6 four. Re-sb-pt 0.25 500 4.0 24 17.0 28.0 90.1 0.6 5. Sb-pt-re 0.02 300 1.0 48 16.5 26.0 88.1 0.7 6. Sb-pt-re 1.0 600 1.0 four 20.0 25.5 89.3 0.5 7. Sb-pt-re 0.25 - - - 15.5 25.1 89.3 0.9 8. Simultaneous application of Sb-Pt-Re 0.25 - - - 10.7 22.7 81.2 1.2

Claims (2)

1. A method of preparing a trimetallic alumina-platinum catalyst containing, along with platinum, rhenium and antimony, by impregnating alumina with aqueous solutions of compounds of the corresponding elements, followed by drying, calcination and reduction, characterized in that, in order to increase aromatic and isomerizing activity, as well as stability catalyst, antimony is introduced into the composition of the catalyst as the first or second element in an amount of 0.02-1.0 wt.%. 2. The method according to claim 1, characterized in that the recovery of the catalyst is carried out after the introduction of antimony at a temperature of 300-600 ° C and a pressure of 0.1-4.0 MPa for 4-48 hours and after the final introduction of all elements.