RU2246987C1 - Method of preparing petroleum product hydrofining catalysts - Google Patents

Abstract

FIELD: petrochemical process catalysts.

SUBSTANCE: preparation of catalyst comprises two-step impregnation of preliminarily calcined carrier with first ammonium heptamolybdate solution and then, after intermediate heat treatment at 100-200°C, with cobalt and/or nickel nitrate solution followed by final heat treatment including drying at 100-200°C and calcination at 400-650°C. Catalyst contains 3.0-25.0% MoO3, 1.0-8.0% CoO and/or NiO on carrier: alumina, silica, or titanium oxide.

EFFECT: enhanced hydrodesulfurization and hydrogenation activities allowing involvement of feedstock with high contents of sulfur and unsaturated hydrocarbons, in particular in production of environmentally acceptable motor fuels.

3 cl, 4 tbl, 13 ex

Description

The present invention relates to catalysis, in particular to methods for the preparation of catalysts for hydrotreating petroleum products, and can be used in the refining and petrochemical industries.

A known method of producing alumina-nickel-molybdenum catalyst for hydrotreating gasoline by mixing a mixture of fractions of 10-40 and 40-200 microns of aluminum oxide powder (ratio of fractions 1: 0.25-2.33) with ammonium molybdenum acid (ammonium heptamolybdate (GMA) - (NH ₄ ) ₆ Mo ₇ O ₂₄ · 4Н ₂ O) and nickel nitric acid (nickel nitrate (НН) -Ni (NO ₃ ) ₂ · 6Н ₂ O) in the presence of a peptizing agent (aqueous nitric acid solution), followed by molding, drying, drying and calcining [ A.S. USSR No. 701700, class In 01 J 37/02, 1979]. The main disadvantage of this method is the low mechanical strength of the resulting catalyst.

Closest to the invention, the achieved effect is a method of preparing a catalyst for hydrotreating petroleum products, which consists in obtaining a mixture including natural aluminosilicate, mixing the prepared mixture with a mixing liquid, followed by molding, heat treatment of the obtained granules (drying and calcination), impregnating the carrier with solutions of hydrogenating (active) metal salts and final heat treatment. Increasing the mechanical strength of the catalyst is achieved by obtaining a high-strength carrier by mixing aluminum hydroxide with 10-30% of natural aluminosilicate. The carrier obtained is impregnated in two stages with solutions of active metals: a solution of ammonium heptamolybdate in the first stage and a solution of cobalt nitrate or nickel nitrate in the second with intermediate and final heat treatments, including drying and calcination at 200-500 ° C for 2-10 hours [RF Patent No. 2100079, class B 01 J 37/04, 37/16, 23/883 // (B 01 J 23/883, 101: 34, 101: 62), 1997]. The main disadvantage of this method is the low hydrodesulfurization and hydrogenating activity, which limits the possibility of using a catalyst in the hydrotreatment of liquid petroleum products, for example, with a high content of unsaturated compounds (the so-called secondary raw materials). The insufficient hydrodesulfurization activity of the catalyst according to this method does not allow to obtain motor fuels that meet modern environmental requirements (for example, with a sulfur content in diesel fuel of less than 0.05 wt.%).

The technical problem solved by the invention is the development of a method for preparing a catalyst for hydrotreating petroleum products with increased hydrodesulfurization and hydrogenating activities.

This technical problem is solved by the method of preparing a catalyst for hydrotreating oil products by two-stage impregnation of a pre-calcined carrier with a solution of ammonium heptamolybdate in the first stage and a solution of cobalt nitrate and / or nickel nitrate in the second with intermediate heat treatment between stages at a temperature of 100-200 ° C and final heat treatment, including drying at a temperature of 100-200 ° C and calcination at a temperature of 400-650 ° C. The resulting catalyst has the following composition, wt.%:

MoO ₃ - 3.0-25.0

CoO and / or NiO - 1.0-8.0

the carrier is the rest.

As the catalyst carrier, alumina, or silica, or silica is used.

The common features of the present invention and the prototype is a two-stage impregnation of a pre-calcined carrier with a solution of ammonium heptamolybdate in the first stage and solutions of active metals in the second with intermediate and final heat treatments, including drying and calcination.

The main distinguishing feature of the invention is that in the second stage of the carrier impregnation a solution of cobalt nitrate and / or nickel nitrate is used, the intermediate heat treatment is carried out at a temperature of 100-200 ° C, and the final heat treatment, including drying and calcination, is carried out respectively at a temperature of 100 -200 ° C and 400-650 ° C.

Additional distinguishing features are:

- the composition of the obtained catalyst, wt.%:

MoO ₃ - 3.0-25.0

CoO and / or NiO - 1.0-8.0

media - the rest

- use as a carrier of aluminum oxide, or silicon oxide, or titanium oxide.

The proposed set of features of a method of preparing a catalyst for hydrotreating petroleum products meets the condition of patentability "Inventive step", based on the following. From the prior art at the date of filing the application for the invention it was not known that the proposed combination of features leads to the solution of the above problem. As a result of this, it becomes possible not only to obtain environmentally friendly motor fuels in the process of hydrotreating oil products from sulfur and unsaturated compounds, but also to involve raw materials with a higher content of sulfur and unsaturated hydrocarbons in the processing.

The proposed method is illustrated by the following examples.

Example 1

67 g of granules of a pre-calcined carrier — active alumina — are poured into 75 ml of an aqueous GMA solution with a concentration of 300 g of MoO ₃ / L and incubated for the time required to obtain an intermediate product containing 27 wt.% MoO ₃ , dried at a temperature of 150 ° C for 6 hours. Then, the dried intermediate is impregnated with 30 ml of an aqueous solution of cobalt containing 31.1 g of cobalt nitrate (NK), dried at a temperature of 150 ° C for 6 hours and calcined at 550 ° C for 4 hours.

As the carrier used active alumina brand AOA-1 (GOST 8136-85) with the following characteristics: diameter - 5.0 mm; mechanical split strength (0.1 mm knife) - 1.1 kg / mm; bulk density - 0.55 g / cm ³ ; pore volume (water absorption) - 0.8 cm ³ / year

The finished catalyst has the following composition, wt.%:

MoO ₃ - 25.0

CoO - 8.0

Al ₂ O ₃ - the rest.

Example 2

82 g of carrier granules — active alumina — are impregnated with 50 ml of an aqueous GMA solution containing 17.2 g of GMA and dried at a temperature of 150 ° C. for 6 hours. Then, the dried intermediate is impregnated with 30 ml of an aqueous solution of cobalt containing 15.6 g NK, dried at a temperature of 150 ° C for 6 hours and calcined at 550 ° C for 4 hours

As the carrier used active alumina brand AN-2 / S (TU 2163-004-47317879-2000 with amendment 1) with the following characteristics: diameter - 2.0 mm; mechanical split strength (0.1 mm knife) - 1.5 kg / mm; bulk density - 0.65 g / cm ³ ; pore volume (water absorption) - 0.61 cm ³ / year

The finished catalyst has the following composition, wt.%:

MoO ₃ - 14.0

CoO - 4.0

Al ₂ O ₃ - the rest.

Analogously to example 1, by varying the composition of the active components, the catalysts are prepared according to examples 4 and 7 and analogously to example 2, by varying the composition of the active components and the nature of the carrier, the catalysts are obtained according to examples 3, 5, 6, 8-11.

Example 12 (prototype).

To 500 g of aluminum hydroxide powder, add 100 g of natural aluminosilicate and mix in a mixing machine for 5-10 minutes until a homogeneous mixture is obtained, after which 180 ml of 10% phosphoric acid are poured and stirred for 1 hour. The resulting mass is extruded through a die with a hole diameter of 2 mm. The obtained granules are first dried at a temperature of 180 ° C, and then calcined at 550 ° C for 24 hours. The calcined granules are poured with a 17.5% GMA solution (at the rate of 1.5 volume of solution per 1 volume of carrier) and kept in solution within 4 hours. Then the excess solution is drained, and the impregnated granules are dried and calcined at a temperature of 500 ° C for 3 hours.

After cooling the granules, they are placed in a solution of cobalt nitrate with a concentration of 10%, and also at the rate of 1.5 volume of the solution per 1 volume of granules and kept in the solution for 3 hours. Then, drying and calcination are carried out at 500 ° C for 3 hours.

The finished catalyst has the following composition, wt.%:

MoO ₃ - 14.0

CoO - 4.0

Al ₂ O ₃ - SiO ₂ - the rest.

Example 13 (prototype).

To 500 g of aluminum hydroxide powder, add 100 g of natural aluminosilicate and mix in a mixing machine for 5-10 minutes until a homogeneous mixture is obtained, after which 180 ml of 10% phosphoric acid are poured and stirred for 1 hour. The resulting mass is extruded through a die with a hole diameter of 2 mm. The obtained granules are first dried at a temperature of 180 ° C, and then calcined at 550 ° C for 24 hours. The calcined granules are poured with a 17.5% GMA solution (at the rate of 1.5 volume of solution per 1 volume of carrier) and kept in solution within 4 hours. Then the excess solution is drained, and the impregnated granules are dried and calcined at a temperature of 300 ° C for 3 hours.

After cooling the granules, they are placed in a solution of nickel nitrate with a concentration of 10%, and also at the rate of 1.5 volume of the solution per 1 volume of granules and kept in the solution for 3 hours. Then, drying and calcination are carried out at 500 ° C for 3 hours.

The finished catalyst has the following composition, wt.%:

MoO ₃ - 14.0

NiO - 4.0

Al ₂ O ₃ -SiO ₂ - the rest.

The composition obtained in examples 1-13 of the catalysts and the characteristics of their heat treatment conditions are given in table. 1

Table 1
The composition and characteristics of the conditions of heat treatment of catalysts Sample Composition,% mass Carrier Temperature ° C MoO ₃ Soo Nio intermediate heat treatment final heat treatment drying calcination Example 1 25.0 8.0 - Al ₂ O ₃ 150 150 550 Example 2 14.0 4.0 - Al ₂ O ₃ 150 150 550 Example 3 3.0 1,0 - Al ₂ O ₃ 150 150 550 Example 4 25.0 - 8.0 Al ₂ O ₃ 100 100 400 Example 5 14.0 - 4.0 Al ₂ O ₃ 100 100 400 Example 6 3.0 - 1,0 Al ₂ O ₃ 100 100 400 Example 7 25.0 4.0 4.0 Al ₂ O ₃ 200 200 500 Example 8 14.0 2.0 2.0 Al ₂ O ₃ 200 200 600 Example 9 3.0 0.5 0.5 Al ₂ O ₃ 200 200 650 Example 10 14.0 - 4.0 SiO ₂ 200 200 500 Example 11 14.0 4.0 - TiO ₂ 200 200 600 Example 12 (prototype) 14.0 4.0 - Al ₂ O ₃ -SiO ₂ 500 200 500 Example 13 (prototype) 14.0 - 4.0 Al ₂ O ₃ -SiO ₂ 300 200 500

The catalysts prepared according to the proposed method according to examples 2, 5, 8 and the catalysts according to the prototype (examples 12 and 13) were tested during hydrotreating a model mixture (toluene - 80.0%, hexene-1 - 19.0% and thiophene-1, 0%) at a temperature of 350 ° C, a pressure of 2.0 MPa, a volumetric feed rate of 3.0 h ^-1 and a ratio of H ₂ : feed 300 nm ³ / m ³ . An important point in hydrotreating this mixture is the maximum removal of sulfur (thiophene) and olefins (hexenes) with minimal hydrogenation of toluene. The hydrodesulfurization activity of the catalysts was determined by the thiophene content in the hydrogenate (column 6), and the hydrogenation activity was determined by the decrease in the mass fraction of hexenes in the hydrogenate (column 1).

The results of catalytic tests (for 20 hours) are shown in table 2.

table 2 Catalyst Mass fraction of the hydrogenated component,% hexenes hexane toluene cyclohexane thiophene 1 2 3 4 6 5 Example 2 0.1 18.9 79 1,065 0.0020 Example 5 0.05 18.95 78.5 1,598 0.0030 Example 8 0.05 18.95 79.5 0.533 0.0010 Example 10 0.09 18.91 79.8 0.213 0.0045 Example 11 0,07 18.93 79.7 0.320 0.0040 Example 12 (prototype) 0.15 18.85 79.6 0.426 0.0055 Example 13 (prototype) 0.12 18.88 79.8 0.213 0.0060

As can be seen from the data of table 2, the catalysts of the proposed method (examples 2, 5, 8, 10 and 11) in hydrodesulfurization and hydrogenating activities are superior to the catalysts of the prototype (examples 12 and 13). It should be noted that the catalyst of Example 8, containing 2.0% CoO and 2.0% NiO, is most active both in the removal of thiophene and in the hydrogenation of hexenes with the least hydrogenation of toluene.

The catalysts according to examples 1, 2 and 13 (prototype), as well as industrial catalysts GO-70 and GO-86 were tested on a pilot plant during hydrotreatment of straight-run diesel fraction: fraction 180-360 ° С; density - 842 kg / m ³ ; sulfur content - 1.0%. Process conditions: temperature - 340 and 360 ° C; pressure - 20 atm .; volumetric feed rate - 4 h ^-1 ; the ratio of H ₂ : raw materials - 500 nm ³ / m ³ . The hydrodesulfurization activity of the catalysts was determined by the decrease in the hydrogen mass of the sulfur mass fraction (columns 2 and 3) and was calculated as the degree of conversion from (columns 4 and 5) by the formula:

K (%) = (C _s -C _p ) · 100 / C _s ,

where C _s and C _p - sulfur content in the raw material and product (hydrogenate),%, respectively.

The results of catalytic tests (for 72 hours) are shown in table 3.

Table 3 Catalyst Mass fraction of sulfur in the hydrogenate,% The degree of conversion,% 340 ° C 360 ° C 340 ° C 360 ° C 1 2 3 4 5 Example 1 0,065 0,034 93.5 96.1 Example 2 0,070 0,040 93.0 95.5 Example 13 (prototype) 0.147 0,079 85.3 92.1 GO-70 0.165 0,085 83.5 91.5 GO-86 0.145 0,080 85.5 92.0

As can be seen from the data in table 3, the catalysts of the proposed method for hydrodesulfurization and hydrogenating activities are superior to the catalyst of the prototype (example 13) and industrial catalysts GO-70 and GO-86.

The catalysts according to examples 2, 3, 5, 6, 8, 9, 12 (prototype) and 13 (prototype) were tested in a pilot installation during the hydrotreatment of the benzene-toluene-xylene pyrocondensate fraction: styrene and sulfur content, respectively, 1.3 and 0 , 06%. Catalytic test conditions: t - 230 and 270 ° C; p - 5.0 MPa; v - 2 h ^-1 ; H ₂ : feedstock - 1000 nm ³ / m ³ . The test duration of the catalyst at the test temperature was 24 hours

The results of the catalytic tests are shown in table 4.

Table 4 Catalyst Mass fraction of sulfur in the hydrogenate,% Mass fraction of styrene in hydrogenate,% 230 ° C 270 ° C 230 ° C 270 ° C 1 2 3 4 5 Example 2 0.0025 0.0020 0.1 0.1 Example 3 0.0030 0.0025 0.2 0.1 Example 5 0.0020 0.0015 0.1 0.1 Example 6 0,025 0.0018 0.2 0.1 Example 8 0.0015 0.0010 0.1 0.1 Example 9 0.0027 0.0012 0.2 0.1 Example 11 0.0026 0.0011 0.1 0.1 Example 12 (prototype) 0.0035 0.0025 0.3 0.2 Example 13 (prototype) 0.0040 0.0030 0.3 0.2

As can be seen from the data in table 4, the catalysts of the proposed method for hydrodesulfurization (columns 2 and 3) and hydrogenating (columns 4 and 5) activities are superior to the catalysts of the prototype (examples 12 and 13).

Claims (3)

1. A method of preparing a catalyst for hydrotreating petroleum products by two-stage impregnation of a pre-calcined carrier with a solution of ammonium heptamolybdate in the first stage and solutions of active metals in the second with intermediate and final heat treatments, including drying and calcination, characterized in that the cobalt nitrate and / or nickel nitrate and intermediate heat treatment are carried out at a temperature of 100-200 ° C, and the final heat treatment, including drying and calcination, is carried out ootvetstvenno at a temperature of 100-200 ° C and 400-650 ° C. 2. The method according to claim 1, characterized in that the obtained catalyst has the following composition, wt.%: MoO ₃ 3.0-25.0 CoO and / or NiO 1.0-8.0 Media Else 3. The method according to claim 1, characterized in that as the carrier use alumina, or silicon oxide, or titanium oxide.