RU2493910C1 - Zeolite-containing catalyst, method for production thereof and method of converting straight-run gasoline fraction to high-octane gasoline component with low benzene content - Google Patents

Abstract

FIELD: chemistry.SUBSTANCE: invention relates to oil refining and petrochemical industry, particularly to methods of producing catalysts for converting a straight-run gasoline fraction into a high-octane gasoline component with low benzene content. Described is a catalyst which contains the following, wt %: H-ZSM-5 type high-silica zeolite with silica modulus SiO/AlO= 30-50 - 94.0-99.0, cobalt molybdo-bismuthate or molybdo-phosphate 1.0-6.0, formed during heat treatment. Described is a method of producing a catalyst, which involves hydrothermal crystallisation of a reaction mixture at 120-180°C, which contains sources of silicon, aluminium and alkali metal oxides, hexamethylenediamine and water, followed by drying and calcining, mechanochemical treatment in a vibration mill, moulding with further saturation of the H-form of the H-ZSM-5 type high-silica zeolite with silica modulus SiO/AIO=30-50 with chloride solutions of corresponding heteropoly compounds: cobalt molybdo-bismuthate or cobalt molybdo-phosphate, as a modifying additive, followed by mechanochemical treatment in a vibration mill for 0.1-24 hours, moulding the catalyst mass into granules, drying and calcining at 540-550°C for 0.1-12 hours. Described is a method of converting a straight-run gasoline fraction into high-octane gasoline component with low benzene content in the presence of the catalyst described above at 350-425°C, volume rate of 1.0-2.0 hand pressure of 0.1-1.0 MPa.EFFECT: high activity and selectivity of the catalyst.3 cl, 1 tbl, 7 ex

Description

The invention relates to the refining and petrochemical industries, in particular, to methods for producing catalysts for converting a straight-run gasoline fraction into a high-octane gasoline component with a low benzene content.

The main industrial process for producing high-octane gasolines and aromatic hydrocarbons is the catalytic reforming of straight-run gasoline fractions on modified alumina-platinum catalysts, which is carried out at high temperatures of 450 ÷ 570 ° C, high pressure of 0.1 ÷ 3.5 MPa and in a hydrogen-containing gas environment. The disadvantages of the process of catalytic reforming of straight-run gasolines are the high temperature and pressure of the process, the use of expensive Pt-containing catalyst, hydrogen-containing gas and the high content of benzene and aromatic hydrocarbons in the reaction products.

A known method of preparing a catalyst for oligomerization and aromatization of low molecular weight hydrocarbons C ₂ ÷ C ₁₂ , containing a pentasil family zeolite with a silicate module SiO ₂ / Al ₂ O ₃ = 20 ÷ 80, modified with zinc oxide, platinum and boron oxide, a binder - alumina ( Pat. RU No. 2144845, B01J 29/44, C10G 35/095, 1998).

The disadvantages of this catalyst are the use of an expensive Pt-modifier and a low yield of 34.7 wt.% Of the liquid products of the reaction of NGL conversion at 600 ° C.

A known method of producing a catalyst for the conversion of low molecular weight hydrocarbons to high octane gasoline or aromatic hydrocarbons containing a pentasil zeolite with a silicate module SiO ₂ / Al ₂ O ₃ = 20 ÷ 80, modified with zinc oxide, platinum and phosphorus oxide, a binder is alumina (Pat . RU No. 2144846, B01J 29/44, C10G 35/095, 1998).

The disadvantages of this catalyst are the use of an expensive Pt-modifier and a low yield of 54.2 wt.% Of the liquid reaction products of the conversion of NGL at 600 ° C.

A known method of producing high-octane gasoline with a low content of benzene from raw materials, including catalytic reforming of gasoline feedstock to produce catalysis, the separation of hydrogen-containing gas from catalysis and the separation of high-octane gasoline and stabilization gases from the obtained unstable product (Pat. RU No. 2213124, C10G 35/095, 59/02, 2002).

Then, a gasoline fraction containing more than 5.0 wt.% Benzene and aliphatic hydrocarbons is isolated from high-octane catalyzate, and it is contacted with a catalyst including a zeolite of the pentasil group under the conditions of formation of aromatic hydrocarbons from aliphatic components of the fraction and the conversion of at least part of benzene, and the resulting product is mixed with an unstable reformate.

The disadvantages of this method are the multi-stage and complexity of the process for producing high-octane gasolines.

A known zeolite catalyst and a method for converting a straight-run gasoline fraction of oil into a high-octane gasoline component (Pat. RU No. 23233778, B01J 29/42, 2006). The catalyst contains a high-silica zeolite with a molar ratio of SiO ₂ / Al ₂ O ₃ = 60 with a residual Na ₂ O content of not more than 0.02 wt.%, Modified with Pt, Ni, Zn or Fe metals, which are part of the catalyst in the form of nanosized powders and their content is not more than 1.5 wt.%.

The method of converting the gasoline fraction of oil into a high-octane component of gasoline is carried out by contacting them with a catalyst at 300 ÷ 400 ° C, atmospheric pressure and a catalyst load of 2.0 h ^-1 for raw materials.

The disadvantage of this method is the rather high content of aromatic hydrocarbons in the catalysis.

A known catalyst for the conversion of aliphatic hydrocarbons C ₂ ÷ C ₁₂ , a method for its production and a method for converting aliphatic hydrocarbons C ₂ ÷ C ₁₂ into high-octane gasoline and / or aromatic hydrocarbons (Pat. RU No. 2235590, B01J 29/46, 2003). The catalyst contains an iron aluminosilicate with a zeolite structure of type H-ZSM-5 with a silicate module SiO ₂ / Al ₂ O ₃ = 20 ÷ 160, SiO ₂ / Fe ₂ O ₃ = 30 ÷ 5000, which is obtained by hydrothermal crystallization of the reaction mixture at 120-180 ° C for 1 ÷ 6 days, containing sources of silicon oxide, aluminum oxide, alkali metal oxide, hexamethylenediamine and water, with further mixing of iron-aluminum silicate with compounds of modifying metals, hardening additives and a binder, followed by mechanochemical processing, molding of the catalyst mass, drying and calcination . As a modifying component it contains at least one oxide of an element selected from the group of copper, zinc, gallium, lanthanum, molybdenum, rhenium in an amount of 0.1 ÷ 10.0 wt.%.

The method of converting aliphatic hydrocarbons C ₂ ÷ C ₁₂ to high-octane gasoline and / or aromatic hydrocarbons in the presence of a catalyst is carried out at 300 ÷ 550 ° C, a space velocity of 0.5 ÷ 5.0 h ^-1 and a pressure of 0.1 ÷ 1.5 MPa .

The disadvantage of this method is the high content of benzene and aromatic hydrocarbons in the catalysis.

The closest in essence technical solution is a zeolite-containing catalyst, a method for its production and a method for converting a straight-run gasoline fraction into a high-octane gasoline component with a low benzene content, adopted as a prototype (Pat. RU No. 2446882, B01J 29/40, 2010). The zeolite-containing catalyst contains a high-silica zeolite of the type H-ZSM-5 with a silicate module SiO ₂ / Al ₂ O ₃ = 30 ÷ 50; as a modifying component it contains metal, at least one of the group: copper, tungsten, molybdenum, introduced into high-silica zeolite in the form of nanosized metal powders, in an amount of 1.0 ÷ 3.0 wt.%; the catalyst is formed during the heat treatment.

The zeolite-containing catalyst is obtained by hydrothermal crystallization of the reaction mixture at 120-180 ° C for 1-6 days, containing sources of silicon oxide, aluminum oxide, alkali metal oxide, hexamethylene diamine and water, with further mixing of high-silica zeolite with nanosized metal powders obtained by electric explosion metal wires in an inert argon gas medium, followed by mechanochemical treatment, molding the catalyst mass, drying and calcining.

The method of converting a straight-run gasoline fraction into a high-octane gasoline component with a low benzene content in the presence of a catalyst is carried out at 350 ÷ 425 ° C, a space velocity of 1.0 ÷ 2.0 h ^-1 and a pressure of 0.1 ÷ 1.0 MPa.

The disadvantage of the method adopted for the prototype is not a sufficiently high yield of the high-octane component of gasoline in the reaction products.

The objective of the invention is to obtain an active and selective catalyst for the process of converting straight-run gasoline fractions into a high-octane gasoline component with a low benzene content.

The technical result is achieved by the fact that the proposed zeolite-containing catalyst for processing straight-run gasoline fraction into a high-octane gasoline component with a low benzene content is obtained by mechanochemical treatment of the H-form of high-silica zeolite type H-ZSM-5 with a silicate module SiO ₂ / Al ₂ O ₃ = 30 ÷ 50 in a vibrating mill for 0.1 ÷ 24 hours, molding the catalyst mass into granules, drying and impregnating the catalyst mass with hydrochloric acid solutions of the corresponding heteropoly compounds: cobalt molybdum bismuthate or molybdofo cobalt phosphate, as a modifying additive, in an amount of 1.0 ÷ 6.0 wt.%, followed by drying and the catalyst was formed during heat treatment at 540 ÷ 550 ° C for 0.1 ÷ 12 hours

Under the action of mechanochemical and high-temperature treatments of zeolite with supported heteropoly compounds: cobalt molybdum bismuthate or cobalt molybdophosphate, the high-silica zeolite H-ZSM-5 is modified by the active components of the heteropoly compounds: cobalt molybdum bismuthate, selective cobalt formation and molybdenum.

The invention is illustrated by the following examples.

Example 1. (prototype). To 200 g of water glass (29% SiO ₂ , 9% Na ₂ O, 62% H ₂ O), 11.8 g of hexamethylenediamine (R) in 100 ml of H ₂ O, 24.15 g of Al (NO ₃ ) are added with stirring. ₃ · 9H ₂ O in 160 ml of H ₂ O, 1 g of “seed” of high-silica zeolite and a 0.1 N HNO ₃ solution is added. The resulting mixture was loaded into stainless steel autoclaves, heated to 175 ÷ 180 ° C and kept under stirring for 2 ÷ 6 days, and then cooled. The synthesized product is washed with water, dried and calcined at 550–600 ° C for 12 hours. For conversion to the H form, zeolites are decationed by treatment with a 25% solution of NH ₄ Cl (10 ml of solution per 1 g of zeolite) at 90 ° C for 2 hours, then washed water, dried at 110 ° C and calcined at 540 ° C for 6 hours. Get H-ZSM-5 with a silicate module SiO ₂ / Al ₂ O ₃ = 30, the crystallinity of the product is 96%.

Then 10 g of H-ZSM-5 with a silicate module SiO ₂ / Al ₂ O ₃ = 30 is subjected to mechanochemical treatment in a vibrating mill for 8 hours, after which the catalyst mass is formed into granules, dried for 2 hours at 20 ÷ 30 ° C, then at 110 ° From 4 hours and calcined for 8 hours at 540 ÷ 550 ° C.

Example 2. (prototype). H-ZSM-5 with a silicate module SiO ₂ / Al ₂ O ₃ = 50 was obtained in the same manner as in Example 1, but instead of 24.15 g of Al (NO ₃ ) ₃ · 9H ₂ O, 14.475 g of Al (NO ₃ ) were taken ₃ · 9H ₂ O.

Then, 9.9 g of H-ZSM-5 with a silicate module SiO ₂ / Al ₂ O ₃ = 50 are mixed with 0.1 g of Mo nanopowder (NRP) and subjected to mechanochemical treatment in a vibration mill for 4 hours. The resulting catalyst mass is formed into granules, dried for 2 hours at 110 ° C and calcined for 8 hours at 540 ÷ 550 ° C.

The obtained zeolite-containing catalyst has a composition, wt.%:

H-ZSM-5 (SiO ₂ / Al ₂ O ₃ = 50) - 99.0; Mo - 1.0

Example 3. Same as in example 2, but instead of 9.9 g of H-ZSM-5, 3.96 g of H-ZSM-5 with a silicate module SiO ₂ / Al ₂ O ₃ = 50 are taken and the zeolite granules are impregnated with a hydrochloric acid solution in which 0.04 g of heteropoly compound (HPS) of cobalt molybdum bismuthate crystalline hydrate [Co [H ₃ BiMo ₁₂ O ₄₀ ] · 13H ₂ O] · 12H ₂ O was dissolved in terms of the moisture capacity of the zeolite. The zeolite is impregnated at 40 ÷ 50 ° C and stirring for 2 hours, after which the zeolite is dried at 110 ° C for 6 hours and calcined for 8 hours at 540 ÷ 550 ° C.

The obtained zeolite-containing catalyst has a composition, wt.%:

H-ZSM-5 (SiO ₂ / Al ₂ O ₃ = 50) - 99.0; GPS cobalt molybdenum bismuthate crystalline hydrate - 1.0

Example 4. Same as in example 3, but instead of 3.96 g of H-ZSM-5, 3.92 g of H-ZSM-5 with a silicate module SiO ₂ / Al ₂ O ₃ = 50 are taken and the zeolite granules are impregnated with a hydrochloric acid solution in which 0.08 g of heteropoly compound (HPS) of cobalt molybdum bismuthate crystalline hydrate [Co [H ₃ BiMo ₁₂ O ₄₀ ] · 13H ₂ O] · 12H ₂ O was dissolved by the water capacity of the zeolite. The zeolite is impregnated at 40 ÷ 50 ° C and stirring for 3 hours, after which the zeolite is dried at 110 ° C for 4 hours and calcined for 8 hours at 540 ÷ 550 ° C.

The obtained zeolite-containing catalyst has a composition, wt.%:

H-ZSM-5 (SiO ₂ / Al ₂ O ₃ = 50) - 98.0; GPS cobalt molybdenum bismuthate crystalline hydrate - 2.0.

Example 5. Same as in example 3, but instead of 3.96 g of H-ZSM-5, 3.76 g of H-ZSM-5 with silica module SiO ₂ / Al ₂ O ₃ = 50 are taken and the zeolite granules are impregnated with hydrochloric acid solution in which 0.24 g of the heteropoly compound (HPS) of cobalt molybdum bismuthate crystalline hydrate [Co [H ₃ BiMo ₁₂ O ₄₀ ] · 13H ₂ O] · 12H ₂ O is dissolved according to the moisture capacity of the zeolite. The zeolite is impregnated at 40 ÷ 0 ° C and stirring for 2 hours, after which the zeolite is dried at 110 ° C for 6 hours and calcined for 8 hours at 540 ÷ 550 ° C.

The obtained zeolite-containing catalyst has a composition, wt.%:

H-ZSM-5 (SiO ₂ / Al ₂ O ₃ = 50) - 94.0; GPS cobalt molybdenum bismuthate crystalline hydrate - 6.0.

Example 6. Same as in example 2, but instead of 9.9 g of H-ZSM-5, 3.96 g of H-ZSM-5 with a silicate module SiO ₂ / Al ₂ O ₃ = 50 are taken and the zeolite granules are impregnated with hydrochloric acid solution in which 0.04 g of heteropoly compound (HPS) of cobalt molybdophosphate crystalline hydrate [Co ₃ [PMo ₁₂ O ₄₀ ] · 14H ₂ O are dissolved in terms of the moisture capacity of the zeolite. The zeolite is impregnated at 40 ÷ 50 ° C and stirring for 2 hours, after which the zeolite is dried at 110 ° C for 4 hours and calcined for 8 hours at 540 ÷ 550 ° C.

The obtained zeolite-containing catalyst has a composition, wt.%:

H-ZSM-5 (SiO ₂ / Al ₂ O ₃ = 50) - 99.0; GPS cobalt molybdophosphate crystalline hydrate - 1.0.

Example 7. Same as in example 6, but instead of 9.9 g of H-ZSM-5, 3.76 g of H-ZSM-5 with a silicate module SiO ₂ / Al ₂ O ₃ = 50 are taken and the zeolite granules are impregnated with a hydrochloric acid solution in which 0.24 g of the heteropoly compound (HPS) of cobalt molybdophosphate crystalline hydrate [Co ₃ [PMo ₁₂ O ₄₀ ] · 14H ₂ O is dissolved by the moisture capacity of the zeolite. The zeolite is impregnated at 40 ÷ 50 ° C and stirring for 3 hours, after which the zeolite is dried at 100 ° C for 4 hours and calcined for 8 hours at 540 ÷ 550 ° C.

The obtained zeolite-containing catalyst has a composition, wt.%:

H-ZSM-5 (SiO ₂ / Al ₂ O ₃ = 50) - 94.0; GPS cobalt molybdophosphate crystalline hydrate - 6.0.

The obtained catalysts are tested in the process of converting aliphatic hydrocarbons (straight-run gasoline fraction 40 ÷ 185 ° С) into a high-octane gasoline component in an automated flow-through installation with a stationary catalyst layer at temperatures of 350 ÷ 425 ° С, bulk feed rate 1.0 ÷ 2.0 h ^-1 and a pressure of 0.1 ÷ 1.0 MPa.

In the process of converting a mixture of aliphatic hydrocarbons (straight-run gasoline fraction 40 ÷ 185 ° C) with an increase in the reaction temperature from 350 to 425 ° C, cracking, dehydrogenation, isomerization, dehydrocyclization and aromatization of paraffin hydrocarbons proceed with the formation of H-ZSM-5 high-silica zeolite mainly in the first stages of the process of olefinic hydrocarbons, which are subsequently converted to isoparaffinic and alkyl aromatic hydrocarbons.

The introduction of modifying additives in the form of heteropoly compounds into the high-silica zeolite of the H-ZSM-5 type: molybdum bismuthate or cobalt molybdophosphate in an amount of 1.0–6.0 wt.% Can significantly increase the yield of the high-octane gasoline component, the yield of alkyl aromatic hydrocarbons and lower the yield of benzene to 1, 0 ÷ 2.0 wt.% From straight-run gasoline fractions, compared with unmodified zeolite.

The examples in the table clarify the invention without limiting it.

As can be seen from examples of catalysts 1–7 of the table, catalysts 3–7 have a higher yield (60–82%) of liquid reaction products — high-octane gasoline from straight-run gasoline fractions than the catalysts of the prototype (examples 1 and 2).

Thus, the proposed catalysts for the conversion of aliphatic hydrocarbons of a straight-run gasoline fraction into a high-octane gasoline component and aromatic hydrocarbons based on a high-silica zeolite of the H-ZSM-5 type with a silicate module SiO ₂ / Al ₂ O ₃ = 30-50 and modified by heteropoly compounds: molybdisulfate or molybdisulfate cobalt in an amount of 1.0 ÷ 6.0 wt.% can increase the output of high-octane gasoline up to 60 ÷ 82% and the yield of alkyl aromatic hydrocarbons from aliphatic hydrocarbons straight-run gasoline FR ktsii 40 ÷ 185 ° C and reduce the benzene content in catalyzate ÷ 2.0 to 1.0 wt.%.

Preliminary mechanochemical activation of high-silica zeolite of the type H-ZSM-5, introduction of zeolite heteropoly compounds of molybdum bismuthate or cobalt molybdophosphate in an amount of 1.0 ÷ 6.0 wt.% And subsequent drying and calcination at 540 ÷ 550 ° C leads to the formation of active components from heteropoly compounds molybdum bismuthate or cobalt molybdophosphate on the surface of the zeolite and allows you to get a highly dispersed, active and selective catalyst. The introduction of zeolite heteropoly compounds of molybdenum bismuthate or cobalt molybdophosphate in an amount of 1.0 ÷ 6.0 wt.% Allows to increase the yield of high-octane gasoline to 60 ÷ 82% and the yield of alkyl aromatic hydrocarbons from aliphatic hydrocarbons of straight-run gasoline fraction.

A method of producing a high-octane gasoline component with a low benzene content from a straight-run gasoline fraction in the presence of catalysts based on high-silica zeolite type H-ZSM-5 with a silicate module SiO ₂ / Al ₂ O ₃ = 30 ÷ 50 and modified with heteropoly compounds: molybdenum bismuthate or cobalt molybdophosphate 1.0 ÷ 6.0 wt.%, Allow to increase the yield of high-octane gasoline and the yield of alkyl aromatic hydrocarbons from aliphatic hydrocarbons of straight-run gasoline fraction 40 ÷ 185 ° C than in the presence of a catalyst of the prototype (Example 1-2).

Table Conversion of straight-run gasoline fraction on zeolite-containing catalysts Catalyst Example No. T _p , ° C V _about , h ^-1 The yield of products, wt.% Estimated Octane Number, MI gas phase liquid phase benzene arenas one 350 2.0 34.9 65.1 1,2 21.8 92.3 (prototype of Pat. RU No. 2446882) 375 2.0 36.8 63,2 1,5 23,4 94.7 400 2.0 42.9 57.1 2,8 26.7 95.5 425 2.0 45.1 54.9 3.6 31.5 96.5 2 350 2.0 22.2 77.8 0.8 17.6 91.9 (prototype of Pat. RU No. 2446882) 375 2.0 30,4 69.6 1.4 23.1 94.4 400 2.0 37.3 62.7 1.8 27.7 95.2 425 2.0 41.8 58.2 2.0 32,7 96.8 3 350 2.0 33.8 66,2 1,1 23,2 93.0 375 2.0 34.7 65.3 1.3 25.8 94.6 400 2.0 39.3 60.7 2,3 29.4 96.1 425 2.0 40,4 59.6 3.0 31.7 96.8 four 350 2.0 31.3 68.7 1,2 25,2 94.5 375 2.0 32.9 67.1 1.7 28.9 96.4 400 2.0 35.0 65.0 2.0 31.9 97.1 425 2.0 37.0 63.0 2,4 32,5 98.2 5 350 2.0 19.0 81.0 0.8 20,4 91.9 350 1,0 27.5 72.5 1.3 25.1 93.5 375 2.0 23,2 76.8 1,1 23,2 92.9 400 2.0 27.5 72.5 1.4 25.1 93.6 425 2.0 29.4 70.6 1,5 25.5 93.8 6 350 2.0 17.6 82,4 0.8 19.5 91.9 375 2.0 21.7 78.3 1,1 22.0 92.9 400 2.0 26.1 73.9 1.4 24.3 94.4 425 2.0 34.6 65,4 1.9 31.8 96.8 7 350 2.0 12,4 87.6 0.6 16,0 88.8 375 2.0 18.6 81.4 0.8 18.3 90.5 400 2.0 22.5 77.5 1,1 20.9 91.8 400 1,0 26.7 73.3 1.4 22.1 92.9 425 2.0 27.3 72.7 1,5 23.5 93,4

Claims (3)

1. Zeolite-containing catalyst for converting straight-run gasoline fraction into a high-octane gasoline component with a low benzene content, characterized in that it contains high-silica zeolite type H-ZSM-5 with a silicate module SiO ₂ / Al ₂ O ₃ = 30 ÷ 50, as a modifying the component contains heteropoly compounds based on: molybdobismuthate or cobalt molybdophosphate in an amount of 1.0 ÷ 6.0 wt.%; the catalyst is formed during the heat treatment and has the following composition, wt.%:
High-silica zeolite type H-ZSM-5 with silicate module SiO ₂ / Al ₂ O ₃ = 30 ÷ 50 94.0 ÷ 99.0 Cobalt molybdum bismuthate or cobalt molybdophosphate 1,0 ÷ 6,0 2. The method of producing a zeolite-containing catalyst according to claim 1, characterized in that the high-silica zeolite type H-ZSM-5 with a silicate module SiO ₂ / Al ₂ O ₃ = 30 ÷ 50 is obtained by hydrothermal crystallization of the reaction mixture at 120 ÷ 180 ° C for 1 ÷ 6 days., Containing sources of silicon oxide, alumina, alkali metal oxide, hexamethylenediamine and water, followed by drying at 100 ÷ 110 ° C for 2 ÷ 4 hours, calcination at 550 ÷ 600 ° C for 6 ÷ 8 hours, mechanochemical treatment in a vibrating mill for 0.1 ÷ 12 hours, molding of the catalyst mass and further impregnation of catalysis H-ZSM-5 mass fraction with hydrochloric acid solutions of heteropoly compounds: molybdum bismuthate or cobalt molybdophosphate in an amount of 1.0–6.0 wt.%, followed by drying at 100–110 ° С for 2–4 h and calcination at 540–550 ° From 8-12 hours 3. A method of converting a straight-run gasoline fraction into a high-octane gasoline component with a low benzene content in the presence of a catalyst, characterized in that the catalyst according to claim 1 is used and the process of converting a straight-run gasoline fraction into a high-octane gasoline component with a low benzene content is carried out at 350 ÷ 425 ° C volumetric velocity of 1.0 ÷ 2.0 h ^-1 and a pressure of 0.1 ÷ 1.0 MPa.