CN109395716B

CN109395716B - Yield-increasing light aromatic hydrocarbon catalyst

Info

Publication number: CN109395716B
Application number: CN201710709603.2A
Authority: CN
Inventors: 李经球; 张�荣; 孔德金
Original assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Current assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Priority date: 2017-08-18
Filing date: 2017-08-18
Publication date: 2021-10-01
Anticipated expiration: 2037-08-18
Also published as: CN109395716A

Abstract

The invention relates to a yield-increasing light aromatic hydrocarbon catalyst, which mainly solves the problems of low hydrogenation selectivity of polycyclic aromatic hydrocarbon and high loss rate of monocyclic aromatic hydrocarbon in the prior art. The invention provides a polycyclic aromatic hydrocarbon selective hydrogenation catalyst, which comprises: the technical scheme that the catalyst contains a non-acidic or weakly acidic porous carrier and at least two metal elements or compounds selected from VIII, IVB and VB loaded on the carrier, and the metal elements or compounds are distributed on the surface of the carrier in a nuclear shell layer manner, so that the hydrogenation selectivity of the polycyclic aromatic hydrocarbon is remarkably improved, and the loss of monocyclic aromatic hydrocarbon is reduced.

Description

Yield-increasing light aromatic hydrocarbon catalyst

Technical Field

The invention relates to a yield-increasing light aromatic hydrocarbon catalyst and a preparation method thereof.

Background

The polycyclic aromatic hydrocarbon refers to an aromatic hydrocarbon component with a bicyclic structure and a polycyclic structure, and exists in the catalytic cracking, ethylene tar and PX production processes in a large amount, for example, the annual yield of catalytic cracking light cycle oil exceeds 1000 ten thousand tons, and most of the aromatic hydrocarbon component is used as a diesel oil blending component. With the increasing demand of PX in China in recent years, PX has a situation of short supply and short demand. Realizing the large-scale of an aromatic hydrocarbon combination device and the diversification of raw materials is one of the key factors for solving the current problems. Therefore, it is of great significance to fully utilize the polycyclic aromatic hydrocarbons co-produced by the aromatic hydrocarbon combination device and research the polycyclic aromatic hydrocarbons co-produced by the oil refining device to produce the light aromatic hydrocarbons. From the view of the reaction process, one of the most critical steps for realizing the conversion from the polycyclic aromatic hydrocarbon to the monocyclic aromatic hydrocarbon is to realize the selective hydrogenation of the polycyclic aromatic hydrocarbon and partially hydrogenate the polycyclic aromatic hydrocarbon to generate a monocyclic aromatic hydrocarbon component. In a system with coexistence of monocyclic aromatic hydrocarbon and polycyclic aromatic hydrocarbon, the realization of the selective hydrogenation of the aromatic hydrocarbon is an important process for improving the yield of the monocyclic aromatic hydrocarbon. While the hydrogenation saturation of monocyclic aromatics such as benzene and toluene is controlled during the production of monocyclic aromatics, metals such as platinum, palladium, non-noble metals molybdenum and nickel are reported to be used for the hydrogenation saturation of polycyclic aromatics.

CN104117386A discloses a polycyclic aromatic hydrocarbon hydrogenation ring-opening catalyst, which is a Beta molecular sieve component containing 5-100% and noble metals selected from Pt, Ir and Pd of 0.1-3% loaded on the Beta molecular sieve component.

CN102688770A discloses an aromatic hydrogenation catalyst, which is composed of mesoporous zeolite and noble metal, and improves the hydrogenation and dearomatization activity and sulfur resistance of the catalyst.

CN103301874B discloses a method for selective ring opening of polycyclic aromatic hydrocarbons by hydrogenation and a catalyst composition, comprising an acidic molecular sieve loaded VIII group metal oxide and a Mo-containing catalyst, wherein the Mo-containing catalyst is a bimetallic sulfide formed by Mo and transition metal, and the yield of a selective ring opening product is remarkably improved by applying a combined catalyst and a water additive.

CN103666553 discloses a process for hydroconversion of polycyclic aromatic hydrocarbons, wherein polycyclic aromatic hydrocarbons are at least partially saturated in a hydrogenation reaction zone to obtain a conversion rate of polycyclic aromatic hydrocarbons of more than 40% and a yield of monocyclic aromatic hydrocarbons of 4-80%; and then the conversion rate of polycyclic aromatic hydrocarbon is more than 85 percent and the relative yield of monocyclic aromatic hydrocarbon is 4-30 percent through the reaction of a hydrocracking reaction zone, thereby reducing the hydrogen consumption of polycyclic aromatic hydrocarbon conversion.

None of the above patent documents relates to a technique for partially hydrogenating a polycyclic aromatic hydrocarbon with high selectivity in a system in which monocyclic and polycyclic aromatic hydrocarbons coexist.

Disclosure of Invention

The invention aims to solve the technical problems of low hydrogenation selectivity of polycyclic aromatic hydrocarbons and low yield of monocyclic aromatic hydrocarbons in the prior art, and provides a novel selective hydrogenation catalyst for polycyclic aromatic hydrocarbons, which has the advantages of high selective hydrogenation rate of polycyclic aromatic hydrocarbons and low loss of monocyclic aromatic hydrocarbons when the catalyst is used for treating materials containing monocyclic aromatic hydrocarbons and polycyclic aromatic hydrocarbons.

In order to solve the technical problems, the invention adopts the following technical scheme: yield-increasing light aromatic hydrocarbon catalyst

The method comprises the following steps: contains a non-acidic or weakly acidic porous carrier and at least two metal elements or compounds selected from VIII, IVB and VB loaded on the carrier; the metal elements or compounds are distributed on the surface of the carrier in a nuclear shell layer.

In the technical scheme, the non-acidic or weakly acidic porous carrier is selected from at least one of alumina, amorphous silica-alumina, kaolin and aluminosilicate. The metal is at least two selected from Pt, Pd, Ir, Rh, Ti, V, Zr and Nb.

The nuclear phase layer metal is at least one of metals of Ti, V, Zr and Nb and compounds thereof. The shell phase layer metal is at least one selected from Pt, Pd, Ir, Rh metal and their compounds.

In a more optimized scheme, the nuclear phase layer metal simultaneously comprises a mixture of Zr and Nb, wherein the weight ratio of compounds of Zr and Nb is (0.1-10): 1; the mixture of Zr and Nb has a synergistic effect in enhancing the selective hydrogenation of the fused ring compound.

In a more optimized scheme, the shell phase layer metal simultaneously comprises a mixture of Pt and Pd, wherein the weight ratio of compounds of Pt and Pd is (0.1-5): 1; the Pt and Pd mixture has synergistic effect in improving the selective hydrogenation activity of the condensed ring compound.

The selective hydrogenation catalyst for the polycyclic aromatic hydrocarbon comprises, by weight, 0.01-20 parts of nuclear phase layer metal in an optimal scheme, wherein the nuclear phase layer metal content is 0.1-10 parts of the total weight of the catalyst; the content of the metal in the shell phase layer is 0.01-10 parts of the total weight of the catalyst, and the optimized scheme is 0.02-5 parts.

In order to solve the second technical problem, the invention adopts the following technical scheme: a preparation method of a light aromatic hydrocarbon catalyst for increasing yield comprises the following steps:

a) dissolving salt containing nuclear phase layer metal in water or non-aqueous solution, loading a layer of metal compound on a carrier by the methods of precipitation, physical adhesion and impregnation, drying, and roasting at the temperature of 400-600 ℃ to prepare the catalyst I with the nuclear phase layer structure.

b) Dissolving salt containing shell phase layer metal in water or non-aqueous solution, loading on the catalyst I by a dipping, precipitation or coating method, drying, and roasting at the temperature of 400-600 ℃ to prepare the yield-increasing light aromatic hydrocarbon catalyst;

wherein, the metal salt in the step a) is selected from at least one of titanium-containing compound, vanadium-containing compound, zirconium-containing compound and niobium-containing compound, and the nonaqueous solution is selected from one of alcohol compound, ketone compound and petroleum ether; b) the metal salt in the step (A) is at least one selected from platinum-containing compounds, palladium-containing compounds, iridium-containing compounds and rhodium-containing compounds, and the non-aqueous solution is one selected from alcohol compounds, ketone compounds and petroleum ether.

The catalyst is reacted under the conditions that the reaction temperature is 100-500 ℃, the reaction pressure is 0.5-8MPa, the hydrogen-hydrocarbon molar ratio is 1-10 and the feed weight space velocity is 0.5-20.

According to the invention, based on the interaction between the core shell layer loaded metals, the electronic characteristics of the shell layer metal can be effectively adjusted, so that the adsorption strength of the shell layer metal to the aromatic hydrocarbon is adjusted, and the selective hydrogenation activity to the polycyclic aromatic hydrocarbon is improved. When the catalyst is used for treating the polycyclic aromatic hydrocarbon material, the catalyst has the advantages of high selective hydrogenation rate of the polycyclic aromatic hydrocarbon and low loss of monocyclic aromatic hydrocarbon.

The invention is further illustrated but is not limited by the following description of the examples:

Detailed Description

[ example 1 ]

The preparation method comprises the steps of soaking 20 g of alumina ball carrier in a certain zirconium chloride solution in the same volume, drying at 120 ℃ for 4 hours, roasting at 550 ℃ for 4 hours to obtain a modified catalyst A1 with the zirconium content of 3% (wt), and soaking the catalyst A1 in a certain chloroplatinic acid solution in the same volume to obtain a core-shell metal layer catalyst B1 with the platinum content of 0.3% (wt).

5 g of core-shell metal layer catalyst B1 is put into a reactor, hydrogen is introduced to reduce for 3 hours at 450 ℃, and then the temperature is reduced to

And (3) introducing hydrogen and contacting the material containing the toluene and the naphthalene with a catalyst at 370 ℃ to perform reaction activity investigation. The reaction conditions are as follows: the total weight space velocity is 10 hours^-1The reaction temperature is 370 ℃, the reaction pressure is 3.0MPa, and the hydrogen-hydrocarbon molecular ratio is 4.0. The reaction raw materials were toluene and naphthalene (40: 60 by weight), and the reaction performance was as shown in table 1. In the table, R2/R1 represents the ratio of the hydrogenation rate of naphthalene to the hydrogenation rate of toluene, and reflects the hydrogenation selectivity of the catalyst to polycyclic aromatic hydrocarbons.

[ example 2 ]

The preparation method comprises the steps of soaking 20 g of alumina ball carrier in a certain zirconium chloride solution in the same volume, drying at 120 ℃ for 4 hours, roasting at 550 ℃ for 4 hours to obtain a modified catalyst A2 with the zirconium content of 6% (wt), and soaking the catalyst A2 in a certain chloroplatinic acid solution in the same volume to obtain a core-shell metal layer catalyst B2 with the platinum content of 0.3% (wt).

5 g of core-shell metal layer catalyst B2 was placed in a reactor, and hydrogen was introduced to reduce at 450 ℃ for 3 hours, and then cooled to 370 ℃, and hydrogen and a material containing toluene and naphthalene were introduced to contact the catalyst for reactivity investigation. The reaction conditions are as follows: the total weight space velocity is 10 hours^-1The reaction temperature is 370 ℃, the reaction pressure is 3.0MPa, and the hydrogen-hydrocarbon molecular ratio is 4.0. The reaction raw materials were toluene and naphthalene (40: 60 by weight), and the reaction performance was as shown in table 1.

[ example 3 ]

The preparation method comprises the steps of soaking 20 g of alumina ball carrier in a certain zirconium chloride solution in the same volume, drying at 120 ℃ for 4 hours, roasting at 550 ℃ for 4 hours to obtain a modified catalyst A3 with the zirconium content of 3% (wt), and soaking the catalyst A3 in a certain chloroplatinic acid solution in the same volume to obtain a core-shell metal layer catalyst B3 with the platinum content of 0.5% (wt).

5 g of core-shell metal layer catalyst B3 was placed in a reactor, and hydrogen was introduced to reduce at 450 ℃ for 3 hours, and then cooled to 350 ℃, and hydrogen and a material containing toluene and naphthalene were introduced to contact the catalyst for reaction activity investigation. The reaction conditions are as follows: the total weight space velocity is 10 hours^-1The reaction temperature is 370 ℃, the reaction pressure is 3.0MPa, and the hydrogen-hydrocarbon molecular ratio is 4.0. The reaction raw materials were toluene and naphthalene (40: 60 by weight), and the reaction performance was as shown in table 1.

[ example 4 ]

The preparation method comprises the steps of soaking 20 g of alumina ball carrier in a certain zirconium chloride solution in the same volume, drying at 120 ℃ for 4 hours, roasting at 550 ℃ for 4 hours to obtain a modified catalyst A4 with the zirconium content of 3% (wt), and soaking the catalyst A4 in a certain palladium chloride acid solution in the same volume to obtain a core-shell metal layer catalyst B4 with the palladium content of 0.3% (wt).

5 g of core-shell metal layer catalyst B4 is placed in a reactor, hydrogen is introduced to reduce for 3 hours at 450 ℃, then the temperature is reduced to 350 ℃, and hydrogen, toluene and naphthalene containing materials and catalysis are introducedAgent contact was performed for reactivity studies. The reaction conditions are as follows: the total weight space velocity is 10 hours^-1The reaction temperature is 370 ℃, the reaction pressure is 3.0MPa, and the hydrogen-hydrocarbon molecular ratio is 4.0. The reaction raw materials were toluene and naphthalene (40: 60 by weight), and the reaction performance was as shown in table 1.

[ example 5 ]

The preparation method comprises the steps of soaking 20 g of alumina ball carrier in a certain zirconium chloride solution in the same volume, drying at 120 ℃ for 4 hours, roasting at 550 ℃ for 4 hours to obtain a modified catalyst A5 with the zirconium content of 3% (wt), and soaking a certain chloroiridic acid solution in the same volume of the catalyst A5 to obtain a core-shell metal layer catalyst B5 with the iridium content of 0.3% (wt).

5 g of core-shell metal layer catalyst B5 was placed in a reactor, and hydrogen was introduced to reduce at 450 ℃ for 3 hours, and then cooled to 350 ℃, and hydrogen and a material containing toluene and naphthalene were introduced to contact the catalyst for reaction activity investigation. The reaction conditions are as follows: the total weight space velocity is 10 hours^-1The reaction temperature is 370 ℃, the reaction pressure is 3.0MPa, and the hydrogen-hydrocarbon molecular ratio is 4.0. The reaction raw materials were toluene and naphthalene (40: 60 by weight), and the reaction performance was as shown in table 1.

[ example 6 ]

Soaking 20 g of alumina ball carrier in a certain vanadium nitrate solution in the same volume, drying at 120 ℃ for 4 hours, roasting at 550 ℃ for 4 hours to obtain a modified catalyst A6 with the vanadium content of 3% (wt), and soaking the catalyst A6 in a certain chloroplatinic acid solution in the same volume to obtain a core-shell metal layer catalyst B6 with the Pt content of 0.3% (wt).

5 g of core-shell metal layer catalyst B6 was placed in a reactor, and hydrogen was introduced to reduce at 450 ℃ for 3 hours, and then cooled to 350 ℃, and hydrogen and a material containing toluene and naphthalene were introduced to contact the catalyst for reaction activity investigation. The reaction conditions are as follows: the total weight space velocity is 10 hours^-1The reaction temperature is 370 ℃, the reaction pressure is 3.0MPa, and the hydrogen-hydrocarbon molecular ratio is 4.0. The reaction raw materials were toluene and naphthalene (40: 60 by weight), and the reaction performance was as shown in table 1.

[ example 7 ]

20 g of alumina ball carrier is taken, dipped with a certain titanium trichloride solution in the same volume, dried for 4 hours at 120 ℃, roasted for 4 hours at 550 ℃ to prepare a modified catalyst A7 with the titanium content of 3 percent (wt), and the catalyst A7 is dipped with a certain chloroplatinic acid solution in the same volume to obtain a core-shell metal layer catalyst B7 with the platinum content of 0.3 percent (wt).

5 g of core-shell metal layer catalyst B7 was placed in a reactor, and hydrogen was introduced to reduce at 450 ℃ for 3 hours, and then cooled to 350 ℃, and hydrogen and a material containing toluene and naphthalene were introduced to contact the catalyst for reaction activity investigation. The reaction conditions are as follows: the total weight space velocity is 10 hours^-1The reaction temperature is 370 ℃, the reaction pressure is 3.0MPa, and the hydrogen-hydrocarbon molecular ratio is 4.0. The reaction raw materials were toluene and naphthalene (40: 60 by weight), and the reaction performance was as shown in table 1.

[ example 8 ]

Soaking 20 g of alumina ball carrier in a certain niobium oxalate solution in the same volume, drying at 120 ℃ for 4 hours, roasting at 550 ℃ for 4 hours to prepare a modified catalyst A8 with the niobium content of 3 percent (wt), and soaking the catalyst A8 in a certain chloroplatinic acid solution in the same volume to obtain a core-shell metal layer catalyst B8 with the platinum content of 0.3 percent (wt).

5 g of core-shell metal layer catalyst B8 was placed in a reactor, and hydrogen was introduced to reduce at 450 ℃ for 3 hours, and then cooled to 350 ℃, and hydrogen and a material containing toluene and naphthalene were introduced to contact the catalyst for reaction activity investigation. The reaction conditions are as follows: the total weight space velocity is 10 hours^-1The reaction temperature is 370 ℃, the reaction pressure is 3.0MPa, and the hydrogen-hydrocarbon molecular ratio is 4.0. The reaction raw materials were toluene and naphthalene (40: 60 by weight), and the reaction performance was as shown in table 1.

[ example 9 ]

A certain amount of zirconium chloride and sodium vanadate solution is soaked in 20 g of alumina ball carrier in an equal volume, the alumina ball carrier is dried at 120 ℃ for 4 hours, and is roasted at 550 ℃ for 4 hours to prepare a modified catalyst A9 with 1 percent (wt) of zirconium content and 2 percent (wt) of vanadium content, and a certain amount of chloroplatinic acid and palladium chloride solution is soaked in a catalyst A9 in an equal volume to obtain a core-shell metal layer catalyst B9 with 0.1 percent (wt) of platinum content and 0.2 percent of palladium content.

5 g of core-shell metal layer catalyst B9 was placed in a reactor, and hydrogen was introduced to reduce at 450 ℃ for 3 hours, and then cooled to 350 ℃, and hydrogen and a material containing toluene and naphthalene were introduced to contact the catalyst for reaction activity investigation. The reaction conditions are as follows: the total weight space velocity is 10 hours^-1The reaction temperature is 370 ℃, the reaction pressure is 3.0MPa, and the hydrogen-hydrocarbon molecular ratio is 4.0. The reaction raw materials were toluene and naphthalene (40: 60 by weight), and the reaction performance was as shown in table 1.

[ example 10 ]

A modified catalyst A10 with zirconium content of 1% (wt) and titanium content of 2% (wt) is prepared by isovolumetrically soaking 20 g of alumina ball carrier in a certain zirconium chloride and titanium chloride solution, drying at 120 ℃ for 4 hours, and calcining at 550 ℃ for 4 hours, and a core-shell metal layer catalyst B10 with platinum content of 0.1% (wt) and palladium content of 0.2% is prepared by isovolumetrically soaking the catalyst A10 in a certain chloroplatinic acid and palladium chloride solution.

5 g of core-shell metal layer catalyst B10 was placed in a reactor, and hydrogen was introduced to reduce at 450 ℃ for 3 hours, and then cooled to 350 ℃, and hydrogen and a material containing toluene and naphthalene were introduced to contact the catalyst for reaction activity investigation. The reaction conditions are as follows: the total weight space velocity is 10 hours^-1The reaction temperature is 370 ℃, the reaction pressure is 3.0MPa, and the hydrogen-hydrocarbon molecular ratio is 4.0. The reaction raw materials were toluene and naphthalene (40: 60 by weight), and the reaction performance was as shown in table 1.

[ example 11 ]

20 g of alumina ball carrier is taken, dipped with a certain zirconium chloride and niobium oxalate solution in equal volume, dried for 4 hours at 120 ℃, roasted for 4 hours at 550 ℃ to prepare a modified catalyst A11 with 1 percent (wt) of zirconium content and 2 percent (wt) of niobium content, and the catalyst A11 is dipped with a certain chloroplatinic acid and palladium chloride solution in equal volume to obtain a core-shell metal layer catalyst B11 with 0.1 percent (wt) of platinum content and 0.2 percent of palladium content.

5 g of core-shell metal layer catalyst B11 was placed in a reactor, and hydrogen was introduced to reduce at 450 ℃ for 3 hours, and then cooled to 350 ℃, and hydrogen and a material containing toluene and naphthalene were introduced to contact the catalyst for reaction activity investigation. The reaction conditions are as follows: the total weight space velocity is 10 hours^-1The reaction temperature is 370 ℃, the reaction pressure is 3.0MPa, and the hydrogen-hydrocarbon molecular ratio is 4.0. The reaction raw materials were toluene and naphthalene (40: 60 by weight), and the reaction performance was as shown in table 1.

[ example 12 ]

20 g of alumina ball carrier is taken, a certain amount of sodium vanadate and titanium trichloride solution is soaked in the same volume, the alumina ball carrier is dried at 120 ℃ for 4 hours, and is roasted at 550 ℃ for 4 hours, so as to prepare a modified catalyst A12 with 1% (wt) of vanadium content and 2% (wt) of titanium content, and a certain amount of chloroplatinic acid and palladium chloride solution is soaked in the catalyst A12 in the same volume, so as to obtain a core-shell metal layer catalyst B12 with 0.1% (wt) of platinum content and 0.2% of palladium content.

5 g of core-shell metal layer catalyst B12 was placed in a reactor, and hydrogen was introduced to reduce at 450 ℃ for 3 hours, and then cooled to 350 ℃, and hydrogen and a material containing toluene and naphthalene were introduced to contact the catalyst for reaction activity investigation. The reaction conditions are as follows: the total weight space velocity is 10 hours^-1The reaction temperature is 370 ℃, the reaction pressure is 3.0MPa, and the hydrogen-hydrocarbon molecular ratio is 4.0. The reaction raw materials were toluene and naphthalene (40: 60 by weight), and the reaction performance was as shown in table 1.

[ example 13 ]

20 g of alumina ball carrier is taken, a certain amount of sodium vanadate and niobium oxalate solution is soaked in the same volume, the mixture is dried for 4 hours at the temperature of 120 ℃, and is roasted for 4 hours at the temperature of 550 ℃, so that a modified catalyst A13 with the vanadium content of 1% (wt) and the niobium content of 2% (wt) is prepared, and a certain amount of chloroplatinic acid and palladium chloride solution is soaked in the catalyst A13 in the same volume, so that a core-shell metal layer catalyst B13 with the platinum content of 0.1% (wt) and the palladium content of 0.2% is obtained.

5 g of core-shell metal layer catalyst B13 was placed in a reactor, and hydrogen was introduced to reduce at 450 ℃ for 3 hours, and then cooled to 350 ℃, and hydrogen and a material containing toluene and naphthalene were introduced to contact the catalyst for reaction activity investigation. The reaction conditions are as follows: the total weight space velocity is 10 hours^-1The reaction temperature is 370 ℃, the reaction pressure is 3.0MPa, and the hydrogen-hydrocarbon molecular ratio is 4.0. The reaction raw materials were toluene and naphthalene (40: 60 by weight), and the reaction performance was as shown in table 1.

[ example 14 ]

20 g of alumina ball carrier is taken, dipped with a certain titanium chloride and niobium oxalate solution in equal volume, dried for 4 hours at 120 ℃, roasted for 4 hours at 550 ℃ to prepare a modified catalyst A14 with 1 percent (wt) of titanium and 2 percent (wt) of niobium, and the catalyst A14 is dipped with a certain chloroplatinic acid and palladium chloride solution in equal volume to obtain a core-shell metal layer catalyst B14 with 0.1 percent (wt) of platinum and 0.2 percent of palladium.

5 g of core-shell metal layer is catalyzedPlacing the agent B14 in a reactor, introducing hydrogen to reduce for 3 hours at 450 ℃, then cooling to 350 ℃, introducing hydrogen and contacting the material containing toluene and naphthalene with a catalyst to perform reaction activity investigation. The reaction conditions are as follows: the total weight space velocity is 10 hours^-1The reaction temperature is 370 ℃, the reaction pressure is 3.0MPa, and the hydrogen-hydrocarbon molecular ratio is 4.0. The reaction raw materials were toluene and naphthalene (40: 60 by weight), and the reaction performance was as shown in table 1.

[ example 15 ]

A certain amount of zirconium chloride and niobium oxalate solution is soaked in 20 g of alumina ball carrier in the same volume, the alumina ball carrier is dried at 120 ℃ for 4 hours, the alumina ball carrier is roasted at 550 ℃ for 4 hours to prepare a modified catalyst A15 with 1 percent (wt) of zirconium content and 2 percent (wt) of niobium content, and a certain amount of chloroplatinic acid and rhodium chloride solution is soaked in a catalyst A15 in the same volume to obtain a core-shell metal layer catalyst B135 with 0.1 percent (wt) of platinum content and 0.2 percent of rhodium content.

5 g of core-shell metal layer catalyst B15 was placed in a reactor, and hydrogen was introduced to reduce at 450 ℃ for 3 hours, and then cooled to 350 ℃, and hydrogen and a material containing toluene and naphthalene were introduced to contact the catalyst for reaction activity investigation. The reaction conditions are as follows: the total weight space velocity is 10 hours^-1The reaction temperature is 370 ℃, the reaction pressure is 3.0MPa, and the hydrogen-hydrocarbon molecular ratio is 4.0. The reaction raw materials were toluene and naphthalene (40: 60 by weight), and the reaction performance was as shown in table 1.

[ example 16 ]

A certain amount of zirconium chloride and niobium oxalate solution is soaked in 20 g of alumina ball carrier in the same volume, the alumina ball carrier is dried at 120 ℃ for 4 hours, and is roasted at 550 ℃ for 4 hours to prepare a modified catalyst A16 with 1 percent (wt) of zirconium content and 2 percent (wt) of niobium content, and a certain amount of rhodium chloride and chloropalladate solution is soaked in a catalyst A16 in the same volume to obtain a core-shell metal layer catalyst B16 with 0.1 percent (wt) of rhodium content and 0.2 percent of palladium content.

5 g of core-shell metal layer catalyst B16 was placed in a reactor, and hydrogen was introduced to reduce at 450 ℃ for 3 hours, and then cooled to 350 ℃, and hydrogen and a material containing toluene and naphthalene were introduced to contact the catalyst for reaction activity investigation. The reaction conditions are as follows: the total weight space velocity is 10 hours^-1The reaction temperature is 370 ℃, the reaction pressure is 3.0MPa, and the hydrogen-hydrocarbon molecular ratio is 4.0. The raw material of the reaction is toluene and naphthalene40:60 (by weight), the reaction properties are shown in Table 1.

[ example 17 ]

A certain amount of zirconium chloride and niobium oxalate solution is soaked in 20 g of alumina sphere carrier in the same volume, the alumina sphere carrier is dried at 120 ℃ for 4 hours, the alumina sphere carrier is roasted at 550 ℃ for 4 hours to prepare a modified catalyst A17 with 1 percent (wt) of zirconium content and 2 percent (wt) of niobium content, and a certain amount of rhodium chloride, chloroiridic acid and solution are soaked in the catalyst A17 in the same volume to obtain a core-shell metal layer catalyst B17 with 0.1 percent (wt) of rhodium content and 0.2 percent of iridium content.

5 g of core-shell metal layer catalyst B17 was placed in a reactor, and hydrogen was introduced to reduce at 450 ℃ for 3 hours, and then cooled to 350 ℃, and hydrogen and a material containing toluene and naphthalene were introduced to contact the catalyst for reaction activity investigation. The reaction conditions are as follows: the total weight space velocity is 10 hours^-1The reaction temperature is 370 ℃, the reaction pressure is 3.0MPa, and the hydrogen-hydrocarbon molecular ratio is 4.0. The reaction raw materials were toluene and naphthalene (40: 60 by weight), and the reaction performance was as shown in table 1.

[ example 18 ]

20 g of alumina ball carrier is taken, dipped with a certain zirconium chloride and niobium oxalate solution in equal volume, dried for 4 hours at 120 ℃, roasted for 4 hours at 550 ℃ to prepare a modified catalyst A18 with 1 percent (wt) of zirconium content and 2 percent (wt) of niobium content, and the catalyst A18 is dipped with a certain chloroplatinic acid and iridium chloride solution in equal volume to obtain a core-shell metal layer catalyst B18 with 0.1 percent (wt) of platinum content and 0.2 percent of iridium content.

5 g of core-shell metal layer catalyst B18 was placed in a reactor, and hydrogen was introduced to reduce at 450 ℃ for 3 hours, and then cooled to 350 ℃, and hydrogen and a material containing toluene and naphthalene were introduced to contact the catalyst for reaction activity investigation. The reaction conditions are as follows: the total weight space velocity is 10 hours^-1The reaction temperature is 370 ℃, the reaction pressure is 3.0MPa, and the hydrogen-hydrocarbon molecular ratio is 4.0. The reaction raw materials were toluene and naphthalene (40: 60 by weight), and the reaction performance was as shown in table 1.

[ example 19 ]

20 g of alumina ball carrier is taken, dipped with a certain zirconium chloride and niobium oxalate solution in equal volume, dried for 4 hours at 120 ℃, roasted for 4 hours at 550 ℃ to prepare a modified catalyst A19 with 1 percent (wt) of zirconium content and 2 percent (wt) of niobium content, and the catalyst A19 is dipped with a certain chloroplatinic acid and palladium chloride solution in equal volume to obtain a core-shell metal layer catalyst B19 with 0.03 percent (wt) of platinum content and 0.27 percent of palladium content.

5 g of core-shell metal layer catalyst B19 was placed in a reactor, and hydrogen was introduced to reduce at 450 ℃ for 3 hours, and then cooled to 350 ℃, and hydrogen and a material containing toluene and naphthalene were introduced to contact the catalyst for reaction activity investigation. The reaction conditions are as follows: the total weight space velocity is 10 hours^-1The reaction temperature is 370 ℃, the reaction pressure is 3.0MPa, and the hydrogen-hydrocarbon molecular ratio is 4.0. The reaction raw materials were toluene and naphthalene (40: 60 by weight), and the reaction performance was as shown in table 1.

[ example 20 ]

20 g of alumina ball carrier is taken, dipped with a certain zirconium chloride and niobium oxalate solution in equal volume, dried for 4 hours at 120 ℃, roasted for 4 hours at 550 ℃ to prepare a modified catalyst A20 with 1 percent (wt) of zirconium content and 2 percent (wt) of niobium content, and the catalyst A20 is dipped with a certain chloroplatinic acid and rhodium chloride solution in equal volume to obtain a core-shell metal layer catalyst B20 with 0.1 percent (wt) of platinum content and 0.2 percent of rhodium content.

5 g of core-shell metal layer catalyst B20 was placed in a reactor, and hydrogen was introduced to reduce at 450 ℃ for 3 hours, and then cooled to 350 ℃, and hydrogen and a material containing toluene and naphthalene were introduced to contact the catalyst for reaction activity investigation. The reaction conditions are as follows: the total weight space velocity is 10 hours^-1The reaction temperature is 370 ℃, the reaction pressure is 3.0MPa, and the hydrogen-hydrocarbon molecular ratio is 4.0. The reaction raw materials were toluene and naphthalene (40: 60 by weight), and the reaction performance was as shown in table 1.

[ example 21 ]

The preparation method comprises the steps of soaking 20 g of amorphous silicon-aluminum ball carrier in a certain zirconium chloride and niobium oxalate solution in an equal volume, drying at 120 ℃ for 4 hours, roasting at 550 ℃ for 4 hours to obtain a modified catalyst A21 with 1% (wt) of zirconium content and 2% (wt) of niobium content, and soaking a certain chloroplatinic acid and palladium chloride solution in an equal volume in a catalyst A21 to obtain a core-shell metal layer catalyst B21 with 0.1% (wt) of platinum content and 0.2% of palladium content.

5 g of core-shell metal layer catalyst B21 is placed in a reactor, hydrogen is introduced to reduce for 3 hours at 450 ℃, then the temperature is reduced to 350 ℃, and hydrogen andthe material containing toluene and naphthalene was contacted with a catalyst for reactivity examination. The reaction conditions are as follows: the total weight space velocity is 10 hours^-1The reaction temperature is 370 ℃, the reaction pressure is 3.0MPa, and the hydrogen-hydrocarbon molecular ratio is 4.0. The reaction raw materials were toluene and naphthalene (40: 60 by weight), and the reaction performance was as shown in table 1.

[ example 22 ]

A formed carrier of 20 g of Y molecular sieve (Si/Al is 30) and alumina is taken, a certain amount of zirconium chloride and niobium oxalate solution is soaked in the carrier in the same volume, the carrier is dried at 120 ℃ for 4 hours and roasted at 550 ℃ for 4 hours, a modified catalyst A22 with the zirconium content of 1 percent (wt) and the niobium content of 2 percent (wt) is prepared, a certain amount of chloroplatinic acid and palladium chloride solution is soaked in the catalyst A22 in the same volume, and a core-shell metal layer catalyst B22 with the platinum content of 0.1 percent (wt) and the palladium content of 0.2 percent is obtained.

5 g of core-shell metal layer catalyst B22 was placed in a reactor, and hydrogen was introduced to reduce at 450 ℃ for 3 hours, and then cooled to 350 ℃, and hydrogen and a material containing toluene and naphthalene were introduced to contact the catalyst for reaction activity investigation. The reaction conditions are as follows: the total weight space velocity is 10 hours^-1The reaction temperature is 370 ℃, the reaction pressure is 3.0MPa, and the hydrogen-hydrocarbon molecular ratio is 4.0. The reaction raw materials were toluene and naphthalene (40: 60 by weight), and the reaction performance was as shown in table 1.

Comparative example 1

20 g of alumina ball carrier is taken and dipped into a certain chloroplatinic acid solution with the same volume to obtain the catalyst B23 with the platinum content of 0.3 percent (wt).

5 g of catalyst B23 was placed in a reactor, and reduced by introducing hydrogen at 450 ℃ for 3 hours, then cooled to 350 ℃ and introduced with hydrogen and the material containing toluene and naphthalene was contacted with the catalyst for activity investigation. The reaction conditions are as follows: the total weight space velocity is 10 hours^-1The reaction temperature is 370 ℃, the reaction pressure is 3.0MPa, and the hydrogen-hydrocarbon molecular ratio is 4.0. The reaction raw materials were toluene and naphthalene (40: 60 by weight), and the reaction performance was as shown in table 1.

Comparative example 2

20 g of alumina ball carrier is taken and dipped into a certain chloroplatinic acid and chloropalladate solution in equal volume to obtain the catalyst B24 with the platinum content of 0.1 percent (wt) and the palladium content of 0.2 percent.

5 g of catalyst B24 was placed in a reactor, and reduced by introducing hydrogen at 450 ℃ for 3 hours, then cooled to 350 ℃ and introduced with hydrogen and the material containing toluene and naphthalene was contacted with the catalyst for activity investigation. The reaction conditions are as follows: the total weight space velocity is 10 hours^-1The reaction temperature is 370 ℃, the reaction pressure is 3.0MPa, and the hydrogen-hydrocarbon molecular ratio is 4.0. The reaction raw materials were toluene and naphthalene (40: 60 by weight), and the reaction performance was as shown in table 1.

Comparative example 3

20 g of alumina ball carrier is taken and dipped into a certain solution of zirconium chloride and niobium oxalate in the same volume to obtain the catalyst B25 with the zirconium content of 1 percent (wt) and the niobium content of 2 percent.

5 g of catalyst B25 was placed in a reactor, and reduced by introducing hydrogen at 450 ℃ for 3 hours, then cooled to 350 ℃ and introduced with hydrogen and the material containing toluene and naphthalene was contacted with the catalyst for activity investigation. The reaction conditions are as follows: the total weight space velocity is 10 hours^-1The reaction temperature is 370 ℃, the reaction pressure is 3.0MPa, and the hydrogen-hydrocarbon molecular ratio is 4.0. The reaction raw materials were toluene and naphthalene (40: 60 by weight), and the reaction performance was as shown in table 1.

TABLE 1

Claims

1. The method for increasing the yield of light aromatic hydrocarbons is characterized in that a catalyst for increasing the yield of light aromatic hydrocarbons is adopted, and the catalyst comprises the following components:

A) containing a non-acidic or weakly acidic porous carrier and supported thereon

B) At least two metallic elements or compounds selected from VIII, IVB, VB;

wherein the metal elements or compounds are distributed on the surface of the carrier in a nuclear shell layer; the nuclear phase layer metal is at least one of metals of Ti, V, Zr and Nb and compounds thereof; the shell phase layer metal is at least one selected from Pt, Pd, Ir, Rh metal and their compounds.

2. The method according to claim 1, wherein the non-acidic or weakly acidic porous support is selected from at least one of alumina, amorphous silica-alumina, kaolin, aluminosilicate.

3. The method of claim 1, wherein the core phase layer metal content is 0.01 to 20 parts by weight based on the total weight of the catalyst.

4. The process of claim 1 wherein the shell phase metal content is from 0.01 to 10 parts by weight based on the total weight of the catalyst.

5. The method according to any one of claims 1 to 4, wherein the preparation method of the light aromatic hydrocarbon stimulation catalyst comprises the following steps:

a) dissolving salt containing nuclear phase layer metal in water or non-aqueous solution, loading a layer of metal compound on a carrier by methods of precipitation, physical adhesion and impregnation, drying, and roasting at the temperature of 400-600 ℃ to prepare a catalyst I with a nuclear phase layer structure;

b) dissolving salt containing shell phase layer metal in water or non-aqueous solution, loading on a catalyst I with a core phase layer structure by using a dipping, adsorbing, precipitating or coating method, drying, and roasting at the temperature of 400-600 ℃ to prepare the yield-increasing light aromatic hydrocarbon catalyst;

6. The process as claimed in claim 1, wherein the reaction temperature is 100 ℃ and 500 ℃, the reaction pressure is 0.5 to 8MPa, the hydrogen-hydrocarbon molar ratio is 1 to 10, and the space velocity of the feed weight is 0.5 to 20.