Aromatization catalyst, its preparation method and application

Abstract

The present invention discloses an aromatization catalyst, a preparation method thereof and an application thereof. Based on the total weight of the catalyst, it comprises the following components: a) 0.5 to 20% of at least one selected from Zn, Ga, Ag, Mo, W, noble metals and their oxides; b) 0.5 to 15% of at least one selected from P, B, Si, Fe, Cu, Co, Mn, Ni, rare earth elements and their oxides; c) 24 to 60% of a molecular sieve treated with a composite acid; d) 10 to 30% of at least one selected from SiO2, Al2O3, TiO2 and ZrO2; e) 20 to 65% of kaolin. When the catalyst of the present invention is used in the aromatization process, it has high BTX selectivity and BTX yield.

Description

Technical Field

[0001] The present invention relates to the technical field of aromatic hydrocarbon preparation, and particularly relates to an aromatization catalyst, a preparation method thereof, and an application thereof. Background Art

[0002] Ethylene, propylene, and aromatic hydrocarbons are three of the most important basic organic chemical raw materials. Aromatic hydrocarbons mainly come from the catalytic reforming of the petroleum route and the extraction process of pyrolysis gasoline by-products in steam cracking. Direct conversion of coal-based methanol, which is rich in resources, into aromatic hydrocarbons has practical significance for alleviating the shortage of aromatic hydrocarbons, increasing the added value of methanol downstream products, and extending the coal chemical and natural gas chemical industry chains.

[0003] The conversion of oxygenates to olefins or aromatic hydrocarbons is an exothermic reaction. Moreover, the catalyst is prone to rapid deactivation due to carbon deposition. Compared with traditional fixed-bed reactors, fluidized-bed reactors can quickly remove reaction heat and enable rapid catalyst reaction regeneration. Therefore, petrochemical companies, universities, and research institutions at home and abroad have developed different technologies for preparing olefins or aromatic hydrocarbons from oxygenates based on fluidized-bed reactors.

[0004] CN105435839B reports a methanol-to-aromatic hydrocarbon catalyst containing two molecular sieves and a preparation method thereof. The composition of the catalyst is as follows: based on the weight of the catalyst, the total content of zinc-aluminum composite modified ZSM-5 molecular sieve and nickel modified Y-type molecular sieve is 40wt% - 85wt%, the content of rare earth oxide is 0.5wt% - 5.0wt%, and the balance is alumina binder; the weight ratio of the zinc-aluminum composite modified ZSM-5 molecular sieve to the modified Y-type molecular sieve is 9:1 - 1:1. Research shows that on the twelve-membered ring molecular sieve catalyst, such as Y-type molecular sieve and mordenite, there is a high content of C8+ heavy aromatic hydrocarbons in the methanol conversion products. Therefore, adding Y-type molecular sieve in this invention will lead to an increase in the content of heavy aromatic hydrocarbons in the products and a decrease in the BTX selectivity and yield.

[0005] CN105013524B reports a cadmium- and manganese-containing molecular sieve catalyst for preparing aromatic hydrocarbons from methanol and a preparation method thereof. The catalyst described in this invention contains cadmium, manganese, and ZSM-5 molecular sieve. The silica-aluminum molar ratio in the catalyst is SiO2 / Al2O3 = 10 - 200. Based on the total weight of the catalyst, the weight percentage of cadmium in the catalyst is 0.1 - 10% in the form of CdO, the weight percentage of manganese in the catalyst is 0.01 - 3% in the form of MnO, and the weight percentage of ZSM-5 molecular sieve in the catalyst is 87% - 99.89%. Cadmium is a toxic substance, and adding it to the catalyst poses a serious environmental pollution problem.

[0006] CN105195213B discloses an in-situ synthesis method of a catalyst for methanol / dimethyl ether conversion to aromatics. Specifically, a mixed slurry is first prepared by mixing a silicon source, an aluminum source and water, and microsphere particles containing silicon-aluminum oxides are obtained by spray drying; then the microsphere particles containing silicon-aluminum oxides are calcined to obtain a microsphere catalyst support; then the microsphere catalyst support, a template agent, a first metal component precursor, a phosphorus modifier, an acid-base regulator and water are made into a mixed solution, which is filled into a stainless steel synthesis kettle, heated for isothermal crystallization, and the solid product is separated; the solid product is washed with deionized water until neutral, dried and calcined to obtain ZSM-5 molecular sieve-containing. Finally, the microsphere catalyst is impregnated in a second metal component precursor solution, dried and calcined to obtain a microsphere catalyst for methanol / dimethyl ether conversion to aromatics. This method can effectively prevent the deactivation of the catalyst caused by the combination of the metal component and the binder on the catalyst. Some modifiers are introduced into the molecular sieve synthesis precursor, however, it is very difficult to control the modification effect of this part of the modifier.

[0007] Among aromatic products, BTX (benzene-toluene-xylene mixture) light aromatics are currently the most widely used aromatic products and also the most industrially valuable aromatic products at present. The C8+ heavy aromatics in the aromatization products need to be converted into BTX light aromatics through a secondary processing process, which increases the production cost of BTX light aromatics. Improving the BTX yield in the aromatization process or the aromatic production process has always been an important direction for the improvement of the aromatic industrial process. However, the existing aromatization fluidized bed catalysts have the technical problems of low BTX selectivity and low BTX yield. Summary of the Invention

[0008] In view of the above problems existing in the prior art, the present invention provides a new aromatization catalyst and its preparation method. When the catalyst of the present invention is used in the aromatization process, it has high BTX selectivity and BTX yield.

[0009] In the first aspect of the present invention, an aromatization catalyst is provided, which contains the following components based on the total weight of the catalyst:

[0010] a) 0.5-20% of at least one selected from Zn, Ga, Ag, Mo, W, noble metals and their oxides;

[0011] b) 0.5-15% of at least one selected from P, B, Si, Fe, Cu, Co, Mn, Ni, rare earth elements and their oxides;

[0012] c) 24-60% of a molecular sieve treated with a composite acid;

[0013] d) 10-30% of at least one selected from SiO2, Al2O3, TiO2 and ZrO2;

[0014] e) 20 to 65% is selected from kaolin.

[0015] In some embodiments of the catalyst according to the present invention, preferably, the method for preparing the composite acid-treated molecular sieve includes: subjecting a molecular sieve with a template agent to acid treatment using a composite acid, wherein the composite acid includes a non-complexing acid having no complexing effect on Al and a complexing acid having a complexing effect on Al.

[0016] In some embodiments of the catalyst according to the present invention, preferably, the non-complexing acid is selected from citric acid and / or oxalic acid.

[0017] In some embodiments of the catalyst according to the present invention, preferably, the complexing acid is selected from at least one of nitric acid, hydrochloric acid, sulfuric acid, acetic acid, and phosphoric acid.

[0018] In some embodiments of the catalyst according to the present invention, preferably, in the composite acid, the molar percentage of the complexing acid is 30 to 80%.

[0019] In some embodiments of the catalyst according to the present invention, preferably, the conditions for the acid treatment include: a liquid-solid ratio of 1.5 to 20:1, preferably 2.5 to 8:1.

[0020] In some embodiments of the catalyst according to the present invention, preferably, the conditions for the acid treatment include: a temperature of 20 to 99 °C, preferably 50 to 85 °C.

[0021] In some embodiments of the catalyst according to the present invention, preferably, the conditions for the acid treatment include: a composite acid concentration of 0.1 to 5 mol / L, preferably 0.3 to 1.5 mol / L.

[0022] In some embodiments of the catalyst according to the present invention, preferably, the conditions for the acid treatment include: a treatment time of 0.5 to 96 h.

[0023] The inventors of the present invention have found through research that for the aromatization process, the commonly used molecular sieve components are ZSM-5 or ZSM-11 molecular sieves. The molecular size of BTX light aromatics is relatively small and is mainly generated within the pore channels of the molecular sieve, while the molecular size of C8+ heavy aromatics is relatively large, and this part of the heavy aromatics should be mainly generated on the outer surface of the molecular sieve. The synthesized molecular sieves often contain acidic centers on the outer surface, that is, framework or non-framework aluminum on the outer surface. Therefore, the presence of acidic centers on the outer surface is the main reason for the poor BTX selectivity of the aromatization catalyst. The technical solution of the present invention, which uses a composite acid to treat a molecular sieve containing a template agent to remove the non-selective acidic centers on the outer surface and then uses it to prepare an aromatization catalyst, can solve the above technical problems and is used in the industrial process of aromatics preparation.

[0024] In some embodiments of the catalyst according to the present invention, preferably, the molecular sieve is selected from ZSM-5 and / or ZSM-11.

[0025] In some embodiments of the catalyst according to the present invention, preferably, the composite acid-treated molecular sieve includes micron-sized large crystal molecular sieve and small crystal molecular sieve.

[0026] In some embodiments of the catalyst according to the present invention, preferably, the crystal size of the small crystal molecular sieve is 100 nm to 990 nm.

[0027] In some embodiments of the catalyst according to the present invention, preferably, the crystal size of the micron-sized large crystal molecular sieve is 1000 nm to 20000 nm.

[0028] In some embodiments of the catalyst according to the present invention, preferably, by weight percentage, the weight percentage of the small crystal molecular sieve in the composite acid-treated molecular sieve is 5 to 50%.

[0029] In some embodiments of the catalyst according to the present invention, preferably, the weight of component a) is 2 to 10%. That is, a) 2 to 10% is selected from at least one of Zn, Ga, Ag, Mo, W, noble metals and their oxides. In the present invention, "at least one of Zn, Ga, Ag, Mo, W, noble metals and their oxides" means at least one of Zn and its oxide, Ga and its oxide, Ag and its oxide, Mo and its oxide, W and its oxide, noble metals and their oxides.

[0030] In some embodiments of the catalyst according to the present invention, preferably, the weight of component b) is 1.5 to 9%. That is, b) 1.5 to 9% is selected from at least one of P, B, Si, Fe, Cu, Co, Mn, Ni, rare earth elements and their oxides. In the present invention, "P, B, Si, Fe, Cu, Co, Mn, Ni, rare earth elements and their oxides" means at least one of P and its oxide, B and its oxide, Si and its oxide, Fe and its oxide, Cu and its oxide, Co and its oxide, Mn and its oxide, Ni and its oxide, rare earth elements and their oxides.

[0031] In some embodiments of the catalyst according to the present invention, preferably, the weight of component c) is 36 to 52%. That is, d) 36 to 52% is selected from at least one of SiO2, Al2O3, TiO2 and ZrO2.

[0032] In some embodiments of the catalyst according to the present invention, preferably, the weight of component e) is 35 to 55%. That is, e) 35 to 55% is selected from kaolin.

[0033] In the present invention, based on the total weight of the catalyst, the total amount of component a), component b), component c), component d), and component e) is 100%.

[0034] In some embodiments of the catalyst according to the present invention, the molecular sieve with a template agent, wherein the template agent can be, but is not limited to, at least one of ethylenediamine, n-butylamine, hexamethylenediamine, triethylamine, tetrapropylammonium hydroxide, and ethanolamine.

[0035] The second aspect of the present invention provides a method for preparing an aromatization catalyst, comprising:

[0036] S1. Acid-treating the molecular sieve with a template agent using a composite acid to obtain a composite acid-treated molecular sieve;

[0037] S2. Mixing the composite acid-treated molecular sieve with component d), component e), and water, shaping, and calcining to obtain a support;

[0038] S3. Mixing the support with an aqueous solution containing component a) and component b), and drying and calcining;

[0039] Wherein, based on the total weight of the catalyst, the composition and weight percentage of each component are:

[0040] a) 0.5 - 20% of soluble salts selected from at least one of Zn, Ga, Ag, Mo, W, and noble metals;

[0041] b) 0.5 - 15% of soluble salts selected from at least one of P, B, Si, Fe, Cu, Co, Mn, Ni, and rare earth elements;

[0042] c) 24 - 60% of composite acid-treated molecular sieve;

[0043] d) 10 - 30% of at least one selected from SiO2, Al2O3, TiO2, and ZrO2;

[0044] e) 20 - 65% of kaolin.

[0045] In some embodiments of the preparation method according to the present invention, preferably, the preparation method of the composite acid-treated molecular sieve includes: acid-treating the molecular sieve with a template agent using a composite acid, wherein the composite acid includes a non-complexing acid that has no complexing effect on Al and a complexing acid that has a complexing effect on Al.

[0046] In some embodiments of the preparation method according to the present invention, preferably, the non-complexing acid is selected from citric acid and / or oxalic acid.

[0047] In some embodiments of the preparation method according to the present invention, preferably, the complex acid is selected from at least one of nitric acid, hydrochloric acid, sulfuric acid, acetic acid, and phosphoric acid.

[0048] In some embodiments of the preparation method according to the present invention, preferably, in the composite acid, the molar percentage of the complex acid is 30-80%.

[0049] In some embodiments of the preparation method according to the present invention, preferably, the conditions for the acid treatment include: the liquid-solid ratio is 1.5-20:1, preferably 2.5-8:1.

[0050] In some embodiments of the preparation method according to the present invention, preferably, the conditions for the acid treatment include: the temperature is 20-99 °C, preferably 50-85 °C.

[0051] In some embodiments of the preparation method according to the present invention, preferably, the conditions for the acid treatment include: the concentration of the composite acid is 0.1-5 mol / L, preferably 0.3-1.5 mol / L.

[0052] In some embodiments of the preparation method according to the present invention, preferably, the conditions for the acid treatment include: the treatment time is 0.5-96 h.

[0053] In some embodiments of the preparation method according to the present invention, preferably, the molecular sieve is selected from ZSM-5 and / or ZSM-11.

[0054] In some embodiments of the preparation method according to the present invention, preferably, the weight of component a) is 2-10%. That is, a) 2-10% is selected from soluble salts containing at least one of Zn, Ga, Ag, Mo, W, and noble metals.

[0055] In some embodiments of the preparation method according to the present invention, preferably, the weight of component b) is 1.5-9%. That is, b) 1.5-9% is selected from soluble salts containing at least one of P, B, Si, Fe, Cu, Co, Mn, Ni, and rare earth elements.

[0056] In some embodiments of the preparation method according to the present invention, preferably, the weight of component c) is 36-52%. That is, d) 36-52% is selected from at least one of SiO2, Al2O3, TiO2, and ZrO2.

[0057] In some embodiments of the preparation method according to the present invention, preferably, the weight of component e) is 35-55%. That is, e) 35-55% is selected from kaolin.

[0058] In the present invention, based on the total weight of the catalyst, the total amount of component a), component b), component c), component d), and component e) is 100%.

[0059] In some embodiments of the preparation method according to the present invention, a molecular sieve with a template agent, wherein the template agent can be, but is not limited to, at least one of ethylenediamine, n-butylamine, hexamethylenediamine, triethylamine, tetrapropylammonium hydroxide, and ethanolamine.

[0060] In some embodiments of the preparation method according to the present invention, preferably, after the acid treatment in S1 and before S2, the preparation method further includes sequentially performing water washing, drying, calcination, and ammonia exchange treatment.

[0061] In some embodiments of the preparation method according to the present invention, preferably, the forming method can be, but is not limited to, spray forming.

[0062] In some embodiments of the preparation method according to the present invention, preferably, the calcination conditions can include, but are not limited to, 450°C to 650°C, calcination for 4h to 24h.

[0063] In some embodiments of the preparation method according to the present invention, preferably, the drying conditions can include, but are not limited to, 100°C to 180°C, calcination for 4h to 24h.

[0064] In some embodiments of the preparation method according to the present invention, the aqueous solution containing component a) and component b) can be an aqueous solution containing a soluble salt of component a) and a soluble salt of component b). For example, when component a) is Zn, it can be zinc nitrate, etc., and when component b) is phosphorus, it can be phosphoric acid, etc.

[0065] The third aspect of the present invention provides an aromatization catalyst obtained according to the above preparation method.

[0066] In some embodiments of the catalyst according to the present invention, preferably, the molecular sieve treated with a composite acid includes a micron-sized large crystal molecular sieve and a small crystal molecular sieve.

[0067] In some embodiments of the catalyst according to the present invention, preferably, the crystal size of the small crystal molecular sieve is 100nm to 990nm.

[0068] In some embodiments of the catalyst according to the present invention, preferably, the crystal size of the micron-sized large crystal molecular sieve is 1000nm to 20000nm.

[0069] In some embodiments of the catalyst according to the present invention, preferably, by weight percentage, the small crystal molecular sieve accounts for 5 to 50% of the weight of the molecular sieve treated with a composite acid.

[0070] In some embodiments of the catalyst according to the present invention, preferably, the weight of component a) is 2 to 10%. That is, a) 2 to 10% is selected from at least one of Zn, Ga, Ag, Mo, W, noble metals, and their oxides.

[0071] In some embodiments of the catalyst according to the present invention, preferably, the weight of component b) is 1.5 to 9%. That is, b) 1.5 to 9% is selected from at least one of P, B, Si, Fe, Cu, Co, Mn, Ni, rare earth elements, and their oxides.

[0072] In some embodiments of the catalyst according to the present invention, preferably, the weight of component c) is 36 to 52%. That is, c) 36 to 52% is selected from at least one of SiO2, Al2O3, TiO2, and ZrO2.

[0073] In some embodiments of the catalyst according to the present invention, preferably, the weight of component e) is 35 to 55%. That is, e) 35 to 55% is selected from kaolin.

[0074] In the present invention, based on the total weight of the catalyst, the total amount of component a), component b), component c), component d), and component e) is 100%.

[0075] The fourth aspect of the present invention provides a method for preparing an aromatic hydrocarbon, comprising: contacting a reaction raw material with a catalyst, wherein the catalyst is the above-mentioned aromatization catalyst or the aromatization catalyst obtained according to the above-mentioned preparation method.

[0076] In some embodiments of the method according to the present invention, preferably, the reaction raw material is at least one of an oxygen-containing compound and a hydrocarbon compound. For example, but not limited to, methanol.

[0077] In some embodiments of the method according to the present invention, preferably, the weight hourly space velocity of the reaction raw material is 0.1 to 10.0 h -1 .

[0078] In some embodiments of the method according to the present invention, preferably, the temperature of the reaction is 370 to 650 °C.

[0079] In some embodiments of the method according to the present invention, preferably, the pressure of the reaction is 0.01 to 4.0 MPa.

[0080] Advantages of the present invention:

[0081] The present invention uses a composite acid formed by a non-complexing acid that has no complexing effect on Al and a complexing acid that has a complexing effect on Al to "directionally and selectively" remove the framework and non-framework Al on the outer surface of the molecular sieve with a template agent, that is, the acidic centers on the outer surface. The selective removal of the outer surface acidic centers is beneficial to inhibiting the side reactions of continuous alkylation on the outer surface, thereby reducing the generation of heavy aromatics of C8+ and improving the BTX selectivity of the catalyst. And the molecular sieve treated with the composite acid has a template agent, so the treatment with the composite acid does not affect the number and distribution of the acidic centers in the pores. These acid centers are the active centers of aromatization. Therefore, the acid treatment does not affect the aromatization activity and the total aromatics yield of the catalyst. Compared with the existing aromatization catalysts, the aromatization catalyst prepared by the method of the present invention not only retains a high aromatization activity and the total aromatics yield, but also the removal of non-selective acidic centers on the outer surface improves the BTX selectivity and yield of the catalyst. Detailed Embodiments

[0082] To make the present invention more easily understood, the present invention will be described in detail below in conjunction with embodiments. These embodiments are only illustrative and are not limited to the application scope of the present invention.

[0083] The test methods of the present invention and the equipment used in the tests are as follows:

[0084] (1) The sizes of the micron large crystal molecular sieve and the small crystal molecular sieve are characterized by surface scanning electron microscopy SEM.

[0085] (2) The total aromatics yield, BTX yield, and BTX selectivity in this patent are defined as follows:

[0086] The total aromatics yield (carbon-based) of the catalyst is defined as the ratio of the total mass of the aromatic products, excluding the water generated in the reaction, to the weight of all hydrocarbons, excluding the water in the products, in the aromatization products.

[0087] The definition of the BTX yield is the ratio of the total mass of the BTX products, excluding the water generated in the reaction, to the weight of all hydrocarbons, excluding the water in the products, in the aromatization products.

[0088] The definition of the BTX selectivity is the ratio of the BTX yield to the total aromatics yield.

[0089]

Example 1

[0090] (1) Use ZSM-5 micron molecular sieve (silica-alumina ratio is 60) with a template agent (ethylenediamine) and small crystal ZSM-5 molecular sieve with a template agent (tetrapropylammonium hydroxide), where the small crystal molecular sieve is 15 wt% of the small crystal and micron composite molecular sieve. The composite molecular sieve is treated for 48 h under the conditions of a liquid-solid ratio of 5:1, a temperature of 50 °C, and a composite acid concentration of 0.5 mol / L. The composite acid is HCl and oxalic acid, with oxalic acid being 0.2 mol / L and HCl being 0.3 mol / L. After the acid treatment, it is washed with distilled water, dried at 120 °C for 8 h, and calcined at 550 °C for 4 h to remove the template agent to obtain molecular sieve TZ1. After ammonia exchange of TZ1 to remove metal cations, hydrogen-type molecular sieve HZ1 is obtained.

[0091] (2) Take 600 g of molecular sieve HZ1, 500 g of Al sol (20% Al2O3), 200 g of kaolin, and 3000 g of water, mix them evenly, and obtain spray particles SP1 with an average particle size of 65 microns by spray forming. SP1 is calcined at 550 °C for 4 h to obtain carrier ZT1.

[0092] (3) Take 180 g of carrier ZT1 and impregnate it with 135 g of an aqueous solution containing 43.6 g of zinc nitrate and 13.0 g of phosphoric acid (85 wt%). After impregnation, it is dried at 120 °C for 8 h and calcined at 550 °C for 4 h to obtain aromatization fluidized bed catalyst a. The relevant composition information of catalyst a is shown in Table 1.

[0093]

Example 2

[0094] Use the same method as in Example 1, except that the liquid-solid ratio in step (1) is changed from 5:1 to 2.5:1. Finally, catalyst b is obtained. The relevant composition information of catalyst b is shown in the table.

[0095]

Example 3

[0096] Use the same method as in Example 1, except that the liquid-solid ratio in step (1) is changed from 5:1 to 8:1. Finally, catalyst c is obtained. The relevant composition information of catalyst c is shown in the table.

[0097]

Example 4

[0098] Use the same method as in Example 1, except that the liquid-solid ratio in step (1) is changed from 5:1 to 1.5:1. Finally, catalyst d is obtained. The relevant composition information of catalyst d is shown in the table.

[0099]

Example 5

[0100] Use the same method as in Example 1, except that the liquid-solid ratio in step (1) is changed from 5:1 to 20:1. Finally, catalyst e is obtained. The relevant composition information of catalyst e is shown in the table.

[0101]

Example 6

[0102] The same method as in Example 1 was adopted, except that the temperature of 50°C in step (1) was replaced with 85°C. Catalyst f was finally obtained, and the relevant composition information of catalyst f is shown in the table.

[0103]

Example 7

[0104] The same method as in Example 1 was adopted, except that the concentration of the composite acid in step (1) was changed from 0.5 mol / L to 0.3 mol / L, and the ratio of the complexing acid to the non-complexing acid in the composite acid remained unchanged. Catalyst g was finally obtained, and the relevant composition information of catalyst g is shown in the table.

[0105]

Example 8

[0106] The same method as in Example 1 was adopted, except that the concentration of the composite acid in step (1) was changed from 0.5 mol / L to 1.5 mol / L, and the ratio of the complexing acid to the non-complexing acid in the composite acid remained unchanged. Catalyst h was finally obtained, and the relevant composition information of catalyst h is shown in the table.

[0107]

Example 9

[0108] The same method as in Example 1 was adopted, except that the concentration of the composite acid in step (1) was changed from 0.5 mol / L to 0.1 mol / L, and the ratio of the complexing acid to the non-complexing acid in the composite acid remained unchanged. Catalyst i was finally obtained, and the relevant composition information of catalyst i is shown in the table.

[0109]

Example 10

[0110] The same method as in Example 1 was adopted, except that the concentration of the composite acid in step (1) was changed from 0.5 mol / L to 5 mol / L, and the ratio of the complexing acid to the non-complexing acid in the composite acid remained unchanged. Catalyst j was finally obtained, and the relevant composition information of catalyst j is shown in the table.

[0111]

Example 11

[0112] The same method as in Example 1 was adopted, except that the composite acid in step (1) was changed from HCl and oxalic acid (0.3 mol / L of HCl and 0.2 mol / L of oxalic acid) to acetic acid and citric acid (0.2 mol / L of citric acid and 0.3 mol / L of acetic acid). Catalyst k was finally obtained, and the relevant composition information of catalyst k is shown in the table.

[0113]

Example 12

[0114] The same method as in Example 1 was adopted, except that the composite acid in step (1) was HCl and oxalic acid, with HCl being 0.3 mol / L and oxalic acid being 0.2 mol / L, which was replaced by the composite acid being HCl and citric acid, with HCl being 0.3 mol / L and citric acid being 0.2 mol / L. Catalyst l was finally obtained, and the relevant composition information of catalyst l is shown in the table.

[0115]

Example 13

[0116] The same method as in Example 1 was adopted, except that the composite molecular sieve in step (1) was replaced by ZSM-11 molecular sieve with a template agent (hexamethylenediamine) and small crystal ZSM-11 molecular sieve with a template agent (hexamethylenediamine). Catalyst m was finally obtained, and the relevant composition information of catalyst m is shown in the table.

[0117]

Example 14

[0118] ZSM-5 micron molecular sieve (silica-alumina ratio of 60) with a template agent (ethylenediamine) and small crystal ZSM-5 molecular sieve with a template agent (tetrapropylammonium hydroxide) were used, where the small crystal molecular sieve was 15 wt% of the small crystal and micron composite molecular sieve. Under the conditions of a liquid-solid ratio of 5:1, a temperature of 50 °C, and a composite acid concentration of 0.5 mol / L, the treatment time was 48 h. The composite acid was HCl and oxalic acid, with HCl being 0.3 mol / L and oxalic acid being 0.2 mol / L. After the acid treatment, it was washed with distilled water, dried at 120 °C for 8 h, and calcined at 550 °C for 4 h to remove the template agent to obtain molecular sieve TZ14. After ammonia exchange of TZ14 to remove metal cations, hydrogen-type molecular sieve HZ14 was obtained.

[0119] (2) 500 g of molecular sieve HZ14, 500 g of silica sol (40 wt% SiO2), 250 g of kaolin, and 3000 g of water were mixed evenly and then spray-molded to obtain spray particles SP14 with an average particle size of 65 microns. SP14 was calcined at 550 °C for 4 h to obtain carrier ZT14.

[0120] (3) 190 g of carrier ZT14 was impregnated with 140 g of an aqueous solution containing 8.35 g of silver nitrate and 19.2 g of iron nitrate. After impregnation, it was dried at 120 °C for 8 h and calcined at 550 °C for 4 h to obtain aromatization fluidized bed catalyst n, and the relevant composition information of catalyst n is shown in Table 1.

[0121]

Comparative Example 1

[0122] (1) ZSM-5 micron molecular sieve with a templating agent (ethylenediamine) (silica-alumina ratio is 60) and small crystal ZSM-5 molecular sieve with a templating agent (tetrapropylammonium hydroxide) are used, where the small crystal molecular sieve is 15 wt% of the small crystal and micron composite molecular sieve. After calcination at 550 °C for 4 h to remove the templating agent, molecular sieve TZ1 is obtained. After ammonia exchange to remove metal cations, hydrogen-type molecular sieve HZ18 is obtained.

[0123] (2) 600 g of molecular sieve HZ18, 500 g of Al sol (20% Al2O3), 200 g of kaolin, and 3000 g of water are mixed evenly and then spray formed to obtain spray particles SP18 with an average particle size of 65 microns. SP18 is calcined at 550 °C for 4 h to obtain carrier ZT18.

[0124] (3) 180 g of carrier ZT18 is impregnated with 135 g of an aqueous solution containing 43.6 g of zinc nitrate and 13.0 g of phosphoric acid (85 wt%). After impregnation, it is dried at 120 °C for 8 h and calcined at 550 °C for 4 h to obtain aromatization fluidized bed catalyst d1. The relevant composition information of catalyst d1 is shown in Table 1.

[0125]

Comparative Example 2

[0126] (1) ZSM-5 micron molecular sieve with a templating agent (ethylenediamine) (silica-alumina ratio is 60) and small crystal ZSM-5 molecular sieve with a templating agent (tetrapropylammonium hydroxide) are used, where the small crystal molecular sieve is 15 wt% of the small crystal and micron composite molecular sieve. At a liquid-solid ratio of 5:1, a temperature of 50 °C, and treated with 0.5 mol / L HCl for 48 h. After the acid treatment, it is washed with distilled water, dried at 120 °C for 8 h, and calcined at 550 °C for 4 h to remove the templating agent to obtain molecular sieve TZ19. After ammonia exchange to remove metal cations, hydrogen-type molecular sieve HZ19 is obtained.

[0127] (2) 600 g of molecular sieve HZ19, 500 g of Al sol (20% Al2O3), 200 g of kaolin, and 3000 g of water are mixed evenly and then spray formed to obtain spray particles SP19 with an average particle size of 65 microns. SP19 is calcined at 550 °C for 4 h to obtain carrier ZT19.

[0128] (3) 180 g of carrier ZT19 is impregnated with 135 g of an aqueous solution containing 43.6 g of zinc nitrate and 13.0 g of phosphoric acid (85 wt%). After impregnation, it is dried at 120 °C for 8 h and calcined at 550 °C for 4 h to obtain aromatization fluidized bed catalyst d2. The relevant composition information of catalyst d2 is shown in Table 1.

[0129]

Comparative Example 3

[0130] (1) ZSM-5 micron molecular sieve with a template agent (ethylenediamine) (silica-alumina ratio of 60) and small crystal ZSM-5 molecular sieve with a template agent (tetrapropylammonium hydroxide) are used, where the small crystal molecular sieve accounts for 15 wt% of the small crystal and micron composite molecular sieve. At a liquid-solid ratio of 5:1, a temperature of 50 °C, and a treatment time of 48 h with 0.5 mol / L oxalic acid. After the acid treatment, it is washed with distilled water, dried at 120 °C for 8 h, and calcined at 550 °C for 4 h to remove the template agent to obtain molecular sieve TZ20. After ammonia exchange of TZ20 to remove metal cations, hydrogen-type molecular sieve HZ20 is obtained.

[0131] (2) 600 g of molecular sieve HZ20, 500 g of aluminum sol (20 wt% Al2O3), 200 g of kaolin, and 3000 g of water are mixed evenly and then spray formed to obtain spray particles SP21 with an average particle size of 65 microns. SP21 is calcined at 550 °C for 4 h to obtain carrier ZT20.

[0132] (3) 180 g of carrier ZT20 is impregnated with 135 g of an aqueous solution containing 43.6 g of zinc nitrate and 13.0 g of phosphoric acid (85 wt%). After impregnation, it is dried at 120 °C for 8 h and calcined at 550 °C for 4 h to obtain aromatization fluidized bed catalyst d3. The relevant composition information of catalyst d3 is shown in Table 1.

[0133]

[0134]

[0135]

Test Example

[0136] The catalysts obtained in Examples 1-14 and Comparative Examples 1-3 are evaluated separately.

[0137] The evaluation conditions of the catalyst are as follows: using 100% methanol as the raw material, a reaction temperature of 480 °C, and the weight hourly space velocity of methanol WHSV = 1.0 h -1 , and the reaction pressure is atmospheric pressure. The results are shown in Table 2.

[0138] Table 2

[0139]

[0140] The above are only the preferred examples of the present invention. It should be pointed out that for those of ordinary skill in the art, under the technical inspiration provided by the present invention, as common general knowledge in the art, other equivalent variations and improvements can also be made, which should also be regarded as the protection scope of the present invention.

Claims

1. An aromatization catalyst, based on the total weight of the catalyst, comprises the following components: a) 0.5 - 20% of at least one selected from Zn, Ga, Mo, W, noble metals and their oxides; b) 0.5 - 15% of at least one selected from P, B, Si, Fe, Cu, Co, Mn, Ni, rare earth elements and their oxides; c) 24 - 60% of a molecular sieve treated with a composite acid; d) 10 - 30% of at least one selected from SiO2, Al2O3, TiO2 and ZrO2; e) 20 - 65% of kaolin; The preparation method of the molecular sieve treated with the composite acid includes: The molecular sieve with a template agent is treated with a composite acid, wherein the composite acid includes a non-complexing acid having no complexing effect on Al and a complexing acid having a complexing effect on Al; The conditions for the acid treatment include: liquid-solid ratio of 1.5 - 20:1; temperature of 20 - 99 °C; composite acid concentration of 0.1 - 5 mol / L; treatment time of 0.5 - 96 h; The molecular sieve is selected from ZSM-5 and / or ZSM-11; In the composite acid, the molar percentage of the complexing acid is 30 - 80%; 2. The catalyst according to claim 1, characterized in that, The non-complexing acid is selected from citric acid and / or oxalic acid; and / or, the complexing acid is selected from at least one of nitric acid, hydrochloric acid, sulfuric acid, acetic acid and phosphoric acid; and / or, the noble metal is selected from Ag.

3. The catalyst according to claim 1, wherein The conditions for the acid treatment include: liquid-solid ratio of 2.5 - 8:1; and / or, temperature of 50 - 85 °C; and / or, composite acid concentration of 0.3 - 1.5 mol / L.

4. The catalyst according to any one of claims 1-3, characterized in that, The molecular sieve treated with the composite acid includes microcrystalline molecular sieve and small crystal molecular sieve; the crystal size of the small crystal molecular sieve is 100 nm - 990 nm; the crystal size of the microcrystalline molecular sieve is 1000 nm - 20000 nm.

5. The catalyst according to claim 4, characterized in that, By weight percentage, the small crystal molecular sieve accounts for 5 - 50% of the weight of the molecular sieve treated with the composite acid.

6. The catalyst according to any one of claims 1-3, characterized in that, The weight of component a) is 2 - 10%; and / or, the weight of component b) is 1.5 - 9%; and / or, the weight of component c) is 36 - 52%, and / or, the weight of component e) is 35 - 55%.

7. A preparation method of an aromatization catalyst, comprising: S1. Treat a molecular sieve with a template agent with a composite acid to obtain the molecular sieve component c) treated with the composite acid; S2. Mix the molecular sieve component c) treated with the composite acid with component d), component e) and water, and form and calcine to obtain a carrier; S3. Mix the carrier with an aqueous solution containing component a) and component b), and dry and calcine; wherein, based on the total weight of the catalyst, the composition and weight percentage of each component are: a) 0.5 - 20% of a water-soluble compound selected from at least one of Zn, Ga, Mo, W and noble metals; b) 0.5 - 15% of a water-soluble compound selected from at least one of P, B, Si, Fe, Cu, Co, Mn, Ni and rare earth elements; c) 24 - 60% of a molecular sieve treated with a composite acid; d) 10 - 30% of at least one selected from SiO2, Al2O3, TiO2 and ZrO2; e) 20 to 65% is selected from kaolin; The composite acid includes a non-complexing acid having no complexing effect on Al and a complexing acid having a complexing effect on Al; The conditions for the acid treatment include: a liquid-solid ratio of 1.5 to 20:1; a temperature of 20 to 99 °C; a composite acid concentration of 0.1 to 5 mol / L; a treatment time of 0.5 to 96 h; The molecular sieve is selected from ZSM-5 and / or ZSM-11; In the composite acid, the molar percentage of the complexing acid is 30 to 80%.

8. The preparation method according to claim 7, wherein The non-complexing acid is selected from citric acid and / or oxalic acid; and / or, the complexing acid is selected from at least one of nitric acid, hydrochloric acid, sulfuric acid, acetic acid, and phosphoric acid; and / or, the noble metal is selected from Ag.

9. The preparation method according to claim 7, wherein, The conditions for the acid treatment include: a liquid-solid ratio of 2.5 to 8:1; and / or, a temperature of 50 to 85 °C; and / or, a composite acid concentration of 0.3 to 1.5 mol / L.

10. The preparation method according to any one of claims 7-9, characterized in that, The molecular sieve treated with the composite acid includes a micron-large crystal molecular sieve and a small crystal molecular sieve; the crystal size of the small crystal molecular sieve is 100 nm to 990 nm; the crystal size of the micron-large crystal molecular sieve is 1000 nm to 20000 nm.

11. The preparation method according to claim 10, characterized in that, By weight percentage, the small crystal molecular sieve accounts for 5 to 50% of the molecular sieve treated with the composite acid.

12. The preparation method according to any one of claims 7-9, characterized in that, After the acid treatment in S1 and before S2, the preparation method further includes sequentially performing water washing, drying, calcination, and ammonia exchange treatment.

13. An aromatization catalyst obtained by the preparation method according to any one of claims 7-12.

14. A method for preparing an aromatic hydrocarbon, comprising: Contacting a reaction raw material with the catalyst, wherein the catalyst is the aromatization catalyst according to any one of claims 1-6 and 13.

15. The method for preparing aromatic hydrocarbons according to claim 14, wherein The reaction raw material is at least one of an oxygen-containing compound and a hydrocarbon compound; and / or, the weight hourly space velocity of the reaction raw material is 0.1~10.0h -1 ; and / or, the temperature of the reaction is 370 to 650 °C; and / or, the pressure of the reaction is 0.01 to 4.0 MPa.

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