Alkyl aromatic hydrocarbon dehydrogenation catalyst, its preparation method and application

Abstract

The present invention discloses an alkylaromatic dehydrogenation catalyst, a preparation method thereof and an application. The catalyst comprises Fe2O3, K2O, CeO2, WO3, SrO, MnFe2O4, K2TiO3, and at least one selected from GeO2, SnO2 or PbO2. When the catalyst of the present invention is used in the process of dehydrogenating alkylaromatic to alkenylaromatic, it can overcome the problems of low activity and poor stability of low-potassium catalysts under low temperature and high space velocity in the prior art, and the iron ion concentration in the aqueous phase of the dehydrogenated liquid can still be below 0.00009 mg / L after stable operation for 3000 hours.

Description

Technical Field

[0001] The invention belongs to the field of catalyst preparation, and particularly relates to a catalyst for preparing alkylene aromatics by dehydrogenating alkyl aromatics, and a preparation method and application thereof. Background Art

[0002] Industrially, alkenyl aromatics are mainly produced by catalytic dehydrogenation of alkyl aromatics. One of the keys to this method is to select a dehydrogenation catalyst with high activity, high selectivity and good stability. Catalysts for catalytic dehydrogenation of alkyl aromatics are mainly divided into two categories: one is the Fe-K-Cr series, such as US Patents US4152300, US4144197, and Chinese Patent CN87100517. Although this type of catalyst has good activity and stability, it has been eliminated due to the presence of chromium, which is not very environmentally friendly; the other is the Fe-K-Ce-Mo series, such as Chinese Patents CN201210021958.X and CN200875018406.5. This type of catalyst not only replaces Cr with Ce and Mo, but also has a significantly improved activity and stability compared with the former. The main problem with it is the high K2O content, which is generally 10-20%.

[0003] Alkyl aromatic dehydrogenation catalysts generally use iron-based catalysts with iron oxide as the main active component and potassium oxide as the main co-catalyst. However, the slow loss and migration of potassium under the scouring of high-temperature water vapor is one of the main reasons for the irreversible deactivation of the catalyst. Currently, reducing the potassium content is the mainstream of the development of alkyl aromatic dehydrogenation catalysts.

[0004] As far as the industrial dehydrogenation of ethylbenzene to produce styrene is concerned, its annual output is mostly above 100,000 tons / year. China already has several sets of equipment with an annual scale of more than 500,000 tons. The high reaction temperature leads to many by-products and high energy consumption, which has always been a problem that has troubled styrene manufacturers. If the dehydrogenation reaction temperature can be reduced by 5°C or even 10°C, and the air velocity can be increased, more styrene products can be obtained, and the unit product material consumption and energy consumption can be reduced. For industrial equipment, no equipment needs to be changed, and no additional investment is required. A large amount of water vapor and electricity expenses can be saved in one year. In addition, since the dehydrogenation reaction operates at low temperature, it also has positive significance for extending the life of the catalyst and reducing the high temperature resistance requirements of the equipment material. Therefore, developing a low-potassium catalyst suitable for operation under low temperature and high air velocity conditions, with higher activity and better stability, and significantly reducing energy consumption has always been the direction of researchers' efforts. Summary of the invention

[0005] One of the technical problems to be solved by the present invention is the problem that the alkylaromatic dehydrogenation catalyst with low potassium content in the prior art has low activity and poor stability under low temperature and high space velocity conditions. A new catalyst for preparing alkenyl aromatic hydrocarbons by dehydrogenation of alkyl aromatic hydrocarbons is provided. The catalyst has a low potassium content and has good activity and stability for preparing alkenyl aromatic hydrocarbons by dehydrogenation of alkyl aromatic hydrocarbons under low temperature and high space velocity conditions, so as to obtain more products, effectively reduce energy consumption, extend the operation cycle of the device, reduce the catalyst renewal cost and the output loss caused by frequent catalyst replacement.

[0006] Another technical problem to be solved by the present invention is to provide a preparation method of the catalyst corresponding to solving the first technical problem.

[0007] The third technical problem to be solved by the present invention is to provide a method for preparing alkenyl aromatic hydrocarbons by dehydrogenation of alkyl aromatic hydrocarbons corresponding to solving the first technical problem.

[0008] To solve the above-mentioned first technical problem, the technical solution adopted by the present invention is as follows:

[0009] A catalyst for preparing alkenyl aromatic hydrocarbons by dehydrogenation of alkyl aromatic hydrocarbons, based on the mass of the catalyst, comprises the following components:

[0010] (a) 66% to 79% of Fe2O3;

[0011] (b) 2.4% to 5.2% of K2O;

[0012] (c) 6.1% to 11.9% of CeO2;

[0013] (d) 0.5% to 5% of WO3;

[0014] (e) 0.5% to 5% of SrO;

[0015] (f) 0.8% to 7.7% of MnFe2O4;

[0016] (g) 0.5% to 5% of K2TiO3;

[0017] (h) 0.5% to 2.5% of component H, and component H is selected from at least one of GeO2, SnO2 or PbO2.

[0018] In the above technical solution, in the catalyst, the content of MnFe2O4 is preferably 2% to 6%.

[0019] In the above technical solution, in the catalyst, the content of K2TiO3 is preferably 1% to 4%.

[0020] In the above technical solution, the catalyst preferably does not contain molybdenum oxide.

[0021] In the above technical solution, in the catalyst, CeO2 is derived from cerium oxalate and / or cerium hydroxide.

[0022] In the above technical solution, the catalyst may further contain other components, such as Nb2O5.

[0023] In the above technical solution, the catalyst does not contain a binder component. To solve the second of the above technical problems, the technical solution adopted by the present invention is as follows:

[0024] In the technical solution of the first of the above technical problems, the preparation method of the catalyst includes the following steps:

[0025] Mix an Fe source, a K source, a Ce source, a W source, an Sr source, MnFe2O4, K2TiO3, and a component H source (the component H source is selected from at least one of a Ge source, a Sn source, and a Pb source) and a pore-forming agent, and form them into a shape by mixing. After drying and calcination, the obtained catalyst is obtained.

[0026] In the above technical solution, preferably, mix an Fe source, a K source, a Ce source, a W source, an Sr source, and at least one selected from a Ge source, a Sn source, and a Pb source and a pore-forming agent, then add MnFe2O4 and K2TiO3 and continue to mix, and then add water (preferably deionized water) to mix and form a shape to obtain a catalyst precursor; the catalyst precursor is dried and calcined to obtain the catalyst.

[0027] In the above technical solution, the Fe source is iron oxide red and iron oxide yellow, and their weight ratio is preferably iron oxide red: iron oxide yellow = (0.5 - 1.2): 1.

[0028] In the above technical solution, the K source is potassium carbonate. The Ce source is cerium oxalate and / or cerium hydroxide; the W source is at least one of a tungsten salt or an oxide. The Sr source is at least one of an oxide or a carbonate. The Ge source, Sn source, and Pb source are each independently selected from at least one of their salts or oxides.

[0029] In the above technical solution, the pore-forming agent is selected from at least one of graphite, polystyrene microspheres, and sodium carboxymethyl cellulose, preferably sodium carboxymethyl cellulose, and its addition amount is 2.4% - 6.1% of the total weight of the catalyst.

[0030] In the above technical solution, no binder is added during the catalyst preparation process, and the binder includes one of kaolin, diatomite, and cement.

[0031] In the above technical solution, the addition amount of deionized water is not particularly limited, and those skilled in the art can reasonably control the dryness and humidity for extrusion needs. For example, but not limited to, the addition amount is 19.8% - 35.2% of the total weight of the catalyst raw materials.

[0032] In the above technical solution, during the preparation of the catalyst, the drying is preferably carried out by a three-step method, namely drying at 35-55°C for 2-4 hours, drying at 75-95°C for 2-4 hours, and drying at 115-135°C for 2-4 hours.

[0033] In the above technical solution, during the preparation of the catalyst, the calcination is preferably carried out by a three-step method, namely calcining at 425-575°C for 0.5-4 hours, calcining at 625-775°C for 0.5-4 hours, and calcining at 820-875°C for 0.5-4 hours.

[0034] To solve the third of the above technical problems, a method for dehydrogenating alkyl aromatic hydrocarbons to prepare alkenyl aromatic hydrocarbons is provided, wherein the catalyst of the present invention is used.

[0035] In the above technical solution, the method includes: a step of obtaining alkenyl aromatic hydrocarbons by dehydrogenating alkyl aromatic hydrocarbons as raw materials in the presence of the catalyst of the present invention.

[0036] In the above technical solution, the alkyl aromatic hydrocarbon can be ethylbenzene, diethylbenzene, methyl ethylbenzene, etc. The corresponding alkenyl aromatic hydrocarbon is styrene, divinylbenzene, methylstyrene, etc.

[0037] In the above technical solution, the reaction conditions of the method are as follows: reaction temperature 575-595°C, liquid hourly space velocity 1.2-2.0 h -1 -1, water ratio (weight) 1.0-2.0, pressure -70-0 kPa.

[0038] Compared with the prior art, the present invention has the following beneficial technical effects:

[0039] The inventors have found through research that by adding an appropriate amount of manganese ferrite, an appropriate amount of potassium titanate, and at least one selected from GeO2, SnO2, and PbO2 to the iron-potassium-cerium-tungsten-strontium alkyl aromatic hydrocarbon dehydrogenation catalyst system, the activity and stability of the low-potassium content catalyst under low-temperature and high-space velocity conditions can be significantly improved. The possible reason is that the addition of MnFe2O4 and K2TiO3 enhances the reduction resistance of trivalent iron, reduces the instability of potassium. On the other hand, no binder component is introduced, reducing the introduction of inefficient substances, further stabilizing and dispersing the active phase of the catalyst, accelerating the rate of the water-gas reaction between water vapor and surface carbon deposition of the catalyst, and enhancing the self-regeneration ability of the catalyst.

[0040] Using the catalyst of the present invention at -50 kPa and an ethylbenzene volume space velocity of 1.6 h- 1Under the conditions of a reaction temperature of 585 °C and a weight ratio of water / ethylbenzene of 1.4, the conversion rate of ethylbenzene can reach 73.7%. After stable operation for 3000 hours under low temperature and high space velocity conditions, the conversion rate of ethylbenzene can still reach 73.4%. The concentration of iron ions in the aqueous phase of the dehydrogenation liquid can hardly be detected, achieving good technical effects. Detailed implementation manners

[0041] The present invention will be further elaborated in detail below through examples.

[0042] In the examples and comparative examples of the present invention, the activity evaluation of the catalyst was carried out in an isothermal fixed bed. For the activity evaluation of the ethylbenzene dehydrogenation to styrene catalyst, the process is briefly described as follows:

[0043] Deionized water and ethylbenzene were respectively input into a preheating mixer through metering pumps, preheated and mixed into a gaseous state, and then entered the reactor. The reactor was heated by an electric heating wire to reach a predetermined temperature. The inner diameter of the reactor was a 1″ stainless steel tube, which was filled with 100 ml of catalyst with a particle size of 3 mm. The reactants flowing out of the reactor were condensed with water and analyzed for their composition by a gas chromatograph. Taking the dehydrogenation of ethylbenzene to prepare styrene as an example,

[0044] The conversion rate of ethylbenzene and the selectivity of styrene were calculated according to the following formulas:

[0045]

[0046]

[0047] The loss of the active component of the sample was determined by measuring the concentration of iron ions in the aqueous phase of the dehydrogenation liquid. The instrument was a PE-Zeeman 5000 type atomic absorption spectrometer, with an analysis line of 404.4 nm, a lamp current of 10 mA, and a slit of 0.7 nm.

[0048] [Example 1]

[0049] Mix 36.74 parts of iron oxide red equivalent to Fe2O3, 36.74 parts of iron oxide yellow equivalent to Fe2O3, 4.66 parts of potassium carbonate equivalent to K2O, 9.64 parts of cerium oxalate equivalent to CeO2, 2.58 parts of ammonium tungstate equivalent to WO3, 2.38 parts of strontium carbonate equivalent to SrO, 1.68 parts of GeO2 and 5.69 parts of sodium carboxymethyl cellulose in a kneader for 0.2 hours. Add 3.16 parts of MnFe2O4 and 2.42 parts of K2TiO3, and then stir for 1.8 hours. Add deionized water accounting for 27.7% of the total weight of the catalyst raw materials, mix for 0.55 hours, take out and extrude into particles with a diameter of 3 mm and a length of 6 mm, put them into an oven, bake at 45 °C for 2.5 hours, 85 °C for 2.5 hours, 128 °C for 3 hours, and then place them in a muffle furnace and calcine at 555 °C for 2.5 hours, 675 °C for 3 hours, 865 °C for 3 hours to obtain the finished catalyst. The catalyst composition is listed in Table 1.

[0050] Load 100 ml of the catalyst into the reactor and carry out activity evaluation under the conditions of -50 kPa, a liquid hourly space velocity of 1.6 h-1 -1 , a reaction temperature of 585 °C, and a water / ethylbenzene weight ratio of 1.4. The evaluation results are listed in Table 2. After 3000 hours of evaluation, collect the dehydrogenation liquid. After separating the aqueous phase and the oil phase, measure the iron ion concentration in the aqueous phase of the dehydrogenation liquid. The test results are listed in Table 2.

[0051] [Comparative Example 1]

[0052] Except for not using MnFe2O4, K2TiO3 and GeO2, the relative proportion relationships of the other components, the catalyst preparation method, the catalyst evaluation conditions and the analysis method are the same as those in Example 1. The specific composition is: 36.74 parts of iron oxide red equivalent to Fe2O3, 36.74 parts of iron oxide yellow equivalent to Fe2O3, 4.66 parts of potassium carbonate equivalent to K2O, 9.64 parts of cerium oxalate equivalent to CeO2, 2.58 parts of ammonium tungstate equivalent to WO3, 2.38 parts of strontium carbonate equivalent to SrO and 5.28 parts of sodium carboxymethyl cellulose. The catalyst composition is listed in Table 1. The test results are listed in Table 2.

[0053] [Comparative Example 2]

[0054] Except for using iron oxide red, iron oxide yellow and MnO to replace the same proportion of MnFe2O4, and K2O and TiO2 to replace the same proportion of K2TiO3, the relative proportion relationships of the other components, the catalyst preparation method, the catalyst evaluation conditions and the analysis method are the same as those in Example 1. Specifically:

[0055] 37.83 parts of iron oxide red equivalent to Fe2O3, 37.83 parts of iron oxide yellow equivalent to Fe2O3, 5.96 parts of potassium carbonate equivalent to K2O, 9.64 parts of cerium oxalate equivalent to CeO2, 2.58 parts of ammonium tungstate equivalent to WO3, 2.38 parts of strontium carbonate equivalent to SrO, 1.68 parts of GeO2 and 5.69 parts of sodium carboxymethyl cellulose were stirred in a kneader for 0.2 hours, 0.98 parts of MnO and 1.12 parts of TiO2 were added, and then stirred for 1.8 hours. 27.7% of deionized water based on the total weight of the catalyst raw materials was added, and kneaded for 0.55 hours. Then, it was taken out and extruded into particles with a diameter of 3 mm and a length of 6 mm, placed in an oven, dried at 45 °C for 2.5 hours, 85 °C for 2.5 hours, 128 °C for 3 hours, and then placed in a muffle furnace, calcined at 555 °C for 2.5 hours, 675 °C for 3 hours, and 865 °C for 3 hours to obtain the finished catalyst. The catalyst composition is listed in Table 1. The test results are listed in Table 2.

[0056] [Example 2]

[0057] The catalyst was prepared and tested according to the method of Example 1, except that SnO2 was used instead of GeO2.

[0058] The catalyst composition is shown in Table 1, and the test results are listed in Table 2.

[0059] [Comparative Example 3]

[0060] Except that iron oxide red, iron oxide yellow and MnO were used to replace the same proportion of MnFe2O4, and K2O and TiO2 were used to replace the same proportion of K2TiO3, the relative proportion relationship of the remaining components, the catalyst preparation method, the catalyst evaluation conditions and the analysis method were the same as those in Example 2. Specifically:

[0061] 37.83 parts of iron oxide red equivalent to Fe2O3, 37.83 parts of iron oxide yellow equivalent to Fe2O3, 5.96 parts of potassium carbonate equivalent to K2O, 9.64 parts of cerium oxalate equivalent to CeO2, 2.58 parts of ammonium tungstate equivalent to WO3, 2.38 parts of strontium carbonate equivalent to SrO, 1.68 parts of SnO2 and 5.69 parts of sodium carboxymethyl cellulose were stirred in a kneader for 0.2 hours, 0.98 parts of MnO and 1.12 parts of TiO2 were added, and then stirred for 1.8 hours. 27.7% of deionized water based on the total weight of the catalyst raw materials was added, and kneaded for 0.55 hours. Then, it was taken out and extruded into particles with a diameter of 3 mm and a length of 6 mm, placed in an oven, dried at 45 °C for 2.5 hours, 85 °C for 2.5 hours, 128 °C for 3 hours, and then placed in a muffle furnace, calcined at 555 °C for 2.5 hours, 675 °C for 3 hours, and 865 °C for 3 hours to obtain the finished catalyst. The catalyst composition is listed in Table 1. The test results are listed in Table 2.

[0062] [Comparative Example 4]

[0063] The catalyst was prepared and tested according to the method of Example 2, except that cerium oxide was used instead of cerium oxalate.

[0064] The composition of the catalyst is shown in Table 1, and the test results are listed in Table 2.

[0065] [Comparative Example 5]

[0066] The catalyst was tested according to the method of Example 2. The preparation method and specific composition were as follows: Iron oxide red equivalent to 36.74 parts of Fe2O3, iron oxide yellow equivalent to 36.74 parts of Fe2O3, potassium carbonate equivalent to 4.66 parts of K2O, cerium oxalate equivalent to 9.64 parts of CeO2, ammonium tungstate equivalent to 2.58 parts of WO3, strontium carbonate equivalent to 2.38 parts of SrO, 3.16 parts of MnFe2O4, 2.42 parts of K2TiO3, 1.68 parts of SnO2 and 5.69 parts of sodium carboxymethylcellulose were stirred in a kneader for 2 hours, deionized water accounting for 27.7% of the total weight of the catalyst raw materials was added, and the mixture was stirred for 0.55 hours. Then, it was taken out and extruded into particles with a diameter of 3 mm and a length of 6 mm, placed in an oven, dried at 45 °C for 2.5 hours, at 85 °C for 2.5 hours, and at 128 °C for 3 hours. Then, it was placed in a muffle furnace and calcined at 555 °C for 2.5 hours, at 675 °C for 3 hours, and at 865 °C for 3 hours to obtain the finished catalyst. The composition of the catalyst is listed in Table 1, and the test results are listed in Table 2.

[0067] [Example 3]

[0068] Iron oxide red equivalent to 24.25 parts of Fe2O3, iron oxide yellow equivalent to 46.08 parts of Fe2O3, potassium carbonate equivalent to 2.35 parts of K2O, cerium hydroxide equivalent to 11.9 parts of CeO2, ammonium tungstate equivalent to 4.16 parts of WO3, strontium carbonate equivalent to 3.35 parts of SrO, 0.85 parts of PbO2, 0.36 parts of Nb2O5 and 5.69 parts of graphite were stirred in a kneader for 0.2 hours. Then, 5.5 parts of MnFe2O4 and 1.2 parts of K2TiO3 were added, and the mixture was stirred for another 1.8 hours. Deionized water accounting for 27.7% of the total weight of the catalyst raw materials was added, and the mixture was stirred for 0.55 hours. Then, it was taken out and extruded into particles with a diameter of 3 mm and a length of 6 mm, placed in an oven, dried at 45 °C for 2.5 hours, at 85 °C for 2.5 hours, and at 128 °C for 3 hours. Then, it was placed in a muffle furnace and calcined at 555 °C for 2.5 hours, at 675 °C for 3 hours, and at 865 °C for 3 hours to obtain the finished catalyst. The composition of the catalyst is listed in Table 1.

[0069] The catalyst was evaluated and analyzed according to the method of Example 1, and the test results are listed in Table 2.

[0070] [Example 4]

[0071] Mix 30.73 parts of iron oxide red equivalent to Fe2O3, 37.45 parts of iron oxide yellow equivalent to Fe2O3, 3.95 parts of potassium carbonate equivalent to K2O, 6.55 parts of cerium oxalate equivalent to CeO2, 1.72 parts of ammonium tungstate equivalent to WO3, 4.95 parts of strontium carbonate equivalent to SrO, 2.15 parts of GeO2 and 5.69 parts of graphite in a kneader for 0.2 hours. Add 7.65 parts of MnFe2O4 and 4.85 parts of K2TiO3, and then stir for 1.8 hours. Add deionized water accounting for 27.7% of the total weight of the catalyst raw materials, mix for 0.55 hours, take out and extrude into granules with a diameter of 3 mm and a length of 6 mm. Put them into an oven, bake at 45 °C for 2.5 hours, 85 °C for 2.5 hours, 128 °C for 3 hours, and then place them in a muffle furnace, calcine at 555 °C for 2.5 hours, 675 °C for 3 hours, 865 °C for 3 hours to obtain the finished catalyst. The catalyst composition is listed in Table 1.

[0072] Evaluate and analyze the catalyst according to the method of Example 1. The test results are listed in Table 2.

[0073] [Example 5]

[0074] Mix 35.48 parts of iron oxide red equivalent to Fe2O3, 38.45 parts of iron oxide yellow equivalent to Fe2O3, 3.71 parts of potassium carbonate equivalent to K2O, 9.46 parts of cerium oxalate equivalent to CeO2, 4.82 parts of ammonium tungstate equivalent to WO3, 0.83 parts of strontium carbonate equivalent to SrO, 2.45 parts of GeO2 and 5.69 parts of graphite in a kneader for 0.2 hours. Add 0.95 parts of MnFe2O4 and 3.85 parts of K2TiO3, and then stir for 1.8 hours. Add deionized water accounting for 27.7% of the total weight of the catalyst raw materials, mix for 0.55 hours, take out and extrude into granules with a diameter of 3 mm and a length of 6 mm. Put them into an oven, bake at 45 °C for 2.5 hours, 85 °C for 2.5 hours, 128 °C for 3 hours, and then place them in a muffle furnace, calcine at 555 °C for 2.5 hours, 675 °C for 3 hours, 865 °C for 3 hours to obtain the finished catalyst. The catalyst composition is listed in Table 1.

[0075] Evaluate and analyze the catalyst according to the method of Example 1. The test results are listed in Table 2.

[0076] [Example 6]

[0077] Mix 41.69 parts of iron oxide red equivalent to Fe2O3, 36.36 parts of iron oxide yellow equivalent to Fe2O3, 5.05 parts of potassium carbonate equivalent to K2O, 7.15 parts of cerium oxalate equivalent to CeO2, 0.55 parts of ammonium tungstate equivalent to WO3, 0.55 parts of strontium carbonate equivalent to SrO, 2.05 parts of GeO2 and 5.69 parts of sodium carboxymethyl cellulose in a kneader for 0.2 hours. Add 1.85 parts of MnFe2O4 and 4.75 parts of K2TiO3, and then stir for 1.8 hours. Add deionized water accounting for 27.7% of the total weight of the catalyst raw materials, mix for 0.55 hours, take out and extrude into particles with a diameter of 3 mm and a length of 6 mm. Put them into an oven, bake at 45 °C for 2.5 hours, 85 °C for 2.5 hours, 128 °C for 3 hours, and then place them in a muffle furnace, calcine at 555 °C for 2.5 hours, 675 °C for 3 hours, 865 °C for 3 hours to obtain the finished catalyst. The catalyst composition is listed in Table 1.

[0078] Evaluate and analyze the catalyst according to the method of Example 1. The test results are listed in Table 2.

[0079] [Example 7]

[0080] Mix 38.7 parts of iron oxide red equivalent to Fe2O3, 36.4 parts of iron oxide yellow equivalent to Fe2O3, 2.35 parts of potassium carbonate equivalent to K2O, 8.04 parts of cerium oxalate equivalent to CeO2, 3.41 parts of ammonium tungstate equivalent to WO3, 1.35 parts of strontium carbonate equivalent to SrO, 2.35 parts of SnO2 and 5.69 parts of graphite in a kneader for 0.2 hours. Add 6.65 parts of MnFe2O4 and 0.75 parts of K2TiO3, and then stir for 1.8 hours. Add deionized water accounting for 27.7% of the total weight of the catalyst raw materials, mix for 0.55 hours, take out and extrude into particles with a diameter of 3 mm and a length of 6 mm. Put them into an oven, bake at 45 °C for 2.5 hours, 85 °C for 2.5 hours, 128 °C for 3 hours, and then place them in a muffle furnace, calcine at 555 °C for 2.5 hours, 675 °C for 3 hours, 865 °C for 3 hours to obtain the finished catalyst. The catalyst composition is listed in Table 1.

[0081] Evaluate and analyze the catalyst according to the method of Example 1. The test results are listed in Table 2.

[0082] [Comparative Example 6]

[0083] Mix 42.9 parts of iron oxide red equivalent to Fe2O3, 26.8 parts of iron oxide yellow equivalent to Fe2O3, 5.8 parts of potassium carbonate equivalent to K2O, 9.1 parts of cerium oxalate equivalent to CeO2, 2.5 parts of ammonium tungstate equivalent to WO3, 4.75 parts of strontium carbonate equivalent to SrO, 0.65 parts of GeO2 and 5.69 parts of sodium carboxymethyl cellulose in a kneader for 0.2 hours. Add 2.6 parts of MnFe2O4 and 4.9 parts of K2TiO3, and then stir for 1.8 hours. Add deionized water accounting for 27.7% of the total weight of the catalyst raw materials, mix for 0.55 hours, take out and extrude into particles with a diameter of 3 mm and a length of 6 mm. Put them into an oven, bake at 45 °C for 2.5 hours, 85 °C for 2.5 hours, 128 °C for 3 hours, and then place them in a muffle furnace, calcine at 555 °C for 2.5 hours, 675 °C for 3 hours, 865 °C for 3 hours to obtain the finished catalyst. The catalyst composition is listed in Table 1.

[0084] Evaluate and analyze the catalyst according to the method of Example 1. The test results are listed in Table 2.

[0085] [Comparative Example 7]

[0086] Mix 36.5 parts of iron oxide red equivalent to Fe2O3, 38.18 parts of iron oxide yellow equivalent to Fe2O3, 5.55 parts of potassium carbonate equivalent to K2O, 7.75 parts of cerium oxalate equivalent to CeO2, 2.58 parts of ammonium tungstate equivalent to WO3, 1.38 parts of strontium carbonate equivalent to SrO, 1.68 parts of GeO2, 1.21 parts of cement and 5.69 parts of sodium carboxymethyl cellulose in a kneader for 0.2 hours. Add 3.16 parts of MnFe2O4 and 2.01 parts of K2TiO3, and then stir for 1.8 hours. Add deionized water accounting for 27.7% of the total weight of the catalyst raw materials, mix for 0.55 hours, take out and extrude into particles with a diameter of 3 mm and a length of 6 mm. Put them into an oven, bake at 45 °C for 2.5 hours, 85 °C for 2.5 hours, 128 °C for 3 hours, and then place them in a muffle furnace, calcine at 555 °C for 2.5 hours, 675 °C for 3 hours, 865 °C for 3 hours to obtain the finished catalyst. The catalyst composition is listed in Table 1.

[0087] Evaluate and analyze the catalyst according to the method of Example 1. The test results are listed in Table 2.

[0088] [Comparative Example 8]

[0089] 38.36 parts by weight of iron oxide red equivalent to Fe2O3, 37.42 parts by weight of iron oxide yellow equivalent to Fe2O3, 6.45 parts by weight of potassium carbonate equivalent to K2O, 6.15 parts by weight of cerium oxalate equivalent to CeO2, 1.76 parts by weight of ammonium tungstate equivalent to WO3, 2.73 parts by weight of strontium carbonate equivalent to SrO, 2.18 parts by weight of GeO2, 1.55 parts by weight of ammonium molybdate equivalent to MoO3 and 5.69 parts by weight of sodium carboxymethylcellulose were stirred in a kneader for 0.2 hours. Then, 1.62 parts by weight of MnFe2O4 and 1.78 parts by weight of K2TiO3 were added, and the mixture was stirred for another 1.8 hours. Next, deionized water accounting for 27.7% of the total weight of the catalyst raw materials was added, and the mixture was blended for 0.55 hours. After that, the mixture was taken out and extruded into granules with a diameter of 3 mm and a length of 6 mm, which were then placed in an oven and dried at 45 °C for 2.5 hours, at 85 °C for 2.5 hours, and at 128 °C for 3 hours. Then, the granules were placed in a muffle furnace and calcined at 555 °C for 2.5 hours, at 675 °C for 3 hours, and at 865 °C for 3 hours to obtain the finished catalyst. The catalyst composition is listed in Table 1.

[0090] The catalyst was evaluated and analyzed according to the method of Example 1, and the test results are listed in Table 2.

[0091] [Comparative Example 9]

[0092] 36.5 parts by weight of iron oxide red equivalent to Fe2O3, 37.4 parts by weight of iron oxide yellow equivalent to Fe2O3, 3.55 parts by weight of potassium carbonate equivalent to K2O, 7.75 parts by weight of cerium oxalate equivalent to CeO2, 2.58 parts by weight of ammonium tungstate equivalent to WO3, 1.38 parts by weight of strontium carbonate equivalent to SrO, 1.15 parts by weight of GeO2 and 5.69 parts by weight of graphite were stirred in a kneader for 0.2 hours. Then, 8.15 parts by weight of MnFe2O4 and 1.54 parts by weight of K2TiO3 were added, and the mixture was stirred for another 1.8 hours. Next, deionized water accounting for 27.7% of the total weight of the catalyst raw materials was added, and the mixture was blended for 0.55 hours. After that, the mixture was taken out and extruded into granules with a diameter of 3 mm and a length of 6 mm, which were then placed in an oven and dried at 45 °C for 2.5 hours, at 85 °C for 2.5 hours, and at 128 °C for 3 hours. Then, the granules were placed in a muffle furnace and calcined at 555 °C for 2.5 hours, at 675 °C for 3 hours, and at 865 °C for 3 hours to obtain the finished catalyst. The catalyst composition is listed in Table 1.

[0093] The catalyst was evaluated and analyzed according to the method of Example 1, and the test results are listed in Table 2.

[0094] [Comparative Example 10]

[0095] Mix 29.97 parts of iron oxide red of Fe2O3, iron oxide yellow equivalent to 44.05 parts of Fe2O3, potassium carbonate equivalent to 4.85 parts of K2O, cerium oxalate equivalent to 7.11 parts of CeO2, ammonium tungstate equivalent to 3.42 parts of WO3, strontium carbonate equivalent to 2.35 parts of SrO, 0.85 parts of GeO2 and 5.69 parts of graphite in a kneader for 0.2 hours. Add 1.65 parts of MnFe2O4 and 5.75 parts of K2TiO3, and then stir for 1.8 hours. Add deionized water accounting for 27.7% of the total weight of the catalyst raw materials, mix for 0.55 hours, take out and extrude into particles with a diameter of 3 mm and a length of 6 mm. Put them into an oven, dry at 45°C for 2.5 hours, dry at 85°C for 2.5 hours, dry at 128°C for 3 hours, and then place them in a muffle furnace, calcine at 555°C for 2.5 hours, calcine at 675°C for 3 hours, and calcine at 865°C for 3 hours to obtain the finished catalyst. The catalyst composition is listed in Table 1.

[0096] Evaluate and analyze the catalyst according to the method of Example 1, and the test results are listed in Table 2.

[0097] [Example 8]

[0098] Mix iron oxide red equivalent to 30.7 parts of Fe2O3, iron oxide yellow equivalent to 45.2 parts of Fe2O3, potassium carbonate equivalent to 5.05 parts of K2O, cerium oxalate equivalent to 8.84 parts of CeO2, ammonium tungstate equivalent to 2.58 parts of WO3, strontium carbonate equivalent to 1.38 parts of SrO, 1.15 parts of GeO2 and 5.69 parts of graphite in a kneader for 0.2 hours. Add 1.85 parts of MnFe2O4 and 3.25 parts of K2TiO3, and then stir for 1.8 hours. Add deionized water accounting for 27.7% of the total weight of the catalyst raw materials, mix for 0.55 hours, take out and extrude into particles with a diameter of 3 mm and a length of 6 mm. Put them into an oven, dry at 45°C for 2.5 hours, dry at 85°C for 2.5 hours, dry at 128°C for 3 hours, and then place them in a muffle furnace, calcine at 555°C for 2.5 hours, calcine at 675°C for 3 hours, and calcine at 865°C for 3 hours to obtain the finished catalyst. The catalyst composition is listed in Table 1.

[0099] Evaluate and analyze the catalyst according to the method of Example 1. The difference is that the catalyst evaluation conditions are changed, i.e., -50 kPa, liquid hourly space velocity of 1.8 h -1 、reaction temperature of 575°C, and weight ratio of water / ethylbenzene of 1.4.

[0100] Table 1 (to be continued)

[0101]

[0102] Table 1 (continued)

[0103]

[0104] Table 2

[0105]

[0106] The embodiments described in the present invention are only detailed descriptions of the technical solutions of the present invention, but the present invention is not limited to the above embodiments, that is, the present invention does not depend on the steps described in the above embodiments to be implemented. In summary, any improvements made by those skilled in the art to the present invention, including the replacement of the raw materials and additives described in the present invention, the selection of specific implementation manners, etc., all fall within the protection scope and the disclosure scope of the present invention.

Claims

1. A catalyst for dehydrogenating alkylaromatics to prepare alkenylaromatics, based on the mass of the catalyst, comprises the following components: (a) 66% - 79% of Fe2O3; (b) 2.4% - 5.2% of K2O; (c) 6.1% - 11.9% of CeO2; (d) 0.5% - 5% of WO3; (e) 0.5% - 5% of SrO; (f) 0.8% - 7.7% of MnFe2O4; (g) 0.5% - 5% of K2TiO3; (h) 0.5% - 2.5% of component H, and component H is selected from at least one of GeO2, SnO2 or PbO2; The preparation method of the catalyst comprises the following steps: Mix an Fe source, a K source, a Ce source, a W source, an Sr source, and a component H source and a pore-forming agent, then add MnFe2O4 and K2TiO3 and continue to mix, and then add water to mix and form, and obtain the catalyst through drying and calcination, wherein the component H source is selected from at least one of a Ge source, an Sn source, and a Pb source; In the catalyst, CeO2 is derived from cerium oxalate and / or cerium hydroxide.

2. The catalyst according to claim 1, characterized in that, In the catalyst, the content of MnFe2O4 is 2% - 6%; and / or, in the catalyst, the content of K2TiO3 is 1% - 4%.

3. The catalyst according to claim 1, characterized in that, The catalyst does not contain molybdenum oxide.

4. A preparation method of the catalyst according to any one of claims 1 - 2, comprising the following steps: Mix an Fe source, a K source, a Ce source, a W source, an Sr source, and a component H source and a pore-forming agent, then add MnFe2O4 and K2TiO3 and continue to mix, and then add water to mix and form, and obtain the catalyst through drying and calcination, wherein the component H source is selected from at least one of a Ge source, an Sn source, and a Pb source.

5. The preparation method according to claim 4, characterized in that, The Fe source is iron oxide red and iron oxide yellow, and the weight ratio thereof is iron oxide red: iron oxide yellow = (0.5 - 1.2): 1; And / or, the K source is potassium carbonate; the Ce source is cerium oxalate and / or cerium hydroxide; the W source is at least one of a tungsten salt or an oxide; the Sr source is at least one of an oxide or a carbonate; the Ge source, the Sn source, and the Pb source are each independently selected from at least one of its salt or oxide.

6. The preparation method according to claim 4, characterized in that, No binder is added during the preparation process of the catalyst.

7. The preparation method according to claim 4, characterized in that, The drying adopts a three-step method, that is, drying at 35 - 55 °C for 2 - 4 hours, drying at 75 - 95 °C for 2 - 4 hours, and drying at 115 - 135 °C for 2 - 4 hours.

8. The preparation method according to claim 4, characterized in that The calcination adopts a three-step method, that is, calcining at 425 - 575 °C for 0.5 - 4 hours, calcining at 625 - 775 °C for 0.5 - 4 hours, and calcining at 820 - 875 °C for 0.5 - 4 hours.

9. A method for preparing alkenyl aromatic hydrocarbons by dehydrogenating alkyl aromatic hydrocarbons, characterized in that, A catalyst prepared by using the catalyst according to any one of claims 1 - 3 or the preparation method according to any one of claims 4 - 8.

10. The method according to claim 9, characterized in that, The method includes: a step of using an alkylaromatic as a raw material and performing a dehydrogenation reaction in the presence of the catalyst to obtain an alkenylaromatic; wherein, the alkylaromatic is at least one of ethylbenzene, diethylbenzene, and methyl ethylbenzene; the alkenylaromatic is correspondingly at least one of styrene, divinylbenzene, and methylstyrene.

11. The method according to claim 9 or 10, characterized in that, The reaction conditions are as follows: the reaction temperature is 575 - 595 °C, the liquid hourly space velocity is 1.2 - 2.0 h -1 , the water ratio is 1.0 - 2.0 by weight, and the pressure is -70 - 0 kPa.

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