CN111054363A

CN111054363A - Catalyst for preparing butadiene by oxidative dehydrogenation of butylene

Info

Publication number: CN111054363A
Application number: CN201811201454.XA
Authority: CN
Inventors: 曾铁强; 缪长喜; 吴文海; 樊志贵
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: 2018-10-16
Filing date: 2018-10-16
Publication date: 2020-04-24

Abstract

The invention relates to a catalyst for preparing butadiene by oxidative dehydrogenation of butylene, which mainly solves the problems of low butylene conversion rate and low butadiene selectivity in the existing production process of preparing butadiene by oxidative dehydrogenation of butylene. The invention relates to a catalyst for preparing butadiene by oxidative dehydrogenation of butylene, which uses gamma-Fe₂O₃Me of spinel Structure^ⅡFe₂O₄As a main component, wherein the divalent metal Me is selected from at least one of Zn, Mg or Mn, toThe technical scheme of preparing the catalyst by using at least one oxide of VIB group elements as an auxiliary agent through the methods of precipitation, washing, drying, roasting and forming better solves the problem, efficiently and stably prepares butadiene products, improves the selectivity of butadiene and can be used in the industrial production of preparing butadiene by oxidative dehydrogenation of butylene.

Description

Catalyst for preparing butadiene by oxidative dehydrogenation of butylene

Technical Field

The invention relates to a catalyst for preparing butadiene by oxidative dehydrogenation of butylene.

Background

Butadiene is the primary feedstock for the production of synthetic rubber, second only to ethylene and propylene in petrochemical olefin feedstocks. From the downstream consumption situation, butadiene is mainly used for producing synthetic rubber, wherein the consumption ratios for producing polybutadiene rubber, styrene-butadiene rubber and SBS elastomer are respectively 31%, 28% and 20%, the total consumption ratio is 79%, and the consumption ratio for producing ABS resin is 16%. Butadiene is also used in the production of adiponitrile (nylon 66 monomer), sulfolane, anthraquinone, tetrahydrofuran, and other products. Worldwide butadiene consumption was about 1056.2 ten thousand tons in 2012.

The industrial production method of butadiene mainly comprises two methods of carbon four extraction separation and butylene dehydrogenation which are co-produced in the process of preparing ethylene by steam cracking. The method for obtaining butadiene by adopting carbon four extraction is economically advantageous, and about 97 percent of butadiene produced in the world can be extracted by cracking carbon four. However, butadiene is obtained as a by-product of the cracking unit, and it is difficult to increase its yield by adding the cracking unit. Moreover, as refinery feedstocks are upgraded, butadiene production will be reduced and ethylene plant feedstocks upgraded, creating a continuing bias in global butadiene supply.

With the rapid development of the synthetic rubber and resin industry and the wider and wider application of butadiene, the market demand of butadiene is continuously increased. Butadiene obtained by extracting naphtha cracking products cannot meet market demands, but butadiene products cannot be provided in the new energy field, coal chemical industry and large-scale shale gas development, so people pay attention to other butadiene production methods, and research on butylene oxidative dehydrogenation technology is wide.

The carbon four-fraction of the refinery contains a large amount of butylene, the carbon four-fraction has low use added value as civil fuel, and the high-selectivity conversion of the butylene into butadiene has obvious economic benefit and has important significance for the comprehensive utilization of carbon four-fraction resources. The process route for producing butadiene by oxidative dehydrogenation of butylene has great application prospect.

The Oxo-D process of the TPC group of the United states (formerly Texas Petrochemical) and the O-X-D process of Philips of the United states are typical processes for preparing butadiene through oxidative dehydrogenation of butene. The Oxo-D process adopts mixed feeding of butylene, water vapor and air, and carries out dehydrogenation reaction on an iron catalyst bed layer, wherein the reaction temperature is 550-600 ℃, the selectivity of butadiene is about 93 percent, and the conversion rate of butylene reaches 65 percent. In the O-X-D process, butylene, water vapor and air are used for carrying out oxidative dehydrogenation reaction in a fixed bed reactor, the reaction temperature is 480-600 ℃, the conversion rate of butylene is 75-80%, and the selectivity of butadiene is 88-92%.

The domestic butylene oxidative dehydrogenation catalyst is subjected to two stages of a molybdenum-based catalyst and an iron-based catalyst. The industrial production proves that the combined process of the H-198 iron-based catalyst and the guide baffle fluidized bed and the combined process of the B-02 iron-based catalyst and the two-section axial adiabatic fixed bed can enable the comprehensive economic benefit of the domestic butylene oxidative dehydrogenation device to reach the level of the concurrent American TPC group butylene oxidative dehydrogenation device. Since the 80 th century, with the continuous new construction of large-scale domestic ethylene plants, the carbon four extraction technology obtains the great economic advantage of butadiene, the production process of butadiene is gradually replaced by the carbon four extraction method, and the butylene oxidation plant in China is completely stopped in the early 90 th century.

Since the late 60 s, researchers have been working on developing new efficient catalysts to increase the yield and selectivity of butadiene, to improve the economics of the production process, and to reduce the adverse effects on the environment. Having a spinel structure (A)²⁺B₂ ³⁺O₄) The ferrite catalyst of (a) was the result of this study. Such as ZnFe₂O₄、MnFe₂O₄、MgFe₂O₄、ZnPdFeO₄And Mg_0.1Zn_0.9Fe₂O₄And the like. The ferrite spinel catalyst has higher activity and selectivity for oxidative dehydrogenation of butylene, and has the advantages of less oxygen-containing byproducts, long service life, high economic benefit, less three-waste pollution and the like, which cause wide attention at home and abroad. The butylene is oxidized and dehydrogenated on the catalyst, the conversion rate can reach more than 70 percent, and the selectivity can reach more than 90 percent. Ferrite catalyst based on spinel structure in butenedioic acidGood effects are obtained in the reaction for preparing butadiene by chemical dehydrogenation (CN104226352A, CN103102238A, CN103079695A and the like).

However, the existing production processes for preparing butadiene by oxidative dehydrogenation of butene still have the problems of low butene conversion rate, severe deep oxidation reaction and low butadiene selectivity. In order to make the process route for the oxidative dehydrogenation of butene to butadiene more competitive, there is a need to increase the catalyst activity and butadiene selectivity.

Disclosure of Invention

The invention aims to solve the technical problems of low conversion rate of butylene and low selectivity of butadiene in the existing production process of preparing butadiene by oxidative dehydrogenation of butylene, and provides a novel catalyst for preparing butadiene by oxidative dehydrogenation of butylene. The second technical problem to be solved by the present invention is to provide a method for preparing a catalyst corresponding to the first technical problem, wherein the method for preparing the catalyst is simple. The third technical problem to be solved by the invention is to provide a process method for preparing butadiene by oxidative dehydrogenation of butylene, which corresponds to one of the technical problems to be solved, and the butadiene product is efficiently and stably prepared in the oxidative dehydrogenation reaction of butylene, and the process method has the advantages of high butadiene selectivity, high catalyst activity and high stability.

In order to solve the first technical problem, the technical scheme adopted by the invention is as follows: a catalyst for preparing butadiene by oxidative dehydrogenation of butene comprises the following components:

a) with gamma-Fe₂O₃Me of spinel Structure^ⅡFe₂O₄Me is at least one of Zn, Mg or Mn, gamma-Fe as main component₂O₃With Me^ⅡFe₂O₄The molar ratio of (0.1-10): 10;

b) taking at least one oxide of VIB group elements as an auxiliary agent, and taking each auxiliary agent element and Me^ⅡFe₂O₄The molar ratio of (0.02-1): 10.

in the above technical solution, preferably, the divalent metal Me^ⅡAt least one selected from Zn and Mg.

The above techniqueIn this scheme, preferably, gamma-Fe₂O₃With Me^ⅡFe₂O₄The molar ratio of (0.1-5): 10, more preferably, gamma-Fe₂O₃With Me^ⅡFe₂O₄The molar ratio of (0.5-5): 10.

in the above technical solution, preferably, the group vib element is at least one selected from Cr and Mo.

In the above technical solution, preferably, the VIB group element and Me are^ⅡFe₂O₄The molar ratio of (0.05-0.5): 10.

in order to solve the technical problem II, the invention adopts the following steps to prepare the catalyst:

a) preparing a mixed solution containing the components of the catalyst and fully stirring;

b) co-precipitating the mixed solution with an alkaline solution at a suitable pH value;

c) the precipitated product is worked up.

In the technical scheme, the pH value in the precipitation process is 6-12, the washing temperature is 10-80 ℃, the drying temperature is 90-150 ℃, the drying time is 1-24 hours, the roasting temperature is 400-550 ℃, the roasting time is 1-24 hours, and the preferable roasting time is 1-12 hours; the alkaline solution is selected from one of ammonia water, sodium hydroxide or potassium hydroxide, wherein the ammonia water is the best, and the concentration of the ammonia water is preferably 10-30%.

In order to solve the third technical problem, the butadiene production method provided by the invention can adopt the following process steps:

with butene, O₂And the mixed gas of water vapor is used as a raw material, and the ratio of butylene: oxygen: the volume ratio of water vapor is 1: (0.1-20): (1-10). The reaction inlet temperature is 300-500 ℃, and the mass space velocity of the butylene is 0.2-6.0 h^-1And the raw materials are contacted with a catalyst for reaction to obtain butadiene.

The water is preheated to steam before entering the reactor and is fully mixed with the raw material gas.

The catalyst of the invention can be used in a fixed bed or fluidized bed reactor.

Compared with the prior art, the invention has remarkable advantages and outstanding effects of α -and gamma-crystal form Fe₂O₃The difference of catalytic performance is obvious, α -Fe₂O₃The structure is corundum type, oxygen ions are packed in a hexagonal closest packing mode along the direction vertical to the third-order axis, and Fe ions are filled in an octahedral gap of 2/3 between two oxygen ion layers. gamma-Fe₂O₃The invention researches and discovers that α -Fe is compared₂O₃、γ-Fe₂O₃Crystal structure and catalytic performance for oxidative dehydrogenation of butene, gamma-Fe₂O₃Has better catalytic activity and butadiene selectivity because of more cation vacancy and surface [ O ]]The species can easily participate in the oxidation reaction, and the products of the two reduced by the butylene are Fe₃O₄，Fe₃O₄Also has a trans-spinel structure, and thus gamma-Fe₂O₃Has better structural stability. The invention adopts gamma-crystal form Fe₂O₃As a catalyst component, the activity of the catalyst is obviously improved. The addition of the auxiliary component further improves the catalyst activity and the butadiene selectivity. The catalyst has better activity, selectivity and stability, and reduces the cost of the catalytic dehydrogenation process.

The butylene oxidative dehydrogenation reaction is carried out on a micro catalytic reaction device of a continuous flow quartz tube reactor. Analysis of products the contents of alkane, alkene, butadiene, etc. in the dehydrogenated product were analyzed on-line using HP-5890 gas chromatograph (HP-AL/S capillary column, 50 m.times.0.53 mm.times.15 μm; FID detector) and the conversion of the reaction and the product selectivity were calculated. When the catalyst prepared by the method is used for butylene oxidative dehydrogenation, the selectivity of butadiene can reach 96%, the catalyst has good performance and high stability, and a good technical effect is achieved.

The invention is further illustrated by the following examples.

Detailed Description

[ example 1 ]

An appropriate amount of ferric nitrate (Fe (NO) was weighed₃)₃·9H₂O), chromium nitrate (Cr (NO)₃)₃·9H₂O), magnesium nitrate (Mg (NO)₃)₂·6H₂O) and zinc nitrate (Zn (NO)₃)₂·6H₂O) is dissolved in 4L of deionized water and stirred uniformly to form a solution. Then, the solution and 20% ammonia water solution are subjected to coprecipitation, the pH value of the precipitate is kept at 9.5, the precipitation temperature is room temperature, then a solid sample in the precipitate product is separated by a centrifugal separator, 4L deionized water is used for washing, and the obtained solid is dried in an oven for 4 hours at 110 ℃. And roasting the dried sample in a muffle furnace at 500 ℃ for 4 hours to obtain a catalyst 1, and grinding the catalyst 1 into particles of 40-60 meshes for catalyst evaluation. The molar ratio of the elemental composition of catalyst 1 was Mg_0.2Zn_0.8Fe₂O₄·0.4γ-Fe₂O₃·0.02CrO_x。

[ example 2 ]

An appropriate amount of ferric nitrate (Fe (NO) was weighed₃)₃·9H₂O), chromium nitrate (Cr (NO)₃)₃·9H₂O), magnesium nitrate (Mg (NO)₃)₂·6H₂O) and zinc nitrate (Zn (NO)₃)₂·6H₂O) is dissolved in 4L of deionized water and stirred uniformly to form a solution. Then, the solution and 10% ammonia water solution are subjected to coprecipitation, the pH value of the precipitate is kept at 6.0, the precipitation temperature is 10 ℃, then a solid sample in the precipitate product is separated by a centrifugal separator, 4L deionized water is used for washing, and the obtained solid is dried in an oven for 24 hours at the temperature of 90 ℃. And roasting the dried sample in a muffle furnace at 400 ℃ for 4 hours to obtain a catalyst 2, and grinding the catalyst 2 into particles of 40-60 meshes for catalyst evaluation. The molar ratio of the element composition of the catalyst 2 is Mg_0.2Zn_0.8Fe₂O₄·0.05γ-Fe₂O₃·0.02CrO_x。

[ example 3 ]

An appropriate amount of ferric nitrate (Fe (NO) was weighed₃)₃·9H₂O), chromium nitrate (Cr (NO)₃)₃·9H₂O), magnesium nitrate (Mg (NO)₃)₂·6H₂O) and zinc nitrate (Zn (NO)₃)₂·6H₂O) is dissolved in 4L of deionized water and stirred uniformly to form a solution. Then, the solution and 30% ammonia water solution are subjected to coprecipitation, the pH value of the precipitate is kept at 12, the precipitation temperature is 80 ℃, then a solid sample in the precipitate product is separated by a centrifugal separator, 4L deionized water is used for washing, and the obtained solid is dried in an oven for 1 hour at 150 ℃. And roasting the dried sample in a muffle furnace at 550 ℃ for 1 hour to obtain a catalyst 3, and grinding the catalyst 3 into particles of 40-60 meshes for catalyst evaluation. The molar ratio of the elemental composition of catalyst 3 is Mg_0.2Zn_0.8Fe₂O₄·0.5γ-Fe₂O₃·0.02CrO_x。

[ example 4 ]

An appropriate amount of ferric nitrate (Fe (NO) was weighed₃)₃·9H₂O), chromium nitrate (Cr (NO)₃)₃·9H₂O), magnesium nitrate (Mg (NO)₃)₂·6H₂O) and zinc nitrate (Zn (NO)₃)₂·6H₂O) is dissolved in 4L of deionized water and stirred uniformly to form a solution. Then the catalyst precursor solution and 15% ammonia solution were coprecipitated, the precipitation pH was maintained at 8.0 and the precipitation temperature was 40 ℃, then a solid sample in the precipitated product was separated with a centrifuge, washed with 4L deionized water, and the resulting solid was dried in an oven at 110 ℃ for 4 hours. And roasting the dried sample in a muffle furnace at 500 ℃ for 4 hours to obtain a catalyst 4, and grinding the catalyst 4 into particles of 40-60 meshes for catalyst evaluation. Catalyst 4 had an elemental composition in a molar ratio of Mg_0.2Zn_0.8Fe₂O₄·0.01γ-Fe₂O₃·0.02CrO_x。

[ example 5 ]

An appropriate amount of ferric nitrate (Fe (NO) was weighed₃)₃·9H₂O), chromium nitrate (Cr (NO)₃)₃·9H₂O), magnesium nitrate (Mg (NO)₃)₂·6H₂O) and zinc nitrate (Zn (NO)₃)₂·6H₂O) is dissolved in 4L of deionized water and stirred uniformly to form a solution. Then coprecipitating the catalyst precursor solution with 25% ammonia water solution, precipitatingThe precipitation pH was maintained at 10.0 and the precipitation temperature was 60 ℃ and a sample of the solid in the precipitated product was separated by a centrifuge, washed with 4L of deionized water and the resulting solid dried in an oven at 110 ℃ for 4 hours. And roasting the dried sample in a muffle furnace at 500 ℃ for 4 hours to obtain a catalyst 5, and grinding the catalyst 5 into particles of 40-60 meshes for catalyst evaluation. The molar ratio of the elemental composition of catalyst 5 is Mg_0.2Zn_0.8Fe₂O₄·0.1γ-Fe₂O₃·0.02CrO_x。

[ example 6 ]

An appropriate amount of ferric nitrate (Fe (NO) was weighed₃)₃·9H₂O), chromium nitrate (Cr (NO)₃)₃·9H₂O), magnesium nitrate (Mg (NO)₃)₂·6H₂O) and zinc nitrate (Zn (NO)₃)₂·6H₂O) is dissolved in 4L of deionized water and stirred uniformly to form a solution. Then the solution and 2M NaOH were coprecipitated, the precipitation pH was maintained at 9.5, the precipitation temperature was room temperature, then a solid sample of the precipitation product was separated with a centrifuge, washed with 4L deionized water, and the resulting solid was dried in an oven at 110 ℃ for 4 hours. And roasting the dried sample in a muffle furnace at 500 ℃ for 4 hours to obtain a catalyst 6, and grinding the catalyst 6 into particles of 40-60 meshes for catalyst evaluation. The molar ratio of the elemental composition of catalyst 6 is Mg_0.2Zn_0.8Fe₂O₄·1.0γ-Fe₂O₃·0.02CrO_x。

[ example 7 ]

An appropriate amount of ferric nitrate (Fe (NO) was weighed₃)₃·9H₂O), chromium nitrate (Cr (NO)₃)₃·9H₂O), magnesium nitrate (Mg (NO)₃)₂·6H₂O) and zinc nitrate (Zn (NO)₃)₂·6H₂O) is dissolved in 4L of deionized water and stirred uniformly to form a solution. Then coprecipitating the above solution with 2M KOH solution, maintaining the pH of the precipitate at 9.5 and the precipitation temperature at room temperature, separating the solid sample from the precipitated product with a centrifuge, washing with 4L deionized water, and drying the solid in an oven at 110 deg.CFor 4 hours. And roasting the dried sample in a muffle furnace at 500 ℃ for 4 hours to obtain a catalyst 7, and grinding the catalyst 7 into particles of 40-60 meshes for catalyst evaluation. The molar ratio of the elemental composition of catalyst 7 was Mg_0.2Zn_0.8Fe₂O₄·0.4γ-Fe₂O₃·0.002CrO_x。

[ example 8 ]

An appropriate amount of ferric nitrate (Fe (NO) was weighed₃)₃·9H₂O), chromium nitrate (Cr (NO)₃)₃·9H₂O), magnesium nitrate (Mg (NO)₃)₂·6H₂O) and zinc nitrate (Zn (NO)₃)₂·6H₂O) is dissolved in 4L of deionized water and stirred uniformly to form a solution. Then the solution and 3M KOH solution are coprecipitated, the precipitation pH value is kept at 9.5, the precipitation temperature is room temperature, then a solid sample in the precipitation product is separated by a centrifugal separator, 4L deionized water is used for washing, and the obtained solid is dried in an oven for 4 hours at 110 ℃. And roasting the dried sample in a muffle furnace at 500 ℃ for 4 hours to obtain a catalyst 8, and grinding the catalyst 8 into particles of 40-60 meshes for catalyst evaluation. The molar ratio of the elemental composition of catalyst 8 is Mg_0.2Zn_0.8Fe₂O₄·0.4γ-Fe₂O₃·0.005CrO_x。

[ example 9 ]

An appropriate amount of ferric nitrate (Fe (NO) was weighed₃)₃·9H₂O), chromium nitrate (Cr (NO)₃)₃·9H₂O), magnesium nitrate (Mg (NO)₃)₂·6H₂O) and zinc nitrate (Zn (NO)₃)₂·6H₂O) is dissolved in 4L of deionized water and stirred uniformly to form a solution. Then, the solution and 20% ammonia water solution are subjected to coprecipitation, the pH value of the precipitate is kept at 9.5, the precipitation temperature is room temperature, then a solid sample in the precipitate product is separated by a centrifugal separator, 4L deionized water is used for washing, and the obtained solid is dried in an oven for 4 hours at 110 ℃. And roasting the dried sample in a muffle furnace at 500 ℃ for 4 hours to obtain a catalyst 9, and grinding the catalyst 9 into particles of 40-60 meshes for catalyst evaluation. Elemental composition molar ratio of catalyst 9For example Mg_0.2Zn_0.8Fe₂O₄·0.4γ-Fe₂O₃·0.05CrO_x。

[ example 10 ]

An appropriate amount of ferric nitrate (Fe (NO) was weighed₃)₃·9H₂O), chromium nitrate (Cr (NO)₃)₃·9H₂O), magnesium nitrate (Mg (NO)₃)₂·6H₂O) and zinc nitrate (Zn (NO)₃)₂·6H₂O) is dissolved in 4L of deionized water and stirred uniformly to form a solution. Then, the solution and 20% ammonia water solution are subjected to coprecipitation, the pH value of the precipitate is kept at 9.5, the precipitation temperature is room temperature, then a solid sample in the precipitate product is separated by a centrifugal separator, 4L deionized water is used for washing, and the obtained solid is dried in an oven for 4 hours at 110 ℃. And roasting the dried sample in a muffle furnace at 500 ℃ for 4 hours to obtain the catalyst 10, and grinding the catalyst 10 into particles of 40-60 meshes for catalyst evaluation. The molar ratio of the elemental composition of catalyst 10 is Mg_0.2Zn_0.8Fe₂O₄·0.4γ-Fe₂O₃·0.1CrO_x。

[ example 11 ]

An appropriate amount of ferric nitrate (Fe (NO) was weighed₃)₃·9H₂O), ammonium molybdate ((NH)₄)₆Mo₇O₂₄·4H₂O), magnesium nitrate (Mg (NO)₃)₂·6H₂O) and zinc nitrate (Zn (NO)₃)₂·6H₂O) is dissolved in 4L of deionized water and stirred uniformly to form a solution. Then, the solution and 20% ammonia water solution are subjected to coprecipitation, the pH value of the precipitate is kept at 9.5, the precipitation temperature is room temperature, then a solid sample in the precipitate product is separated by a centrifugal separator, 4L deionized water is used for washing, and the obtained solid is dried in an oven for 4 hours at 110 ℃. And roasting the dried sample in a muffle furnace at 500 ℃ for 4 hours to obtain the catalyst 11, and grinding the catalyst 11 into particles of 40-60 meshes for catalyst evaluation. The molar ratio of the elemental composition of catalyst 11 is Mg_0.2Zn_0.8Fe₂O₄·0.4γ-Fe₂O₃·0.02MoO_x。

[ example 12 ]

An appropriate amount of ferric nitrate (Fe (NO) was weighed₃)₃·9H₂O), tungstic acid, magnesium nitrate (Mg (NO)₃)₂·6H₂O) and zinc nitrate (Zn (NO)₃)₂·6H₂O) is dissolved in 4L of deionized water and stirred uniformly to form a solution. Then, the solution and 20% ammonia water solution are subjected to coprecipitation, the pH value of the precipitate is kept at 9.5, the precipitation temperature is room temperature, then a solid sample in the precipitate product is separated by a centrifugal separator, 4L deionized water is used for washing, and the obtained solid is dried in an oven for 4 hours at 110 ℃. And roasting the dried sample in a muffle furnace at 500 ℃ for 4 hours to obtain a catalyst 12, and grinding the catalyst 12 into particles of 40-60 meshes for catalyst evaluation. The molar ratio of the elemental composition of catalyst 12 is Mg_0.2Zn_0.8Fe₂O₄·0.4γ-Fe₂O₃·0.02WO_x。

[ example 13 ]

An appropriate amount of ferric nitrate (Fe (NO) was weighed₃)₃·9H₂O), ammonium molybdate ((NH)₄)₆Mo₇O₂₄·4H₂O), chromium nitrate (Cr (NO)₃)₃·9H₂O), magnesium nitrate (Mg (NO)₃)₂·6H₂O) and zinc nitrate (Zn (NO)₃)₂·6H₂O) is dissolved in 4L of deionized water and stirred uniformly to form a solution. Then, the solution and 20% ammonia water solution are subjected to coprecipitation, the pH value of the precipitate is kept at 9.5, the precipitation temperature is room temperature, then a solid sample in the precipitate product is separated by a centrifugal separator, 4L deionized water is used for washing, and the obtained solid is dried in an oven for 4 hours at 110 ℃. And roasting the dried sample in a muffle furnace at 500 ℃ for 4 hours to obtain a catalyst 13, and grinding the catalyst 13 into particles of 40-60 meshes for catalyst evaluation. The molar ratio of the elemental composition of catalyst 13 is Mg_0.2Zn_0.8Fe₂O₄·0.4γ-Fe₂O₃·0.01CrO_x0.01MoO_x。

[ example 14 ]

An appropriate amount of ferric nitrate (Fe (NO) was weighed₃)₃·9H₂O), chromium nitrate (Cr (NO)₃)₃·9H₂O), tungstic acid, magnesium nitrate (Mg (NO)₃)₂·6H₂O) and zinc nitrate (Zn (NO)₃)₂·6H₂O) is dissolved in 4L of deionized water and stirred uniformly to form a solution. Then, the solution and 20% ammonia water solution are subjected to coprecipitation, the pH value of the precipitate is kept at 9.5, the precipitation temperature is room temperature, then a solid sample in the precipitate product is separated by a centrifugal separator, 4L deionized water is used for washing, and the obtained solid is dried in an oven for 4 hours at 110 ℃. And roasting the dried sample in a muffle furnace at 500 ℃ for 4 hours to obtain a catalyst 14, and grinding the catalyst 14 into particles of 40-60 meshes for catalyst evaluation. Catalyst 14 has an elemental composition in a molar ratio of Mg_0.2Zn_0.8Fe₂O₄·0.4γ-Fe₂O₃·0.01CrO_x0.01WO_x。

[ example 15 ]

An appropriate amount of ferric nitrate (Fe (NO) was weighed₃)₃·9H₂O), chromium nitrate (Cr (NO)₃)₃·9H₂O) and magnesium nitrate (Mg (NO)₃)₂·6H₂O) is dissolved in 4L of deionized water and stirred uniformly to form a solution. Then, the solution and 20% ammonia water solution are subjected to coprecipitation, the pH value of the precipitate is kept at 9.5, the precipitation temperature is room temperature, then a solid sample in the precipitate product is separated by a centrifugal separator, 4L deionized water is used for washing, and the obtained solid is dried in an oven for 4 hours at 110 ℃. And roasting the dried sample in a muffle furnace at 500 ℃ for 4 hours to obtain a catalyst 15, and grinding the catalyst 15 into particles of 40-60 meshes for catalyst evaluation. The molar ratio of the elemental composition of the catalyst 15 is MgFe₂O₄·0.4γ-Fe₂O₃·0.02CrO_x。

[ example 16 ]

An appropriate amount of ferric nitrate (Fe (NO) was weighed₃)₃·9H₂O), chromium nitrate (Cr (NO)₃)₃·9H₂O) and zinc nitrate (Zn (NO)₃)₂·6H₂O) is dissolved in 4L of deionized water and stirred uniformly to form a solution. Then will be atThe solution is coprecipitated with 20% ammonia water solution, the pH value of the precipitate is kept at 9.5, the precipitation temperature is room temperature, then a solid sample in the precipitate is separated by a centrifugal separator, 4L deionized water is used for washing, and the obtained solid is dried in an oven for 4 hours at 110 ℃. And roasting the dried sample in a muffle furnace at 500 ℃ for 4 hours to obtain a catalyst 16, and grinding the catalyst 16 into particles of 40-60 meshes for catalyst evaluation. The molar ratio of the elemental composition of the catalyst 16 is ZnFe₂O₄·0.4γ-Fe₂O₃·0.02CrO_x。

[ example 17 ]

An appropriate amount of ferric nitrate (Fe (NO) was weighed₃)₃·9H₂O), chromium nitrate (Cr (NO)₃)₃·9H₂O), magnesium nitrate (Mg (NO)₃)₂·6H₂O) and zinc nitrate (Zn (NO)₃)₂·6H₂O) is dissolved in 4L of deionized water and stirred uniformly to form a solution. Then, the solution and 20% ammonia water solution are subjected to coprecipitation, the pH value of the precipitate is kept at 9.5, the precipitation temperature is room temperature, then a solid sample in the precipitate product is separated by a centrifugal separator, 4L deionized water is used for washing, and the obtained solid is dried in an oven for 4 hours at 110 ℃. And roasting the dried sample in a muffle furnace at 500 ℃ for 4 hours to obtain a catalyst 17, and grinding the catalyst 17 into particles of 40-60 meshes for catalyst evaluation. The molar ratio of the elemental composition of catalyst 17 is Mg_0.9Zn_0.1Fe₂O₄·0.4γ-Fe₂O₃·0.02CrO_x。

[ example 18 ]

An appropriate amount of ferric nitrate (Fe (NO) was weighed₃)₃·9H₂O), chromium nitrate (Cr (NO)₃)₃·9H₂O), magnesium nitrate (Mg (NO)₃)₂·6H₂O) and zinc nitrate (Zn (NO)₃)₂·6H₂O) is dissolved in 4L of deionized water and stirred uniformly to form a solution. Then coprecipitating the above solution with 20% ammonia water solution, maintaining the pH of the precipitate at 9.5 and the precipitation temperature at room temperature, separating the solid sample from the precipitate with a centrifuge, washing with 4L deionized waterThe resulting solid was dried in an oven at 110 ℃ for 4 hours. And roasting the dried sample in a muffle furnace at 500 ℃ for 4 hours to obtain a catalyst 18, and grinding the catalyst 18 into particles of 40-60 meshes for catalyst evaluation. The molar ratio of the elemental composition of catalyst 18 is Mg_0.1Zn_0.9Fe₂O₄·0.4γ-Fe₂O₃·0.02CrO_x。

[ example 19 ]

An appropriate amount of ferric nitrate (Fe (NO) was weighed₃)₃·9H₂O), chromium nitrate (Cr (NO)₃)₃·9H₂O), magnesium nitrate (Mg (NO)₃)₂·6H₂O) and zinc nitrate (Zn (NO)₃)₂·6H₂O) is dissolved in 4L of deionized water and stirred uniformly to form a solution. Then, the solution and 20% ammonia water solution are subjected to coprecipitation, the pH value of the precipitate is kept at 9.5, the precipitation temperature is room temperature, then a solid sample in the precipitate product is separated by a centrifugal separator, 4L deionized water is used for washing, and the obtained solid is dried in an oven for 4 hours at 110 ℃. And roasting the dried sample in a muffle furnace at 500 ℃ for 4 hours to obtain a catalyst 19, and grinding the catalyst 19 into particles of 40-60 meshes for catalyst evaluation. Catalyst 19 has an elemental composition in a molar ratio of Mg_0.5Zn_0.5Fe₂O₄·0.4γ-Fe₂O₃·0.02CrO_x。

[ example 20 ]

An appropriate amount of ferric nitrate (Fe (NO) was weighed₃)₃·9H₂O), chromium nitrate (Cr (NO)₃)₃·9H₂O), manganese nitrate (Mn (NO)₃)₂) And zinc nitrate (Zn (NO)₃)₂·6H₂O) is dissolved in 4L of deionized water and stirred uniformly to form a solution. Then, the solution and 20% ammonia water solution are subjected to coprecipitation, the pH value of the precipitate is kept at 9.5, the precipitation temperature is room temperature, then a solid sample in the precipitate product is separated by a centrifugal separator, 4L deionized water is used for washing, and the obtained solid is dried in an oven for 4 hours at 110 ℃. Roasting the dried sample in a muffle furnace at 500 ℃ for 10 hours to obtain a catalyst 20, and grinding the catalyst 20 into particles of 40-60 meshes for catalyst evaluation. The molar ratio of the elemental composition of catalyst 20 is Mn_0.2Zn_0.8Fe₂O₄·0.4γ-Fe₂O₃·0.02CrO_x。

[ example 21 ]

An appropriate amount of ferric nitrate (Fe (NO) was weighed₃)₃·9H₂O), chromium nitrate (Cr (NO)₃)₃·9H₂O), manganese nitrate (Mn (NO)₃)₂) Magnesium nitrate (Mg (NO)₃)₂·6H₂O) and zinc nitrate (Zn (NO)₃)₂·6H₂O) is dissolved in 4L of deionized water and stirred uniformly to form a solution. Then, the solution and 20% ammonia water solution are subjected to coprecipitation, the pH value of the precipitate is kept at 9.5, the precipitation temperature is room temperature, then a solid sample in the precipitate product is separated by a centrifugal separator, 4L deionized water is used for washing, and the obtained solid is dried in an oven for 4 hours at 110 ℃. And roasting the dried sample in a muffle furnace at 500 ℃ for 24 hours to obtain a catalyst 21, and grinding the catalyst 21 into particles of 40-60 meshes for catalyst evaluation. The molar ratio of the elemental composition of catalyst 21 is Mg_0.1Zn_0.8Mn_0.1Fe₂O₄·0.4γ-Fe₂O₃·0.02CrO_x。

Comparative example 1

An appropriate amount of ferric nitrate (Fe (NO) was weighed₃)₃·9H₂O), magnesium nitrate (Mg (NO)₃)₂·6H₂O), zinc nitrate (Zn (NO)₃)₂·6H₂O) was dissolved in 4L of distilled water and stirred well to form a solution. Then, the above solution was coprecipitated with a 20% aqueous ammonia solution, the pH of the precipitate was maintained at 9.5, the precipitation temperature was room temperature, then a solid sample in the precipitated product was separated by a centrifugal separator, washed with 4L of distilled water, and the resulting solid was dried in an oven at 110 ℃ for 4 hours. And roasting the dried sample in a muffle furnace at 550 ℃ for 4 hours to obtain a catalyst comparative example 1, and grinding the catalyst comparative example 1 into particles of 40-60 meshes for catalyst evaluation. Catalyst comparative example 1 elemental composition Mg_0.2Zn_0.8Fe₂O₄。

Comparative example 2

An appropriate amount of ferric nitrate (Fe (NO) was weighed₃)₃·9H₂Dissolving O) in 4L of deionized water, uniformly stirring to form a solution, then carrying out coprecipitation on the solution and 20% ammonia water solution, keeping the pH value of the precipitate at 9.5, keeping the precipitation temperature at room temperature, separating a solid sample in the precipitate product by using a centrifugal separator, washing the solid sample by using 4L of deionized water, drying the obtained solid in an oven at 110 ℃ for 4 hours, roasting the dried sample in a muffle furnace at 700 ℃ for 4 hours to obtain a catalyst comparative example 2, grinding the dried sample into particles of 40-60 meshes for catalyst evaluation, and carrying out element composition molar ratio α -Fe on the catalyst comparative example 2₂O₃。

Comparative example 3

An appropriate amount of ferric nitrate (Fe (NO) was weighed₃)₃·9H₂O) is dissolved in 4L of deionized water and stirred uniformly to form a solution. And then, carrying out coprecipitation on the solution and a 20% ammonia water solution, violently stirring in the precipitation process, keeping the pH value of the precipitate at 9.5, keeping the precipitation temperature at room temperature, then separating a solid sample in the precipitate product by using a centrifugal separator, washing the solid sample by using 4L deionized water, and drying the obtained solid in an oven at 110 ℃ for 4 hours. And roasting the dried sample in a muffle furnace at 360 ℃ for 4 hours to obtain a catalyst comparative example 3, and grinding the catalyst comparative example 3 into particles of 40-60 meshes for catalyst evaluation. Catalyst comparative example 3 elemental composition molar ratio of γ -Fe₂O₃。

Comparative example 4

An appropriate amount of ferric nitrate (Fe (NO) was weighed₃)₃·9H₂O), chromium nitrate (Cr (NO)₃)₃·9H₂O), magnesium nitrate (Mg (NO)₃)₂·6H₂O) and zinc nitrate (Zn (NO)₃)₂·6H₂O) is dissolved in 4L of deionized water and stirred uniformly to form a solution. Then, the solution and 20% ammonia water solution are subjected to coprecipitation, the pH value of the precipitate is kept at 9.5, the precipitation temperature is room temperature, then a solid sample in the precipitate product is separated by a centrifugal separator, 4L deionized water is used for washing, and the obtained solid is dried in an oven for 4 hours at 110 ℃. The dried sample was then placed in a muffle furnace at 700 deg.CAnd (3) roasting for 4 hours to obtain a catalyst comparative example 4, and grinding the catalyst comparative example 4 into particles of 40-60 meshes for catalyst evaluation. Catalyst comparative example 4 had a molar ratio of elemental composition of Mg_0.2Zn_0.8Fe₂O₄·0.4α-Fe₂O₃·0.02CrO_x。

Comparative example 5

An appropriate amount of ferric nitrate (Fe (NO) was weighed₃)₃·9H₂O), magnesium nitrate (Mg (NO)₃)₂·6H₂O) and zinc nitrate (Zn (NO)₃)₂·6H₂O) is dissolved in 4L of deionized water and stirred uniformly to form a solution. Then, the solution and 20% ammonia water solution are subjected to coprecipitation, the pH value of the precipitate is kept at 9.5, the precipitation temperature is room temperature, then a solid sample in the precipitate product is separated by a centrifugal separator, 4L deionized water is used for washing, and the obtained solid is dried in an oven for 4 hours at 110 ℃. And roasting the dried sample in a muffle furnace at 500 ℃ for 4 hours to obtain a catalyst comparative example 5, and grinding the catalyst comparative example 5 into particles of 40-60 meshes for catalyst evaluation. Catalyst comparative example 5 had a molar ratio of elemental composition of Mg_0.2Zn_0.8Fe₂O₄·0.4γ-Fe₂O₃。

Comparative example 6

An appropriate amount of ferric nitrate (Fe (NO) was weighed₃)₃·9H₂O), chromium nitrate (Cr (NO)₃)₃·9H₂O), magnesium nitrate (Mg (NO)₃)₂·6H₂O) and zinc nitrate (Zn (NO)₃)₂·6H₂O) is dissolved in 4L of deionized water and stirred uniformly to form a solution. Then, the solution and 20% ammonia water solution are subjected to coprecipitation, the pH value of the precipitate is kept at 9.5, the precipitation temperature is room temperature, then a solid sample in the precipitate product is separated by a centrifugal separator, 4L deionized water is used for washing, and the obtained solid is dried in an oven for 4 hours at 110 ℃. And roasting the dried sample in a muffle furnace at 500 ℃ for 6 hours to obtain a catalyst comparative example 6, and grinding the catalyst comparative example 6 into particles of 40-60 meshes for catalyst evaluation. Comparative catalyst example 6 having a molar ratio of elemental composition of Mg_0.2Zn_0.8Fe₂O₄·0.02CrO_x。

[ example 22 ]

0.5g of the catalysts of examples 1 to 21 and comparative examples 1 to 6 were used for evaluation of oxidative dehydrogenation of butene. The feed gas is a mixture of butylene, oxygen and water vapor, wherein the ratio of butylene: oxygen: the composition molar ratio of water is 1: 0.75: 10. the raw material gas is fully mixed and then introduced into a reactor for oxidative dehydrogenation. The inlet temperature of the reactor is 420 ℃; the reaction pressure is normal pressure; the mass space velocity of the butylene is 0.5h^-1. The catalytic reaction was carried out under the above conditions, and the reaction product was analyzed by gas chromatography. The reaction results are shown in Table 1.

TABLE 1

Butene conversion and butadiene selectivity over 10 hours of reaction

[ example 23 ]

0.5g of the catalyst of example 1 and comparative example 4 was taken for evaluation of oxidative dehydrogenation of butene. The feed gas is a mixture of butylene, oxygen and water vapor, wherein the ratio of butylene: oxygen: the composition molar ratio of water is 1: 0.75: 10. the raw material gas is fully mixed and then introduced into a reactor for oxidative dehydrogenation. The inlet temperature of the reactor is 420 ℃; the reaction pressure is normal pressure; the mass space velocity of the butylene is 0.5h^-1. The catalytic reaction was carried out under the above conditions, and the reaction product was analyzed by gas chromatography. The reaction results are shown in Table 2.

TABLE 2

Claims

1. A catalyst for preparing butadiene by oxidative dehydrogenation of butene comprises the following components:

a) with gamma-Fe₂O₃Me of spinel Structure^ⅡFe₂O₄The main component is a divalent metal Me selected from at least one of Zn, Mg or Mn, gamma-Fe₂O₃With Me^ⅡFe₂O₄The molar ratio of (0.1-10): 10;

2. the catalyst for preparing butadiene by oxidative dehydrogenation of butene according to claim 1, wherein said divalent metal Me is^ⅡAt least one selected from Zn and Mg.

3. The catalyst for preparing butadiene by oxidative dehydrogenation of butene according to claim 1, wherein said γ -Fe₂O₃With Me^ⅡFe₂O₄The molar ratio of (0.1-5): 10.

4. the catalyst for preparing butadiene by oxidative dehydrogenation of butene according to claim 1, wherein said γ -Fe₂O₃With Me^ⅡFe₂O₄The molar ratio of (0.5-5): 10.

5. the catalyst for preparing butadiene by oxidative dehydrogenation of butene according to claim 1, wherein the group VIB element is at least one selected from Cr and Mo.

6. The catalyst for preparing butadiene by oxidative dehydrogenation of butene according to claim 1, wherein said group VIB element and Me are^ⅡFe₂O₄The molar ratio of (0.05-0.5): 10.

7. a preparation method of a catalyst for preparing butadiene by oxidative dehydrogenation of butylene, which adopts the catalyst of any one of claims 1-6, is characterized by comprising the following steps:

c) the precipitated product is worked up.

8. The method for preparing a catalyst according to claim 7, wherein the pH value in the precipitation process is 6 to 12, the washing temperature is 10 to 80 ℃, the drying temperature is 90 to 150 ℃, the drying time is 1 to 24 hours, the roasting temperature is 400 to 550 ℃, and the roasting time is 1 to 24 hours.

9. A process method of a catalyst for preparing butadiene by oxidative dehydrogenation of butylene takes mixed gas of butylene, oxidizing gas and steam as raw materials, the reaction inlet temperature is 300-500 ℃, and the mass space velocity of butylene is 0.2-6.0 h^-1The butadiene is obtained by contact reaction of the raw material and the catalyst of any one of claims 1 to 7.

10. The process for preparing butadiene by oxidative dehydrogenation of butene according to claim 9, wherein the ratio of butene: oxygen: the volume ratio of water vapor is 1: (0.1-20): (1-10).