CN106140204B - A kind of manganese base supported catalyst and its preparation method and application - Google Patents

Abstract

The present invention discloses a kind of manganese base supported catalyst and its preparation method and application.The catalyst is prepared using following steps：（1）Molar concentration is used to spray dipping for the dimethylformamide in water of 0.1 mol/L-0.5 mol/L by carrier of aluminium oxide, spray flux is the 1/5-3/4 of alumina support saturated absorption amount of solution, and is dried；（2）Step（1）Carrier saturation after drying impregnates manganese salt solution and is dried, roasts, and the ammonium thiocyanate that mass fraction is 2-15% is contained in the manganese salt solution；（3）To step（2）Material after roasting, which carries out bromination processing, makes manganese oxide weight content in catalyst be 0.5%-5%, preferably 1%-3%；Manganous bromide weight content is 5%-40%, preferably 10%-30%.The catalyst can significantly improve the selectivity of isobutene.

Description

A kind of manganese base supported catalyst and its preparation method and application

Technical field

The present invention relates to a kind of manganese base supported catalysts and its preparation method and application, relate in particular to one kind with bromine Methane is the manganese base supported catalyst and its preparation method and application of the highly selective preparing isobutene of raw material.

Background technology

Isobutene is a kind of important basic organic chemical industry raw material, and derived product is numerous, and vertical industry chain is complicated, disappears It is in diversified trend to take structure.A variety of high value-added products can be prepared by raw material of isobutene, such as：It is butyl rubber, poly- different A variety of Organic Chemicals such as butylene, methyl tertiary butyl ether(MTBE), isoprene and organic glass and fine chemistry product.Due to isobutyl The market scale of alkene downstream product constantly expands, and imbalance between supply and demand will be protruded gradually, especially in petroleum resources increasingly depleted Under background, the yield of isobutene has become the critical bottleneck for restricting downstream industry development.Therefore, the isobutyl of Non oil-based route is developed Alkene preparation route is extremely urgent.

Methane is the main component of natural gas, therefore methane trans-utilization important grinding of just becoming in gas chemical industry's technology Study carefully content.Especially in recent years, under the overall background that shale gas develops and uses, if it is possible to realize from methane and produce isobutyl Alkene will provide a new approach to obtain isobutene.But methane property is stablized, and it is not easily-activated, become methane chemical industry profit Bottleneck.Domestic and international many researchers carry out methane activation, Study on Transformation one after another, and among these, methane is through halogen functional groupization The technology converted again afterwards is expected to become an important breakthrough mouth for solving methane transformation technology problem.

Many chemical products can be prepared from halide.Chinese patent CN 101041609A, CN 101284232A Disclose it is a kind of by methane in oxygen and HBr/H₂Bromomethane is converted under the action of O, then bromomethane further reacts The hydrocarbon selective of the method for generating C3 ~ C13 mixing high-carbon hydrocarbons, C5 or more is 70%.Wherein, HBr is used in first reactor It in methane bromination, is then discharged in second reactor, is used further to after recovered in back reaction, realizes the cycle of HBr It uses.Wang Ye etc.（CN 102527427A, Jieli He, Ting Xu, Zhihui Wang, et.al. Angew. Chem. Int. Ed. 2012, 51, 2438-2442）Disclose a kind of modified molecular sieve catalyst and its system of halide propylene Preparation Method.By using fluorochemical moditied processing molecular sieve, a kind of catalysis containing appropriate microporous structure and acidity is obtained Agent, the catalyst can effectively be catalyzed the reaction that halide is converted into propylene.Prepared catalyst is converted in bromomethane One way bromomethane conversion ratio is 35 ~ 99% in the reaction of propylene processed, and the selectivity of propylene is 27 ~ 70%；In chloromethanes conversion system third One way methyl chloride conversion rate is 30 ~ 99% in the reaction of alkene, and the selectivity of propylene is 15 ~ 70%.Ivan M. Lorkovic et al. （Ivan M. Lorkovic, Aysen Yilmaz, Gurkan A. Yilmaz, et al. Catalysis Today, 2004, 98, 317-322）It is also proposed that generating bromo-hydrocarbons with the alkane reaction in bromine and natural gas, then urged in metal oxide It converts bromo-hydrocarbons to dimethyl ether, methanol and metal bromide in agent, metal oxygen is obtained after metal bromide oxygen recovery Compound simultaneously releases simple substance bromine, completes the cycle of bromine.

Currently, being mainly methanol, dimethyl ether, acetic acid, high-carbon about purpose product in the existing literature of halide conversion Hydro carbons, ethylene and propylene etc..Using the low-carbon alkene compared with high added value as in the technology of target product, single selectivity of product It is not high, not yet find the relevant report of bromomethane high selectivity isobutene.

Invention content

In view of the deficiencies of the prior art, the present invention provides a kind of urging using bromomethane as the highly selective preparing isobutene of raw material Agent and the preparation method and application thereof.

A kind of preparation method of bromomethane preparing isobutene catalyst, includes the following steps：（1）It is used by carrier of aluminium oxide The dimethylformamide in water spray dipping that molar concentration is 0.1 mol/L-0.5 mol/L, spray flux is alumina support The 1/5-3/4 of saturated absorption amount of solution, and be dried；（2）Step（1）Carrier saturation dipping manganese salt solution after drying is gone forward side by side Row is dry, roasts, and the ammonium thiocyanate that mass fraction is 2-15% is contained in the manganese salt solution；（3）To step（2）After roasting Material, which carries out bromination processing, makes manganese oxide weight content in catalyst be 0.5%-5%, preferably 1%-3%；Manganous bromide weight content is 5%-40%, preferably 10%-30%.

In the preparation method of above-mentioned bromomethane preparing isobutene catalyst, existing aluminium oxide may be used in the alumina support Product can also be prepared by method well known to those skilled in the art.Carrier can be made or choose according to the needs used suitable Suitable particle shape, such as bar shaped, piece shape, cylindricality, spherical shape is made.Forming can be carried out by this field general knowledge.

The preparation method step of above-mentioned bromomethane preparing isobutene catalyst（1）Middle dimethylformamide in water spray dipping Drying temperature is not higher than the decomposition temperature of dimethylformamide afterwards, such as drying temperature is 60 DEG C~150 DEG C, drying time 0.5h ~20h.

The preparation method step of above-mentioned bromomethane preparing isobutene catalyst（2）Middle drying condition is -150 DEG C of temperature 60 C, Preferably 80 DEG C -120 DEG C；Time is 1h-24h, preferably 4h-8h；It can be vacuum drying when dry, or indifferent gas It is dry under body protective condition, it can also dry in air atmosphere.The roasting condition is 300 DEG C -600 DEG C of temperature, preferably 400℃-500℃；Time is 1h-24h, preferably 4h-8h；Can also may be used to be roasted under the conditions of inert gas shielding when roasting To roast in air atmosphere.

In the above method, manganese salt can be inorganic salts, or organic salt, preferably nitrate, hydrochloride, acetic acid One or more of salt, citrate.

The preparation method step of above-mentioned bromomethane preparing isobutene catalyst（3）Described in bromination processing, refer to use gas phase Bromine-containing compound handles the sample for loading manganese oxide.Bromine-containing compound refers in bromomethane, methylene bromide, bromoform One or more, preferably bromomethane.The mixed gas of gas phase bromine-containing compound and inert gas can also be used to carry out bromine Change is handled, and when being handled using mixed gas bromination, bromomethane volumetric concentration is not less than 20%, preferably not less than 30%.Specifically Bromination process is as follows：The sample for loading manganese oxide is placed in continuous fixed bed reactor, 150 are warming up under inert atmosphere DEG C -400 DEG C, preferably 180 DEG C -350 DEG C, more preferably 200 DEG C -300 DEG C, are passed through gas phase bromine-containing compound gas, gas space Speed is 50h^-1-1000 h^-1, preferably 100h^-1-500h^-1；Can be carried out in normal pressure when processing, can also under a certain pressure into Row, system pressure 0.1MPa-0.5MPa（Absolute pressure）, preferably 0.1MPa-0.3MPa（Absolute pressure）, processing time 0.5h-8h, It is preferred that 1h-4h.

Involved inert gas is nitrogen, argon gas, helium in the preparation method of above-mentioned bromomethane preparing isobutene catalyst Deng the gas not chemically reacted under the conditions of involved in the present invention, preferably nitrogen.

The bromomethane preparing isobutene catalyst, manganese oxide weight content is 0.5%-5%, preferably 1%-3% in catalyst；Bromine Change manganese weight content is 5%-40%, preferably 10%-30%；Cerium oxide weight content is 0.1%-2%, preferably 0.5%-1.5%；Oxidation Alumina supporter weight content 60%-95%, preferably 65%-90%.

Application of the above-mentioned catalyst in preparing isobutene, including hydrogen reducing activation is carried out to catalyst, make in catalyst Content of halogen be the 20%-90% for restoring total halogen content in procatalyst, so that halide and above-mentioned hydrogen reducing is lived Catalyst contact after change, to prepare isobutene.

In above application, the condition of the hydrogen reducing activation so that the content of halogen in catalyst is preferably to be urged before restoring The 30%-80% of total halogen content in agent, further preferred 40%-80%.

In above application, the mode of hydrogen reducing activation include under an inert atmosphere by catalyzer temperature-elevating to 300 DEG C- 600℃；It is 200h to then pass to air speed^-1-2000h^-1Hydrogen or hydrogen and inert gas mixed gas, in 0.1MPa- 0.5MPa keeps 2h-16h, and hydrogen volume percentage composition is 10%-95% in mixed gas；Preferably, it is warming up to 350 DEG C -550 ℃；It is 500h to then pass to air speed^-1-1000h^-1Hydrogen or hydrogen and inert gas mixed gas, in 0.1MPa- 0.3MPa keeps 4h-8h, and hydrogen volume percentage composition is 30%-90% in the mixed gas.

The application of above-mentioned catalyst further includes that halide contacts acquisition isobutene with catalyst.The condition of the contact It it is 150 DEG C -350 DEG C including reaction temperature；Reaction pressure is 0.1MPa-5MPa；Air speed is 50h^-1-1000h^-1；It is highly preferred that Reaction temperature is 180 DEG C -300 DEG C more preferably 200-270 DEG C；Reaction pressure is 0.1MPa-3MPa；Air speed is 200h^-1- 500h^-1。

In above application, the halide can be one kind in a halide, methylene halide, three halides Or a variety of, preferably one or more in bromomethane, methylene bromide, bromoform, more preferably bromomethane.

A kind of specific implementation mode in above application, including under inert atmosphere by catalyzer temperature-elevating to 300 DEG C -600 DEG C, Preferably 350 DEG C -550 DEG C；It is 200h to then pass to air speed^-1-2000h^-1, preferably 500h^-1-1000h^-1Hydrogen and inertia The mixed gas of gas, in 0.1MPa-0.5MPa（Absolute pressure）, preferably 0.1MPa-0.3MPa（Absolute pressure）2h-16h is handled, preferably After 4h-8h, it is down to reaction temperature and is passed through halide and reacted.Hydrogen volume percentage composition is 10%- in the gaseous mixture 95%, preferably 30%-90%, more preferably 50%-90%.

In above application, raw material may be the mixed gas of halide and inert gas, halogenated first in mixed gas The volumetric concentration of alkane is 10%-90%, preferably 30%-80%.

Involved inert gas is that nitrogen, argon gas, helium etc. are not sent out under the conditions of involved in the present invention in above application The gas of biochemical reaction, preferably nitrogen.

In above application, the reaction of halide preparing isobutene can carry out in existing any form reactor, such as fixed Bed, fluid bed, fixed fluidized bed, moving bed, the reactor of the forms such as slurry bed system or ebullated bed, preferably fixed bed, fluid bed Reactor.

Compared with prior art, method of the present invention can by bromomethane it is highly selective be converted into isobutene.? In the present invention, carry out absorption occupy-place processing to change active component manganese in carrier being in reduce from the inside to the outside using dimethyl formyl Trend inhibits further deep reaction of the isobutene of generation in diffusion process while improving activity to greatest extent.It adopts The dispersion degree of active component can be improved with the manganese salt solution containing ammonium thiocyanate is added, prepares the active component manganese of little crystal grain Catalyst, to significantly improve the selectivity of low-carbon alkene.Bromomethane conversion preparing isobutene reaction, bromine are carried out by the method for the present invention 50% or more methane conversion, 60% or more selective isobutene.The present invention relates to bromomethanes to convert preparing isobutene catalyst preparation Method is simple, is easy to industrialize.Bromomethane conversion preparing isobutene method of the present invention is mild with reaction condition, selectivity of product is high The advantages that, industrialization easy to implement, application prospect is boundless.

Specific implementation mode

The technology contents and effect further illustrated the present invention with reference to embodiment, but it is not so limited the present invention.

Embodiment 1

Weigh commercial alumina carrier（Kong Rongwei 0.37ml/g, specific surface area 103m²/ g, bar shaped, equivalent diameter 1.5mm）, use molar concentration to spray oxide impregnation alumina supporter for the dimethylformamide in water of 0.1 mol/L, spray flux is The dry 1h of 3/4,150 DEG C of alumina support saturated absorption amount of solution.It weighs appropriate manganese nitrate and is dissolved in deionized water, sulphur cyanogen is added Sour ammonium makes the mass fraction of ammonium thiocyanate in the solution be 2%, and manganese salt solution is carried on above-mentioned aluminium oxide using equi-volume impregnating On carrier, catalyst precarsor is made in 100 DEG C of dry 6h, 450 DEG C of roasting 6h.Catalyst precarsor is placed in continuous flow fixed bed In reactor, catalyst precarsor is handled using the mixed gas of bromomethane and nitrogen, bromomethane volumetric concentration is 60%, handles item Part is 250 DEG C, 0.2MPa（Absolute pressure）, 300h^-1, time 2h is made bromomethane preparing isobutene catalyst, is denoted as C-1.It is catalyzed Agent MnBr₂It is 2% that weight content, which is 18%, MnO weight contents in terms of oxide, in terms of bromide.

Bromomethane conversion preparing isobutene reaction carries out in continuous flow actuating miniature fixed bed reactors.Catalyst loading 5g, Catalyst is activated using preceding using the gaseous mixture of hydrogen and nitrogen, and hydrogen volume content is 70% in mixed gas, activation condition It is 450 DEG C, 0.2MPa（Absolute pressure）, 750h^-1, soak time 6h；It is reduction procatalyst to restore the content of halogen in rear catalyst The 71.91% of middle total halogen content.

After activation, it to be down to reaction temperature, is passed through unstripped gas, unstripped gas is bromomethane and nitrogen mixed gas, wherein Bromomethane volume content is 70%, and reaction temperature is 230 DEG C, reaction pressure 2MPa（Absolute pressure）, air speed 350h^-1.Stable reaction After one hour, sampling analysis.Reaction result is shown in Table 1.

Embodiment 2

Weigh commercial alumina carrier（Kong Rongwei 0.37ml/g, specific surface area 103m²/ g, bar shaped, equivalent diameter 1.5mm）, use molar concentration to spray oxide impregnation alumina supporter for the dimethylformamide in water of 0.5 mol/L, spray flux is The dry 18h of 1/5,70 DEG C of alumina support saturated absorption amount of solution.It weighs appropriate manganese nitrate and is dissolved in deionized water, sulphur cyanogen is added Sour ammonium makes the mass fraction of ammonium thiocyanate in the solution be 15%, and manganese salt solution is carried on above-mentioned oxidation using equi-volume impregnating On alumina supporter, catalyst precarsor is made in 100 DEG C of dry 6h, 400 DEG C of roasting 8h.Catalyst precarsor is placed in continuous flowing to fix In bed reactor, catalyst precarsor is handled using the mixed gas of bromomethane and nitrogen, bromomethane volumetric concentration is 60%, processing Condition is 250 DEG C, 0.2MPa（Absolute pressure）, 300h^-1, time 2h is made bromomethane preparing isobutene catalyst, is denoted as C-2.It is urged Agent MnBr₂It is 2% that weight content, which is 18%, MnO weight contents in terms of oxide, in terms of bromide.

Bromomethane conversion preparing isobutene reaction carries out in continuous flow actuating miniature fixed bed reactors.Catalyst loading 5g, Catalyst is activated using preceding using the gaseous mixture of hydrogen and nitrogen, and hydrogen volume content is 70% in mixed gas, activation condition It is 450 DEG C, 0.2MPa（Absolute pressure）, 750h^-1, soak time 6h；It is reduction procatalyst to restore the content of halogen in rear catalyst The 78.37% of middle total halogen content.

After activation, it to be down to reaction temperature, is passed through unstripped gas, unstripped gas is bromomethane and nitrogen mixed gas, wherein Bromomethane volume content is 70%, and reaction temperature is 230 DEG C, reaction pressure 2MPa（Absolute pressure）, air speed 350h^-1.Stable reaction After one hour, sampling analysis.Reaction result is shown in Table 1.

Embodiment 3

Weigh commercial alumina carrier（Kong Rongwei 0.37ml/g, specific surface area 103m²/ g, bar shaped, equivalent diameter 1.5mm）, use molar concentration to spray oxide impregnation alumina supporter for the dimethylformamide in water of 0.3 mol/L, spray flux is The dry 8h of 1/2,90 DEG C of alumina support saturated absorption amount of solution.It weighs appropriate manganese nitrate and is dissolved in deionized water, sulphur cyanogen is added Sour ammonium makes the mass fraction of ammonium thiocyanate in the solution be 10%, and manganese salt solution is carried on above-mentioned oxidation using equi-volume impregnating On alumina supporter, catalyst precarsor is made in 120 DEG C of dry 4h, 500 DEG C of roasting 4h.Catalyst precarsor is placed in continuous flowing to fix In bed reactor, catalyst precarsor is handled using the mixed gas of bromomethane and nitrogen, bromomethane volumetric concentration is 60%, processing Condition is 250 DEG C, 0.2MPa（Absolute pressure）, 300h^-1, time 2h is made bromomethane preparing isobutene catalyst, is denoted as C-3.It is urged Agent MnBr₂It is 2% that weight content, which is 18%, MnO weight contents in terms of oxide, in terms of bromide.

Bromomethane conversion preparing isobutene reaction carries out in continuous flow actuating miniature fixed bed reactors.Catalyst loading 5g, Catalyst is activated using preceding using the gaseous mixture of hydrogen and nitrogen, and hydrogen volume content is 70% in mixed gas, activation condition It is 450 DEG C, 0.2MPa（Absolute pressure）, 750h^-1, soak time 6h；It is reduction procatalyst to restore the content of halogen in rear catalyst The 56.97% of middle total halogen content.

After activation, it to be down to reaction temperature, is passed through unstripped gas, unstripped gas is bromomethane and nitrogen mixed gas, wherein Bromomethane volume content is 70%, and reaction temperature is 230 DEG C, reaction pressure 0.2MPa（Absolute pressure）, air speed 350h^-1.Reaction is steady After one hour fixed, sampling analysis.Reaction result is shown in Table 1.

Embodiment 4

Weigh commercial alumina carrier（Kong Rongwei 0.37ml/g, specific surface area 103m²/ g, bar shaped, equivalent diameter 1.5mm）, use molar concentration to spray oxide impregnation alumina supporter for the dimethylformamide in water of 0.2 mol/L, spray flux is The dry 18h of 1/3,70 DEG C of alumina support saturated absorption amount of solution.It weighs appropriate manganese nitrate and is dissolved in deionized water, sulphur cyanogen is added Sour ammonium makes the mass fraction of ammonium thiocyanate in the solution be 5%, and manganese salt solution is carried on above-mentioned aluminium oxide using equi-volume impregnating On carrier, catalyst precarsor is made in 100 DEG C of dry 6h, 450 DEG C of roasting 6h.Catalyst precarsor is placed in continuous flow fixed bed In reactor, catalyst precarsor is handled using the mixed gas of bromomethane and nitrogen, bromomethane volumetric concentration is 30%, handles item Part is 250 DEG C, 0.2MPa（Absolute pressure）, 300h^-1, time 2h is made bromomethane preparing isobutene catalyst, is denoted as C-4.It is catalyzed Agent MnBr₂It is 3% that weight content, which is 15%, MnO weight contents in terms of oxide, in terms of bromide.

Bromomethane conversion preparing isobutene reaction carries out in continuous flow actuating miniature fixed bed reactors.Catalyst loading 5g, Catalyst is activated using preceding using the gaseous mixture of hydrogen and nitrogen, and hydrogen volume content is 50% in mixed gas, activation condition It is 550 DEG C, 0.1MPa（Absolute pressure）, 1000h^-1, soak time 4h；It is reduction procatalyst to restore the content of halogen in rear catalyst The 68.21% of middle total halogen content.

After activation, it to be down to reaction temperature, is passed through unstripped gas, unstripped gas is bromomethane and nitrogen mixed gas, wherein Bromomethane volume content is 30%, and reaction temperature is 250 DEG C, reaction pressure 3MPa（Absolute pressure）, air speed 500h^-1.Stable reaction After one hour, sampling analysis.Reaction result is shown in Table 1.

Embodiment 5

Weigh commercial alumina carrier（Kong Rongwei 0.37ml/g, specific surface area 103m²/ g, bar shaped, equivalent diameter 1.5mm）, use molar concentration to spray oxide impregnation alumina supporter for the dimethylformamide in water of 0.2 mol/L, spray flux is The dry 18h of 1/3,70 DEG C of alumina support saturated absorption amount of solution.It weighs appropriate manganese nitrate and is dissolved in deionized water, sulphur cyanogen is added Sour ammonium makes the mass fraction of ammonium thiocyanate in the solution be 10%, and manganese salt solution is carried on above-mentioned oxidation using equi-volume impregnating On alumina supporter, catalyst precarsor is made in 100 DEG C of dry 6h, 450 DEG C of roasting 6h.Catalyst precarsor is placed in continuous flowing to fix In bed reactor, catalyst precarsor is handled using methyl bromide gas, treatment conditions are 250 DEG C, 0.2MPa（Absolute pressure）, 300h^-1, when Between 2h, bromomethane preparing isobutene catalyst is made, is denoted as C-5.Obtain catalyst MnBr₂Weight content is 24% in terms of bromide, MnO weight contents in terms of oxide are 2%.

Bromomethane conversion preparing isobutene reaction carries out in continuous flow actuating miniature fixed bed reactors.Catalyst loading 5g, Catalyst is activated using preceding using the gaseous mixture of hydrogen and nitrogen, and hydrogen volume content is 90% in mixed gas, activation condition It is 350 DEG C, 0.3MPa（Absolute pressure）, 500h^-1, soak time 8h；It is reduction procatalyst to restore the content of halogen in rear catalyst The 58.56% of middle total halogen content.

After activation, it to be down to reaction temperature, is passed through unstripped gas, unstripped gas is bromomethane and nitrogen mixed gas, wherein Bromomethane volume content is 80%, and reaction temperature is 210 DEG C, reaction pressure 0.1MPa（Absolute pressure）, air speed 200h^-1.Reaction is steady After one hour fixed, sampling analysis.Reaction result is shown in Table 1.

Embodiment 6

Weigh commercial alumina carrier（Kong Rongwei 0.37ml/g, specific surface area 103m²/ g, bar shaped, equivalent diameter 1.5mm）, use molar concentration to spray oxide impregnation alumina supporter for the dimethylformamide in water of 0.3 mol/L, spray flux is The dry 8h of 1/2,90 DEG C of alumina support saturated absorption amount of solution.It weighs appropriate manganese nitrate and is dissolved in deionized water, sulphur cyanogen is added Sour ammonium makes the mass fraction of ammonium thiocyanate in the solution be 6%, and manganese salt solution is carried on above-mentioned aluminium oxide using equi-volume impregnating On carrier, catalyst precarsor is made in 100 DEG C of dry 6h, 450 DEG C of roasting 6h.Catalyst precarsor is placed in continuous flow fixed bed In reactor, catalyst precarsor is handled using the mixed gas of bromomethane and nitrogen, bromomethane volumetric concentration is 60%, handles item Part is 250 DEG C, 0.2MPa（Absolute pressure）, 300h^-1, time 2h is made bromomethane preparing isobutene catalyst, is denoted as C-6.It is catalyzed Agent MnBr₂It is 1% that weight content, which is 30%, MnO weight contents in terms of oxide, in terms of bromide.

Bromomethane conversion preparing isobutene reaction carries out in continuous flow actuating miniature fixed bed reactors.Catalyst loading 5g, Catalyst is activated using preceding using the gaseous mixture of hydrogen and nitrogen, and hydrogen volume content is 70% in mixed gas, activation condition It is 450 DEG C, 0.2MPa（Absolute pressure）, 750h^-1, soak time 6h；It is reduction procatalyst to restore the content of halogen in rear catalyst The 78.89% of middle total halogen content.

After activation, it to be down to reaction temperature, is passed through unstripped gas, unstripped gas is bromomethane and nitrogen mixed gas, wherein Bromomethane volume content is 70%, and reaction temperature is 230 DEG C, reaction pressure 2MPa（Absolute pressure）, air speed 350h^-1.Stable reaction After one hour, sampling analysis.Reaction result is shown in Table 1.

Embodiment 7

Weigh commercial alumina carrier（Kong Rongwei 0.37ml/g, specific surface area 103m²/ g, bar shaped, equivalent diameter 1.5mm）, use molar concentration to spray oxide impregnation alumina supporter for the dimethylformamide in water of 0.1 mol/L, spray flux is The dry 1h of 3/4,150 DEG C of alumina support saturated absorption amount of solution.It weighs appropriate manganese nitrate and is dissolved in deionized water, sulphur cyanogen is added Sour ammonium makes the mass fraction of ammonium thiocyanate in the solution be 10%, and manganese salt solution is carried on above-mentioned oxidation using equi-volume impregnating On alumina supporter, catalyst precarsor is made in 100 DEG C of dry 6h, 450 DEG C of roasting 6h.Catalyst precarsor is placed in continuous flowing to fix In bed reactor, catalyst precarsor is handled using the mixed gas of bromomethane and nitrogen, bromomethane volumetric concentration is 60%, processing Condition is 250 DEG C, 0.2MPa（Absolute pressure）, 300h^-1, time 2h is made bromomethane preparing isobutene catalyst, is denoted as C-7.It is urged Agent MnBr₂It is 1% that weight content, which is 10%, MnO weight contents in terms of oxide, in terms of bromide.

Bromomethane conversion preparing isobutene reaction carries out in continuous flow actuating miniature fixed bed reactors.Catalyst loading 5g, Catalyst is activated using preceding using the gaseous mixture of hydrogen and nitrogen, and hydrogen volume content is 70% in mixed gas, activation condition It is 450 DEG C, 0.2MPa（Absolute pressure）, 750h^-1, soak time 6h；It is reduction procatalyst to restore the content of halogen in rear catalyst The 69.21% of middle total halogen content.

After activation, it to be down to reaction temperature, is passed through unstripped gas, unstripped gas is bromomethane and nitrogen mixed gas, wherein Bromomethane volume content is 70%, and reaction temperature is 230 DEG C, reaction pressure 2MPa（Absolute pressure）, air speed 350h^-1.Stable reaction After one hour, sampling analysis.Reaction result is shown in Table 1.

Embodiment 8

Weigh commercial alumina carrier（Kong Rongwei 0.37ml/g, specific surface area 103m²/ g, bar shaped, equivalent diameter 1.5mm）, use molar concentration to spray oxide impregnation alumina supporter for the dimethylformamide in water of 0.5 mol/L, spray flux is The dry 18h of 1/5,70 DEG C of alumina support saturated absorption amount of solution.It weighs appropriate manganese nitrate and is dissolved in deionized water, sulphur cyanogen is added Sour ammonium makes the mass fraction of ammonium thiocyanate in the solution be 5%, and manganese salt solution is carried on above-mentioned aluminium oxide using equi-volume impregnating On carrier, catalyst precarsor is made in 100 DEG C of dry 6h, 450 DEG C of roasting 6h.Catalyst precarsor is placed in continuous flow fixed bed In reactor, catalyst precarsor is handled using the mixed gas of bromomethane and nitrogen, bromomethane volumetric concentration is 60%, handles item Part is 200 DEG C, 0.3MPa（Absolute pressure）, 500h^-1, time 1h is made bromomethane preparing isobutene catalyst, is denoted as C-8.It is catalyzed Agent MnBr₂It is 2% that weight content, which is 18%, MnO weight contents in terms of oxide, in terms of bromide.

Bromomethane conversion preparing isobutene reaction carries out in continuous flow actuating miniature fixed bed reactors.Catalyst loading 5g, Catalyst is activated using preceding using the gaseous mixture of hydrogen and nitrogen, and hydrogen volume content is 70% in mixed gas, activation condition It is 450 DEG C, 0.2MPa（Absolute pressure）, 750h^-1, soak time 6h；It is reduction procatalyst to restore the content of halogen in rear catalyst The 67.41% of middle total halogen content.

After activation, it to be down to reaction temperature, is passed through unstripped gas, unstripped gas is bromomethane and nitrogen mixed gas, wherein Bromomethane volume content is 70%, and reaction temperature is 230 DEG C, reaction pressure 2MPa（Absolute pressure）, air speed 350h^-1.Stable reaction After one hour, sampling analysis.Reaction result is shown in Table 1.

Comparative example 1

Catalyst is prepared by embodiment 1, does not use bromination to handle in preparation process.Evaluation condition is the same as embodiment 1.Reaction knot Fruit is shown in Table 1.

Comparative example 2

It takes catalyst C-1 without reduction activation, directly carries out bromomethane conversion reaction.Reaction condition is the same as embodiment 1.Reaction It the results are shown in Table 1.

Comparative example 3

With embodiment 1, the difference is that during carrying out bromomethane conversion reaction, manganous bromide restores completely.

Reaction result is shown in Table 1.

1 catalyst reaction performance of table

Claims (21)

1. a kind of preparation method of bromomethane preparing isobutene catalyst, it is characterised in that：Include the following steps：（1）With aluminium oxide Molar concentration is used to spray dipping for the dimethylformamide in water of 0.1 mol/L-0.5 mol/L for carrier, spray flux is The 1/5-3/4 of alumina support saturated absorption amount of solution, and be dried；（2）Step（1）Carrier saturation dipping manganese after drying Salting liquid is simultaneously dried, roasts, and the ammonium thiocyanate that mass fraction is 2-15% is contained in the manganese salt solution；（3）To step （2）Material after roasting, which carries out bromination processing, makes manganese oxide weight content in catalyst be 0.5%-5%；Manganous bromide weight content is 5%-40%。

2. according to the method described in claim 1, it is characterized in that：Step（1）After dimethylformamide in water spray dipping Drying temperature is 60 DEG C~150 DEG C, drying time 0.5h~20h.

3. according to the method described in claim 1, it is characterized in that：Step（2）Drying condition is -150 DEG C of temperature 60 C, when Between be 1h-24h, roasting condition is 300 DEG C -600 DEG C of temperature, time 1h-24h.

4. according to the method described in claim 1, it is characterized in that：Step（2）Manganese salt is nitrate, hydrochloride, acetate, lemon One or more of lemon hydrochlorate.

5. according to the method described in claim 1, it is characterized in that：Step（3）Described in bromination processing, refer to being contained using gas phase Bromine compounds handles the sample for loading manganese oxide.

6. according to the method described in claim 5, it is characterized in that：Bromine-containing compound refers to bromomethane, methylene bromide, tribromo first One or more of alkane.

7. according to the method described in claim 1, it is characterized in that：Step（3）It is middle to use gas phase bromine-containing compound and indifferent gas The mixed gas of body carries out bromination processing, and bromomethane volumetric concentration is not less than 20%.

8. according to the method described in claim 1, it is characterized in that：Step（3）In specific bromination process it is as follows：Load is aoxidized The sample of manganese is placed in continuous fixed bed reactor, and 150 DEG C -400 DEG C are warming up under inert atmosphere, is passed through gas phase and is contained bromination Close object gas, gas space velocity 50h^-1-1000 h^-1；System pressure is 0.1MPa-0.5MPa, processing time 0.5h-8h.

9. according to the method described in claim 8, it is characterized in that：It is warming up to 180 DEG C -350 DEG C under inert atmosphere, is passed through gas phase Bromine-containing compound gas, gas space velocity 100h^-1-500h^-1；System pressure is 0.1MPa-0.3MPa, processing time 1h- 4h。

10. catalyst prepared by claim 1 to 9 either method, it is characterised in that：Manganese oxide weight content is in catalyst 0.5%-5%；Manganous bromide weight content is 5%-40%.

11. catalyst according to claim 10, it is characterised in that：Manganese oxide weight content is 1%-3%；Manganous bromide weight Content is 10%-30%.

12. application of any catalyst of claim 10-11 in preparing isobutene, it is characterised in that：Including being carried out to catalyst Hydrogen reducing activates, and it is the 20%-90% for restoring total halogen content in procatalyst to make the content of halogen in catalyst, then makes halogen Catalyst after being activated with above-mentioned hydrogen reducing for methane contacts, to prepare isobutene.

13. application according to claim 12, it is characterised in that：The condition of the hydrogen reducing activation makes in catalyst Content of halogen be restore procatalyst in total halogen content 30%-80%.

14. application according to claim 12, it is characterised in that：The mode of the hydrogen reducing activation is included in indifferent gas By catalyzer temperature-elevating to 300 DEG C -600 DEG C under atmosphere；It is 200h to then pass to air speed^-1-2000h^-1Hydrogen or hydrogen and indifferent gas The mixed gas of body, hydrogen volume percentage composition is 10%-95% in 0.1MPa-0.5MPa holding 2h-16h, mixed gas.

15. application according to claim 14, it is characterised in that：It is warming up to 350 DEG C -550 DEG C；Then passing to air speed is 500h^-1-1000h^-1Hydrogen or hydrogen and inert gas mixed gas, keep 4h-8h in 0.1MPa-0.3MPa, it is described mixed It is 30%-90% to close hydrogen volume percentage composition in gas.

16. application according to claim 12, it is characterised in that：The condition of the contact include reaction temperature be 150 DEG C- 350℃；Reaction pressure is 0.1MPa-5MPa；Air speed is 50h^-1-1000h^-1。

17. application according to claim 16, it is characterised in that：Reaction temperature is 180 DEG C -300 DEG C；Reaction pressure is 0.1MPa-3MPa；Air speed is 200h^-1-500h^-1。

18. application according to claim 12, it is characterised in that：The halide is a halide, dihalo first It is one or more in alkane, three halides.

19. application according to claim 12, it is characterised in that：The halide is bromomethane, methylene bromide, tribromo It is one or more in methane.

20. application according to claim 12, it is characterised in that：Including under inert atmosphere by catalyzer temperature-elevating to 300 DEG C- 600℃；It is 200h to then pass to air speed^-1-2000h^-1Hydrogen and inert gas mixed gas, at 0.1MPa-0.5MPa After managing 2h-16h, it is down to reaction temperature and is passed through halide and reacted, hydrogen volume percentage composition is in the gaseous mixture 10%-95%。

21. application according to claim 20, it is characterised in that：Including under inert atmosphere by catalyzer temperature-elevating to 350 DEG C- 550℃；It is 500h to then pass to air speed^-1-1000h^-1Hydrogen and inert gas mixed gas, at 0.1MPa-0.3MPa It after managing 4h-8h, is down to reaction temperature and is passed through halide and reacted, hydrogen volume percentage composition is 30%- in the gaseous mixture 90%。