CN106140220B - It is a kind of using gallium improved silica as bromomethane preparing isobutene catalyst of carrier and its preparation method and application - Google Patents

Abstract

The present invention discloses a kind of using gallium improved silica as highly selective generation isobutene catalyst of the bromomethane of carrier and its preparation method and application.The silica supports that the catalyst is modified by zinc oxide, zinc bromide and gallium form, and zinc oxide weight content is 0.5% 20%；Zinc bromide weight content is 10% 50%；Gallium oxide weight content is 0.1% 1%；Silica supports weight content 40% 90%.The preparation method of catalyst, comprises the following processes：（1）Gallium oxide is introduced to silica supports；（2）Zinc oxide is introduced to step（1）The gallium modified silica support of gained；（3）Bromination processing is carried out to the carrier after introducing zinc oxide.The catalyst can significantly improve the selectivity of isobutene.

Description

It is a kind of using gallium improved silica as the bromomethane preparing isobutene catalyst of carrier and its Preparation method and application

Technical field

The present invention relates to a kind of bromomethane preparing isobutene catalyst and its preparation method and application, relate in particular to one kind Using gallium improved silica as highly selective preparing isobutene catalyst of the bromomethane of carrier and its preparation method and application.

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.

One 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 The hydrocarbon selective of the method that further reaction generates C3 ~ C13 mixing high-carbon hydrocarbons, C5 or more is 70%.Wherein, HBr is at first It is used for methane bromination in reactor, is then discharged in second reactor, is used further in back reaction, realizes after recovered The recycling of HBr.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 molecules of halide propylene Sieve catalyst and preparation method thereof.By using fluorochemical moditied processing molecular sieve, obtains one kind and containing appropriate microporous knot The catalyst of structure and acidity, the catalyst can effectively be catalyzed the reaction that halide is converted into propylene.Prepared catalysis Agent one way bromomethane conversion ratio in the preparing propylene transformed reaction of bromomethane is 35 ~ 99%, and the selectivity of propylene is 27 ~ 70%； One way methyl chloride conversion rate is 30 ~ 99% in the preparing propylene transformed reaction of chloromethanes, 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 bromo-hydrocarbons is generated with the alkane reaction in bromine and natural gas, Then bromo-hydrocarbons is converted to dimethyl ether, methanol and metal bromide, metal bromide oxygen on metal oxide catalyst Metal oxide is obtained after gas regeneration and 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 using gallium improved silica as the bromomethane Gao Xuan of carrier Selecting property generates isobutene catalyst and its preparation method and application.

A kind of bromomethane preparing isobutene catalyst, the silica supports that catalyst is modified by zinc oxide, zinc bromide and gallium Composition, zinc oxide weight content are 0.5%-20%, preferably 1%-15%, further preferred 1%-9%；Zinc bromide weight content is 10%- 50%, preferably 15%-45%, further preferred 18%-39%；Gallium oxide weight content is 0.1%-1%, preferably 0.3%-0.5%；Two Silica support weight content 40%-90%, preferably 50%-85%, further preferred 55%-80%.

In above-mentioned bromomethane preparing isobutene catalyst, 450 DEG C or less total acid contents（NH3-TPD）For 0.5mmol/g- 1.3mmol/g, preferably 0.6mmol/g-1.2mmol/g, further preferred 0.7mmol-1.1mmol/g, 250 DEG C -350 DEG C Acid content accounts for the 20%-90% of 450 DEG C or less total acid contents, preferably 30%-80%, further preferred 40%-80%.

The preparation method of bromomethane preparing isobutene catalyst, comprises the following processes：（1）Gallium oxide is introduced to silica Carrier；（2）Zinc oxide is introduced to step（1）The gallium modified silica support of gained；（3）To the carrier after introducing zinc oxide Carry out bromination processing.

In the preparation method of above-mentioned bromomethane preparing isobutene catalyst, step（1）Described in silica supports can adopt With existing silica product, can also be prepared by method well known to those skilled in the art.Carrier can be according to the need used It is made or is chosen suitable particle shape, such as bar shaped, piece shape, cylindricality, spherical shape is made.Forming can be known by this field Know and carries out.

The preparation method step of above-mentioned bromomethane preparing isobutene catalyst（1）Described in gallium oxide be introduced to silica load The method of body is method well known to those skilled in the art, such as infusion process, kneading method, sol-gal process, it is preferred to use dipping Mode introduces.The specific method is as follows：Using gallium salt solution impregnated carrier, then dry, high-temperature roasting.The drying condition is, Under air atmosphere, -150 DEG C of temperature 60 C, preferably 80 DEG C -120 DEG C；Time is 1h-24h, preferably 4h-8h.The roasting Condition is, under air atmosphere, 600 DEG C -1000 DEG C of temperature, preferably 700 DEG C -900 DEG C；Time is 1h-24h, preferably 4h- 8h.Gallium salt described in the above method is the inorganic salts, preferably gallium nitrate such as gallium nitrate, gallium chloride, gallium sulfate.

The preparation method step of above-mentioned bromomethane preparing isobutene catalyst（2）Described in zinc oxide be introduced to rear silica The method of carrier is method well known to those skilled in the art, and impregnation method introducing such as may be used.The specific method is as follows：Using Zinc solution impregnation steps（1）Obtained material obtains bromomethane preparing isobutene catalyst precarsor after drying, roasting.It is described 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 when dry Think vacuum drying, or it is dry under the conditions of inert gas shielding, it can also dry in air atmosphere.The roasting item Part is 300 DEG C -600 DEG C of temperature, preferably 400 DEG C -500 DEG C；Time is 1h-24h, preferably 4h-8h；Can be when roasting It roasts, can also roast in air atmosphere under the conditions of inert gas shielding.

In the above method, zinc 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 zinc 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 zinc 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 above-mentioned application using gallium improved silica as the catalyst of carrier in preparing isobutene, including catalyst is carried out 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.

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, Ga improved silicas have suitable acid amount, promote the removing of catalyst bromine in activation process, improve bromine first Alkane activity of conversion.Bromomethane conversion preparing isobutene reaction, 90% or more bromomethane conversion ratio, isobutene are carried out by the method for the present invention 60% or more selectivity.The present invention relates to bromomethane conversion preparing isobutene method for preparing catalyst it is simple, be easy to industrialize.This hair Bright bromomethane conversion preparing isobutene method has many advantages, such as that reaction condition is mild, selectivity of product is high, and industrialization easy to implement is answered It is boundless with foreground.

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.

Acidimetric estimation uses NH in following embodiment and comparative example₃- TPD methods, the instrument model used is the U.S. 2920 chemical adsorption instruments of MICROMERITICS companies AutoChem, specific continuous mode are as follows：By sample at 450 DEG C with helium Purging is cooled to 150 DEG C after 1 hour, introduces the mixed gas of ammonia and helium, ammonia volume content 10%, and Pulse adsorption reaches for five times Balance；Then helium purge 2 hours carries out ammonia with 10 DEG C/min of heating rate temperature programming and is desorbed to 450 DEG C；After desorption Ammonia using TCD detectors detect, quantitatively calculate catalyst surface acid amount.

Embodiment 1

It weighs appropriate gallium nitrate to be dissolved in deionized water, silica supports is carried on using equi-volume impregnating（Kong Rong For 1.06ml/g, specific surface area 387m²/ g, spherical, equivalent diameter 0.5mm）, 100 DEG C of dry 6h, 800 DEG C roast 6h, and system contains The silica supports of gallium oxide.Appropriate zinc nitrate is weighed again to be dissolved in deionized water, is carried on and is contained using equi-volume impregnating Catalyst precarsor ZnO/SiO is made in the silica supports of gallium oxide, 100 DEG C of dry 6h, 450 DEG C of roasting 6h₂.By catalyst Precursor is placed in continuous fixed bed reactor, and catalyst precarsor, bromine first are handled using the mixed gas of bromomethane and nitrogen Alkane volumetric concentration is 60%, and treatment conditions are 250 DEG C, 0.2MPa（Absolute pressure）, 300h^-1, time 2h, obtained bromomethane preparing isobutene Catalyst is denoted as C-1.Obtaining catalyst weight group becomes ZnBr₂Weight content is 30%, ZnO in terms of oxide in terms of bromide Weight content is 4%, Ga₂O₃Weight content is 0.4% in terms of oxide, and 450 DEG C or less total acid contents are 0.98mmol/ in catalyst G, 250 DEG C -350 DEG C of acid content account for the 64.25% of 450 DEG C or less total acid contents.

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 68.80% 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

It weighs appropriate gallium nitrate to be dissolved in deionized water, silica supports is carried on using equi-volume impregnating（Kong Rong For 1.06ml/g, specific surface area 387m²/ g, spherical, equivalent diameter 0.5mm）, 100 DEG C of dry 6h, 800 DEG C roast 6h, and system contains The silica supports of gallium oxide.Appropriate zinc nitrate is weighed again to be dissolved in deionized water, is carried on and is contained using equi-volume impregnating Catalyst precarsor ZnO/SiO is made in the silica supports of gallium oxide, 100 DEG C of dry 6h, 450 DEG C of roasting 6h₂.By catalyst Precursor is placed in continuous fixed bed reactor, and catalyst precarsor, bromine first are handled using the mixed gas of bromomethane and nitrogen Alkane volumetric concentration is 60%, and treatment conditions are 250 DEG C, 0.2MPa（Absolute pressure）, 300h^-1, time 2h, obtained bromomethane preparing isobutene Catalyst is denoted as C-2.Obtaining catalyst weight group becomes ZnBr₂Weight content is 30%, ZnO in terms of oxide in terms of bromide Weight content is 4%, Ga₂O₃Weight content is 0.3% in terms of oxide, and 450 DEG C or less total acid contents are 1.03mmol/ in catalyst G, 250 DEG C -350 DEG C of acid content account for the 57.25% of 450 DEG C or less total acid contents.

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 78.22% 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

It weighs appropriate gallium nitrate to be dissolved in deionized water, silica supports is carried on using equi-volume impregnating（Kong Rong For 1.06ml/g, specific surface area 387m²/ g, spherical, equivalent diameter 0.5mm）, 100 DEG C of dry 6h, 800 DEG C roast 6h, and system contains The silica supports of gallium oxide.Appropriate zinc nitrate is weighed again to be dissolved in deionized water, is carried on and is contained using equi-volume impregnating Catalyst precarsor ZnO/SiO is made in the silica supports of gallium oxide, 100 DEG C of dry 6h, 450 DEG C of roasting 6h₂.By catalyst Precursor is placed in continuous fixed bed reactor, and catalyst precarsor, bromine first are handled using the mixed gas of bromomethane and nitrogen Alkane volumetric concentration is 60%, and treatment conditions are 250 DEG C, 0.2MPa（Absolute pressure）, 300h^-1, time 2h, obtained bromomethane preparing isobutene Catalyst is denoted as C-3.Obtaining catalyst weight group becomes ZnBr₂Weight content is 30%, ZnO in terms of oxide in terms of bromide Weight content is 4%, Ga₂O₃Weight content is 0.5% in terms of oxide, and 450 DEG C or less total acid contents are 0.96mmol/ in catalyst G, 250 DEG C -350 DEG C of acid content account for the 62.88% of 450 DEG C or less total acid contents.

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 70.95% 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 4

It weighs appropriate gallium nitrate to be dissolved in deionized water, silica supports is carried on using equi-volume impregnating（Kong Rong For 1.06ml/g, specific surface area 387m²/ g, spherical, equivalent diameter 0.5mm）, 100 DEG C of dry 6h, 800 DEG C roast 6h, and system contains The silica supports of gallium oxide.Appropriate zinc nitrate is weighed again to be dissolved in deionized water, is carried on and is contained using equi-volume impregnating Catalyst precarsor ZnO/SiO is made in the silica supports of gallium oxide, 100 DEG C of dry 6h, 450 DEG C of roasting 6h₂.By catalyst Precursor is placed in continuous fixed bed reactor, and catalyst precarsor, bromine first are handled using the mixed gas of bromomethane and nitrogen Alkane volumetric concentration is 30%, and treatment conditions are 250 DEG C, 0.2MPa（Absolute pressure）, 300h^-1, time 2h, obtained bromomethane preparing isobutene Catalyst is denoted as C-4.Obtaining catalyst weight group becomes ZnBr₂Weight content is 27%, ZnO in terms of oxide in terms of bromide Weight content is 6%, Ga₂O₃Weight content is 0.4% in terms of oxide, and 450 DEG C or less total acid contents are 0.92mmol/ in catalyst G, 250 DEG C -350 DEG C of acid content account for the 63.97% of 450 DEG C or less total acid contents.

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, 0.1MPa（Absolute pressure）, 1000h^-1, soak time 4h；It is reduction procatalyst to restore the content of halogen in rear catalyst The 69.11% 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 210 DEG C, reaction pressure 3MPa（Absolute pressure）, air speed 200h^-1.Stable reaction After one hour, sampling analysis.Reaction result is shown in Table 1.

Embodiment 5

It weighs appropriate gallium nitrate to be dissolved in deionized water, silica supports is carried on using equi-volume impregnating（Kong Rong For 1.06ml/g, specific surface area 387m²/ g, spherical, equivalent diameter 0.5mm）, 100 DEG C of dry 6h, 800 DEG C roast 6h, and system contains The silica supports of gallium oxide.Appropriate zinc nitrate is weighed again to be dissolved in deionized water, is carried on and is contained using equi-volume impregnating Catalyst precarsor ZnO/SiO is made in the silica supports of gallium oxide, 100 DEG C of dry 6h, 450 DEG C of roasting 6h₂.By catalyst Precursor is placed in continuous fixed bed reactor, and catalyst precarsor is handled using methyl bromide gas, and treatment conditions are 250 DEG C, 0.2MPa（Absolute pressure）, 300h^-1, time 2h is made bromomethane preparing isobutene catalyst, is denoted as C-5.Obtain catalyst weight composition For ZnBr₂It is 2%, Ga that weight content, which is 33%, ZnO weight contents in terms of oxide, in terms of bromide₂O₃Contained with oxide weight calculation amount Amount is 0.4%, and 450 DEG C or less total acid contents are 1.08mmol/g in catalyst, and 250 DEG C -350 DEG C of acid content accounts for 450 DEG C or less always The 54.29% of acid amount.

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, 0.3MPa（Absolute pressure）, 500h^-1, soak time 4h；It is reduction procatalyst to restore the content of halogen in rear catalyst The 79.15% 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 230 DEG C, reaction pressure 0.1MPa（Absolute pressure）, air speed 500h^-1.Reaction is steady After one hour fixed, sampling analysis.Reaction result is shown in Table 1.

Embodiment 6

It weighs appropriate gallium nitrate to be dissolved in deionized water, silica supports is carried on using equi-volume impregnating（Kong Rong For 1.06ml/g, specific surface area 387m²/ g, spherical, equivalent diameter 0.5mm）, 80 DEG C of dry 8h, 900 DEG C roast 4h, and system contains The silica supports of gallium oxide.Appropriate zinc nitrate is weighed again to be dissolved in deionized water, is carried on and is contained using equi-volume impregnating Catalyst precarsor ZnO/SiO is made in the silica supports of gallium oxide, 120 DEG C of dry 4h, 400 DEG C of roasting 8h₂.By catalyst Precursor is placed in continuous fixed bed reactor, and catalyst precarsor, bromine first are handled using the mixed gas of bromomethane and nitrogen Alkane volumetric concentration is 60%, and treatment conditions are 250 DEG C, 0.2MPa（Absolute pressure）, 300h^-1, time 2h, obtained bromomethane preparing isobutene Catalyst is denoted as C-6.Obtaining catalyst weight group becomes ZnBr₂Weight content is 39%, ZnO in terms of oxide in terms of bromide Weight content is 6%, Ga₂O₃Weight content is 0.4% in terms of oxide, and 450 DEG C or less total acid contents are 1.02mmol/ in catalyst G, 250 DEG C -350 DEG C of acid content account for the 63.37% of 450 DEG C or less total acid contents.

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）, 500h^-1, soak time 8h；It is reduction procatalyst to restore the content of halogen in rear catalyst The 71.40% 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 60%, and reaction temperature is 270 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

It weighs appropriate gallium nitrate to be dissolved in deionized water, silica supports is carried on using equi-volume impregnating（Kong Rong For 1.06ml/g, specific surface area 387m²/ g, spherical, equivalent diameter 0.5mm）, 120 DEG C of dry 4h, 700 DEG C roast 8h, and system contains The silica supports of gallium oxide.Appropriate zinc nitrate is weighed again to be dissolved in deionized water, is carried on and is contained using equi-volume impregnating Catalyst precarsor ZnO/SiO is made in the silica supports of gallium oxide, 80 DEG C of dry 8h, 500 DEG C of roasting 4h₂.Before catalyst Body is placed in continuous fixed bed reactor, and catalyst precarsor, bromomethane are handled using the mixed gas of bromomethane and nitrogen Volumetric concentration is 60%, and treatment conditions are 250 DEG C, 0.2MPa（Absolute pressure）, 300h^-1, time 2h, be made bromomethane preparing isobutene urge Agent is denoted as C-7.Obtaining catalyst weight group becomes ZnBr₂Weight content is that 18%, ZnO is counted weight with oxide in terms of bromide Amount content is 2%, Ga₂O₃Weight content is 0.4% in terms of oxide, and 450 DEG C or less total acid contents are 0.87mmol/g in catalyst, 250 DEG C -350 DEG C of acid content accounts for the 62.94% of 450 DEG C or less total acid contents.

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 73.27% 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

It weighs appropriate gallium nitrate to be dissolved in deionized water, silica supports is carried on using equi-volume impregnating（Kong Rong For 1.06ml/g, specific surface area 387m²/ g, spherical, equivalent diameter 0.5mm）, 100 DEG C of dry 6h, 800 DEG C roast 6h, and system contains The silica supports of gallium oxide.Appropriate zinc nitrate is weighed again to be dissolved in deionized water, is carried on and is contained using equi-volume impregnating Catalyst precarsor ZnO/SiO is made in the silica supports of gallium oxide, 100 DEG C of dry 6h, 450 DEG C of roasting 6h₂.By catalyst Precursor is placed in continuous fixed bed reactor, and catalyst precarsor, bromine first are handled using the mixed gas of bromomethane and nitrogen Alkane volumetric concentration is 60%, and treatment conditions are 200 DEG C, 0.3MPa（Absolute pressure）, 500h^-1, time 1h, obtained bromomethane preparing isobutene Catalyst is denoted as C-8.Obtaining catalyst weight group becomes ZnBr₂Weight content is 30%, ZnO in terms of oxide in terms of bromide Weight content is 4%, Ga₂O₃Weight content is 0.4% in terms of oxide, and 450 DEG C or less total acid contents are 0.88mmol/ in catalyst G, 250 DEG C -350 DEG C of acid content account for the 61.53% of 450 DEG C or less total acid contents.

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 74.51% 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 750h^-1.Stable reaction After one hour, sampling analysis.Reaction result is shown in Table 1.

Embodiment 9

It weighs appropriate gallium nitrate to be dissolved in deionized water, silica supports is carried on using equi-volume impregnating（Kong Rong For 1.06ml/g, specific surface area 387m²/ g, spherical, equivalent diameter 0.5mm）, 100 DEG C of dry 6h, 800 DEG C roast 6h, and system contains The silica supports of gallium oxide.Appropriate zinc nitrate is weighed again to be dissolved in deionized water, is carried on and is contained using equi-volume impregnating Catalyst precarsor ZnO/SiO is made in the silica supports of gallium oxide, 100 DEG C of dry 6h, 450 DEG C of roasting 6h₂.By catalyst Precursor is placed in continuous fixed bed reactor, and catalyst precarsor, bromine first are handled using the mixed gas of bromomethane and nitrogen Alkane volumetric concentration is 60%, and treatment conditions are 300 DEG C, 0.1MPa（Absolute pressure）, 100h^-1, time 4h, obtained bromomethane preparing isobutene Catalyst is denoted as C-9.Obtaining catalyst weight group becomes ZnBr₂Weight content is 30%, ZnO in terms of oxide in terms of bromide Weight content is 4%, Ga₂O₃Weight content is 0.4% in terms of oxide, and 450 DEG C or less total acid contents are 1.01mmol/ in catalyst G, 250 DEG C -350 DEG C of acid content account for the 58.29% of 450 DEG C or less total acid contents.

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 75.28% 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 750h^-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.Detailed process is as follows：

It weighs appropriate gallium nitrate to be dissolved in deionized water, silica supports is carried on using equi-volume impregnating（Kong Rong For 1.06ml/g, specific surface area 387m²/ g, spherical, equivalent diameter 0.5mm）, 100 DEG C of dry 6h, 800 DEG C roast 6h, and system contains The silica supports of gallium oxide.Appropriate zinc nitrate is weighed again to be dissolved in deionized water, is carried on and is contained using equi-volume impregnating Catalyst D-1 is made in the silica supports of gallium oxide, 100 DEG C of dry 6h, 450 DEG C of roasting 6h.Obtain catalyst weight composition For ZnO, weight content is 20%, Ga in terms of oxide₂O₃Weight content is 0.4% in terms of oxide, and 450 DEG C or less always in catalyst Acid amount is 0.38mmol/g, and 250 DEG C -350 DEG C of acid content accounts for the 65.60% of 450 DEG C or less total acid contents.

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 78.95% 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 2

It takes catalyst C-1 not activated, directly carries out bromomethane conversion reaction.Unstripped gas is bromomethane and nitrogen mixture Body, wherein bromomethane volume content are 70%, and reaction temperature is 230 DEG C, reaction pressure 2MPa（Absolute pressure）, air speed 350h^-1。 After stable reaction one hour, sampling analysis.Reaction result is shown in Table 1.

Comparative example 3

It weighs appropriate gallium nitrate to be dissolved in deionized water, silica supports is carried on using equi-volume impregnating（Kong Rong For 1.06ml/g, specific surface area 387m²/ g, spherical, equivalent diameter 0.5mm）, 100 DEG C of dry 6h, 800 DEG C roast 6h, and system contains The silica supports of gallium oxide.Appropriate zinc bromide is weighed again to be dissolved in deionized water, is carried on and is contained using equi-volume impregnating Catalyst D-2 is made in the silica supports of gallium oxide, 100 DEG C of dry 6h, the lower 450 DEG C of roastings 6h of nitrogen atmosphere.It is catalyzed Agent weight group becomes ZnBr₂Weight content is 30%, Ga in terms of bromide₂O₃Weight content is 0.4% in terms of oxide, catalyst In 450 DEG C or less total acid contents be 1.16mmol/g, 250 DEG C -350 DEG C of acid content accounts for the 80.39% of 450 DEG C or less total acid contents.

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 48.67% 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.

1 catalyst reaction performance of table

Claims (32)

1. a kind of bromomethane preparing isobutene catalyst, it is characterised in that：The dioxy that catalyst is modified by zinc oxide, zinc bromide and gallium SiClx carrier forms, and zinc oxide weight content is 0.5%-20%；Zinc bromide weight content is 10%-50%；Gallium oxide weight content For 0.1%-1%；Silica supports weight content 40%-85%.

2. catalyst according to claim 1, it is characterised in that：Zinc oxide weight content is 1%-15%；Zinc bromide weight Content is 15%-45%；Gallium oxide weight content is 0.3%-0.5%；Silica supports weight content 50%-85%.

3. catalyst according to claim 2, it is characterised in that：Zinc oxide weight content is 1%-9%；Zinc bromide weight contains Amount is 18%-39%；Silica supports weight content 55%-80%.

4. catalyst according to claim 1, it is characterised in that：450 DEG C or less total acid contents are 0.5mmol/ in catalyst G-1.3mmol/g, 250 DEG C -350 DEG C of acid content account for the 20%-90% of 450 DEG C or less total acid contents.

5. catalyst according to claim 4, it is characterised in that：450 DEG C or less total acid contents are 0.6mmol/ in catalyst G-1.2mmol/g, 250 DEG C -350 DEG C of acid content account for the 30%-80% of 450 DEG C or less total acid contents.

6. catalyst according to claim 5, it is characterised in that：450 DEG C or less total acid contents are 0.7mmol- in catalyst 1.1mmol/g, 250 DEG C -350 DEG C of acid content account for the 40%-80% of 450 DEG C or less total acid contents.

7. the preparation method of any catalyst of claim 1 to 6, it is characterised in that：It comprises the following processes：（1）Gallium oxide is drawn Enter to silica supports；（2）Zinc oxide is introduced to step（1）The gallium modified silica support of gained；（3）To introducing oxygen Change the carrier after zinc and carries out bromination processing.

8. according to the method described in claim 7, it is characterized in that：Step（1）Middle gallium oxide is introduced to silica supports and adopts With infusion process, kneading method or sol-gal process.

9. according to the method described in claim 8, it is characterized in that：Using gallium salt solution impregnated carrier, then dry, roasting.

10. according to the method described in claim 9, it is characterized in that：60 DEG C -150 DEG C, time 1h-24h of drying temperature, roasting Burn 600 DEG C -1000 DEG C of temperature, time 1h-24h.

11. according to the method described in claim 10, it is characterized in that：80 DEG C -120 DEG C, time 4h-8h of drying temperature, roasting Burn 700 DEG C -900 DEG C of temperature, time 4h-8h.

12. according to the method described in claim 9, it is characterized in that：The gallium salt is gallium nitrate, gallium chloride or gallium sulfate.

13. according to the method described in claim 7, it is characterized in that：Step（2）Described in zinc oxide be introduced to step（1）Institute The gallium modified silica support obtained uses infusion process.

14. according to the method for claim 13, it is characterised in that：Using zinc solution impregnation steps（1）Obtained material, Bromomethane preparing isobutene catalyst precarsor is obtained after drying, roasting.

15. according to the method for claim 14, it is characterised in that：60 DEG C -150 DEG C of drying temperature；Time is 1h-24h；Roasting Burn 300 DEG C -600 DEG C of temperature；Time is 1h-24h.

16. according to the method for claim 15, it is characterised in that：80 DEG C -120 DEG C of drying temperature；Time is 4h-8h；Roasting Burn 400 DEG C -500 DEG C of temperature；Time 4h-8h.

17. according to the method for claim 14, it is characterised in that：Zinc salt is nitrate, hydrochloride, acetate, citric acid One or more of salt.

18. according to the method described in claim 7, 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 zinc oxide.

19. according to the method for claim 18, it is characterised in that：Bromine-containing compound refers to bromomethane, methylene bromide, tribromo One or more of methane.

20. according to the method for claim 18, it is characterised in that：Using the mixing of gas phase bromine-containing compound and inert gas Gas carries out bromination processing, and bromomethane volumetric concentration is not less than 20%.

21. according to the method for claim 18, it is characterised in that：The sample for loading zinc oxide is placed in continuous flowing to fix In bed reactor, it is warming up to 150 DEG C -400 DEG C under inert atmosphere, is passed through gas phase bromine-containing compound gas, gas space velocity 50h^-1- 1000 h^-1；System pressure is 0.1MPa-0.5MPa, processing time 0.5h-8h.

22. according to the method for claim 21, it is characterised in that：180 DEG C -350 DEG C are warming up under inert atmosphere, gas space Speed is 100h^-1-500h^-1；System pressure is 0.1MPa-0.3MPa, processing time 1h-4h.

23. application of the catalyst described in claim 1 in preparing isobutene, it is characterised in that：Including carrying out hydrogen to catalyst Reduction activation, it is to restore the 20%-90% of halogen total weight content in procatalyst to make the halogen weight content in catalyst, then Catalyst after making halide be activated with above-mentioned hydrogen reducing contacts, to prepare isobutene.

24. application according to claim 23, it is characterised in that：The condition of the hydrogen reducing activation makes in catalyst Halogen weight content be restore procatalyst in halogen total weight content 30%-80%.

25. application according to claim 23, 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.

26. application according to claim 25, 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.

27. application according to claim 23, it is characterised in that：The condition of the contact includes that reaction temperature is 150 ℃-350℃；Reaction pressure is 0.1MPa-5MPa；Air speed is 50h^-1-1000h^-1。

28. application according to claim 27, 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。

29. application according to claim 23, it is characterised in that：The halide is a halide, dihalo first It is one or more in alkane, three halides.

30. application according to claim 23, 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%。

31. application according to claim 30, 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%。

32. application according to claim 23, it is characterised in that：The reaction of halide preparing isobutene is in fixed bed, fluidisation It is carried out in bed, moving bed, slurry bed system or fluidized bed reactor reactor.