CN106140228B - A kind of bromomethane preparing isobutene catalyst and its preparation method and application of cocrystallization preparation - Google Patents

Abstract

The present invention discloses a kind of bromomethane preparing isobutene catalyst and its preparation method and application of cocrystallization preparation.The preparation method of catalyst, comprises the following processes: (1) preparing the aqueous solution containing polyalcohol, zinc salt and aluminium salt；(2) it will be evaporated under the mixed solution reduced pressure of step (1), obtain solid crystal, then grind；(3) calcination steps (2) obtained solid under the oxygen and inert gas mixed atmosphere continuously flowed, then forms；(4) bromination processing is carried out to sample obtained by step (3), zinc oxide weight content is 0.5%-20% in the catalyst after bromination, and zinc bromide weight content is 10%-50%.The catalyst can significantly improve the selectivity of isobutene for the reaction of bromomethane preparing isobutene.

Description

A kind of bromomethane preparing isobutene catalyst of cocrystallization preparation and preparation method thereof and Using

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 Cocrystallization prepares the highly selective preparing isobutene catalyst of methane and its methods and applications.

Background technique

Isobutene is a kind of important basic organic chemical industry raw material, and derived product is numerous, and vertical industry chain is complicated, is disappeared Take structure in diversified trend.A variety of high value-added products can be prepared by raw material of isobutene, such as: butyl rubber, gather it is 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 increasingly depleted in petroleum resources 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 of shale gas development and utilization, 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 benefit 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 further method that reaction generates C3 ~ C13 mixing high-carbon hydrocarbon, the hydrocarbon selective of C5 or more are 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.(CN 102527427A, Jieli He, Ting Xu, the Zhihui Wang, et.al. such as Wang Ye 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 contain 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 dimethyl ether, methanol and metal bromide, metal bromide oxygen are converted by bromo-hydrocarbons on metal oxide catalyst Metal oxide is obtained after gas regeneration and releases simple substance bromine, completes the circulation 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..In the technology using the low-carbon alkene compared with high added value as target product, single selectivity of product It is not high, not yet find the relevant report of bromomethane high selectivity isobutene.

Summary of the invention

In view of the deficiencies of the prior art, the present invention provides one kind prepares the highly selective generation of bromomethane in cocrystallization method Isobutene catalyst and its preparation method and application.

A kind of preparation method of bromomethane preparing isobutene catalyst, comprises the following processes:

(1) aqueous solution containing polyalcohol, zinc salt and aluminium salt is prepared；

(2) it will be evaporated under the mixed solution reduced pressure of step (1), obtain solid crystal, then grind；

(3) calcination steps (2) obtained solid under the oxygen and inert gas mixed atmosphere continuously flowed, then forms；

(4) bromination processing is carried out to sample obtained by step (3), zinc oxide weight content is in the catalyst after bromination 0.5%-20%, zinc bromide weight content are 10%-50%.

Polyalcohol described in the preparation method step (1) of above-mentioned bromomethane preparing isobutene catalyst be selected from carbon number 4-7 it Between and containing there are three the alcohols of the above hydroxyl, preferably xylitols, glucose；The zinc salt and aluminium salt are selected from nitrate, salt One of hydrochlorate, sulfate, acetate, preferably nitrate；It is polynary in the aqueous solution containing polyalcohol, zinc salt and aluminium salt Alcohol matter amount is 0.5-4 times of zinc and aluminum material amount summation, and preferably 1-3 times, polyalcohol molar concentration is 1mol/L- in solution 5mol/L, preferably 2mol/L-4mol/L.

Mixed solution evaporated temperature described in the preparation method step (2) of above-mentioned bromomethane preparing isobutene catalyst is 40 DEG C -80 DEG C, preferably 50 DEG C -70 DEG C.

The gaseous mixture of oxygen and inert gas described in the preparation method step (3) of above-mentioned bromomethane preparing isobutene catalyst Oxygen volumetric concentration is 1%-10%, preferably 2%-6% in point；Maturing temperature is 400 DEG C -800 DEG C, preferably 500 DEG C -700 DEG C； Calcining time is 4h-72h, preferably 12h-36h；Gaseous mixture air speed is 500h^-1-5000h^-1, preferably 1000^-1-3000^-1.Institute It states molding to carry out by this field general technology method, such as the methods of extrusion, tabletting, spin, can be made according to the needs of use Or suitable particle shape is chosen, such as bar shaped, piece shape, cylindricality, spherical shape is made.

The processing of bromination described in the preparation method step (4) of above-mentioned bromomethane preparing isobutene catalyst, refers to using gas phase Bromine-containing compound handles the sample of load zinc oxide.Bromine-containing compound refers to bromomethane, methylene bromide, in bromoform One or more, preferably bromomethane.Bromine can also be carried out using the mixed gas of gas phase bromine-containing compound and inert gas Change processing, 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 being placed in continuous fixed bed reactor, is warming up to 150 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 are 0.1MPa-0.5MPa(absolute pressure), preferably 0.1MPa-0.3MPa(absolute pressure), the processing time is 0.5h-8h, It is preferred that 1h-4h.

Inert gas involved in the preparation method step (4) of above-mentioned bromomethane preparing isobutene catalyst is nitrogen, argon The gas that gas, helium etc. do not chemically react under the conditions of involved in the present invention, preferably nitrogen.

A kind of bromomethane preparing isobutene catalyst, is made of zinc oxide, zinc bromide and aluminum oxide, and zinc oxide weight contains Amount is 0.5%-20%, preferably 1%-15%, further preferred 1%-9%；Zinc bromide weight content be 10%-50%, preferably 15%-45%, Further preferred 18%-39%；Aluminum oxide 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) are 0.5mmol/g- 1.3mmol/g, preferably 0.6mmol/g-1.2mmol/g, further preferred 0.7mmol/g-1.1mmol/g, 250 DEG C -350 DEG C Acid content account for the 20%-90%, preferably 30%-80%, further preferred 40%-80% of 450 DEG C or less total acid contents.

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, then make halide and above-mentioned hydrogen reducing living Catalyst contact after change, to prepare isobutene.

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

In above-mentioned application, the mode of hydrogen reducing activation include under an inert atmosphere by catalyzer temperature-elevating to 300 DEG C- 600℃；Then passing to air speed is 200h^-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 ℃；Then passing to air speed is 500h^-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%, more preferably 50%-90% in the mixed gas.

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

In above-mentioned application, the condition of the contact includes that reaction temperature is 150 DEG C -350 DEG C；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。

By catalyzer temperature-elevating to 300 DEG C -600 DEG C under one of above-mentioned application specific embodiment, including inert atmosphere, Preferably 350 DEG C -550 DEG C；Then passing to air speed is 200h^-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) processing 2h-16h, 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-mentioned 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%.

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

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

Compared with prior art, method of the present invention can by bromomethane it is highly selective be converted into isobutene.This The catalyst for inventing the cocrystallization method preparation being related to utilizes the difference of zinc salt and aluminium salt crystallinity, goes out Zn and Al fractional crystallization Come, while using the gluing of polyalcohol effect two kinds of crystal of dispersion, guaranteeing that there is weak interaction, same time-division between Zn and Al It dissipates uniform.Bromomethane conversion preparing isobutene reaction, 90% or more bromomethane conversion ratio, isobutene selection are carried out by the method for the present invention Property 80% or more.The present invention relates to bromomethane conversion preparing isobutene method for preparing catalyst it is simple, be easy to industrialize.Bromine of the present invention Methane conversion preparing isobutene method has many advantages, such as that reaction condition is mild, selectivity of product is high, industrialization easy to accomplish, before Scape is boundless.

Specific embodiment

Technology contents and effect of the invention are further illustrated below with reference to embodiment, but are not so limited the present invention.

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

Embodiment 1

With making xylitol, aluminum nitrate, zinc nitrate aqueous solution, wherein xylose determining alcohol is 3mol/L, aluminum nitrate and zinc nitrate Total concentration is 1.5 mol/L.Mixed solution is heated to 60 DEG C, is evaporated under a reduced pressure, solid crystal object is obtained, is crushed. After crushing solid oxygen, nitrogen mixed atmosphere under roast, oxygen volumetric concentration be 4%, 600 DEG C of maturing temperature, calcining time For 24 hours, gaseous mixture air speed 2000h^-1, catalyst precarsor ZnO/Al is made₂O₃.It is anti-that catalyst precarsor is placed in continuous flow fixed bed It answers in device, handles catalyst precarsor using the mixed gas of bromomethane and nitrogen, bromomethane volumetric concentration is 80%, treatment conditions It is 250 DEG C, 0.2MPa(absolute pressure), 300h^-1, time 2h, be made bromomethane preparing isobutene catalyst, be denoted as C-1.Obtain catalyst Weight group becomes ZnBr₂It is 4% that weight content, which is 30%, ZnO weight content in terms of oxide, in terms of bromide, 450 in catalyst DEG C or less total acid content be 0.94mmol/g, 250 DEG C -350 DEG C of acid content accounts for the 78.37% 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), 750h^-1, activation time 6h；Restoring the content of halogen in rear catalyst is reduction procatalyst The 61.77% 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, and reaction pressure is 2MPa(absolute pressure), air speed 350h^-1.Stable reaction After one hour, sampling analysis.Reaction result is shown in Table 1.

Embodiment 2

With making xylitol, aluminum nitrate, zinc nitrate aqueous solution, wherein xylose determining alcohol is 2mol/L, aluminum nitrate and zinc nitrate Total concentration is 2 mol/L.Mixed solution is heated to 70 DEG C, is evaporated under a reduced pressure, solid crystal object is obtained, is crushed.Powder It is broken after solid oxygen, nitrogen mixed atmosphere under roast, oxygen volumetric concentration be 6%, 500 DEG C of maturing temperature, calcining time 12h, gaseous mixture air speed 1000h^-1, catalyst precarsor ZnO/Al is made₂O₃.It is anti-that catalyst precarsor is placed in continuous flow fixed bed It answers in device, handles catalyst precarsor using the mixed gas of bromomethane and nitrogen, bromomethane volumetric concentration is 80%, treatment conditions It is 250 DEG C, 0.2MPa(absolute pressure), 300h^-1, time 2h, be made bromomethane preparing isobutene catalyst, be denoted as C-2.Obtain catalyst Weight group becomes ZnBr₂It is 4% that weight content, which is 30%, ZnO weight content in terms of oxide, in terms of bromide, 450 in catalyst DEG C or less total acid content be 0.81mmol/g, 250 DEG C -350 DEG C of acid content accounts for the 69.35% 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, activation time 6h；Restoring the content of halogen in rear catalyst is reduction procatalyst The 69.57% 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, and reaction pressure is 2MPa(absolute pressure), air speed 350h^-1.Stable reaction After one hour, sampling analysis.Reaction result is shown in Table 1.

Embodiment 3

With making xylitol, aluminum nitrate, zinc nitrate aqueous solution, wherein xylose determining alcohol is 2mol/L, aluminum nitrate and zinc nitrate Total concentration is 1mol/L.Mixed solution is heated to 50 DEG C, is evaporated under a reduced pressure, solid crystal object is obtained, is crushed.It crushes Afterwards solid oxygen, nitrogen mixed atmosphere under roast, oxygen volumetric concentration be 2%, 700 DEG C of maturing temperature, calcining time for 24 hours, Gaseous mixture air speed 3000h^-1, catalyst precarsor ZnO/Al is made₂O₃.Catalyst precarsor is placed in continuous fixed bed reactor In, catalyst precarsor is handled using the mixed gas of bromomethane and nitrogen, bromomethane volumetric concentration is 80%, treatment conditions 250 DEG C, 0.2MPa(absolute pressure), 300h^-1, time 2h, be made bromomethane preparing isobutene catalyst, be denoted as C-3.Obtain catalyst weight Group becomes ZnBr₂It is 4% that weight content, which is 30%, ZnO weight content in terms of oxide, in terms of bromide, in catalyst 450 DEG C with Lower total acid content is 1.02mmol/g, and 250 DEG C -350 DEG C of acid content accounts for the 66.27% 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, activation time 6h；Restoring the content of halogen in rear catalyst is reduction procatalyst The 52.18% 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, and reaction pressure is 2MPa(absolute pressure), air speed 350h^-1.Stable reaction After one hour, sampling analysis.Reaction result is shown in Table 1.

Embodiment 4

With making xylitol, aluminum nitrate, zinc nitrate aqueous solution, wherein xylose determining alcohol is 4mol/L, aluminum nitrate and zinc nitrate Total concentration is 2 mol/L.Mixed solution is heated to 60 DEG C, is evaporated under a reduced pressure, solid crystal object is obtained, is crushed.Powder It is broken after solid oxygen, nitrogen mixed atmosphere under roast, oxygen volumetric concentration be 4%, 600 DEG C of maturing temperature, calcining time For 24 hours, gaseous mixture air speed 2000h^-1, catalyst precarsor ZnO/Al is made₂O₃.It is anti-that catalyst precarsor is placed in continuous flow fixed bed It answers in device, handles catalyst precarsor using the mixed gas of bromomethane and nitrogen, bromomethane volumetric concentration is 80%, treatment conditions It is 250 DEG C, 0.2MPa(absolute pressure), 300h^-1, time 2h, be made bromomethane preparing isobutene catalyst, be denoted as C-4.Obtain catalyst Weight group becomes ZnBr₂It is 4% that weight content, which is 30%, ZnO weight content in terms of oxide, in terms of bromide, 450 in catalyst DEG C or less total acid content be 0.93mmol/g, 250 DEG C -350 DEG C of acid content accounts for the 74.86% 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 400 DEG C, 0.1MPa(absolute pressure), 1000h^-1, activation time 8h；Restoring the content of halogen in rear catalyst is reduction procatalyst The 63.45% 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 40%, and reaction temperature is 230 DEG C, and reaction pressure is 2MPa(absolute pressure), air speed 200h^-1.Stable reaction After one hour, sampling analysis.Reaction result is shown in Table 1.

Embodiment 5

With making xylitol, aluminum nitrate, zinc nitrate aqueous solution, wherein xylose determining alcohol is 3mol/L, aluminum nitrate and zinc nitrate Total concentration is 1 mol/L.Mixed solution is heated to 50 DEG C, is evaporated under a reduced pressure, solid crystal object is obtained, is crushed.Powder It is broken after solid oxygen, nitrogen mixed atmosphere under roast, oxygen volumetric concentration be 2%, 500 DEG C of maturing temperature, calcining time 36h, gaseous mixture air speed 2000h^-1, catalyst precarsor ZnO/Al is made₂O₃.It is anti-that catalyst precarsor is placed in continuous flow fixed bed It answers in device, handles catalyst precarsor using the mixed gas of bromomethane and nitrogen, bromomethane volumetric concentration is 80%, treatment conditions It is 250 DEG C, 0.2MPa(absolute pressure), 300h^-1, time 2h, be made bromomethane preparing isobutene catalyst, be denoted as C-5.Obtain catalyst Weight group becomes ZnBr₂It is 4% that weight content, which is 30%, ZnO weight content in terms of oxide, in terms of bromide, 450 in catalyst DEG C or less total acid content be 1.07mmol/g, 250 DEG C -350 DEG C of acid content accounts for the 61.1% 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 50% in mixed gas, activation condition It is 350 DEG C, 0.3MPa(absolute pressure), 500h^-1, activation time 4h；Restoring the content of halogen in rear catalyst is reduction procatalyst The 73.45% 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 250 DEG C, and reaction pressure is 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

Glucose, aluminum nitrate, zinc nitrate aqueous solution are prepared, wherein concentration of glucose is 3mol/L, aluminum nitrate and zinc nitrate Total concentration is 1.5 mol/L.Mixed solution is heated to 60 DEG C, is evaporated under a reduced pressure, solid crystal object is obtained, is crushed. After crushing solid oxygen, nitrogen mixed atmosphere under roast, oxygen volumetric concentration be 4%, 600 DEG C of maturing temperature, calcining time For 24 hours, gaseous mixture air speed 2000h^-1, catalyst precarsor ZnO/Al is made₂O₃.It is anti-that catalyst precarsor is placed in continuous flow fixed bed It answers in device, handles catalyst precarsor using the mixed gas of bromomethane and nitrogen, bromomethane volumetric concentration is 80%, treatment conditions It is 250 DEG C, 0.2MPa(absolute pressure), 300h^-1, time 2h, be made bromomethane preparing isobutene catalyst, be denoted as C-6.Obtain catalyst Weight group becomes ZnBr₂It is 4% that weight content, which is 30%, ZnO weight content in terms of oxide, in terms of bromide, 450 in catalyst DEG C or less total acid content be 0.92mmol/g, 250 DEG C -350 DEG C of acid content accounts for the 77.21% 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 500 DEG C, 0.2MPa(absolute pressure), 1000h^-1, activation time 6h；Restoring the content of halogen in rear catalyst is reduction procatalyst The 58.24% 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 210 DEG C, and reaction pressure is 02MPa(absolute pressure), air speed 500h^-1.Reaction is steady After one hour fixed, sampling analysis.Reaction result is shown in Table 1.

Embodiment 7

With making xylitol, aluminum nitrate, zinc nitrate aqueous solution, wherein xylose determining alcohol is 3mol/L, aluminum nitrate and zinc nitrate Total concentration is 1.5 mol/L.Mixed solution is heated to 60 DEG C, is evaporated under a reduced pressure, solid crystal object is obtained, is crushed. After crushing solid oxygen, nitrogen mixed atmosphere under roast, oxygen volumetric concentration be 4%, 600 DEG C of maturing temperature, calcining time For 24 hours, gaseous mixture air speed 2000h^-1, catalyst precarsor ZnO/Al is made₂O₃.It is anti-that catalyst precarsor is placed in continuous flow fixed bed It answers in device, handles catalyst precarsor using the mixed gas of bromomethane and nitrogen, bromomethane volumetric concentration is 30%, treatment conditions It is 300 DEG C, 0.3MPa(absolute pressure), 100h^-1, time 4h, be made bromomethane preparing isobutene catalyst, be denoted as C-7.Obtain catalyst Weight group becomes ZnBr₂It is 4% that weight content, which is 30%, ZnO weight content in terms of oxide, in terms of bromide, 450 in catalyst DEG C or less total acid content be 0.92mmol/g, 250 DEG C -350 DEG C of acid content accounts for the 77.54% 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, activation time 6h；Restoring the content of halogen in rear catalyst is reduction procatalyst The 60.21% 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 60%, and reaction temperature is 230 DEG C, and reaction pressure is 3MPa(absolute pressure), air speed 350h^-1.Stable reaction After one hour, sampling analysis.Reaction result is shown in Table 1.

Embodiment 8

With making xylitol, aluminum nitrate, zinc nitrate aqueous solution, wherein xylose determining alcohol is 3mol/L, aluminum nitrate and zinc nitrate Total concentration is 1.5 mol/L.Mixed solution is heated to 60 DEG C, is evaporated under a reduced pressure, solid crystal object is obtained, is crushed. After crushing solid oxygen, nitrogen mixed atmosphere under roast, oxygen volumetric concentration be 4%, 600 DEG C of maturing temperature, calcining time For 24 hours, gaseous mixture air speed 2000h^-1, catalyst precarsor ZnO/Al is made₂O₃.It is anti-that catalyst precarsor is placed in continuous flow fixed bed Answer in device, handle catalyst precarsor using methyl bromide gas, treatment conditions are 200 DEG C, 0.1MPa(absolute pressure), 500h^-1, the time 1h is made bromomethane preparing isobutene catalyst, is denoted as C-8.Catalyst weight group is obtained as ZnBr₂Contained with bromide weight calculation amount Amount be 30%, ZnO weight content in terms of oxide is 4%, and 450 DEG C or less total acid contents are 0.95mmol/g in catalyst, 250 DEG C- 350 DEG C of acid content accounts for the 76.81% 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, activation time 6h；Restoring the content of halogen in rear catalyst is reduction procatalyst The 62.99% 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, and reaction pressure is 2MPa(absolute pressure), air speed 350h^-1.Stable reaction After one hour, sampling analysis.Reaction result is shown in Table 1.

Embodiment 9

With making xylitol, aluminum nitrate, zinc nitrate aqueous solution, wherein xylose determining alcohol is 3mol/L, aluminum nitrate and zinc nitrate Total concentration is 1.5 mol/L.Mixed solution is heated to 60 DEG C, is evaporated under a reduced pressure, solid crystal object is obtained, is crushed. After crushing solid oxygen, nitrogen mixed atmosphere under roast, oxygen volumetric concentration be 4%, 600 DEG C of maturing temperature, calcining time For 24 hours, gaseous mixture air speed 2000h^-1, catalyst precarsor ZnO/Al is made₂O₃.It is anti-that catalyst precarsor is placed in continuous flow fixed bed It answers in device, handles catalyst precarsor using the mixed gas of bromomethane and nitrogen, bromomethane volumetric concentration is 80%, treatment conditions It is 250 DEG C, 0.2MPa(absolute pressure), 300h^-1, time 2h, be made bromomethane preparing isobutene catalyst, be denoted as C-1.Obtain catalyst Weight group becomes ZnBr₂It is 6% that weight content, which is 39%, ZnO weight content in terms of oxide, in terms of bromide, 450 in catalyst DEG C or less total acid content be 1.03mmol/g, 250 DEG C -350 DEG C of acid content accounts for the 75.44% 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, activation time 6h；Restoring the content of halogen in rear catalyst is reduction procatalyst The 65.53% 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, and reaction pressure is 2MPa(absolute pressure), air speed 350h^-1.Stable reaction After one hour, sampling analysis.Reaction result is shown in Table 1.

Embodiment 10

With making xylitol, aluminum nitrate, zinc nitrate aqueous solution, wherein xylose determining alcohol is 3mol/L, aluminum nitrate and zinc nitrate Total concentration is 1.5 mol/L.Mixed solution is heated to 60 DEG C, is evaporated under a reduced pressure, solid crystal object is obtained, is crushed. After crushing solid oxygen, nitrogen mixed atmosphere under roast, oxygen volumetric concentration be 4%, 600 DEG C of maturing temperature, calcining time For 24 hours, gaseous mixture air speed 2000h^-1, catalyst precarsor ZnO/Al is made₂O₃.It is anti-that catalyst precarsor is placed in continuous flow fixed bed It answers in device, handles catalyst precarsor using the mixed gas of bromomethane and nitrogen, bromomethane volumetric concentration is 80%, treatment conditions It is 250 DEG C, 0.2MPa(absolute pressure), 300h^-1, time 2h, be made bromomethane preparing isobutene catalyst, be denoted as C-1.Obtain catalyst Weight group becomes ZnBr₂It is 2% that weight content, which is 18%, ZnO weight content in terms of oxide, in terms of bromide, 450 in catalyst DEG C or less total acid content be 0.89mmol/g, 250 DEG C -350 DEG C of acid content accounts for the 79.27% 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, activation time 6h；Restoring the content of halogen in rear catalyst is reduction procatalyst The 60.89% 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, and reaction pressure is 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.Detailed process is as follows:

With making xylitol, aluminum nitrate, zinc nitrate aqueous solution, wherein xylose determining alcohol is 3mol/L, aluminum nitrate and zinc nitrate Total concentration is 1.5 mol/L.Mixed solution is heated to 60 DEG C, is evaporated under a reduced pressure, solid crystal object is obtained, is crushed. After crushing solid oxygen, nitrogen mixed atmosphere under roast, oxygen volumetric concentration be 4%, 600 DEG C of maturing temperature, calcining time For 24 hours, gaseous mixture air speed 2000h^-1, catalyst D-1 is made.Catalyst weight group is obtained as ZnO weight content in terms of oxide It is 20%, 450 DEG C or less total acid contents are 0.29mmol/g in catalyst, and 250 DEG C -350 DEG C of acid content accounts for 450 DEG C or less total acids The 54.7% of 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 70% in mixed gas, activation condition It is 450 DEG C, 0.2MPa(absolute pressure), 750h^-1, activation time 6h.

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, and reaction pressure is 2MPa(absolute pressure), air speed 350h^-1.Stable reaction After one hour, sampling analysis.Reaction result is shown in Table 1.

Comparative example 2

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

1 catalyst reaction performance of table

Claims (24)

1. a kind of preparation method of bromomethane preparing isobutene catalyst, it is characterised in that: comprise the following processes:

(1) aqueous solution containing polyalcohol, zinc salt and aluminium salt is prepared, the polyalcohol is xylitol or glucose；

(2) it will be evaporated under the mixed solution reduced pressure of step (1), obtain solid crystal, then grind；

(3) calcination steps (2) obtained solid under the oxygen and inert gas mixed atmosphere continuously flowed, then forms；

(4) bromination processing is carried out to sample obtained by step (3), zinc oxide weight content is 0.5%- in the catalyst after bromination 20%, zinc bromide weight content is 10%-50%.

2. according to the method described in claim 1, it is characterized by: zinc salt described in step (1) and aluminium salt are selected from nitrate, salt One of hydrochlorate, sulfate, acetate；The amount of polyol agent is in the aqueous solution containing polyalcohol, zinc salt and aluminium salt 0.5-4 times of the amount summation of zinc and aluminum material；Polyalcohol molar concentration is 1mol/L-5mol/L in solution.

3. according to the method described in claim 2, it is characterized by: zinc salt described in step (1) and aluminium salt are nitrate；It is described The amount of polyol agent is 1-3 times of the amount summation of zinc and aluminum material in aqueous solution containing polyalcohol, zinc salt and aluminium salt, in solution Polyalcohol molar concentration is 2mol/L-4mol/L.

4. according to the method described in claim 1, it is characterized by: mixed solution evaporated temperature described in step (2) be 40 DEG C- 80℃。

5. according to the method described in claim 1, it is characterized by: the gaseous mixture of oxygen and inert gas described in step (3) Oxygen volumetric concentration is 1%-10% in point；Maturing temperature is 400 DEG C -800 DEG C, calcining time 4h-72h；Gaseous mixture air speed is 500h^-1-5000h^-1。

6. according to the method described in claim 1, it is characterized by: the processing of bromination described in step (4) is referred to and is contained using gas phase Bromine compounds handles the sample of load zinc oxide.

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

8. according to the method described in claim 6, it is characterized by: using gas phase bromine-containing compound and inert gas gaseous mixture Body carries out bromination processing, and bromomethane volumetric concentration is not less than 20%.

9. according to the method described in claim 6, it is characterized by: specific bromination process is as follows: the sample of zinc oxide will be loaded It is placed in continuous fixed bed reactor, 150 DEG C -400 DEG C is warming up under inert atmosphere, be passed through gas phase bromine-containing compound gas Body, gas space velocity 50h^-1-1000 h^-1, system pressure 0.1MPa-0.5MPa, the processing time is 0.5h-8h.

10. according to the method described in claim 9, it is characterized by: inert atmosphere is argon atmosphere or helium atmosphere.

11. the catalyst of claims 1 to 10 either method preparation, it is characterised in that: catalyst is by zinc oxide, zinc bromide and three Al 2 O composition, zinc oxide weight content are 0.5%-20%；Zinc bromide weight content is 10%-50%；Aluminum oxide weight Content 40%-85%.

12. catalyst according to claim 11, it is characterised in that: zinc oxide weight content is 1%-15%；Zinc bromide weight Amount content is 10%-45%；Aluminum oxide weight content is 50%-85%.

13. catalyst according to claim 12, it is characterised in that: zinc oxide weight content is 1%-9%；Zinc bromide weight Content is 18%-39%；Aluminum oxide weight content is 55%-80%.

14. catalyst according to claim 11, it is characterised in that: 450 DEG C or less total acid contents are in catalyst 0.5mmol/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.

15. application of the catalyst described in claim 11 in preparing isobutene, it is characterised in that: including carrying out hydrogen to catalyst Reduction activation makes the content of halogen in catalyst restore the 20%-90% of total halogen content in procatalyst, then makes halogenated first Catalyst after alkane is activated with above-mentioned hydrogen reducing contacts, to prepare isobutene.

16. application according to claim 15, 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%.

17. application according to claim 15, 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；Then passing to air speed is 200h^-1-2000h^-1Hydrogen or hydrogen and indifferent gas The mixed gas of body keeps 2h-16h in 0.1MPa-0.5MPa, and hydrogen volume percentage composition is 10%-95% in mixed gas.

18. application according to claim 17, it is characterised in that: be 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 Closing hydrogen volume percentage composition in gas is 30%-90%.

19. application according to claim 15, it is characterised in that: the halide is a halide, dihalo first One of alkane, three halides are a variety of.

20. application according to claim 19, it is characterised in that: the halide is bromomethane, methylene bromide, tribromo One of methane is a variety of.

21. application according to claim 15, 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。

22. application according to claim 21, 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。

23. application according to claim 15, it is characterised in that: including under inert atmosphere by catalyzer temperature-elevating to 300 DEG C- 600℃；Then passing to air speed is 200h^-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.

24. application according to claim 15, 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.