CN106140223A

CN106140223A - A kind of bromomethane preparing isobutene catalyst and its preparation method and application

Info

Publication number: CN106140223A
Application number: CN201510135835.2A
Authority: CN
Inventors: 张信伟; 张舒冬; 李�杰; 孙晓丹; 倪向前; 尹泽群; 刘全杰; 张喜文
Original assignee: China Petroleum and Chemical Corp; Sinopec Fushun Research Institute of Petroleum and Petrochemicals
Current assignee: China Petroleum and Chemical Corp; Sinopec Fushun Research Institute of Petroleum and Petrochemicals
Priority date: 2015-03-27
Filing date: 2015-03-27
Publication date: 2016-11-23
Anticipated expiration: 2035-03-27
Also published as: CN106140223B

Abstract

The invention discloses a kind of bromomethane preparing isobutene catalyst and its preparation method and application.The preparation method of catalyst, including following process: zinc oxide/or auxiliary agent oxide zirconium are introduced to silica supports by (1), then high-temperature roasting processes；(2) residue zinc oxide is introduced to the silica supports of step (1) gained, and then low-temperature bake processes；(3) carrier after introducing zinc oxide being carried out bromination process, bromination to zinc oxide weight content is 0.5%-20%, and zinc bromide weight content is 10%-50%.This catalyst can provide the selectivity of isobutene..

Description

A kind of bromomethane preparing isobutene catalyst 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 a kind of bromomethane height selectivity preparing isobutene catalyst with improved silica as carrier and its preparation method and application.

Background technology

Isobutene. is a kind of important basic organic chemical industry raw material, and its derived product is numerous, and vertical industry chain is complicated, and consumption structure is diversified trend.Multiple high value-added product can be prepared for raw material, such as: multiple Organic Chemicals and the fine chemistry products such as butyl rubber, polyisobutylene, methyl tertiary butyl ether(MTBE), isoprene and lucite with isobutene..Owing to the market scale of isobutene. downstream product constantly expands, its imbalance between supply and demand will gradually highlight, and particularly under the background of petroleum resources exhaustion day by day, the yield of isobutene. has become the critical bottleneck of restriction downstream industry development.Therefore, the isobutene. syntheti c route of exploitation Non oil-based route, extremely the most urgent.

Methane is the main component of natural gas, the important research content during therefore methane trans-utilization just becomes gas chemical industry's technology.The most in recent years, under the overall background that shale gas develops, if it is possible to realize producing isobutene. from methane, a new approach will be provided for obtaining isobutene..But methane stable in properties, the most easily-activated, become the bottleneck of methane chemical utilization.The most many researcheres carry out methane activation, Study on Transformation, among these, the technology that methane converts after halogen functional groupization more one after another, are expected to become the important breakthrough mouth solving a methane transformation technology difficult problem.

Can the many chemical products of preparation from halide.Chinese patent CN 101041609A, CN 101284232A disclose one by methane at oxygen and HBr/H₂Being converted into bromomethane under the effect of O, then bromomethane reacts the method generating C3 ~ C13 mixing high-carbon hydrocarbon further, and the hydrocarbon selective of more than C5 is 70%.Wherein, HBr for methane bromination, then discharges in first reactor in second reactor, recovered after be used further in back reaction, it is achieved the recycling of HBr.(CN 102527427A, the Jieli such as Wang Ye He, Ting Xu, Zhihui Wang, et.al. Angew. Chem. Int. Ed. 2012,51,2438-2442) modified molecular sieve catalyst disclosing a kind of halide propylene and preparation method thereof.By using fluorochemical moditied processing molecular sieve, obtaining a kind of containing appropriate microporous structure and the catalyst of acidity, this catalyst can effectively be catalyzed halide and be converted into the reaction of propylene.Prepared catalyst one way bromomethane conversion ratio in the reaction that bromomethane is preparing propylene transformed is 35 ~ 99%, and the selectivity of propylene is 27 ~ 70%；In the reaction that chloromethanes is preparing propylene transformed, one way methyl chloride conversion rate is 30 ~ 99%, 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 generate bromo-hydrocarbons with bromine with the alkane reaction in natural gas, then on metal oxide catalyst, bromo-hydrocarbons is converted into dimethyl ether, methanol and metal bromide, obtain metal-oxide after metal bromide oxygen recovery and discharge simple substance bromine, completing the circulation of bromine.

It is mainly methanol, dimethyl ether, acetic acid, higher hydrocarbons, ethylene and propylene etc. currently, with respect to purpose product in the existing document that halide converts.In the technology with the low-carbon alkene of relatively high added value as target product, single selectivity of product is the highest, not yet finds the relevant report of bromomethane high selectivity isobutene..

Summary of the invention

For the deficiencies in the prior art, the invention provides a kind of bromomethane height with improved silica as carrier and selectively produce isobutene catalyst and its preparation method and application.

The preparation method of a kind of bromomethane preparing isobutene catalyst, including following process: zinc oxide/or auxiliary agent oxide zirconium are introduced to silica supports by (1), then high-temperature roasting processes；(2) residue zinc oxide is introduced to the silica supports of step (1) gained, and then low-temperature bake processes；(3) carrier after introducing zinc oxide being carried out bromination process, bromination to zinc oxide weight content is 0.5%-20%, and zinc bromide weight content is 10%-50%.

In the preparation method of above-mentioned bromomethane preparing isobutene catalyst, step (1) described silica supports can use existing silica product, it is also possible to prepares by method well known to those skilled in the art.Suitable particle shape can be made or be chosen to carrier according to the needs used, as made bar shaped, sheet shape, cylindricality, spherical etc..Shaping can be carried out by this area general knowledge.

Described in the preparation method step (1) of above-mentioned bromomethane preparing isobutene catalyst, zinc oxide and/or auxiliary agent zirconium oxide are introduced to the method that the method for silica supports is well known to those skilled in the art, as impregnation method can be used to introduce.Concrete grammar is as follows: use zinc salt, promoter metal zirconium salt solution dipping carrier, then dry, high-temperature roasting.Described drying condition is, under air atmosphere, and temperature 60 C-150 DEG C, preferably 80 DEG C-120 DEG C；Time is 1h-24h, preferably 4h-8h.Described roasting condition is, under air atmosphere, and temperature 600 DEG C-1000 DEG C, preferably 700 DEG C-900 DEG C；Time is 1h-24h, preferably 4h-8h.The zinc oxide amount introduced described in step (1) accounts for the 1%-20%, preferably 5%-15% of total zinc that catalyst introduces in mol.

Described in the preparation method step (2) of above-mentioned bromomethane preparing isobutene catalyst, zinc oxide is introduced to the method that the method for silica supports is well known to those skilled in the art, as impregnation method can be used to introduce.Concrete grammar is as follows: the material using zinc solution impregnation steps (1) to obtain, and obtains bromomethane preparing isobutene catalyst precarsor after drying, roasting.Described drying condition is, temperature 60 C-150 DEG C, preferably 80 DEG C-120 DEG C；Time is 1h-24h, preferably 4h-8h；Can be vacuum drying time dry, it is also possible to for being dried under the conditions of inert gas shielding, it is also possible to be dried in air atmosphere.Described roasting condition is, temperature 300 DEG C-600 DEG C, preferably 400 DEG C-500 DEG C；Time is 1h-24h, preferably 4h-8h；It can be roasting under the conditions of inert gas shielding during roasting, it is also possible to roasting in air atmosphere.

In said method step (1) and step (2), zinc salt can be inorganic salt, it is also possible to for one or more in organic salt, preferably nitrate, hydrochlorate, acetate, citrate.

Bromination described in the preparation method step (3) of above-mentioned bromomethane preparing isobutene catalyst processes, and refers to use gas phase bromine-containing compound to process the sample of load zinc oxide.Bromine-containing compound refers to one or more in bromomethane, methylene bromide, bromoform, preferably bromomethane.Gas phase bromine-containing compound can also be used to carry out bromination process with the mixed gas of noble gas, and when using mixed gas bromination to process, bromomethane volumetric concentration is not less than 20%, preferably not less than 30%.Concrete bromination process is as follows: be placed in continuous fixed bed reactor by the sample of load zinc oxide, 150 DEG C-400 DEG C it are warming up under inert atmosphere, preferably 180 DEG C-350 DEG C, more preferably 200 DEG C-300 DEG C, being passed through gas phase bromine-containing compound gas, gas space velocity is 50h^-1-1000 h^-1, preferably 100h^-1-500h^-1；Can carry out at normal pressure during process, it is also possible to carry out under a certain pressure, system pressure is 0.1MPa-0.5MPa(absolute pressure), preferably 0.1MPa-0.3MPa(absolute pressure), the process time is 0.5h-8h, preferably 1h-4h.

Noble gas involved in the preparation method of above-mentioned bromomethane preparing isobutene catalyst is the gas that nitrogen, argon, helium etc. do not occur chemical reaction under the conditions of involved in the present invention, preferably nitrogen.

A kind of bromomethane preparing isobutene catalyst, containing zinc oxide, zinc bromide and silica supports, zinc oxide weight content is 0.5%-20%, preferably 1%-15%, further preferred 1%-9%；Zinc bromide weight content is 10%-50%, preferably 15%-45%, further preferred 18%-39%；Silica supports weight content 40%-90%, preferably 50%-85%, further preferred 55%-80%.

In above-mentioned bromomethane preparing isobutene catalyst, it is also possible to containing appropriate auxiliary agent zirconium, zirconium counts weight content in the catalyst as 0.1%-10% with element, preferably 0.5%-5%, more preferably 0.5%-3%.

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

The application in preparing isobutene of the above-mentioned catalyst with improved silica as carrier, hydrogen reducing activation is carried out including to catalyst, making the content of halogen in catalyst is the 20%-90% of total halogen content in reduction procatalyst, then the catalyst after making halide activate with above-mentioned hydrogen reducing contacts, to prepare isobutene..

In above-mentioned application, the condition of described hydrogen reducing activation makes the content of halogen in catalyst be preferably the 30%-80%, further preferred 40%-80% of total halogen content in reduction procatalyst.

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

The application of above-mentioned catalyst, also includes that halide contacts acquisition isobutene. with catalyst.The condition of described 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。

In above-mentioned application, described halide can be one or more in one or more in a halide, methylene halide, three halides, preferably bromomethane, methylene bromide, bromoform, more preferably bromomethane.

A kind of detailed description of the invention in above-mentioned application, including under inert atmosphere by catalyzer temperature-elevating to 300 DEG C-600 DEG C, preferably 350 DEG C-550 DEG C；Then passing to air speed is 200h^-1-2000h^-1, preferably 500h^-1-1000h^-1The mixed gas of hydrogen and noble gas, in 0.1MPa-0.5MPa(absolute pressure), preferably 0.1MPa-0.3MPa(absolute pressure) process 2h-16h, preferably 4h-8h after, be down to reaction temperature and be passed through halide and react.In described gaseous mixture, hydrogen volume percentage composition is 10%-95%, preferably 30%-90%, more preferably 50%-90%.

In above-mentioned application, raw material can also be the mixed gas of halide and noble gas, and in mixed gas, the volumetric concentration of halide is 10%-90%, preferably 30%-80%.

Noble gas involved in above-mentioned application is the gas that nitrogen, argon, helium etc. do not occur chemical reaction under the conditions of involved in the present invention, preferably nitrogen.

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

Compared with prior art, bromomethane height can be optionally converted into isobutene. by the method that the present invention relates to.In the present invention, a part of zinc oxide of preferential dipping, form strong interaction species through high-temperature roasting with silicon dioxide, can preferably realize Electron Transfer.Carry out bromomethane by the inventive method and convert preparing isobutene reaction, bromomethane conversion ratio more than 80%, selective isobutene more than 70%.The present invention relates to bromomethane conversion preparing isobutene method for preparing catalyst simple, it is easy to industrialization.Bromomethane of the present invention converts preparing isobutene method and has reaction condition gentleness, selectivity of product advantages of higher, easily realizes industrialization, and application prospect is boundless.

Detailed description of the invention

Further illustrate technology contents and the effect of the present invention below in conjunction with embodiment, but be not so limited the present invention.

In following example and comparative example, acidimetric estimation uses NH₃-TPD method, the INSTRUMENT MODEL of employing is MICROMERITICS company of U.S. AutoChem 2920 chemical adsorption instruments, concrete to measure process as follows: sample being cooled to 150 DEG C by helium purge after 1 hour at 450 DEG C, introduces the mixed gas of ammonia and helium, ammonia volume content 10%, Pulse adsorption reaches balance for five times；Helium purge 2 hours, then carries out ammonia with the programming rate temperature programming of 10 DEG C/min and is desorbed to 450 DEG C；Ammonia after desorption uses the detection of TCD detector, quantitative Analysis catalyst surface acid amount.

Embodiment 1

Weighing appropriate zinc nitrate to be dissolved in deionized water, (pore volume is 1.06ml/g, and specific surface area is 387m to use equi-volume impregnating to be carried on silica supports²/ g, spherical, equivalent diameter 0.5mm), 100 DEG C of dry 6h, 800 DEG C of roasting 6h, the system silica supports containing zinc oxide, wherein zinc oxide introduction volume accounts for catalyst in mol and always introduces the 10% of zinc.Weigh appropriate zinc nitrate again to be dissolved in deionized water, use equi-volume impregnating to be carried on the silica supports containing zinc oxide, 100 DEG C of dry 6h, 450 DEG C of roasting 6h, prepare catalyst precarsor ZnO/SiO₂.Being placed in continuous fixed bed reactor by catalyst precarsor, use bromomethane to process catalyst precarsor with the mixed gas of nitrogen, bromomethane volumetric concentration is 80%, and treatment conditions are 250 DEG C, 0.2MPa(absolute pressure), 300h^-1, time 2h, prepare bromomethane preparing isobutene catalyst, be designated as C-1.Obtain catalyst weight and consist of ZnBr₂In terms of bromide, weight content is 30%, and ZnO weight content in terms of oxide is 4%, and in catalyst, less than 450 DEG C total acid contents are 0.88mmol/g, and the acid content of 250 DEG C-350 DEG C accounts for the 76.51% of less than 450 DEG C total acid contents.

Bromomethane converts preparing isobutene reaction to be carried out in flowing micro fixed-bed reactor continuously.Catalyst loading amount 5g, catalyst uses the gaseous mixture activation of hydrogen and nitrogen before use, and in mixed gas, hydrogen volume content is 70%, and activation condition is 450 DEG C, 0.2MPa(absolute pressure), 750h^-1, soak time 6h；Reduction rear catalyst in content of halogen be reduction procatalyst in total halogen content 65.30%.

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

Embodiment 2

Weighing appropriate zinc nitrate to be dissolved in deionized water, (pore volume is 1.06ml/g, and specific surface area is 387m to use equi-volume impregnating to be carried on silica supports²/ g, spherical, equivalent diameter 0.5mm), 100 DEG C of dry 6h, 800 DEG C of roasting 6h, the system silica supports containing zinc oxide, wherein zinc oxide introduction volume accounts for catalyst in mol and always introduces the 5% of zinc.Weigh appropriate zinc nitrate again to be dissolved in deionized water, use equi-volume impregnating to be carried on the silica supports containing zinc oxide, 100 DEG C of dry 6h, 450 DEG C of roasting 6h, prepare catalyst precarsor ZnO/SiO₂.Being placed in continuous fixed bed reactor by catalyst precarsor, use bromomethane to process catalyst precarsor with the mixed gas of nitrogen, bromomethane volumetric concentration is 80%, and treatment conditions are 250 DEG C, 0.2MPa(absolute pressure), 300h^-1, time 2h, prepare bromomethane preparing isobutene catalyst, be designated as C-2.Obtain catalyst weight and consist of ZnBr₂In terms of bromide, weight content is 30%, and ZnO weight content in terms of oxide is 4%, and in catalyst, less than 450 DEG C total acid contents are 0.91mmol/g, and the acid content of 250 DEG C-350 DEG C accounts for the 74.53% of less than 450 DEG C total acid contents.

Bromomethane converts preparing isobutene reaction to be carried out in flowing micro fixed-bed reactor continuously.Catalyst loading amount 5g, catalyst uses the gaseous mixture activation of hydrogen and nitrogen before use, and in mixed gas, hydrogen volume content is 70%, and activation condition is 450 DEG C, 0.2MPa(absolute pressure), 750h^-1, soak time 6h；Reduction rear catalyst in content of halogen be reduction procatalyst in total halogen content 57.31%.

Embodiment 3

Weighing appropriate zinc nitrate to be dissolved in deionized water, (pore volume is 1.06ml/g, and specific surface area is 387m to use equi-volume impregnating to be carried on silica supports²/ g, spherical, equivalent diameter 0.5mm), 100 DEG C of dry 6h, 800 DEG C of roasting 6h, the system silica supports containing zinc oxide, wherein zinc oxide introduction volume accounts for catalyst in mol and always introduces the 15% of zinc.Weigh appropriate zinc nitrate again to be dissolved in deionized water, use equi-volume impregnating to be carried on the silica supports containing zinc oxide, 100 DEG C of dry 6h, 450 DEG C of roasting 6h, prepare catalyst precarsor ZnO/SiO₂.Being placed in continuous fixed bed reactor by catalyst precarsor, use bromomethane to process catalyst precarsor with the mixed gas of nitrogen, bromomethane volumetric concentration is 80%, and treatment conditions are 250 DEG C, 0.2MPa(absolute pressure), 300h^-1, time 2h, prepare bromomethane preparing isobutene catalyst, be designated as C-3.Obtain catalyst weight and consist of ZnBr₂In terms of bromide, weight content is 30%, and ZnO weight content in terms of oxide is 4%, and in catalyst, less than 450 DEG C total acid contents are 0.83mmol/g, and the acid content of 250 DEG C-350 DEG C accounts for the 79.92% of less than 450 DEG C total acid contents.

Bromomethane converts preparing isobutene reaction to be carried out in flowing micro fixed-bed reactor continuously.Catalyst loading amount 5g, catalyst uses the gaseous mixture activation of hydrogen and nitrogen before use, and in mixed gas, hydrogen volume content is 70%, and activation condition is 450 DEG C, 0.2MPa(absolute pressure), 750h^-1, soak time 6h；Reduction rear catalyst in content of halogen be reduction procatalyst in total halogen content 62.17%.

Embodiment 4

Weighing appropriate zinc nitrate to be dissolved in deionized water, (pore volume is 1.06ml/g, and specific surface area is 387m to use equi-volume impregnating to be carried on silica supports²/ g, spherical, equivalent diameter 0.5mm), 100 DEG C of dry 6h, 800 DEG C of roasting 6h, the system silica supports containing zinc oxide, wherein zinc oxide introduction volume accounts for catalyst in mol and always introduces the 10% of zinc.Weigh appropriate zinc nitrate again to be dissolved in deionized water, use equi-volume impregnating to be carried on the silica supports containing zinc oxide, 100 DEG C of dry 6h, 450 DEG C of roasting 6h, prepare catalyst precarsor ZnO/SiO₂.Being placed in continuous fixed bed reactor by catalyst precarsor, use bromomethane to process catalyst precarsor with the mixed gas of nitrogen, bromomethane volumetric concentration is 80%, and treatment conditions are 250 DEG C, 0.2MPa(absolute pressure), 300h^-1, time 2h, prepare bromomethane preparing isobutene catalyst, be designated as C-4.Obtain catalyst weight and consist of ZnBr₂In terms of bromide, weight content is 18%, and ZnO weight content in terms of oxide is 2%, and in catalyst, less than 450 DEG C total acid contents are 0.73mmol/g, and the acid content of 250 DEG C-350 DEG C accounts for the 75.42% of less than 450 DEG C total acid contents.

Bromomethane converts preparing isobutene reaction to be carried out in flowing micro fixed-bed reactor continuously.Catalyst loading amount 5g, catalyst uses the gaseous mixture activation of hydrogen and nitrogen before use, and in mixed gas, hydrogen volume content is 70%, and activation condition is 450 DEG C, 0.2MPa(absolute pressure), 750h^-1, soak time 6h；Reduction rear catalyst in content of halogen be reduction procatalyst in total halogen content 59.27%.

Embodiment 5

Weighing appropriate zinc nitrate to be dissolved in deionized water, (pore volume is 1.06ml/g, and specific surface area is 387m to use equi-volume impregnating to be carried on silica supports²/ g, spherical, equivalent diameter 0.5mm), 100 DEG C of dry 6h, 800 DEG C of roasting 6h, the system silica supports containing zinc oxide, wherein zinc oxide introduction volume accounts for catalyst in mol and always introduces the 10% of zinc.Weigh appropriate zinc nitrate again to be dissolved in deionized water, use equi-volume impregnating to be carried on the silica supports containing zinc oxide, 100 DEG C of dry 6h, 450 DEG C of roasting 6h, prepare catalyst precarsor ZnO/SiO₂.Being placed in continuous fixed bed reactor by catalyst precarsor, use bromomethane to process catalyst precarsor with the mixed gas of nitrogen, bromomethane volumetric concentration is 80%, and treatment conditions are 250 DEG C, 0.2MPa(absolute pressure), 300h^-1, time 2h, prepare bromomethane preparing isobutene catalyst, be designated as C-5.Obtain catalyst weight and consist of ZnBr₂In terms of bromide, weight content is 39%, and ZnO weight content in terms of oxide is 6%, and in catalyst, less than 450 DEG C total acid contents are 0.95mmol/g, and the acid content of 250 DEG C-350 DEG C accounts for the 76.77% of less than 450 DEG C total acid contents.

Bromomethane converts preparing isobutene reaction to be carried out in flowing micro fixed-bed reactor continuously.Catalyst loading amount 5g, catalyst uses the gaseous mixture activation of hydrogen and nitrogen before use, and in mixed gas, hydrogen volume content is 50%, and activation condition is 550 DEG C, 0.1MPa(absolute pressure), 1000h^-1, soak time 4h；Reduction rear catalyst in content of halogen be reduction procatalyst in total halogen content 63.48%.

After activation terminates, being down to reaction temperature, be passed through unstripped gas, unstripped gas is bromomethane and nitrogen mixed gas, and wherein bromomethane volume content is 30%%, and reaction temperature is 230 DEG C, and reaction pressure is 2MPa(absolute pressure), air speed is 200h^-1.After stable reaction one hour, sampling analysis.Reaction result is shown in Table 1.

Embodiment 6

Weighing appropriate zinc nitrate to be dissolved in deionized water, (pore volume is 1.06ml/g, and specific surface area is 387m to use equi-volume impregnating to be carried on silica supports²/ g, spherical, equivalent diameter 0.5mm), 80 DEG C of dry 8h, 900 DEG C of roasting 4h, the system silica supports containing zinc oxide, wherein zinc oxide introduction volume accounts for catalyst in mol and always introduces the 10% of zinc.Weigh appropriate zinc nitrate again to be dissolved in deionized water, use equi-volume impregnating to be carried on the silica supports containing zinc oxide, 80 DEG C of dry 8h, 500 DEG C of roasting 4h, prepare catalyst precarsor ZnO/SiO₂.Being placed in continuous fixed bed reactor by catalyst precarsor, use bromomethane to process catalyst precarsor with the mixed gas of nitrogen, bromomethane volumetric concentration is 80%, and treatment conditions are 250 DEG C, 0.2MPa(absolute pressure), 300h^-1, time 2h, prepare bromomethane preparing isobutene catalyst, be designated as C-6.Obtain catalyst weight and consist of ZnBr₂In terms of bromide, weight content is 30%, and ZnO weight content in terms of oxide is 4%, and in catalyst, less than 450 DEG C total acid contents are 0.86mmol/g, and the acid content of 250 DEG C-350 DEG C accounts for the 73.28% of less than 450 DEG C total acid contents.

Bromomethane converts preparing isobutene reaction to be carried out in flowing micro fixed-bed reactor continuously.Catalyst loading amount 5g, catalyst uses the gaseous mixture activation of hydrogen and nitrogen before use, and in mixed gas, hydrogen volume content is 90%, and activation condition is 350 DEG C, 0.3MPa(absolute pressure), 500h^-1, soak time 4h；Reduction rear catalyst in content of halogen be reduction procatalyst in total halogen content 55.69%.

After activation terminates, being down to reaction temperature, be passed through unstripped gas, unstripped gas is bromomethane and nitrogen mixed gas, and wherein bromomethane volume content is 80%, and reaction temperature is 210 DEG C, and reaction pressure is 3MPa(absolute pressure), air speed is 500h^-1.After stable reaction one hour, sampling analysis.Reaction result is shown in Table 1.

Embodiment 7

Weighing appropriate zinc nitrate to be dissolved in deionized water, (pore volume is 1.06ml/g, and specific surface area is 387m to use equi-volume impregnating to be carried on silica supports²/ g, spherical, equivalent diameter 0.5mm), 120 DEG C of dry 4h, 700 DEG C of roasting 8h, the system silica supports containing zinc oxide, wherein zinc oxide introduction volume accounts for catalyst in mol and always introduces the 10% of zinc.Weigh appropriate zinc nitrate again to be dissolved in deionized water, use equi-volume impregnating to be carried on the silica supports containing zinc oxide, 120 DEG C of dry 4h, 400 DEG C of roasting 8h, prepare catalyst precarsor ZnO/SiO₂.Being placed in continuous fixed bed reactor by catalyst precarsor, use bromomethane to process catalyst precarsor with the mixed gas of nitrogen, bromomethane volumetric concentration is 80%, and treatment conditions are 250 DEG C, 0.2MPa(absolute pressure), 300h^-1, time 2h, prepare bromomethane preparing isobutene catalyst, be designated as C-7.Obtain catalyst weight and consist of ZnBr₂In terms of bromide, weight content is 30%, and ZnO weight content in terms of oxide is 4%, and in catalyst, less than 450 DEG C total acid contents are 0.85mmol/g, and the acid content of 250 DEG C-350 DEG C accounts for the 72.99% of less than 450 DEG C total acid contents.

Bromomethane converts preparing isobutene reaction to be carried out in flowing micro fixed-bed reactor continuously.Catalyst loading amount 5g, catalyst uses the gaseous mixture activation of hydrogen and nitrogen before use, and in mixed gas, hydrogen volume content is 70%, and activation condition is 450 DEG C, 0.2MPa(absolute pressure), 750h^-1, soak time 6h；Reduction rear catalyst in content of halogen be reduction procatalyst in total halogen content 54.12%.

After activation terminates, being down to reaction temperature, be passed through unstripped gas, unstripped gas is bromomethane and nitrogen mixed gas, and wherein bromomethane volume content is 70%, and reaction temperature is 230 DEG C, and reaction pressure is 0.1MPa(absolute pressure), air speed is 350h^-1.After stable reaction one hour, sampling analysis.Reaction result is shown in Table 1.

Embodiment 8

Weighing appropriate zinc nitrate to be dissolved in deionized water, (pore volume is 1.06ml/g, and specific surface area is 387m to use equi-volume impregnating to be carried on silica supports²/ g, spherical, equivalent diameter 0.5mm), 100 DEG C of dry 6h, 800 DEG C of roasting 6h, the system silica supports containing zinc oxide, wherein zinc oxide introduction volume accounts for catalyst in mol and always introduces the 10% of zinc.Weigh appropriate zinc nitrate again to be dissolved in deionized water, use equi-volume impregnating to be carried on the silica supports containing zinc oxide, 100 DEG C of dry 6h, 450 DEG C of roasting 6h, prepare catalyst precarsor ZnO/SiO₂.Being placed in continuous fixed bed reactor by catalyst precarsor, use bromomethane to process catalyst precarsor with the mixed gas of nitrogen, bromomethane volumetric concentration is 30%, and treatment conditions are 300 DEG C, 0.3MPa(absolute pressure), 100h^-1, time 4h, prepare bromomethane preparing isobutene catalyst, be designated as C-8.Obtain catalyst weight and consist of ZnBr₂In terms of bromide, weight content is 30%, and ZnO weight content in terms of oxide is 4%, and in catalyst, less than 450 DEG C total acid contents are 0.79mmol/g, and the acid content of 250 DEG C-350 DEG C accounts for the 75.46% of less than 450 DEG C total acid contents.

Bromomethane converts preparing isobutene reaction to be carried out in flowing micro fixed-bed reactor continuously.Catalyst loading amount 5g, catalyst uses the gaseous mixture activation of hydrogen and nitrogen before use, and in mixed gas, hydrogen volume content is 70%, and activation condition is 450 DEG C, 0.2MPa(absolute pressure), 750h^-1, soak time 6h；Reduction rear catalyst in content of halogen be reduction procatalyst in total halogen content 60.54%.

Embodiment 9

Weighing appropriate zinc nitrate to be dissolved in deionized water, (pore volume is 1.06ml/g, and specific surface area is 387m to use equi-volume impregnating to be carried on silica supports²/ g, spherical, equivalent diameter 0.5mm), 100 DEG C of dry 6h, 800 DEG C of roasting 6h, the system silica supports containing zinc oxide, wherein zinc oxide introduction volume accounts for catalyst in mol and always introduces the 10% of zinc.Weigh appropriate zinc nitrate again to be dissolved in deionized water, use equi-volume impregnating to be carried on the silica supports containing zinc oxide, 100 DEG C of dry 6h, 450 DEG C of roasting 6h, prepare catalyst precarsor ZnO/SiO₂.Being placed in continuous fixed bed reactor by catalyst precarsor, use bromomethane to process catalyst precarsor, treatment conditions are 200 DEG C, 0.1MPa(absolute pressure), 500h^-1, time 1h, prepare bromomethane preparing isobutene catalyst, be designated as C-9.Obtain catalyst weight and consist of ZnBr₂In terms of bromide, weight content is 30%, and ZnO weight content in terms of oxide is 4%, and in catalyst, less than 450 DEG C total acid contents are 0.91mmol/g, and the acid content of 250 DEG C-350 DEG C accounts for the 75.7% of less than 450 DEG C total acid contents.

Bromomethane converts preparing isobutene reaction to be carried out in flowing micro fixed-bed reactor continuously.Catalyst loading amount 5g, catalyst uses the gaseous mixture activation of hydrogen and nitrogen before use, and in mixed gas, hydrogen volume content is 70%, and activation condition is 450 DEG C, 0.2MPa(absolute pressure), 750h^-1, soak time 6h；Reduction rear catalyst in content of halogen be reduction procatalyst in total halogen content 59.81%.

Embodiment 10

Weigh appropriate zinc nitrate, zirconium nitrate is dissolved in deionized water, and (pore volume is 1.06ml/g, and specific surface area is 387m to use equi-volume impregnating to be carried on silica supports²/ g, spherical, equivalent diameter 0.5mm), 100 DEG C of dry 6h, 800 DEG C of roasting 6h, the system silica supports containing zinc oxide, wherein zinc oxide introduction volume accounts for catalyst in mol and always introduces the 10% of zinc.Weigh appropriate zinc nitrate again to be dissolved in deionized water, use equi-volume impregnating to be carried on the silica supports containing zinc oxide, 100 DEG C of dry 6h, 450 DEG C of roasting 6h, prepare catalyst precarsor ZnO/SiO₂.Being placed in continuous fixed bed reactor by catalyst precarsor, use bromomethane to process catalyst precarsor with the mixed gas of nitrogen, bromomethane volumetric concentration is 80%, and treatment conditions are 250 DEG C, 0.2MPa(absolute pressure), 300h^-1, time 2h, prepare bromomethane preparing isobutene catalyst, be designated as C-10.Obtain catalyst weight and consist of ZnBr₂In terms of bromide, weight content is 30%, and ZnO weight content in terms of oxide is 4%, and zirconium weight content in terms of element is 2%, and in catalyst, less than 450 DEG C total acid contents are 0.9mmol/g, and the acid content of 250 DEG C-350 DEG C accounts for the 76.17% of less than 450 DEG C total acid contents.

Bromomethane converts preparing isobutene reaction to be carried out in flowing micro fixed-bed reactor continuously.Catalyst loading amount 5g, catalyst uses the gaseous mixture activation of hydrogen and nitrogen before use, and in mixed gas, hydrogen volume content is 70%, and activation condition is 450 DEG C, 0.2MPa(absolute pressure), 750h^-1, soak time 6h；Reduction rear catalyst in content of halogen be reduction procatalyst in total halogen content 58.90%.

Comparative example 1

Prepare catalyst by embodiment 1, preparation process does not use bromination process.Detailed process is as follows:

Weighing appropriate zinc nitrate to be dissolved in deionized water, (pore volume is 1.06ml/g, and specific surface area is 387m to use equi-volume impregnating to be carried on silica supports²/ g, spherical, equivalent diameter 0.5mm), 100 DEG C of dry 6h, 800 DEG C of roasting 6h, the system silica supports containing zinc oxide, wherein zinc oxide introduction volume accounts for catalyst in mol and always introduces the 10% of zinc.Weigh appropriate zinc nitrate again to be dissolved in deionized water, use equi-volume impregnating to be carried on the silica supports containing zinc oxide, 100 DEG C of dry 6h, 450 DEG C of roasting 6h, prepare catalyst D-1.Obtain catalyst weight consisting of ZnO weight content in terms of oxide is 20%, and in catalyst, less than 450 DEG C total acid contents are 0.58mmol/g, and the acid content of 250 DEG C-350 DEG C accounts for the 77.5% of less than 450 DEG C total acid contents.

Bromomethane converts preparing isobutene reaction to be carried out in flowing micro fixed-bed reactor continuously.Catalyst loading amount 5g, catalyst uses the gaseous mixture activation of hydrogen and nitrogen before use, and in mixed gas, hydrogen volume content is 70%, and activation condition is 450 DEG C, 0.2MPa(absolute pressure), 750h^-1, soak time 6h.

Comparative example 2

Take catalyst C-1 the most activated, directly carry out bromomethane conversion reaction.Unstripped gas is bromomethane and nitrogen mixed gas, and wherein bromomethane volume content is 70%, and reaction temperature is 230 DEG C, and reaction pressure is 2MPa(absolute pressure), air speed is 350h^-1.After stable reaction one hour, sampling analysis.Reaction result is shown in Table 1.

Table 1 catalyst reaction performance

Claims

1. the preparation method of a bromomethane preparing isobutene catalyst, it is characterised in that: including following process: zinc oxide and/or auxiliary agent oxide zirconium are introduced to silica supports by (1), then high-temperature roasting processes；(2) residue zinc oxide is introduced to the silica supports of step (1) gained, and then low-temperature bake processes；(3) carrier after introducing zinc oxide being carried out bromination process, bromination to zinc oxide weight content is 0.5%-20%, and zinc bromide weight content is 10%-50%.

Method the most according to claim 1, it is characterised in that: zinc oxide and/or auxiliary agent zirconium oxide described in step (1) are introduced to silica supports and use impregnation method.

Method the most according to claim 2, it is characterised in that: use zinc salt, promoter metal zirconium salt solution dipping carrier, then dry, high-temperature roasting.

Method the most according to claim 3, it is characterized in that: baking temperature 60 DEG C-150 DEG C, the time is 1h-24h, sintering temperature 600 DEG C-1000 DEG C, time is 1h-24h, and the zinc oxide amount introduced described in step (1) accounts for the 1%-20% of total zinc that catalyst introduces in mol.

Method the most according to claim 4, it is characterised in that: baking temperature 80 DEG C-120 DEG C；Time is 4h-8h, temperature 700 DEG C-900 DEG C, and the time is 4h-8h, and the zinc oxide amount introduced described in step (1) accounts for the 5%-15% of total zinc that catalyst introduces in mol.

Method the most according to claim 1, it is characterised in that: in step (2), zinc oxide is introduced to silica supports and uses impregnation method introducing.

Method the most according to claim 6, it is characterised in that: the material using zinc solution impregnation steps (1) to obtain, obtain bromomethane preparing isobutene catalyst precarsor after drying, roasting.

Method the most according to claim 7, it is characterised in that: baking temperature 60 DEG C-150 DEG C, the time is 1h-24h；Sintering temperature 300 DEG C-600 DEG C, the time is 1h-24h.

Method the most according to claim 8, it is characterised in that: baking temperature 80 DEG C-120 DEG C；Time is 4h-8h；Sintering temperature 400 DEG C-500 DEG C；Time is 4h-8h.

Method the most according to claim 6, it is characterised in that: zinc salt is one or more in nitrate, hydrochlorate, acetate, citrate.

11. methods according to claim 1, it is characterised in that: bromination described in step (3) processes and refers to use gas phase bromine-containing compound to process the sample of load zinc oxide.

12. methods according to claim 11, it is characterised in that: bromine-containing compound refers to one or more in bromomethane, methylene bromide, bromoform.

13. methods according to claim 12, it is characterised in that: using gas phase bromine-containing compound to carry out bromination process with the mixed gas of noble gas, bromomethane volumetric concentration is not less than 20%.

14. methods according to claim 11, it is characterised in that: being placed in continuous fixed bed reactor by the sample of load zinc oxide, be warming up to 150 DEG C-400 DEG C, be passed through gas phase bromine-containing compound gas under inert atmosphere, gas space velocity is 50h^-1-1000 h^-1；System pressure is 0.1MPa-0.5MPa, and the process time is 0.5h-8h.

15. methods according to claim 14, it is characterised in that: being warming up to 180 DEG C-350 DEG C under inert atmosphere, gas space velocity is 100h^-1-500h^-1；System pressure is 0.1MPa-0.3MPa, and the process time is 1h-4h.

Catalyst prepared by 16. claim 1 to 15 either method, it is characterised in that: containing zinc oxide, zinc bromide and silica supports, zinc oxide weight content is 0.5%-20%；Zinc bromide weight content is 10%-50%；Silica supports weight content 40%-90%.

17. catalyst according to claim 16, it is characterised in that: zinc oxide weight content is 1%-15%；Zinc bromide weight content is 15%-45%；Silica supports weight content 50%-85%.

18. catalyst according to claim 17, it is characterised in that: zinc oxide weight content is 1%-9%；Zinc bromide weight content is 18%-39%；Silica supports weight content 55%-80%.

19. catalyst according to claim 16, it is characterised in that: containing auxiliary agent zirconium in catalyst, zirconium counts weight content in the catalyst as 0.1%-10% with element.

20. catalyst according to claim 19, it is characterised in that: in catalyst, less than 450 DEG C total acid contents are 0.5mmol/g-1.3mmol/g, and the acid content of 250 DEG C-350 DEG C accounts for the 20%-90% of less than 450 DEG C total acid contents.

The application of catalyst described in 21. claim 16, it is characterized in that: include catalyst is carried out hydrogen reducing activation, making the content of halogen in catalyst is the 20%-90% of total halogen content in reduction procatalyst, then the catalyst after making halide activate with above-mentioned hydrogen reducing contacts, to prepare isobutene..

22. application according to claim 21, it is characterised in that: the condition of described hydrogen reducing activation makes the content of halogen in catalyst be preferably the 30%-80% of total halogen content in reduction procatalyst.

23. application according to claim 21, it is characterised in that: the mode of described hydrogen reducing activation includes under an inert atmosphere by catalyzer temperature-elevating to 300 DEG C-600 DEG C；Then passing to air speed is 200h^-1-2000h^-1Hydrogen or the mixed gas of hydrogen and noble gas, keep 2h-16h at 0.1MPa-0.5MPa, in mixed gas, hydrogen volume percentage composition is 10%-95%.

24. application according to claim 23, 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 the mixed gas of hydrogen and noble gas, keep 4h-8h at 0.1MPa-0.3MPa, in described mixed gas, hydrogen volume percentage composition is 30%-90%.

25. application according to claim 21, it is characterised in that: the condition of described 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。

26. application according to claim 25, it is characterised in that: the condition of described contact includes that reaction temperature is 180 DEG C-300 DEG C；Reaction pressure is 0.1MPa-3MPa；Air speed is 200h^-1-500h^-1。

27. application according to claim 21, it is characterised in that: described halide can be one or more in a halide, methylene halide, three halides.

28. application according to claim 21, it is characterised in that: include catalyzer temperature-elevating to 300 DEG C-600 DEG C under inert atmosphere；Then passing to air speed is 200h^-1-2000h^-The mixed gas of hydrogen and noble gas, after 0.1MPa-0.5MPa processes 2h-16h, be down to reaction temperature and be passed through halide and react, in described gaseous mixture, hydrogen volume percentage composition is 10%-95%.

29. application according to claim 28, it is characterised in that: include catalyzer temperature-elevating to 350 DEG C-550 DEG C under inert atmosphere；Then passing to air speed is 500h^-1-1000h^-1The mixed gas of hydrogen and noble gas, after 0.1MPa-0.3MPa processes 4h-8h, in described gaseous mixture, hydrogen volume percentage composition is 30%-90%.

30. application according to claim 21, it is characterised in that: the reaction of halide preparing isobutene is carried out in fixed bed, fluid bed, fixed fluidized bed, moving bed, slurry bed system or fluidized bed reactor.