CN106140264A

CN106140264A - A kind of catalyst with lanthanum modified zsm-5 zeolite as carrier and its preparation method and application

Info

Publication number: CN106140264A
Application number: CN201510135881.2A
Authority: CN
Inventors: 孙晓丹; 张舒冬; 张信伟; 李�杰; 倪向前; 张喜文; 刘继华
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: CN106140264B

Abstract

The present invention discloses a kind of catalyst with lanthanum modified zsm-5 zeolite as carrier and its preparation method and application.The preparation method of described catalyst, including following process: (1) processes Hydrogen ZSM-5 molecular sieve by lanthanum salt solution impregnation, obtains the Hydrogen ZSM-5 molecular sieve carrier that lanthanum is modified；(2) zinc oxide is introduced to the Hydrogen ZSM-5 molecular sieve carrier that lanthanum is modified；(3) the lanthanum modified zsm-5 zeolite carrier after introducing zinc oxide is carried out bromination process.Catalyst prepared by the method can be used for the reaction of bromomethane preparing isobutene, has bromomethane conversion ratio height, selective isobutene advantages of higher.

Description

A kind of catalyst with lanthanum modified zsm-5 zeolite as carrier and its preparation method and application

Technical field

The present invention relates to a kind of catalyst with lanthanum modified zsm-5 zeolite 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.

Many chemical products can be prepared 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 present invention provides a kind of catalyst with lanthanum modified zsm-5 zeolite as carrier and its preparation method and application.

The preparation method of a kind of catalyst with lanthanum modified zsm-5 zeolite as carrier, including following process: (1) processes Hydrogen ZSM-5 molecular sieve by lanthanum salt solution impregnation, obtains the Hydrogen ZSM-5 molecular sieve carrier that lanthanum is modified；(2) zinc oxide is introduced to the Hydrogen ZSM-5 molecular sieve carrier that lanthanum is modified；(3) the lanthanum modified zsm-5 zeolite carrier after introducing zinc oxide is carried out incomplete bromination process, even if so-called not exclusively bromination processes zinc oxide portion and is converted into zinc bromide.

In above-mentioned preparation method step (1), described Hydrogen ZSM-5 molecular sieve carrier can be existing commercial product, it is also possible to prepare by those skilled in the art's well-known process.Suitable particle shape can be made or be chosen to carrier according to the needs used, and as made bar shaped, sheet shape, cylindricality, spherical etc., shaping can be carried out by this area general knowledge.

In above-mentioned preparation method step (1), use containing lanthanum salt and the aqueous solution incipient impregnation Hydrogen ZSM-5 molecular sieve carrier of high molecular weight water soluble polymer, stand 4h-12h, preferably 4h-8h, 80 DEG C of-120 DEG C of dry 6h-12h, under air atmosphere, rise to 500 DEG C-700 DEG C roasting 4h-8h with 1 DEG C/min ~ 3 DEG C/min, obtain the Hydrogen ZSM-5 molecular sieve that lanthanum is modified.Described lanthanum salt is the inorganic salts, preferably Lanthanum (III) nitrate such as Lanthanum (III) nitrate, lanthanum chloride, lanthanum sulfate；It is 2 ~ 5 that described high molecular weight water soluble polymer refers to the mass ratio of one or more in polyacrylamide (PAM) or polyvinylpyrrolidone (PVP), preferably polyethylene ketopyrrolidine, and high molecular weight water soluble polymer and lanthanum.

In above-mentioned preparation method step (2), described zinc oxide is introduced to the method that the method for lanthanum modified hydrogen ZSM-5 molecular sieve carrier is well known to those skilled in the art, as impregnation method can be used to introduce.Concrete grammar is as follows: uses the carrier that zinc solution dipping is modified, 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-800 DEG C, preferably 400 DEG C-600 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, zinc salt can be inorganic salt, it is also possible to for one or more in organic salt, preferably nitrate, hydrochlorate, acetate, citrate.

In above-mentioned preparation method step (3), described bromination 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.

In above-mentioned preparation method step (3), involved noble gas is the gas that nitrogen, argon, helium etc. do not occur chemical reaction under the conditions of involved in the present invention, preferably nitrogen.

nullA kind of catalyst with lanthanum modified zsm-5 zeolite as carrier，Described catalyst is by zinc oxide、The Hydrogen ZSM-5 molecular sieve carrier composition of zinc bromide and lanthanum modification，Based on the weight content of catalyst，Zinc oxide content is 0.5%-20%，It is preferably 1%-15%，More preferably 1%-9%，Zinc bromide content is 10%-50%，It is preferably 15%-45%，More preferably 18%-39%，The Hydrogen ZSM-5 molecular sieve vector contg of lanthanum modification is 40%-90%，It is preferably 50%-85%，More preferably 55%-80%，In the Hydrogen ZSM-5 molecular sieve carrier that described lanthanum is modified，Lanthanum counts weight content in the carrier as 1%-5% with lanthana，Hydrogen ZSM-5 molecular sieve carrier silica alumina ratio is 20 ~ 200，Preferably 20 ~ 150.

In catalyst of the present invention, less than 450 DEG C total acid content (NH₃-TPD) it is 0.5mmol/g-1.3mmol/g, preferably 0.6mmol/g-1.2mmol/g, further preferred 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 modified zsm-5 zeolite 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%.

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.

In above-mentioned application, 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。

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^-1Hydrogen or the 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 catalyst that prepared by the present invention.In the present invention, lanthanum is the modifying agent of carrier, is also effective auxiliary agent of bromomethane conversion preparing isobutene catalyst, additionally, the interpolation of high molecular weight water soluble polymer can also promote that lanthana preferably disperses on carrier.Carry out bromomethane by the inventive method and convert preparing isobutene reaction, bromomethane conversion ratio more than 85%, selective isobutene more than 50%.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

Weigh appropriate Lanthanum (III) nitrate and PVP(K30) it is dissolved in deionized water, (silica alumina ratio 50, pore volume is 0.23ml/g, and specific surface area is 426m to use equi-volume impregnating to be carried on Hydrogen ZSM-5 molecular sieve carrier²/ g, bar shaped, equivalent diameter 1.5mm), standing 6h, 100 DEG C of dry 9h, rise to 600 DEG C of roasting 6h with the heating rate of 1 DEG C/min, prepare the Hydrogen ZSM-5 molecular sieve carrier that lanthanum is modified, lanthanum is in terms of lanthana, and weight content in the carrier is 3%.

Weigh appropriate zinc nitrate to be dissolved in deionized water, use equi-volume impregnating to be carried on the Hydrogen ZSM-5 molecular sieve carrier that above-mentioned lanthanum is modified, 80 DEG C of dry 8h, 600 DEG C of roasting 4h, prepare catalyst precarsor ZnO/La-ZSM-5.Being placed in continuous fixed bed reactor by 5g catalyst precarsor, use bromomethane to process catalyst precarsor, treatment conditions are 250 DEG C, 0.2MPa(absolute pressure), 100h^-1, time 2h, prepare bromomethane preparing isobutene catalyst, be designated as C-1.Catalyst weight consists of ZnBr₂Weight content is 27%, and ZnO weight content is 6%, and in catalyst, less than 450 DEG C total acid contents are 0.77mmol/g, and the acid content of 250 DEG C-350 DEG C accounts for the 52.1% 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, unstripped gas is bromomethane and nitrogen mixed gas, and wherein bromomethane volume content is 50%, and reaction temperature is 230 DEG C, and reaction pressure is 1MPa(absolute pressure), air speed is 500h^-1, it is passed through unstripped gas procatalyst and activates in a hydrogen atmosphere, reducing condition is 400 DEG C, 0.2MPa(absolute pressure), 1000h^-1, recovery time 4h, reduction rear catalyst in content of halogen be reduction procatalyst in total halogen content 61.38%.After stable reaction one hour, sampling analysis.Reaction result is shown in Table 1.

Embodiment 2

Weigh appropriate zinc nitrate to be dissolved in deionized water, use equi-volume impregnating to be carried on the Hydrogen ZSM-5 molecular sieve carrier that above-mentioned lanthanum is modified, 120 DEG C of dry 4h, 500 DEG C of roasting 8h, prepare catalyst precarsor ZnO/La-ZSM-5.Being placed in continuous fixed bed reactor by 5g 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, 0.3MPa(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 0.8mmol/g, and the acid content of 250 DEG C-350 DEG C accounts for the 56.2% 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, 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 200h^-1.Before being passed through unstripped gas, catalyst activates under the hydrogen mixed atmosphere with nitrogen, and in mixed gas, hydrogen volume content is 80%, and reducing condition is 450 DEG C, 0.3MPa(absolute pressure), 800h^-1, recovery time 4h, reduction rear catalyst in content of halogen be reduction procatalyst in total halogen content 47.96%.After stable reaction one hour, sampling analysis.Reaction result is shown in Table 1.

Embodiment 3

Weigh appropriate zinc nitrate to be dissolved in deionized water, use equi-volume impregnating to be carried on the Hydrogen ZSM-5 molecular sieve carrier that above-mentioned lanthanum is modified, 100 DEG C of vacuum drying 8h, 400 DEG C of roasting 8h, prepare catalyst precarsor ZnO/La-ZSM-5.Being placed in continuous fixed bed reactor by 5g 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, 0.1MPa(absolute pressure), 500h^-1, time 4h, prepare bromomethane preparing isobutene catalyst, be designated as C-3.Obtain catalyst weight and consist of ZnBr₂In terms of bromide, weight content is 33%, and ZnO weight content in terms of oxide is 2%, and in catalyst, less than 450 DEG C total acid contents are 0.82mmol/g, and the acid content of 250 DEG C-350 DEG C accounts for the 59.7% 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, unstripped gas is bromomethane and nitrogen mixed gas, and wherein bromomethane volume content is 80%, and reaction temperature is 200 DEG C, and reaction pressure is 3MPa(absolute pressure), air speed is 350h^-1.Before being passed through unstripped gas, catalyst activates under the hydrogen mixed atmosphere with nitrogen, and in mixed gas, hydrogen volume content is 50%, and reducing condition is 500 DEG C, 0.1MPa(absolute pressure), 500h^-1, recovery time 4h, reduction rear catalyst in content of halogen be reduction procatalyst in total halogen content 43.23%.After stable reaction one hour, sampling analysis.Reaction result is shown in Table 1.

Embodiment 4

Weigh appropriate zinc nitrate to be dissolved in deionized water, use equi-volume impregnating to be carried on the Hydrogen ZSM-5 molecular sieve carrier that above-mentioned lanthanum is modified, 120 DEG C of dry 4h, 500 DEG C of roasting 8h, prepare catalyst precarsor ZnO/La-ZSM-5.Being placed in continuous fixed bed reactor by 5g catalyst precarsor, use bromomethane to process catalyst precarsor, treatment conditions are 200 DEG C, 0.3MPa(absolute pressure), 300h^-1, time 1h, 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 49.8% 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, unstripped gas is bromomethane and nitrogen mixed gas, and wherein bromomethane volume content is 30%, and reaction temperature is 270 DEG C, and reaction pressure is 2MPa(absolute pressure), air speed is 350h^-1.Before being passed through unstripped gas, catalyst activates under the hydrogen mixed atmosphere with nitrogen, and in mixed gas, hydrogen volume content is 70%, and reducing condition is 350 DEG C, 0.3MPa(absolute pressure), 800h^-1, recovery time 6h, reduction rear catalyst in content of halogen be reduction procatalyst in total halogen content 52.39%.After stable reaction one hour, sampling analysis.Reaction result is shown in Table 1.

Embodiment 5

Weigh appropriate Lanthanum (III) nitrate and PVP(K30) it is dissolved in deionized water, (silica alumina ratio 50, pore volume is 0.23ml/g, and specific surface area is 426m to use equi-volume impregnating to be carried on Hydrogen ZSM-5 molecular sieve carrier²/ g, bar shaped, equivalent diameter 1.5mm), standing 6h, 100 DEG C of dry 9h, rise to 600 DEG C of roasting 6h with the heating rate of 1 DEG C/min, prepare the Hydrogen ZSM-5 molecular sieve carrier that lanthanum is modified, lanthanum is in terms of lanthana, and weight content in the carrier is 5%.

Weigh appropriate zinc nitrate to be dissolved in deionized water, use equi-volume impregnating to be carried on the Hydrogen ZSM-5 molecular sieve carrier that above-mentioned lanthanum is modified, 100 DEG C of dry 6h, 500 DEG C of lower roasting 6h of nitrogen protection, prepare catalyst precarsor ZnO/La-ZSM-5.Being placed in continuous fixed bed reactor by 5g catalyst precarsor, use bromomethane to process catalyst precarsor with the mixed gas of nitrogen, bromomethane volumetric concentration is 70%, and treatment conditions are 200 DEG C, 0.3MPa(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 0.86mmol/g, and the acid content of 250 DEG C-350 DEG C accounts for the 64.1% 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, unstripped gas is bromomethane, and reaction temperature is 270 DEG C, and reaction pressure is 2MPa(absolute pressure), air speed is 350h^-1.Before being passed through unstripped gas, catalyst activates under the hydrogen mixed atmosphere with nitrogen, and in mixed gas, hydrogen volume content is 60%, and reducing condition is 550 DEG C, 0.3MPa(absolute pressure), 800h^-1, recovery time 8h, reduction rear catalyst in content of halogen be reduction procatalyst in total halogen content 43.51%.After stable reaction one hour, sampling analysis.Reaction result is shown in Table 1.

Embodiment 6

Weigh appropriate zinc nitrate to be dissolved in deionized water, use equi-volume impregnating to be carried on the Hydrogen ZSM-5 molecular sieve carrier that above-mentioned lanthanum is modified, be dried 4h, roasting 4h under 500 DEG C of nitrogen atmospheres under 120 DEG C of nitrogen atmospheres, prepare catalyst precarsor ZnO/La-ZSM-5.Being placed in continuous fixed bed reactor by 5g catalyst precarsor, use bromomethane to process catalyst precarsor, treatment conditions are 250 DEG C, 0.2MPa(absolute pressure), 100h^-1, time 1h, it is designated as C-6.Obtain catalyst weight and consist of ZnBr₂In terms of bromide, weight content is 35%, and ZnO weight content in terms of oxide is 9%, and in catalyst, less than 450 DEG C total acid contents are 0.84mmol/g, and the acid content of 250 DEG C-350 DEG C accounts for the 61.9% 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, unstripped gas is bromomethane and nitrogen mixed gas, and wherein bromomethane volume content is 50%, and reaction temperature is 230 DEG C, and reaction pressure is 0.1MPa(absolute pressure), air speed is 500h^-1.Before being passed through unstripped gas, catalyst activates under the hydrogen mixed atmosphere with nitrogen, and in mixed gas, hydrogen volume content is 80%, and reducing condition is 450 DEG C, 0.2MPa(absolute pressure), 1000h^-1, recovery time 4h, reduction rear catalyst in content of halogen be reduction procatalyst in total halogen content 50.93%.After stable reaction one hour, sampling analysis.Reaction result is shown in Table 1.

Embodiment 7

Weigh appropriate Lanthanum (III) nitrate and PVP(K30) it is dissolved in deionized water, (silica alumina ratio 50, pore volume is 0.23ml/g, and specific surface area is 426m to use equi-volume impregnating to be carried on Hydrogen ZSM-5 molecular sieve carrier²/ g, bar shaped, equivalent diameter 1.5mm), standing 6h, 100 DEG C of dry 9h, rise to 600 DEG C of roasting 6h with the heating rate of 1 DEG C/min, prepare the Hydrogen ZSM-5 molecular sieve carrier that lanthanum is modified, lanthanum is in terms of lanthana, and weight content in the carrier is 1%.

Weigh appropriate zinc nitrate to be dissolved in deionized water, use equi-volume impregnating to be carried on the Hydrogen ZSM-5 molecular sieve carrier that above-mentioned lanthanum is modified, 120 DEG C of dry 4h, 500 DEG C of roasting 4h, prepare catalyst precarsor ZnO/La-ZSM-5.Being placed in continuous fixed bed reactor by 5g catalyst precarsor, use bromomethane to process catalyst precarsor with the mixed gas of nitrogen, bromomethane volumetric concentration is 90%, and treatment conditions are 300 DEG C, 0.1MPa(absolute pressure), 500h^-1, time 4h, prepare bromomethane preparing isobutene catalyst, be designated as C-7.Obtain catalyst weight and consist of ZnBr₂In terms of bromide, weight content is 20%, and ZnO weight content in terms of oxide is 1%, and in catalyst, less than 450 DEG C total acid contents are 0.74mmol/g, and the acid content of 250 DEG C-350 DEG C accounts for the 51.2% 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, unstripped gas is bromomethane and nitrogen mixed gas, and wherein bromomethane volume content is 80%, and reaction temperature is 200 DEG C, and reaction pressure is 3MPa(absolute pressure), air speed is 350h^-1.Before being passed through unstripped gas, catalyst activates under the hydrogen mixed atmosphere with nitrogen, and in mixed gas, hydrogen volume content is 90%, and reducing condition is 500 DEG C, 0.1MPa(absolute pressure), 500h^-1, recovery time 6h, reduction rear catalyst in content of halogen be reduction procatalyst in total halogen content 54.48%.After stable reaction one hour, sampling analysis.Reaction result is shown in Table 1.

Comparative example 1

Weigh appropriate zinc nitrate to be dissolved in deionized water, use equi-volume impregnating to be carried on the Hydrogen ZSM-5 molecular sieve carrier that above-mentioned lanthanum is modified, 120 DEG C of dry 4h, 500 DEG C of roasting 4h, prepare catalyst Z nO/La-ZSM-5, be designated as 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 0.41mmol/g, and the acid content of 250 DEG C-350 DEG C accounts for the 39.5% 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, 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 200h^-1.Before being passed through unstripped gas, catalyst activates under the hydrogen mixed atmosphere with nitrogen, and in mixed gas, hydrogen volume content is 80%, and reducing condition is 450 DEG C, 0.3MPa(absolute pressure), 800h^-1, recovery time 4h..After stable reaction one hour, sampling analysis.Reaction result is shown in Table 1.

Comparative example 2

Weigh appropriate zinc nitrate to be dissolved in deionized water, use equi-volume impregnating to be carried on the Hydrogen ZSM-5 molecular sieve carrier that above-mentioned lanthanum is modified, 120 DEG C of dry 4h, 500 DEG C of roasting 4h, prepare catalyst precarsor ZnO/La-ZSM-5.Being placed in continuous fixed bed reactor by 5g 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, 0.3MPa(absolute pressure), 300h^-1, time 2h, prepare bromomethane preparing isobutene catalyst, be designated as D-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 0.8mmol/g, and the acid content of 250 DEG C-350 DEG C accounts for the 56.2% 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, 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 200h^-1.After stable reaction one hour, sampling analysis.Reaction result is shown in Table 1.

Comparative example 3

Weighing appropriate zinc nitrate to be dissolved in deionized water, use equi-volume impregnating to be carried on the Hydrogen ZSM-5 molecular sieve carrier that above-mentioned lanthanum is modified, 80 DEG C of nitrogen atmospheres are dried 4h, 500 DEG C of nitrogen atmosphere roasting 4h, prepare catalyst Z nBr₂/ Mg-ZSM-5, is designated as D-3.Obtain catalyst weight and consist of ZnBr₂In terms of bromide, weight content is 30%, and in catalyst, less than 450 DEG C total acid contents are 0.97mmol/g, and the acid content of 250 DEG C-350 DEG C accounts for the 73.3% 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, 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 200h^-1.Before being passed through unstripped gas, catalyst activates under the hydrogen mixed atmosphere with nitrogen, and in mixed gas, hydrogen volume content is 80%, and reducing condition is 450 DEG C, 0.3MPa(absolute pressure), 800h^-1, recovery time 4h, reduction rear catalyst in content of halogen be reduction procatalyst in total halogen content 92.78%.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 the catalyst with lanthanum modified zsm-5 zeolite as carrier, it is characterised in that: comprise the steps:

(1) process Hydrogen ZSM-5 molecular sieve by lanthanum salt solution impregnation, obtain the Hydrogen ZSM-5 molecular sieve carrier that lanthanum is modified；

(2) zinc oxide is introduced to the Hydrogen ZSM-5 molecular sieve carrier that lanthanum is modified；

(3) the lanthanum modified zsm-5 zeolite carrier after introducing zinc oxide is carried out incomplete bromination process.

Method the most according to claim 1, it is characterized in that: step (1) uses containing lanthanum salt and the aqueous solution incipient impregnation Hydrogen ZSM-5 molecular sieve carrier of high molecular weight water soluble polymer, stand 4h-12h, 80 DEG C of-120 DEG C of dry 6h-12h, under air atmosphere, rise to 500 DEG C-700 DEG C roasting 4h-8h with 1 DEG C/min ~ 3 DEG C/min, obtain the Hydrogen ZSM-5 molecular sieve carrier that lanthanum is modified.

Method the most according to claim 2, it is characterised in that: described lanthanum salt is the one in Lanthanum (III) nitrate, lanthanum chloride, lanthanum sulfate；Described high molecular weight water soluble polymer is one or more in polyacrylamide or polyvinylpyrrolidone, and high molecular weight water soluble polymer is 2 ~ 5 with the mass ratio of lanthanum.

Method the most according to claim 3, it is characterised in that: described lanthanum salt is Lanthanum (III) nitrate；Described high molecular weight water soluble polymer is polyvinylpyrrolidone.

Method the most according to claim 3, it is characterised in that: in step (2), zinc oxide is introduced to lanthanum modified hydrogen ZSM-5 molecular sieve carrier and uses infusion process.

Method the most according to claim 5, it is characterised in that: use the zinc solution modified carrier of dipping, and be dried, roasting.

Method the most according to claim 6, it is characterised in that: baking temperature 60 DEG C-150 DEG C, the time is 1h-24h；Sintering temperature 300 DEG C-800 DEG C, the time is 1h-24h.

Method the most according to claim 7, it is characterised in that: baking temperature 80 DEG C-120 DEG C, the time is 4h-8h；Sintering temperature 400 DEG C-600 DEG C, the 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.

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

11. methods according to claim 10, it is characterised in that: bromine-containing compound refers to one or more in bromomethane, methylene bromide, bromoform.

12. methods according to claim 10, it is characterised in that: using gas phase bromine-containing compound to carry out bromination process with the mixed gas of noble gas, when using mixed gas bromination to process, bromomethane volumetric concentration is not less than 20%.

13. methods according to claim 10, it is characterized in that: concrete bromination process is as follows: the sample of load zinc oxide is placed in continuous fixed bed reactor, being warming up to 150 DEG C-400 DEG C under inert atmosphere, be passed through gas phase bromine-containing compound gas, gas space velocity is 50h^-1-1000 h^-1；System pressure is 0.1MPa-0.5MPa, and the process time is 0.5h-8h.

14. methods according to claim 13, it is characterised in that: being warming up to 180 DEG C-350 DEG C under inert atmosphere, be passed through gas phase bromine-containing compound gas, gas space velocity is 100h^-1-500h^-1；System pressure is 0.1MPa-0.3MPa, and the process time is 1h-4h.

15. 1 kinds use catalyst prepared by claim 1 to 14 either method, it is characterized in that: catalyst is made up of the Hydrogen ZSM-5 molecular sieve carrier that zinc oxide, zinc bromide and lanthanum are modified, based on the weight content of catalyst, zinc oxide content is 0.5%-20%, zinc bromide content is 10%-50%, the Hydrogen ZSM-5 molecular sieve vector contg of lanthanum modification is 40%-90%, in the Hydrogen ZSM-5 molecular sieve carrier that described lanthanum is modified, lanthanum counts weight content in the carrier as 1%-5% with lanthana, and Hydrogen ZSM-5 molecular sieve carrier silica alumina ratio is 20 ~ 200.

16. catalyst according to claim 15, it is characterised in that: zinc oxide content is 1%-15%, and zinc bromide content is 15%-45%, and the Hydrogen ZSM-5 molecular sieve vector contg of lanthanum modification is 50%-85%, and Hydrogen ZSM-5 molecular sieve carrier silica alumina ratio is 20 ~ 150.

17. catalyst according to claim 15, 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.

18. catalyst according to claim 17, it is characterised in that: less than 450 DEG C total acid content 0.6mmol/g-1.2mmol/g in catalyst, the acid content of 250 DEG C-350 DEG C accounts for the 30%-80% of less than 450 DEG C total acid contents.

19. catalyst according to claim 18, it is characterised in that: less than 450 DEG C total acid content 0.7mmol-1.1mmol/g in catalyst, the acid content of 250 DEG C-350 DEG C accounts for the 40%-80% of less than 450 DEG C total acid contents.

The application of catalyst described in 20. claim 15, 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..

21. according to the application of catalyst described in claim 20, it is characterised in that: the condition of hydrogen reducing activation makes the content of halogen in catalyst be preferably the 30%-80% of total halogen content in reduction procatalyst.

22. according to the application of catalyst described in claim 20, it is characterised in that: the mode of 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%.

23. according to the application of catalyst described in claim 22, 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%.

24. according to the application of catalyst described in claim 20, it is characterised in that: halide is one or more in a halide, methylene halide, three halides.

25. according to the application of catalyst described in claim 20, it is characterised in that: halide is one or more in bromomethane, methylene bromide, bromoform.

26. according to the application of catalyst described in claim 20, 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。

27. according to the application of catalyst described in claim 26, it is characterised in 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。

28. according to the application of catalyst described in claim 20, it is characterised in that: including catalyzer temperature-elevating to 300 DEG C-600 DEG C under inert atmosphere, then passing to air speed is 200h^-1-2000h^-1Hydrogen or the mixed gas of hydrogen and noble gas, process 2h-16h at 0.1MPa-0.5MPa, be down to reaction temperature and be passed through halide and react, in gaseous mixture, hydrogen volume percentage composition is 10%-95%.

29. according to the application of catalyst described in 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^-1Hydrogen or the mixed gas of hydrogen and noble gas, after 0.1MPa-0.3MPa processes 4h-8h, be down to reaction temperature and be passed through halide and react, in gaseous mixture, hydrogen volume percentage composition is 30%-90%.