CN103831120B

CN103831120B - For Catalysts and its preparation method and the application of methyl tertiary butyl ether(MTBE) cracking

Info

Publication number: CN103831120B
Application number: CN201410106240.XA
Authority: CN
Inventors: 卢冠忠; 王筠松; 李运运; 朱耀国; 陆文龙; 郭杨龙; 郭耘; 王艳芹; 詹望成
Original assignee: East China University of Science and Technology
Current assignee: East China University of Science and Technology
Priority date: 2014-03-21
Filing date: 2014-03-21
Publication date: 2016-05-18
Anticipated expiration: 2034-03-21
Also published as: CN103831120A

Abstract

The invention discloses a kind of for methyl tertiary butyl ether(MTBE) cracking the Z for high-purity isobutylene_xO_y/F/Nb₂O₅/Al₂O₃Type solid acid catalyst and preparation method thereof, according to this preparation method, the component of catalyst and percentage by weight are: Z_xO_y？0.1~8%，F？0.1~25%，Nb₂O₅？0.5~30%，Al₂O_3？20 ~ 95%. The present invention is ensureing under the condition of high methyl tertiary butyl ether(MTBE) cracking conversion ratio, isobutene and methyl alcohol selectively almost reach 100%, do not need to add the inert substances such as water vapour to methyl tertiary butyl ether(MTBE) cracking reaction system simultaneously, and the liquid-containing air speed ratio similar catalyst of reaction significantly improves, can make Energy Intensity Reduction in suitability for industrialized production, utilization rate of equipment and installations significantly promotes.

Description

For Catalysts and its preparation method and the application of methyl tertiary butyl ether(MTBE) cracking

Technical field

The present invention relates to preparation and the application of a kind of methyl tertiary butyl ether(MTBE) cracking for the catalyst of high-purity isobutylene, what relate generally to is that various active component loads on Al₂O₃The above Z for high-purity isobutylene for methyl tertiary butyl ether(MTBE) cracking_xO_y/F/Nb₂O₅/Al₂O₃Type solid acid catalyst.

Background technology

Isobutene has a wide range of applications as a kind of important industrial chemicals. In recent decades, its social required quantity is all the time at rapid growth. It not only can be for the manufacture of gasoline and lube oil additive, but also can be used as important auxiliary agent and the raw material of other chemical products. The isobutene of for example low-purity is the raw material of antioxidant, agricultural chemicals, coating, stabilizing agent and other fine chemical product. High-purity isobutylene is the raw material monomer of butyl rubber, isoprene rubber, polybutene resin, methyl methacrylate etc. Meanwhile, along with the development of petrochemical industry and the exploitation of isobutene downstream new product, the demand of isobutene increases year by year.

The technique of industrial production isobutene has the methods such as sulfuric acid extraction, molecular sieve adsorption, direct hydration method, catalytic cracking method, butane isomery dehydriding, n-butene skeletal isomerization method, tert-butyl alcohol evaporation and etherification method. Etherification method is after methyl alcohol (or other primary alconols) generates highly purified methyl tertiary butyl ether(MTBE) with the isobutene reaction in hybrid C 4 cut, then carries out cracking. Due to methyl tertiary butyl ether(MTBE) catalytic cracking reaction conversion ratio and selectively all very high, reactant can obtain highly purified isobutene through washing and distillation. Methyl tertiary butyl ether(MTBE) synthesis technique matches with cracking technology, form the process route that more advanced carbon four separated and prepared high-purity isobutylene, preparing isobutylene by etherification has been become and prepare at present most study in isobutene method, a kind of most widely used, the most attractive method.

The key of preparing isobutylene by etherification is catalyst. The quality of catalyst directly has influence on the conversion ratio of reaction, the important indicator such as selective. The catalyst of the method, taking solid acid catalyst as main, has: some catalyst of alumina system (USP3170000), silica system (CN1056299), ion exchange resin system (USP4447688), sulfate system (CN2006100309735), molecular sieve system (USP4566016), Phosphoric Acid (EP118085), heteropolyacid system (CN1185992), niobic acid system (JP62106031) and other systems at present. But all more or less there are the following problems for they:

From reacting itself, methyl tertiary butyl ether(MTBE) cracking is the endothermic reaction, improves reaction temperature and is conducive to methyl tertiary butyl ether(MTBE) cracking generation isobutene, improves the conversion ratio of MTBE. But when temperature is high, also can be conducive to the generation of side reaction, as isobutene dimerization causes the loss of isobutene; The methanol dehydration that cracking obtains generates dimethyl ether, and the generation of dimethyl ether can reduce the rate of recovery of methyl alcohol, and causing needs to replenish by the methyl alcohol of this side-reaction consumes in initial etherification reaction system in hybrid C 4 cut etherificate-cracking circulation purification system again; The water producing when simultaneously dimethyl ether generates also can with isobutene hydration, generate the accessory substance tert-butyl alcohol, the generation of multiple accessory substance will affect the purity of product, has increased energy consumption and cost etc. to the separation and purification of product. Partially catalyzed agent is high to MTBE cracking conversion ratio, but reaction time need to add the inert substances such as a large amount of steam, and the rate of recovery of methyl alcohol and isobutene and utilization rate of equipment and installations have reduced widely, make its process complicated, and cause expensive surcharge. The shortcoming of ion-exchange resin catalyst is that resistance to elevated temperatures is poor, and in the time that the temperature of reaction improves, sulfonic acid group wherein easily comes off, and owing to being subject to the restriction of reaction temperature, the conversion ratio of reaction is all lower. The deadly defect of sulfate system catalyst is under reaction condition, and sulfate will decompose gradually, thereby causes the corrosion of equipment and the decline of catalyst activity. The niobic acid system of existing research, as JP6210603, adopts pure niobic acid as catalyst, when LHSV is 4h^-1, reaction temperature is while being 250 DEG C, the conversion ratio of MTBE is 99.2%, but the high cost of pure niobic acid System Catalyst own, the reaction temperature of 250 DEG C is except energy consumption is too large, require also very high to firing equipment, and easily cause accessory substance to increase, affect product purity, increase product rectifying requirement and expense.

Therefore reduce catalyst cost, provide a kind of low energy consumption, low cost under moderate reaction temperature, have high conversion ratio, high air speed and high isobutene and methyl alcohol optionally methyl tertiary butyl ether(MTBE) catalyst for cracking be that related industry department is extremely expected.

Summary of the invention

Therefore target of the present invention is exactly to ensure under the substantially constant prerequisite of methyl alcohol and isobutene high selectivity, existing methyl tertiary butyl ether(MTBE) cracking technology condition, provide one can reduce catalyst cost, reduce reaction temperature, and the catalyst that the volume space velocity of methyl tertiary butyl ether(MTBE) is improved.

A kind of novel load is proposed for this reason in the multicomponent Z of alumina support_xO_y/F/Nb₂O₅/Al₂O₃Type solid acid catalyst, for the low temperature ether solution course of reaction of methyl tertiary butyl ether(MTBE), use ammoniacal liquor to regulate the surface acidity of carrier, improve the conversion ratio of reaction, and add various adjustment of cocatalyst reaction selectivities, reduce the generation of accessory substance, make methyl tertiary butyl ether(MTBE) cracking reaction not need again to add the inert substance of water vapour and so in reaction system, greatly reduce energy consumption, volume space velocity is improved significantly, and has also improved utilization rate of equipment and installations simultaneously.

Multicomponent Z_xO_y/F/Nb₂O₅/Al₂O₃Type solid acid catalyst, its component and weight percentage are:

Z_xO_y0.1~8%

F0.1~25%

Nb₂O₅0.5~30%

Al₂O₃20~95%

Described Al₂O₃For alundum (Al2O3), derive from hydration Al₂O₃、γ-Al₂O₃、η-Al₂O₃Or θ-Al₂O₃In one, preferably γ-Al₂O₃; F is fluoride, derives from the one in the aqueous solution of ammonium fluoride, hydrofluoric acid, sodium fluoride; Nb₂O₅For niobium pentaoxide, derive from niobium oxalate, acetic acid niobium, niobium ammonium complex compound or fluoridize the one in the niobium salting liquids such as niobium; Z_xO_yFor rare earth oxide, derive from the one in the water-soluble salt solution of rare earth element Sm, La, Ce etc.

The preparation of above-mentioned catalyst comprises the steps:

By Al₂O₃Be immersed in ammonia spirit 1 ~ 4 hour, filter, wash to pH be 7.5 ~ 11, filter cake 80 ~ 200 DEG C dry 1 ~ 4 hour; Then product is immersed in prepared containing flooding 1 ~ 8 hour in the niobium salting liquid of certain mass mark, filter, in 80 ~ 200 DEG C dry 1 ~ 4 hour, then within 2 ~ 8 hours, obtain Nb in 200 ~ 850 DEG C of roastings₂O₅/Al₂O₃；

By Nb₂O₅/Al₂O₃Join in the fluoride aqueous solution having prepared and flood 1 ~ 8 hour, filter, in 80 ~ 200 DEG C dry 1 ~ 4 hour, then within 2 ~ 8 hours, obtain F/Nb in 200 ~ 850 DEG C of roastings₂O₅/Al₂O₃；

By F/Nb₂O₅/Al₂O₃Join containing flooding 1 ~ 8 hour in the nitrate aqueous solution of rare earth, filter, in 80 ~ 200 DEG C dry 1 ~ 4 hour, then in 200 ~ 850 DEG C of roastings 2 ~ 8 hours, obtain the multicomponent Z for the preparation of high-purity isobutylene of the present invention_xO_y/F/Nb₂O₅/Al₂O₃Type catalyst;

According to the present invention, the weight concentration of ammoniacal liquor is 0.1% ~ 35%, and optimum scope is 1 ~ 25%; The mass concentration of niobium salting liquid is 0.1 ~ 50%, and optimum scope is 1 ~ 25%; The concentration 0.5% ~ 40% of fluoride aqueous solution, optimum scope is 1% ~ 25%; The mass concentration of rare earth salt aqueous solution is 0.1 ~ 50%, and optimum scope is 1 ~ 25%.

Al in ammoniacal liquor₂O₃Amount be 0.01 ~ 15g/ml; Al in niobium salting liquid₂O₃Amount be 0.01 ~ 15g/ml; Nb in fluoride aqueous solution₂O₅/Al₂O₃Amount be 0.01 ~ 15g/ml; F/Nb in rare earth salt aqueous solution₂O₅/Al₂O₃Amount be 0.01 ~ 15g/ml.

Catalyst of the present invention is for methyl tertiary butyl ether(MTBE) cracking during for the reaction of isobutene, and required reaction temperature is generally 100 ~ 300 DEG C, and optimal reaction temperature is 150 ~ 200 DEG C. Reaction pressure is 0.1 ~ 2MPa, from economic angle and the simple and easy consideration of operation, generally at least equals the saturated vapor of isobutene in the time of condensation temperature and depresses and operate, so optimum response pressure is 0.1 ~ 1.0MPa. The flow velocity of methyl tertiary butyl ether(MTBE), represents with the liquid feed volume (liquid air speed) of per volume of catalyst per hour, is generally 0.1 ~ 15h^-1, optimal liquid air speed is 1 ~ 10h^-1. Prepare as stated above isobutene and methyl alcohol, isobutene and methyl alcohol selectively all can be greater than 99%, the conversion ratio of methyl tertiary butyl ether(MTBE) cracking can be greater than 98%.

From above-mentioned disclosed technical scheme, catalyst of the present invention can carry out methyl tertiary butyl ether(MTBE) cracking reaction at lower temperature, there is high isobutene and methyl alcohol optionally simultaneously, also there is the conversion ratio of high methyl tertiary butyl ether(MTBE) cracking, liquid air speed is improved significantly compared with similar catalyst, and catalyst cost does not need to add the inert substances such as water vapour in methyl tertiary butyl ether(MTBE) cracking reaction system simultaneously, energy consumption is low, and utilization rate of equipment and installations is high at double.

Detailed description of the invention

The following examples will further be described the present invention, but never limit the scope of the invention.

Embodiment 1

By 30 grams of γ-Al₂O₃Join 40ml weight concentration and be 2h in 25% ammoniacal liquor, elimination ammoniacal liquor, put into deionized water wash to pH be 8.5 left and right, filter cake is dry 3h in 200 DEG C of baking ovens; Then product is immersed in the niobium oxalate salting liquid of 100ml3%, floods 5 hours, after filtration, dry 4h in 150 DEG C of baking ovens, roasting 5 hours at 650 DEG C; Then product be impregnated in the Fluorinse of 50ml3%, flood 5 hours, after filtration, dry 4h in 150 DEG C of baking ovens, roasting 5 hours at 800 DEG C.

Above-mentioned catalyst is joined to the La (NO of 50ml2%₃)₃In solution, dip time is 4 hours, after filtration, and dry 4h in 150 DEG C of baking ovens, roasting 5 hours at 650 DEG C; Obtain the multicomponent La for the preparation of high-purity isobutylene of the present invention₂O₃/F/Nb₂O₅/Al₂O₃Catalyst;

20g catalyst is packed in the fixed bed reactors of Φ 20mm diameter, micro-amounts of liquids sampling pump charging for methyl tertiary butyl ether(MTBE), controlling liquid air speed is 6h^-1, reaction temperature is 190 DEG C, MTBE conversion ratio 98.0%, selective isobutene 99.0%, methyl alcohol selective 99.1%.

Embodiment 2

By 30 grams of γ-Al₂O₃Join 40ml weight concentration and be 1h in 10% ammoniacal liquor, elimination ammoniacal liquor, put into deionized water wash to pH be 8.5 left and right, filter cake is dry 3h in 200 DEG C of baking ovens; Then product is immersed in the ammonium niobium oxalate solution of 100ml8%, floods 5 hours, after filtration, dry 4h in 150 DEG C of baking ovens, roasting 5 hours at 650 DEG C; Then product be impregnated in the ammonium fluoride solution of 50ml4%, flood 5 hours, after filtration, dry 4h in 150 DEG C of baking ovens, roasting 5 hours at 800 DEG C.

Above-mentioned catalyst is joined to the Ce (NO of 50ml2%₃)₃In solution, dip time is 4 hours, after filtration, and dry 4h in 150 DEG C of baking ovens, roasting 5 hours at 650 DEG C, obtains the multicomponent Ce for the preparation of high-purity isobutylene of the present invention₂O₃/F/Nb₂O₅/Al₂O₃Catalyst;

20g catalyst is packed in the fixed bed reactors of Φ 20mm diameter, micro-amounts of liquids sampling pump charging for methyl tertiary butyl ether(MTBE), controlling liquid air speed is 6h^-1, reaction temperature is 190 DEG C, MTBE conversion ratio 99.4%, selective isobutene 99.9%, methyl alcohol selective 99.2%.

Embodiment 3

By 30 grams of γ-Al₂O₃Join 40ml weight concentration and be 0.5h in 20% ammoniacal liquor, elimination ammoniacal liquor, put into deionized water wash to pH be 8.5 left and right, filter cake is dry 3h in 200 DEG C of baking ovens; Then product is immersed in the fluoroniobate solution of 100ml5%, floods 5 hours, after filtration, dry 4h in 150 DEG C of baking ovens, roasting 5 hours at 650 DEG C; Then product be impregnated in the hydrogen fluoride solution of 50ml5%, flood 5 hours, after filtration, dry 4h in 150 DEG C of baking ovens, roasting 5 hours at 800 DEG C.

Above-mentioned catalyst is joined to the Sm (NO of 50ml2%₃)₃In solution, dip time is 4 hours, after filtration, and dry 4h in 150 DEG C of baking ovens, roasting 5 hours at 650 DEG C, obtains the multicomponent Sm for the preparation of high-purity isobutylene of the present invention₂O₃/F/Nb₂O₅/Al₂O₃Catalyst;

20g catalyst is packed in the fixed bed reactors of Φ 20mm diameter, micro-amounts of liquids sampling pump charging for methyl tertiary butyl ether(MTBE), controlling liquid air speed is 6h^-1, reaction temperature is 190 DEG C, MTBE conversion ratio 98.6%, selective isobutene 99.4%, methyl alcohol selective 99.5%.

Claims

One kind for methyl tertiary butyl ether(MTBE) cracking the Z for high-purity isobutylene_xO_y/F/Nb₂O₅/Al₂O₃Type solid acid catalyst, is characterized in that catalytic component and percentage by weight are:

Z_xO_y0.1~8%

F0.1~25%

Nb₂O₅0.5~30%

Al₂O₃20~95%

The percentage by weight sum of described catalyst components is 100%,

Wherein said Al₂O₃For alundum (Al2O3), derive from hydration Al₂O₃、γ-Al₂O₃、η-Al₂O₃Or θ-Al₂O₃In one; F is fluoride, derives from the one in the aqueous solution of hydrofluoric acid, ammonium fluoride, sodium fluoride; Nb₂O₅For niobium pentaoxide, derive from the one in niobium oxalate, acetic acid niobium, niobium ammonium complex compound or fluoroniobate solution; Z_xO_yFor rare earth oxide, derive from the one in the water-soluble salt solution of rare earth element Sm, La, Ce.
2. the preparation method of catalyst according to claim 1, is characterized in that:

By Al₂O₃Be immersed in ammonia spirit after 1 ~ 4 hour, filter, wash to pH be 7.5 ~ 11, filter cake 80 ~ 200 DEG C dry 1 ~ 4 hour; By this Al₂O₃Be immersed in prepared containing in the niobium salting liquid of certain mass mark, flood after 1 ~ 8 hour, filter, be dried 1 ~ 4 hour in 80 ~ 200 DEG C, then within 2 ~ 8 hours, obtain Nb in 200 ~ 850 DEG C of roastings₂O₅/Al₂O₃；

By Nb₂O₅/Al₂O₃Join in the fluoride aqueous solution having prepared and flood after 1 ~ 8 hour, filter, filter cake is dried 1 ~ 4 hour at 80 ~ 200 DEG C, then within 2 ~ 8 hours, obtains F/Nb in 200 ~ 850 DEG C of roastings₂O₅/Al₂O₃；

By F/Nb₂O₅/Al₂O₃Join containing in the aqueous solution of rare-earth salts of having prepared, flood after 1 ~ 8 hour, filter, filter cake is dried 1 ~ 4 hour at 80 ~ 200 DEG C, then in 200 ~ 850 DEG C of roastings 2 ~ 8 hours, obtains the multicomponent Z for the preparation of high-purity isobutylene_xO_y/F/Nb₂O₅/Al₂O₃Type solid acid catalyst.
3. the preparation method of catalyst according to claim 2, is characterized in that, the weight concentration of ammoniacal liquor is 0.1% ~ 35%; The mass concentration of niobium salting liquid is 0.1 ~ 50%; The concentration of fluoride aqueous solution is 0.5% ~ 40%; The mass concentration of rare earth salt aqueous solution is 0.1 ~ 50%.
4. the preparation method of catalyst according to claim 3, is characterized in that, the weight concentration of described ammoniacal liquor is 1 ~ 25%.
5. the preparation method of catalyst according to claim 3, is characterized in that, the mass concentration of described niobium salting liquid is 1 ~ 25%.
6. the preparation method of catalyst according to claim 3, is characterized in that, the concentration of described fluoride aqueous solution is 1% ~ 25%.
7. the preparation method of catalyst according to claim 3, is characterized in that, the mass concentration of described rare earth salt aqueous solution is 1 ~ 25%.
8. the preparation method of catalyst according to claim 2, is characterized in that, Al in ammoniacal liquor₂O₃Amount be 0.01 ~ 15g/ml; Al in niobium salting liquid₂O₃Amount be 0.01 ~ 15g/ml; Nb in fluoride aqueous solution₂O₅/Al₂O₃Amount be 0.01 ~ 15g/ml; F/Nb in rare earth salt aqueous solution₂O₅/Al₂O₃Amount be 0.01 ~ 15g/ml.
9. catalyst claimed in claim 1, during for isobutene reaction, is characterized in that for methyl tertiary butyl ether(MTBE) cracking, reaction process condition is: reaction temperature is 100 ~ 300 DEG C, and reaction pressure is 0.1 ~ 2MPa, and liquid air speed is 0.1 ~ 15h^-1。
10. catalyst claimed in claim 9, during for isobutene reaction, is characterized in that for methyl tertiary butyl ether(MTBE) cracking, reaction process condition is: reaction temperature is 150 ~ 200 DEG C, and reaction pressure is 0.1 ~ 1MPa, and liquid air speed is 1 ~ 10h^-1。