The catalyzer that the inventive method is used has high reactivity when making unsaturated nitrile, more lower slightly than the normally used temperature of reaction of these class methods, and at the low-temp reaction of back continuous and effective that wears out.Except the high reactivity in the nitrile building-up reactions, this catalyzer also have many important advantages make technological operation can be efficiently, carry out economically.This catalyzer has good oxidation-reduction stability under the reaction conditions of present method, so just can use the ratio of lower process air and alkene and higher weight hourly space velocity.This catalyzer can utilize ammonia efficiently, and this just greatly reduces the content of unreacted ammonia in the air-flow of outflow reactor, thus reduced be used for and air-flow in the required vitriolic amount of ammonia.These results make and have improved: the 1) operation 2 of present method recovery part) control of Wu Raning.Use lower service temperature to help prolonging catalyst life, reduce the air-flow generation such as problems such as resume combustion to greatest extent.Except lower temperature of reaction, also can make the per pass conversion of nitrile reach 80% or higher.The prior advantage of catalyzer of the present invention is that the main component cost of catalyzer is low, and Preparation of catalysts is very simple and easy.
The reactant that the present invention prepares unsaturated nitrile is the alkene that oxygen, ammonia and straight chain contain 3 carbon atoms, as propylene, iso-butylene and composition thereof.
Alkene can be woven into paraffinic hydrocarbons, and as ethane, propane, butane, pentane, for example propylene-propane miscellany promptly can be used as raw material.So just can use common refinery's gas, though the effect that transforms effectively descends without special the separation.Similarly, thinner such as nitrogen, carbon oxides also may reside in the reaction mixture and the unlikely injurious effects that bring.
One of present method more preferably aspect is to make the miscellany and the catalyzer of propylene or iso-butylene, ammonia, oxygen mixed under comparatively high temps and normal atmosphere or approximate normal atmosphere, preparation vinyl cyanide or methacrylonitrile.Present method directly makes propylene, ammonia, oxygen contact with fluidized catalyst and prepares vinyl cyanide more preferably under comparatively high temps.
Any oxygen source all can use in the method, considers from economic angle, the preferred oxygen that comes from air that adopts, and, use purified relatively molecular oxygen can obtain identical result from the viewpoint of pure technology.In the reactor feed mol ratio of oxygen and alkene should 0.2: 1 to 3.0, preferred ratio is 1.5 to 2.5.
The mol ratio of ammonia and alkene can be 0.5: 1 to 5: 1 scope in the reactor feed, and preferred ratio is 0.9: 1 to 1.3: 1.Ammonia-alkene is not than there being the actual upper limit, but do not have reason to surpass 1.3: 1 usually.When ammonia-alkene ratio is significantly less than stoichiometric calculation ratio in the time of 1: 1, can generate the olefin oxidation derivative of different amounts.Can generate aldehyde and acid when ratio surpasses this range limit, its quantity is insignificant; And work as ratio less than prescribing a time limit under this scope, the growing amount of nitrile is descended.Make the people surprised be, the ammonia-alkene of defined than scope in, ammonia can maximize the use, this is an ideal very.Usually, unreacted alkene and unconverted ammonia all can be recycled.
In some cases, the water that enters in the mixture in the reactor can improve the selectivity of reaction and the productive rate of nitrile.But among the present invention, it is not necessary adding water in raw material, because can generate water in the reaction process.
If interpolation water, the ratio that in general adds the water yield and amount of alkene should be greater than 0.25: 1.This ratio all was special ideal from 1: 1 to 4: 1.Higher ratio also can use, for example greater than about 10: 1.
Being reflected at about 300 ℃ carries out to about 600 ℃ temperature range.Preferred range is from about 380 ℃ to 500 ℃, and particularly preferred scope is from about 400 ℃ to 480 ℃.
The pressure that reaction is carried out is another varying parameter.Can under any pressure, react, but suitable pressure is about 1 normal atmosphere or is higher than normal atmosphere (2 to 5 normal atmosphere).
The apparent duration of contact of reaction is not crucial, and its scope can from 0.1 to 50 second.Certainly, optimum duration of contact is difference according to the alkene of participating in reaction, but be 1 to 15 second usually preferred duration of contact.
The device that any kind suits to carry out in gas phase oxidative ammonolysis all can be used for implementing present method.This method can also may be carried out batchwise continuously.Catalyst bed can be the fixed bed that a large amount of particulate state or spherical catalyst are housed, or preferably is known as the catalyst bed of " fluidized-bed ".Implement method of the present invention and can utilize the fluidisation ammonia oxidation reactor of any routine.For example the reactor of describing in the United States Patent (USP) of announcing 1966.1.18 day 3230246 promptly can be used for implementing the present invention, and this piece patent is hereby incorporated by reference document.In addition, Chang Gui pipeline reactor also can use.
Reactor can reach temperature of reaction before or after the reaction raw materials miscellany imports.But,, reaction is carried out in a continuous manner for large-scale operation.Design has the reflux of unreacting olefin in such system, and also design has the regular regeneration or the reactivate system of catalyzer, for example at high temperature makes catalyzer contact with air and realizes it.
The product of reaction can reclaim with the known any method of this area professional.Thereby wherein a kind of method is to remove reaction product with cold water or suitable solvent wash from the gas that reactor flows out.If desired, available acidated water comes the absorption reaction product and the unconverted ammonia that neutralizes.The available conventional means of final recovery of product is realized.When water is cooked washing composition, add the efficient that suitable wetting agent can improve washing operation therein.If use molecular oxygen as oxidant, separated then that the miscellany of the end product after the nitrile can be with remnants in this process, contained the unreacting olefin that is circulated in the reactor and the miscellany of oxygen carbonic acid gas is removed.If make oxygenant with air rather than with molecular oxygen, then available a kind of non-polar solvent such as hydrocarbon fraction wash the resultant product of having separated nitrile and other carbonyl products, thereby reclaim wherein unreacted alkene.In the case, residual gas can discard.Also add suitable inhibitor in the design and prevent unsaturated product generation polymerization in the recycling step.
The catalyzer that the inventive method is used is miscellany or the compound or the possible mixture of the oxide compound of following substances.They are: molybdenum, bismuth, iron, cobalt, nickel, chromium; Phosphorus or antimony or its miscellany; Basic metal or its miscellany; Optional from alkaline-earth metal, rare earth metal, niobium, thallium, arsenic, magnesium, zinc, cadmium, vanadium, boron, calcium, tin, germanium, manganese, tungsten, tellurium or its miscellany.Its composition is taken temperature by following experiment and is levied:
Mo
aBi
bFe
cCo
dNi
eCr
fX
gY
iZ
iO
k
Wherein X is one or more elements that are selected from phosphorus or antimony or its miscellany; Y is a kind of basic metal or its miscellany; Z is alkaline-earth metal, rare earth metal, niobium, thallium, arsenic, magnesium, zinc, cadmium, vanadium, boron, calcium, tin, germanium, manganese, tungsten, tellurium or its miscellany.(a) wherein is the number of 10-15, (b) be the number of 1-5, (c) be the number of 0.5-5, (d) and (e) being the number of 0.1-6, (f) is the number of 0.1-4, (g) is the number of 0.1-4, (i) be the number of 0.1-2, (j) be the number of 0-3 and (k) for a certain number, its numerical value depends on the valency requirement of other elements of existence.(g) preferable range is 0.75-3.When Y was basic metal except that sodium, preferable range (i) was 0.1-1.5.In addition, the surface-area of this catalyzer is generally less than 100M
2/ g, preferable range is about 20M
2/ g is to about 50M
2/ g.
Those skilled in the art can be with any one prepares catalyzer of the present invention in the several different methods for preparing catalyzer.For example, available co-precipitation various ingredients prepares catalyzer, then with the coprecipitate drying, be milled to suitable size.Perhaps, with ordinary method coprecipitate is made pulpous state or spraying drying.Catalyzer can be squeezed into and granularly also can make its globulate as already known processes in oil.Perhaps, catalyst component can with the carrier of pulpous state mixed and after drying or filling on silicon-dioxide or other carriers.
In two steps solid support material is added catalyzer and can make a kind of very anti abrasive catalyzer.At first, the miscellany of preparation and heat treated catalyst activity component and 0 to 60% (wt) solid support material then, joins remaining carrier substance in the heat treated powdered catalyst.
Introduce the basic metal of catalyzer and can use oxide form, also can be with any through calcining the salt form that can produce oxide compound.Preferred salt is nitrate, because of it is easy to obtain and dissolving easily.
The bismuth of introducing catalyzer can be oxide form or any salt form that can produce oxide compound through calcining.Preferably in catalyzer, be easy to the salt that dispersive water-soluble salt and thermal treatment can produce steady oxide.A kind of source of bismuth is the Bismuth trinitrate that is dissolved in dilute nitric acid solution.The Bismuth trinitrate that use is dissolved in the molten metal nitrate is particularly preferred.
In catalyzer, introduce the iron component and can use any type of iron containing compounds, as long as it produces oxide compound when calcining.The same with other elements, preferred water miscible salt preferably uses iron nitrate so that it can be dispersed in the catalyzer.Can introduce cobalt and nickel with method.
Introduce the molybdenum thing, any type of molybdenum oxide such as molybdenum dioxide, molybdic oxide, five oxide molybdenum or molybdenum sesquioxide all can use; Preferred hydrolyzable or the decomposable molybdenum salt of using.Most preferred raw material is Ammonium Heptamolybdate (AHM).
Introduce the form that phosphorus can alkali metal salts or ammonium salt, preferably phosphoric acid.Optimum method is to use phospho-molybdic acid, has also introduced molybdenum so simultaneously.
Introduce other elements, can again the nitrate that generates be combined with catalyzer earlier with the raw material oxidizing acid such as the nitric acid oxidation of metallic forms.Usually nitrate is all simple and easy gets, and is to use starting material very easily.
This area professional can also use other starting material, when particularly being unsuitable for scale operation from economic angle preferred raw material mentioned above.Generally speaking, any compound that contains required catalyst component all can use, as long as it generates the oxide compound of instant catalyzer (instant catalyst) under can disclosed hereinafter Heating temperature.
This catalyzer has good active when carrier free is used.It also can use with carrier.The preferably whole components about 10% to 90% of vehicle weight.Any known solid support material all can use, as silicon-dioxide, aluminum oxide, zirconium white, titanium oxide, steel aluminium stone, silicon carbide, aluminium oxide-silicon oxide, inorganic phosphate such as aluminum phosphate, silicate, aluminate, borate, carbonate with such as float stone, cover materials such as moral soil and contact with catalyzer under reaction conditions with other and can keep stable material.The silica gel of high dispersing can also be joined in the solid support material.Preferred carrier is a silicon-dioxide, during the preparation catalyzer silicon-dioxide of colloidal sol shape or smoke-like is joined in the slurry to get final product.The weight content of carrier is usually at 10-70%, and preferable range is 40-60% (wt.).
Heating at high temperature can improve activity of such catalysts.Usually, under the temperature between about 110 ℃ to 350 ℃ with catalyzer miscellany spraying drying, about 1 to 24 hour of thermal treatment or longer then.Thermal treatment temp is about 260 ° to about 1000 ℃, and preferable range is 300-400 ℃ to 550-700 ℃.
Usually the calcining of catalyzer is at high temperature time-consuming few.Getting former material samples does drop measuring catalyst activity can determine whether the calcining of carrying out is abundant under any specified criteria.Calcining is preferably in the unlimited stove case to be carried out, and air or oxygen can obtain circulation like this, so that the oxygen that timely supplement consumed is fallen.
In addition, also available before use reductive agent of catalyzer such as ammonia carry out activation or preconditioning, and its condition is to have air in certain amount, and temperature is 260 to 540 ℃.
Following embodiment makes more completely in order to the preferred method of explanation preparation catalyzer of the present invention and to the inventive method and setting forth.Except the preparation unsaturated nitrile, catalyzer of the present invention also can be used for conversion of olefines, as propylene and iso-butylene are changed into corresponding unsaturated aldehyde and unsaturated carboxylic acid.
Embodiment 1-8
Catalyzer used in the embodiment of the invention is by following step preparation.
Embodiment 1
Use the 400ml beaker, about 70 ℃ (~70 ℃) melt Fe (NO together with the metal nitrate of following order
3)
39H
2O (65.08g), Co (NO
3)
26H
2O (121.89g), Ni (NO
3)
26H
2O (65.57g) (AHM), Bi (NO
9)
35H
2O (65.24g), KNO
3(1.63g).With (NH
4)
6M
oO
244H
2O (184.85g) is dissolved in 300ml distilled water, then adds CrO
3(8.05g) make solution.The metal nitrate melts is joined in the above-mentioned solution, add 40% silicon dioxide gel (625g) again.The gained yellow slurry be heated to about 90 ℃ (~90 ℃) while stirring about 3 hours (~3hours), spraying drying then.The denitration under 270 ℃, 2 hours and 425 ℃, 2 hours conditions of gained material, at last in air in 580 ℃ of calcinings 2 hours.
Embodiment 2
In the 400ml beaker, about 70 ℃ (~70 ℃) melt Fe (N) together with the metal nitrate of following order
3O
39H
2O (65.10g), Co (NO
3)
26H
2O (121.93g), Ni (NO
3)
26H
2O (65.6g), Bi (NO
3)
35H
2O (65.20g), KNO
3(1.63g).AHM (184.91g) is dissolved in 300ml distilled water, then adds CrO
3(6.24g) and 85%H
3PO
4(1.86g) make solution.The metal nitrate melts is joined in the above-mentioned solution, add 40% silicon dioxide gel (625g) again.Gained yellow slurry stirring heating about 90 ℃ (~90 ℃), about 3 hours (~3hours), spraying drying then.The denitration under 270 ℃, 2 hours and 425 ℃, 2 hours conditions of gained material, at last in air in 580 ℃ of calcinings 2 hours.
Embodiment 3
In the 400ml beaker, about 70 ℃ (~70 ℃) melt Fe (NO together with the metal nitrate of following order
3)
39H
2O (65.1g), Co (NO
3)
26H
2O (121.9g), Ni (NO
3)
26H
2O (65.6g), Bi (NO
3)
35H
2O (65.3g), KNO
3(1.6g).AHM (184.9g) is dissolved in 300ml distilled water, then adds CrO
3(4.0g) and 85%H
3PO
4(4.65g) make solution.The metal nitrate melts is joined in the above-mentioned solution, add 40% silicon dioxide gel (625g) again.The gained yellow slurry is heated to about 90 ℃ (~90 ℃) about 3 hours (3hours) while stirring, spraying drying then, the denitration under 270 ℃, 2 hours and 425 ℃, 2 hours conditions of gained material, at last in air in 580 ℃ of calcinings 2 hours.
Embodiment 4
Use the 400ml beaker, about 70 ℃ (~70 ℃) melt Fe (NO together with the metal nitrate of following order
3)
39H
2O (65.15g), Co (NO
3)
26H
2O (122.0g), Ni (NO
3)
26H
2O (63.3g), Bi (NO
3)
35H
2O (65.3g), KNO
3(.8g), Cs (NO
3) (1.26g).TheAHM (185.06g) is dissolved in 300ml distilled water, then adds CrO
3(4.03g) and 85%H
3O
4(4.65g) make solution.The metal nitrate melts is joined in the above-mentioned solution, add 40% silicon dioxide gel (625g) again.The gained yellow slurry be heated to about 90 ℃ (~90 ℃) about 3 hours (~3hours), spraying drying then, the denitration under 270 ℃, 2 hours and 425 ℃, 2 hours conditions of gained material, at last in air in 580 ℃ of calcinings 2 hours.
Embodiment 5
Use the 400ml beaker, about 70 ℃ (~70 ℃) melt Fe (NO together with the metal nitrate of following order
3)
39H
2O (62.21g), Co (NO
3)
26H
2O (116.51g), Ni (NO
3)
26H
2O (62.68g), Bi (NO
3)
35H
2O (62.36g), KNO
3(1.56g).AHM (176.7g) is dissolved in 300ml distilled water, then adds CrO
3(3.85g) and 85%H
3PO
4(4.44g) make solution.The metal nitrate melts is joined in the above-mentioned solution, add Sb again
2O
3(11.22g) with 40% silicon dioxide gel (625g).The gained yellow slurry heated about 90 ℃ (~90 ℃) about 3 hours (~3hours), spraying drying then, the denitration under 270 ℃, 2 hours and 425 ℃, 2 hours conditions of gained material, at last in air in 580 ℃ of calcinings 2 hours.
Embodiment 6
Use the 400ml beaker, about 70 ℃ (~70 ℃) melt Fe (NO together with the metal nitrate of following order
3)
39H
2O (59.3g), Co (NO
3)
26H
2O (111.0g), Ni (NO
3)
26H
2O (59.7g), Bi (NO
3)
35H
2O (59.4g), KNO
3(1.5g).AHM (168.4g) is dissolved in 300ml distilled water, then adds CrO
3(3.7g) and 85%H
3PO
4(4.2g) make solution.The metal nitrate melts is joined in the above-mentioned solution, add Sb again
2O
3(22.5g) with 40% silicon dioxide gel (625g).The gained yellow slurry be heated to about 90 ℃ (~90 ℃) about 3 hours (~3hours) spraying drying then, the denitration under 270 ℃, 2 hours and 425 ℃, 2 hours conditions of gained material, at last in air in 580 ℃ of calcinings 2 hours.
Embodiment 7
Use the 400ml beaker, about 70 ℃ (~70 ℃) melt Fe (NO together with the metal nitrate of following order
3)
39H
2O (62.22g), Co (NO
3)
26H
2O (116.54g), Ni (NO
3)
26H
2O (60.46g), Bi (NO
3)
35H
2O (62.38g), KNO
3(.78g) and Cs (NO
3) (1.20g).AHM (176.75g) is dissolved in 300ml distilled water, then adds CrO
3(3.85g) and 85%H
3PO
4(4.44g) make solution.The metal nitrate melts is joined in the above-mentioned solution, add Sb again
2O
3(11.22g) with 40% silicon-dioxide (625g) solution.The gained yellow slurry heat about 90 ℃ (~90 ℃), about 3 hours (~3hours), spraying drying then, the denitration under 270 ℃ of 2 hours and 425 ℃, 2 hours conditions of gained material, at last in air in 580 ℃ of calcinings 2 hours.
Embodiment 8
Use the 400ml beaker, about 70 ℃ (~70 ℃) melt Fe (NO together with the metal nitrate of following order
3)
39H
2O (59.3g), Co (NO
3)
26H
2O (111.0g), Ni (NO
3)
26H
2O (57.6g), Bi (NO
3)
35H
2O (59.4g), KNO
3(0.7g), and Cs (NO
3) (1.2g).AHM (168.3g) is dissolved in 300ml distilled water, then adds CrO
3(3.7g) and 85%H
3PO
4(4.2g) make solution.The metal nitrate melts is joined in the above-mentioned solution, add Sb again
2O
3(22.4g) with 40% silicon dioxide gel (625g).The gained yellow slurry be heated to about 90 ℃ (~90 ℃) about 3 hours (~3hours), spraying drying then, the denitration under 270 ℃ of 2 hours and 425 ℃, 2 hours conditions of gained material, at last in air in 580 ℃ of calcinings 2 hours.
In the given example, the transformation efficiency of unsaturated nitrile is defined as follows:
Change into the per pass conversion (mol of unsaturated nitrile
Table I has been summarized several groups of oxidative ammonolysiss of making hydrocarbon feed and participating in just like the catalyst component that example 1-8 method makes with propylene.Each reaction is all carried out in the 40cc fluidized-bed reactor, and each catalyzer is all at first used NH
3/ N
2440 ℃ of reduction 10 minutes.(reaction) stablized and collected sample after about 40 hours.
Reaction gas flow is collected in containing the bubble-cap washer of cold HCl solution.Then behind end of operation, determine that by Perkin-Elmer Model 154 gas chromatographs this chromatographic instrument is equipped with the gas phase analysis separator column with soap film gas meter mensuration waste gas ratio, exhaust gas constituents.
When reclaimer operation finishes, all washingss with distilled water diluting to about 200g.With the internal standard substance of the methylethylketone that claimed weight (MEK) as about 50g diluting soln of five equilibrium.
The 6ml sample is analyzed in the 5710Hewlett-Packard gas chromatograph, and this chromatographic instrument is equipped with flame ionization detector and carbon packed column (carbopak column).The amount of HCN is then used titration AgNO
3Measure.
Table I embodiment catalyst component temperature vinyl cyanide HCN CO
2The CO vinyl cyanide
(℃) (%ppc) (%ppc) (%ppc) (%ppc) selectivity (%) 1 50%Ho
13Bi
1.67Fe
2.0Co
5.2Ni
2.8K
.2Cr
1.0O
x* 50%SiO
2435 76.2 6.6 6.7 2.9 78.2 2 50%Ho
13Bi
1.67Fe
2.0Co
5.2Ni
2.8K
.2Cr
.8P
.2O
x* 50%SiO
2435 77.7 6.8 6.5 2.8 78.9 3 50%Ho
13Bi
1.67Fe
2.0Co
5.2Ni
2.8K
.2Cr
.5P
.5O
x* 50%SiO
2435 78.0 6.3 6.3 3.1 80.3 4 50%Ho
13Bi
1.67Fe
2.0Co
5.2Ni
2.8K
.1Cs
.08Cr
.5P
.5O
x* 50%SiO
2435 79.1 5.8 5.4 2.6 81.6 5 50%Ho
13Bi
1.67Fe
2.0Co
5.2Ni
2.8K
.2Cr
.5P
.5Sb
1.0O
x* 50%SiO
2435 78.3 5.4 5.4 2.7 81.2 6 50%Ho
13Bi
1.67Fe
2.0Co
5.2Ni
2.8K
.2Cr
.5P
.5Sb
2.1O
x* 50%SiO
2430 80.2 5.5 6.0 2.9 81.8 7 50%Ho
13Bi
1.67Fe
2.0Co
5.2Ni
2.8K
.1Cs
.08Cr
.5P
.5Sb
1.0O
x* 50%SiO
2435 79.4 3.9 5.7 2.7 82.6 8 50%Ho
13Bi
1.67Fe
2.0Co
5.2Ni
2.8K
.1Cs
.08Cr
.5P
.5Sb
2.1O
x* 50%SiO
2435 80.2 5.0 5.3 2.4 83.2