CN1305817C

CN1305817C - Preparation of at least one partial oxidation and/or ammoxidation product of propylene

Info

Publication number: CN1305817C
Application number: CNB038254107A
Authority: CN
Inventors: C·黑希勒; G-P·申德勒; J·佩佐尔特; C·阿达米; O·马赫哈默; K·J·米勒-恩格尔; H·马尔坦
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 2002-09-27
Filing date: 2003-09-18
Publication date: 2007-03-21
Anticipated expiration: 2023-09-18
Also published as: ZA200503358B; CN1703387A; CN1310855C; DE10245585A1; CN1701054A

Abstract

Preparation of at least one partial oxidation and/or ammoxidation product of propylene involves subjecting crude propylene (prepared by dehydrogenation or oxydehydrogenation in the presence and/or absence of oxygen) in the presence of unconverted propane as a constituent of a gas mixture 2 which comprises a total 4C-hydrocarbon content of at most 3 vol.%, to a heterogeneously catalyzed gas phase partial oxidation and/or ammoxidation. Preparation of at least one partial oxidation and/or ammoxidation product of propylene involves: (a) subjecting crude propane in the presence of and/or absence of oxygen to a homogeneously and/or a heterogeneously catalyzed dehydrogenation and/or oxydehydrogenation to obtain a propane- and propylene-containing gas mixture 1; (b) optionally removing and/or converting to other compounds a portion of the constituents other than propane and propylene contained in the gas mixture 1 to obtain a gas mixture 1' comprising propane and propylene and also compounds other than oxygen, propane and propylene; and (c) subjecting gas mixture 1 and/or gas mixture 1' as a constituent of a gas mixture 2 to a heterogeneously catalyzed gas phase partial oxidation and/or partial gas phase ammoxidation of propylene contained in gas mixture 1 and/or 1'. The total content of 4C-hydrocarbons of gas mixture 2 is at most 3 vol.%.

Description

At least a incomplete oxidation of propylene and/or the preparation of ammoxidation product

The present invention relates to prepare the incomplete oxidation of at least a propylene and/or the method for ammoxidation product, in the method:

A) in the first step, the existence of oxygen and/thick propane is carried out homogeneous phase and/or heterogeneous catalyst dehydrogenation and/or oxydehydrogenation in the presence of not, contain the gaseous mixture 1 of propane and propylene with production,

And

B) if suitable, to be present in the part component except that propane and propylene in the gaseous mixture 1 that in the first step, generates from gaseous mixture 1, to separate also/or be converted into other compound, thereby by gaseous mixture 1 production contain the gaseous mixture 1 of the compound outside propane and propylene and deoxygenation, propane and the propylene ', and at least one further step

C) with gaseous mixture 1 and/or gaseous mixture 1 ' as the component of gaseous mixture 2 be present in gaseous mixture 1 and/or gaseous mixture 1 ' in the heterogeneous catalyst gas phase incomplete oxidation and/or the incomplete gas phase ammonoxidation of propylene.

With regard to this paper, thick propane is not only to contain propane and possible propylene, but also contain outside propane and the propylene at least a, usually at least two or three and the frequent gas that contains propane of at least four kinds or five kinds compounds.These compounds can detect in thick propane by the chromatography of for example gas-chromatography and so on.

With regard to this paper, the oxygen that the oxydehydrogenation effect of propane is existed is forced to carry out and is not wherein had free hydrogen to generate the dehydrogenation that maybe can detect as intermediate.The conventional dehydrogenation of carrying out with heat absorption is different, and oxydehydrogenation is heat release.The oxydehydrogenation of propane can be at elevated temperatures, carry out (promptly not having for example solid catalyst in the presence of homogeneous catalyst; Referring to for example US-A3798283) or in the presence of heterogeneous catalyst, carry out (promptly on solid catalyst; Referring to DE-A2058054 and DE-A 19530494).

Conventional dehydrogenation is identical substantially therewith, and wherein dehydrogenation is (referring to for example EP-A 731077 and the WO 01/96270) that carries out under the situation of the active participation that does not have oxygen.In this case, the main by product of generation is a hydrogen, rather than the water that generates in the oxydehydrogenation situation.

With regard to this paper, the complete oxidation of propylene is that all carbon that are present in propylene all are converted into carbon oxides (CO, CO ₂) conversion.Herein, other reaction of all of propylene and molecular oxygen all is included in the term " incomplete oxidation ".The feature of ammoxidation is also to relate to ammonia in the reaction.

In this article, preferred incomplete oxidation of propylene and/or ammoxidation product are propenal, vinylformic acid, propylene oxide and vinyl cyanide.

The product of propylene incomplete oxidation and/or ammonia oxidation is important intermediate, for example can be used for preparing polymkeric substance.

This incomplete oxidation and/or ammoxidation are carried out (can control the amount of ammonia in the reaction gas mixture in a manner known way, thereby carry out basically the just reaction of incomplete oxidation or be the overlapping of the reaction of incomplete ammonia oxidation or these two kinds of reactions) according to known method itself.Their heterogeneously catalysed gas phase reactions on solid (normally oxidation) catalyzer.

Can quote from DE-A 2 351 151 (propylene is converted into the example that propenal and/or acrylic acid example and propylene are converted into vinyl cyanide) and EP-A 372 972 (propylene is converted into the example of propylene oxide) by way of example.

As oxygenant, use molecular oxygen usually.Can with for example pure state or with in incomplete oxidation and/or oxidative ammonolysis, be essentially inert gasses blended form (for example air) molecular oxygen added in the reaction gas mixture.Reactant in the reaction gas mixture is often also by at least a rare gas element (N for example ₂, H ₂O, CO, CO ₂, stable hydrocarbon is as C ₁-C ₅Hydrocarbon (described in DE-A 1924431 and EP-A 293224), He and/or Ar etc.) dilution, to help heat extraction and reaction safety carried out.DE-B 2251364 special recommendations use butane as inert dilution gas.As mentioned above, the characteristics of ammoxidation are also to have ammonia.

Different with the situation of laboratory test and pilot plant test, the propylene feedstocks of using on the technical scale is not chemical purified propylene usually, but contains impurity but the higher crude propylene (for example " polymerization-grade " or " chemical grade " of purity; Referring to DE-A 10131297).

The segregation of this purer crude propylene is comparatively complicated, and spends more.It is begun by thick alkane usually, and generally comprises the purification step (referring to for example DE-A 3 521 458) that at least one is gone out unreacted alkane separation from the propylene that generates by physical method.Purification step generally includes the alkene of removing outside the propylene and is different from the by product of propylene with other, comprises the accessory constituent that is present at first in the thick alkane.

Above-mentioned separation usually needs big investment, and because the similarity of olefin/paraffin, is unusual consumes energy.Therefore, they only use together with refining cracking unit and steamed cracking unit usually, and only because the major part to the crude propylene that makes by this way has big demand (" scale economics ") in polymerization (for example preparing polypropylene) subsequently, and result value gets a promotion, thereby is only worth.

These ratios of carrying out the crude propylene of incomplete oxidation and/or ammonia oxidation are inferior important, and be actually accessory requirement, the crude propylene that Here it is produces by this way still has the reason of acceptable price during as the raw material of incomplete oxidation and/or ammonia oxidation.

Have only when might clipped or during whole described separation, the price of this raw material just can obviously reduce.

As the method that addresses this problem, EP-B 938463 suggestions, in the first step, for example in the presence of oxygen and heterogeneous catalyst with the dehydrogenation of thick propane part, manufacturing contains first gaseous mixture of propylene and propane, this mixture is carried out heterogeneous catalyst gas phase incomplete oxidation as the component former state (promptly not carrying out intermediate treatment) of second gaseous mixture, and the propylene oxidation that will be present in first gaseous mixture is propenal and/or vinylformic acid.

About the purity problem of used thick propane, EP-B 938463 points out below third column the 40th row: " purity of raw material alkane is not particularly limited." " and the raw material alkane can be the mixture of multiple alkane.Charging can comprise at least 30 moles of %, preferred at least 50 moles of %, the more preferably propane of at least 80 moles of % usually.The alkane source that is used for the inventive method, promptly propane feed is not crucial.”

Below the 3rd hurdle the 17th row, EP-B 938463 also points out: " therefore, after reclaiming propenal, the uncondensable gas that comprises propane can recycle without important, extra purification step.”

The basic instruction with EP-B 938463 of the instruction of EP-A 117146 is suitable, different is EP-A117146 recommends to propane when carrying out heterogeneous catalyst dehydrogenation eliminating oxygen.

In addition, about the problem of above-mentioned cycling stream, EP-A 117146 points out below the 11st page of the 14th row: " because light hydrocarbon and heavy hydrocarbon by product, for example methane, ethane, ethene, butane and butylene, with propenal or C ₃Seethe with excitement under the temperature that the boiling point of hydrocarbon differs greatly, therefore can they be separated by distillation.Perhaps, can purge the logistics of the by product that comprises the amount of concentrating." feasibility of this circulation gas purge stream is also shown in EP-B 938463 the 11st hurdle the 10th row.

These two documents are not all recognized the necessity of isolating above-mentioned accessory constituent before incomplete oxidation and/or ammonia oxidation.

After EP-B 938463 and EP-A 117146, WO 01/96270 has proposed opinion again.For example, it is pointed out below page 4 the 10th row: " in the methods of the invention, the feed gas mixture of delivering to oxidation stage B can also contain other component certainly outside said components, for example CO, CO ₂, H ₂The rare gas of O, for example He and/or Ar, hydrogen, methane, ethene, butane, butylene, butine, pentane, propine, propadiene and/propenal.”

In addition, about being used for the thick propane of dehydrogenation step, WO 01/96270 points out below the 15th page of the 26th row: " in the present invention, the propane that importantly is used for stage A needs not to be pure propane.On the contrary, used propane can comprise other gas that is up to 50 volume %, for example ethane, methane, ethene, butane, butylene, propine, acetylene, H ₂S, SO ₂, pentane etc.”

Though WO 01/96270 also is recommended in before the incomplete oxidation that first gaseous mixture is further used for being present in propylene wherein, isolate at least a portion and be present in hydrogen in first gaseous mixture that in dehydrogenation step, generates and contain propane and propylene, and in this sepn process, optionally isolate other component outside propane and the propylene, substantially all isolate in case of necessity, and EP-B731077 thinks, particularly preferably, before further using first gaseous mixture, from this first gaseous mixture, quantitatively remove and remove propane, all other components outside propylene and the possible molecular oxygen, but, any sepn process that is used for this purpose all has disadvantageous effect to the economy of whole process, and, secondly, find that the process that is used for this Quantitative Separation that some above-mentioned documents are recommended is more inappropriate.For example, absorption/desorption process that WO 01/96270 recommends the 16th page of bottom belongs to latter event, finds that in recent detection it is unsuitable for relatively for example from C ₃Separation of C in the hydrocarbon ₄Hydrocarbon.

In drawing prior art, do not recognize the necessity of following steps: after dehydrogenation and/or oxydehydrogenation step or even before this step, isolate specific accessory constituent, thereby in oxidation and/or ammonia oxidation step, when raw material changes thick propane into by crude propylene, generating the generation that reduces by product outside the required target product.Though prior art recognizes that the by product that generates along with the change of raw material variation has also taken place (according to WO 01/96270, for example had propane when incomplete oxidation, can increase the formation of propionic aldehyde and/or propionic acid; But the advantage of not isolating propane certain embodiments from the propylene that generates is not endowed prior meaning), but this is not considered to especially crucial, because pre-separation is more more complicated with separating of by product than target product usually.In view of this background, also think the separating of the by product that under any circumstance all must carry out target product and generation.

This suggestion for example also can seen among EP-A 1192987, DE-A 10122027, EP-A 608838, EP-A529853, DE-A 10051419 or the DE-A 10119933 significantly, they are recommended in single reaction zone (carrying out at least two reaction zones usually) and implement this paper begin the method locating to define on catalyst charge, and the activating oxide composition of described catalyst charge is made up of at least a poly-metal deoxide that contains elements Mo, V and Te and/or Sb.The basis of this process is that the activating oxide composition of being correlated with can either catalysis generates the oxidative dehydrogenation (following referring to for example EP-B938463 the 4th hurdle the 37th row) of propylene by propane, incomplete oxidation that again can catalyzing propone and/oxidative ammonolysis.In the nature of things, in this process gaseous mixture 1 former state be used for the incomplete oxidation of carrying out subsequently and/the ammonia oxidation step.

But, for example EP-A 1192987 suggestion below the 9th page of the 26th row: " similarly, without limits to the source of alkane.It can be used as pure substance and buys, and also can be used as with the mixture of alkene and/or other impurity to buy.In addition, alkane (regardless of its source) and alkene (regardless of its source) can mix as required." fully similarly, DE-A 10122027 points out at page 3 the 35/36th row: " purity for the propane that is used for the inventive method does not have extra high requirement." WO 0196271 thinks that equally the very big thick propane of purity difference is available.

The weak point of the above suggestion of prior art is, they do not solve following problem: may be present in the component in the cheap thick propane or in the first step, generate by these components and thereby be present in compound in first gaseous mixture (they do not exist, or only be present in the used usually thick propane with trace, thereby its negative effect is out in the cold always so far), the heterogeneous catalyst incomplete oxidation of carrying out subsequently and/ammonia oxidation in, owing to reduced catalyzer required propylene incomplete oxidation and/activity and/or selectivity aspect the ammonia oxidation become catalyzer poison.

By conscientious careful research, have now found that C ₄Hydrocarbon (compound that constitutes by 4 carbon atoms and hydrogen) generally and particularly wherein the group of alkene representative (1-butylene, anti--2-butylene, suitable-2-butylene and iso-butylene) and particularly wherein 1-butylene formed this catalyzer poison.But saturated representative and other undersaturated representative also have negative effect.

Yet C ₄Hydrocarbon (for example normal butane, Trimethylmethane, anti--2-butylene, suitable-2-butylene, iso-butylene, 1,3-divinyl, 1,2-divinyl, ethyl acetylene and/or 2-butyne) be to follow propane everywhere and the compound that exists, thereby be present in the cheap thick propane with bigger amount usually.For saturated C ₄Hydrocarbon, situation are particularly like this.Under the condition of incomplete dehydrogenation of propane and/or oxydehydrogenation, always by saturated C ₄Hydrocarbon generates at least some C ₄Alkene, the 1-butylene of especially special trouble.

The purpose of this invention is to provide this paper begin the preparation propylene locating to describe at least a incomplete oxidation and/method of ammoxidation product.Different with the method for prior art, the inventive method has been considered the above-mentioned fact.

We find, above-mentioned purpose by a kind of at least a incomplete oxidation for preparing propylene and/method of ammoxidation product is achieved, in the method:

And

C) with gaseous mixture 1 and/or gaseous mixture 1 ' as the component of gaseous mixture 2 be present in gaseous mixture 1 and/or gaseous mixture 1 ' in the heterogeneous catalyst gas phase incomplete oxidation and/or the incomplete gas phase ammonoxidation of propylene,

The content of 1-butylene in the gaseous mixture 2≤1 volume % wherein.

In inventive method, based on the amount that is present in these components in the gaseous mixture 1, outside propane and the propylene, be converted into gaseous mixture 1 ' process in from mixture 1, separate also/or the amount that is converted into the component of other compound reach as high as 5 weight %, or reach as high as 10 weight %, or reach as high as 20 weight %, or reach as high as 30 or 40 weight %, or reach as high as 60 weight %, or reach as high as 70 or 80 weight %, or reach as high as 85 or 90 weight %, or reach as high as 94 weight %, or reach as high as 96 or 98 weight %, or reach as high as 99 weight % or higher.

According to the present invention, the content of 1-butylene in the gaseous mixture 2≤0.9 volume % or≤0.75 volume % or≤0.6 volume % or≤0.5 volume % or≤0.4 volume %, preferred especially≤0.3 volume %, very particularly preferably≤0.2 volume % and more preferably≤0.1 volume % or≤0.05 volume % or≤0.03 volume % or≤0.01 volume %.No longer comprise under the situation of any 1-butylene at gaseous mixture 2, this disadvantageous effect of process occurs not more at all.But total appraisal from economy, have reason and accept the part disadvantageous effect of 1-butylene in the gaseous mixture 2, and the content of letting alone in gaseous mixture 2 is the value of 〉=0.001 volume %, or 〉=0.003 volume % or 〉=0.006 volume % or under extreme case 〉=0.009 volume %.

In the method for the invention, preferred above-mentioned restriction not only is applicable to the amount that is present in 1-butylene in the gaseous mixture 2, and be applicable to simultaneously various other possible representatives (promptly instead-2-butylene, suitable-2-butylene, iso-butylene) of butylene independently of one another, and very particularly preferably be applicable to the total amount of butylene in the gaseous mixture 2 simultaneously.This means the gaseous mixture 2 that is suitable for the object of the invention be for example following those, wherein:

The total content of the content of-1-butylene≤1 volume % and butylene≤1 volume %; Or

The total content of the content of-1-butylene≤0.5 volume % and butylene≤1 volume %; Or

The total content of the content of-1-butylene≤0.3 volume % and butylene≤1 volume %; Or

The total content of the content of-1-butylene≤0.5 volume % and butylene≤0.75 volume %; Or

The total content of the content of-1-butylene≤0.75 volume % and butylene≤1 volume %; Or

The total content of the content of-1-butylene≤0.4 volume % and butylene≤1 volume %; Or

The total content of the content of-1-butylene≤0.2 volume % and butylene≤1 volume %; Or

The total content of the content of-1-butylene≤0.5 volume % and butylene≤0.5 volume %; Deng.

The inventive method provides two kinds of possible approach of observing above-mentioned restriction substantially; Wherein can adopt only or adopt two kinds of approach simultaneously in the two.

At first, raw material can be or not contain C ₄Hydrocarbon or only contain the C of following amount ₄The thick propane of hydrocarbon: limit 1-butylene, (total) butylene and (total) C in the gaseous mixture 2 according to the inventive method ₄The restriction of hydrocarbon content is observed.Possible C in the thick propane ₄What content of hydrocarbon is compatible with the inventive method to depend on the final condition that the inventive method the first step is adopted especially, and can be determined in several trial tests that are subject to these specific border conditions in all cases by those skilled in the art.

If must from the thick propane of commerce, isolate C ₄Hydrocarbon, this can carry out in self known mode, for example by purifying.Certainly, all other separation methods, for example adsorption/desorption (as pressure-swing absorption), extraction and/or adsorption/desorption also are fine.

In addition, perhaps, can from gaseous mixture 1, isolate C as selecting ₄Hydrocarbon is overall, particularly 1-butylene or butylene, thereby make these components contents according to the present invention with gaseous mixture 1 further as gaseous mixture 1 ' before be in or be lower than according to the present invention and the restriction that will observe.Only for example undertaken in the process of oxydehydrogenation or dehydrogenation step, for example when having generated interfering C by for example propane by disproportionation and/or metathesis ₄During hydrocarbon, just adopt this method.Particularly when the portion gas circulation method that has adopted DE-A 10211275 in the first step in the inventive method (carrying out in the situation of catalytic dehydrogenation), this possibility has increased.About separation method, can use combination or stripping (being preferably pressure absorbs), pressure-swing absorption, purification and/or the extraction of for example absorption and desorption described in the DE-A10131297.Adopting under the steam stripped situation, need guarantee can not introduce C by used stripping gas ₄Hydrocarbon.

Be present in propane and propylene (after for example the product gas mixture that generates from catalytic dehydrogenating reaction, adsorbing) in the absorbing medium if go out form with enrichment by the air stripping, can be suitable for a kind of in the inventive method, promptly, if the amount of stripping gas is selected suitablely, the gaseous mixture 1 that produces by stripping ' can be directly used in gas phase incomplete oxidation and/or incomplete gas phase ammonoxidation, and thereby be identical with gaseous mixture 2.In this case, the components contents outside gaseous mixture 1 ' middle propane, propylene and the oxygen is generally 35 to 55 volume %.If prepare propenal produced according to the present invention and/or vinylformic acid, this process is preferred.

Certainly, above-mentioned C ₄The removal of hydrocarbon also can be followed the removal of the component that is different from propane and propylene.Certainly in all cases also may cutting out partial propane and/propylene.

According to the present invention, for the disadvantageous effect to economy that limits total separation costs and cause thus, described separation method should be specially at C ₄The removal of hydrocarbon.

This means, under normal circumstances, in the methods of the invention, gaseous mixture 1 ' will still comprise at least 〉=0.1 volume %, usually 〉=0.2 volume % or 〉=0.3 volume % or 〉=0.4 volume % or 〉=0.5 volume %, often 〉=0.6 volume % or 〉=0.8 volume % or 〉=1 volume % or 〉=2 volume % or 〉=3 volume % or 〉=5 volume %, probably 〉=10 volume % or 〉=15 volume % or 〉=20 volume % or 〉=25 volume % or 〉=30 volume % or 〉=component except that propane and propylene and oxygen of 35 volume %.

But, the gaseous mixture 1 of the inventive method ' in the ratio of component except that propane and propylene and oxygen be generally≤80 volume % or≤70 volume % or≤60 volume % or≤50 volume % or≤40 volume %.

According to the present invention, above-mentioned separation should be carried out to such an extent that gaseous mixture 2 is not only met according to the present invention be the content of suitable 1-butylene and the content and the total content of (if applicable) butylene of (if applicable) other butylene isomer, and have simultaneously≤3 volume % or≤2.5 volume %, preferred≤2 volume % and very particularly preferably≤0.5 volume % or≤0.3 volume % or≤total C of 0.1 volume % ₄Hydrocarbon content.This is because found C ₄Existing in propylene incomplete oxidation and/or the ammonia oxidation process of hydrocarbon (particularly normal butane and/or Trimethylmethane) is normally disadvantageous.

No longer comprise any C at gaseous mixture 2 at all ₄Under the situation of hydrocarbon, C ₄The disadvantageous effect of hydrocarbon just no longer manifests at all.But, have reason and accept C in the gaseous mixture 2 from the total appraisal of economy ₄Some disadvantageous effects of hydrocarbon, and the content of letting alone in gaseous mixture 2 is the value of 〉=0.05 volume %, or 〉=0.07 volume % or 〉=0.09 volume % or 〉=0.1 volume % or under extreme case 〉=0.2 volume %.

This just means what purpose of the present invention particularly realized under following situation: for gaseous mixture 2, one of restriction that the content of 1-butylene is applied according to the present invention and while are in this article to C at least ₄One of restriction that the total content of hydrocarbon applies has obtained observing.

In other words, comprise those that for example meet one of following specification collocation according to the present invention for suitable gaseous mixture 2:

The content of-1-butylene≤1 volume % and C ₄The total content of hydrocarbon≤3 volume %; Or

The content of-1-butylene≤1 volume % and C ₄The total content of hydrocarbon≤2 volume %; Or

The content of-1-butylene≤0.5 volume % and C ₄The total content of hydrocarbon≤3 volume %; Or

The content of-1-butylene≤0.5 volume % and C ₄The total content of hydrocarbon≤2 volume %; Or

The content of-1-butylene≤0.75 volume % and C ₄The total content of hydrocarbon≤3 volume %; Or

The content of-1-butylene≤0.75 volume % and C ₄The total content of hydrocarbon≤2 volume %; Or

The content of-1-butylene≤0.4 volume % and C ₄The total content of hydrocarbon≤3 volume %; Or

The content of-1-butylene≤0.4 volume % and C ₄The total content of hydrocarbon≤2 volume %; Or

The content of-1-butylene≤0.4 volume % and C ₄The total content of hydrocarbon≤1 volume %; Or

The content of-1-butylene≤0.3 volume % and C ₄The total content of hydrocarbon≤3 volume %; Or

The content of-1-butylene≤0.3 volume % and C ₄The total content of hydrocarbon≤2 volume %; Or

The content of-1-butylene≤0.3 volume % and C ₄The total content of hydrocarbon≤1 volume %; Deng.

In this bright method, the gaseous mixture 2 that meets at least one restriction that in this article total content of butylene in the gaseous mixture 2 is applied simultaneously is particularly advantageous.

In other words, the gaseous mixture 2 that is suitable for the object of the invention is particularly including meeting those of one of following specification collocation:

The total content of the content of-1-butylene≤1 volume % and butylene≤1 volume % and C ₄The total content of hydrocarbon≤3 volume %; Or

The total content of the content of-1-butylene≤0.75 volume % and butylene≤1 volume % and C ₄The total content of hydrocarbon≤3 volume %; Or

The total content of the content of-1-butylene≤0.5 volume % and butylene≤1 volume % and C ₄The total content of hydrocarbon≤3 volume %; Or

The total content of the content of-1-butylene≤0.3 volume % and butylene≤1 volume % and C ₄The total content of hydrocarbon≤3 volume %; Or

The total content of the content of-1-butylene≤0.5 volume % and butylene≤0.75 volume % and C ₄The total content of hydrocarbon≤3 volume %; Or

The total content of the content of-1-butylene≤0.5 volume % and butylene≤0.5 volume % and C ₄The total content of hydrocarbon≤3 volume %; Or

The total content of the content of-1-butylene≤0.5 volume % and butylene≤0.5 volume % and C ₄The total content of hydrocarbon≤2 volume %; Deng.

According to the present invention, it is particularly advantageous using following method: not only observe 1-butylene content and C in the above-mentioned gas mixture 2 ₄The combination of hydrocarbon total content and possible butylene total content, and use simultaneously the admixture of gas 1 of other component except propane and propylene and oxygen that contains following amount ': at least 〉=0.1 volume % or 〉=0.2 volume % or 〉=0.3 volume % or 〉=0.4 volume % or 〉=0.5 volume % or 〉=0.6 volume % or 〉=0.8 volume % or 〉=1 volume % or 〉=2 volume % or 〉=3 volume % or 〉=5 volume % or 〉=10 volume % or 〉=15 volume % or 〉=20 volume % or 〉=25 volume % or 〉=30 volume % (but common≤80% volume or≤70% volume or≤60% volume or≤50% volume).

The research of carrying out in the context of the present invention shows that also for fear of total burning of unacceptable propylene in incomplete oxidation and/or ammonia oxidation, in the methods of the invention, common the hanging down of the content of propane is favourable in the gaseous mixture 2.According to the present invention, in the gaseous mixture 2 content of propane be preferably≤60 volume % or≤50 volume %.The content of having found propane in the gaseous mixture 2 is 20 to 40 volume %, for example about 30 volume % are particularly advantageous.

If ignore the content (promptly also the content of any ammonia not being taken into account in the radix of volume %) of any ammonia that under the situation of producing nitrile, uses, be suitable for the gaseous mixture 2 of the inventive method thereby normally such: at first, observe according to the present invention, preferably also have the total content of butylene and especially preferably also have C to 1-butylene content wherein ₄The restriction of the total content of hydrocarbon, and secondly, have following component:

The O of 7 to 15 volume % ₂,

The propylene of 5 to 10 volume %,

The propane of 15 to 40 volume %, 25 to 35 volume % normally,

The nitrogen of 25 to 60 volume %, 40 to 60 volume % normally,

Be total up to CO, the CO of 1 to 5 volume % ₂And H ₂O reaches

Other composition of 0 to 5 volume %.

When using gas mixture 2 was present in propylene heterogeneous catalyst incomplete oxidation in the gaseous mixture 2 with preparation propenal and/or vinylformic acid, this was a particularly suitable.

In addition, the possible gaseous mixture 2 that is used for all heterogeneous catalyst incomplete oxidations of propylene and/or ammonia oxidation that the inventive method comprises is still ignored any NH that generates nitrile here particularly including having following composition ₃Content (also being in the radix of per-cent):

H ₂O≤60 volume %, usually≤20 volume %, be generally 0 to 5 volume %;

N ₂≤ 80 volume %, usually≤70 volume %, be generally 40 to 60 volume %;

O ₂Reach as high as 20 volume %, be generally 2 to 20 volume %, be generally 5

To 15 volume %;

CO≤2 volume %, usually≤1 volume %, be generally 0 to 0.5 volume %;

CO ₂≤ 5 volume %, usually≤3 volume %, be generally 0 to 2 volume %;

Ethane≤10 volume %, usually≤5 volume %, be generally 0 to 2 volume %;

Ethene≤5 volume %, usually≤2 volume %, be generally 0 to 0.5 volume %;

Methane≤5 volume %, usually≤2 volume %, be generally 0 to 0.2 volume %;

Propane＞0 ,≤50 volume % are generally 10 to 50 volume %, are generally 20

To 40 volume %;

Cyclopropane≤0.1 volume %, usually≤0.05 volume %, be generally 0 to 150 volume ppm;

Propine≤0.1 volume %, usually≤0.05 volume %, be generally 0 to 150 volume ppm;

Propadiene≤0.1 volume %, usually≤0.05 volume %, be generally 0 to 150 volume ppm;

Propylene is greater than 0 ,≤30 volume %, usually 〉=2 ,≤20 volume %, be generally 5

To 10 volume %;

H ₂≤ 30 volume %, usually≤20 volume %, be generally 0 to 10 volume %;

Trimethylmethane≤3 volume %, preferred≤2 volume %, often be 0.1 to 1 volume %;

Normal butane≤3 volume %, preferred≤2 volume %, often be 0.1 to 1 volume %;

Instead-and 2-butylene≤1 volume %, preferred≤0.5 volume %, often 〉=and 0.003 volume % ,≤0.1

Volume %;

Suitable-2-butylene≤1 volume %, preferred≤0.5 volume %, often 〉=0.003 volume % ,≤0.1

Volume %;

1-butylene≤1 volume %, preferred≤0.5 volume %, often 〉=and 0.003 volume % ,≤0.1

Volume %;

Iso-butylene≤1 volume %, preferred≤0.5 volume %, often 〉=and 0.003 volume % ,≤0.1

Volume %;

1,3-butadiene≤1 volume %, preferred≤0.5 volume %, often 〉=and 0.003 volume % ,≤0.1

Volume %;

1≤1 volume %, preferred≤0.5 volume %, often 〉=0 to 0.01 volume %;

Ethyl acetylene≤0.5 volume %, preferred≤0.3 volume %, often be 0 to 0.1 volume %; And

2-butyne≤0.5 volume %, preferred≤0.3 volume %, often be 0 to 0.1 volume %.

The gaseous mixture 2 that is suitable for the object of the invention also comprises and not only meets above-mentioned specification but also also meet those of following specification simultaneously:

Other total unsaturated C ₄Hydrocarbon≤0.5 volume %, preferred≤0.3 volume %, often be 0 to 0.1 volume %;

Total C ₅Hydrocarbon≤0.1 volume %, usually≤0.05 volume %, be generally 0 to 300 volume ppm;

Total C ₆-C ₈Hydrocarbon≤200 volume ppm, usually≤150 volume ppm, be generally 0 to 30 volume ppm;

Acetone≤100 volume ppm;

C ₁-C ₄Alcohol≤100 volume ppm;

C ₂-C ₄Aldehyde≤100 volume ppm;

Acetylene≤10 volume ppm;

Total carbonyl containing compound is (with Ni (CO) ₄Calculate)≤100 volume ppm;

Chlorine≤the 1mg/kg of ionization is generally 0 to 0.2mg/kg;

Total chlorine-containing compound is represented≤1mg/kg with Cl, is generally 0 to 0.2mg/kg;

Total fluorochemicals is represented≤1mg/kg with F, is generally 0 to 0.2mg/kg; And

Total sulfocompound represents≤10mg/kg with S, often is 0 to 1mg/kg, is generally 0 to 0.1mg/kg;

Condition is in all said circumstanceses, the total content of all butylene is preferred≤and 1 volume % (preferred≤0.75 volume % and very particularly preferably≤0.5 volume % especially) and preferred especially C simultaneously ₄The total content of hydrocarbon≤3 volume % (preferred≤2 volume % and preferred≤1 volume %) especially.

Unaccounted compound (component) does not preferably exist in gaseous mixture 2 of the present invention, promptly can not detect.

This gaseous mixture 2 generally also can obtain in the methods of the invention, if particularly adopt described separation method with gaseous mixture 1 be converted into the gaseous mixture 1 that meets specified requirement according to the present invention ', contain when the first step is to use＞100 ppm by weight or 〉=150 ppm by weight or 〉=C of 200 ppm by weight ₄Hydrocarbon or for example reach as high as 6 volume % (as 0.1 volume % or 0.5 volume % to 6 volume %) as described in C ₄When the thick propane of hydrocarbon carries out, especially when they meet following specification:

The content of propane 〉=90 volume %, usually 〉=93 volume %, general 〉=95 volume %;

The content of propane and propylene≤99.75 volume % or≤99.5 volume %, usually≤99 volume % or≤98 volume %, general≤97 volume %;

C ₄The total content of hydrocarbon≤6 volume %, usually≤5 volume %, general≤4 volume %; But often 〉=0.5 volume % or 〉=1 volume %, sometimes 〉=2 volume % or even 〉=3 volume %;

The content of 1-butylene≤0.5 volume %, usually≤0.3 volume %, general≤0.1 volume %; But often 〉=5 volume ppm, sometimes 〉=10 volume ppm or even 〉=20 volume ppm;

The total content of butylene≤0.5 volume %, usually≤0.3 volume %, general≤0.1 volume %; But often 〉=10 volume ppm, sometimes 〉=20 volume ppm or even 〉=30 volume ppm;

The content of ethane≤10 volume %, usually≤5 volume %, be generally 0 to 2 volume %;

The content of ethene≤5 volume %, usually≤2 volume %, be generally 0 to 0.5 volume %;

The content of methane≤5 volume %, usually≤2 volume %, be generally 0 to 0.2 volume %;

The content of cyclopropane≤0.1 volume %;

The content of propylene≤10 volume %, usually≤5 volume %, general≤2 volume %;

C outside propane and the propylene ₃The total content of hydrocarbon≤0.3 volume %;

C ₅The volume % of the total content of hydrocarbon≤O.3; And

C ₆-C ₈The total content of hydrocarbon≤600 volume ppm.

The thick propane that is suitable for the object of the invention also comprises and not only meets above-mentioned specification but also also meet those of following specification simultaneously:

The total content of oxygen-containing organic compound≤300 volume ppm;

The content of acetylene≤30 volume ppm;

Content≤the 1mg/kg of the chlorine of ionization;

The total content of chlorine-containing compound is represented≤1mg/kg with Cl;

The total content of fluorochemicals is represented≤1mg/kg with F;

The total content of sulfocompound with S represent≤(in the situation of catalytic dehydrogenation, based on the propane that is present in wherein, reaction mixture comprises the sulfocompound (H for example of 1 to 1000 volume ppm, preferred 1 to 100 volume ppm to 10mg/kg ₂S and/or methyl-sulfide) may be favourable, this is because they can, at first, passivation (reactor) steel constituent, for example Ni, Cr and Fe (this can reduce the cracking of undesirable propane), and secondly, the activation catalyst system therefor is (referring to " catalytic dehydrogenation of lower alkane " (Catalytic dehydrogenation of lower alkanes), Resasco, DanielE.; Haller, Gary L., University Oklahoma, USA, Catalysis (1994), 11,379-411));

Condition be the content of 1-butylene preferred≤0.1 volume %, and the preferred especially total content≤0.1 volume % of butylene simultaneously, and C simultaneously very particularly preferably ₄The total content of hydrocarbon≤3 volume % or≤2.5 volume % or≤2 volume %.

When such gaseous mixture 1 was present in the heterogeneous catalyst gas phase incomplete oxidation of the propylene in the gaseous mixture 1 and/or ammonia oxidation as the component of gaseous mixture 2, the specification of Ding Yi thick propane generally was suitable for method of the present invention under the described conditions.Here, according to the present invention, in the first step of the inventive method, limited oxydehydrogenation and/or conversion rate of dehydrogenation have whole favourable effect, and this fact is useful.For each stable hydrocarbon that exists, this transformation efficiency is generally 〉=5 moles of %, but≤30 moles of %, often≤25 moles of % and normal≤20 moles of %.

More than specified (but also comprise all other) thick propane of being suitable for the inventive method comprise usually at least 0.25 volume % or at least 0.5 volume % or at least 1 volume %, often at least 1.5 volume % or at least 2 volume % and often the component except that propane and propylene of at least 2.5 volume % or at least 3 volume % (but these components often≤10 volume %, usually≤7 volume % also generally≤5 volume %).These content of non-essential substance also are applicable to other the thick propane that is suitable for the inventive method usually, for example do not contain C ₄Those of hydrocarbon.But they can comprise 〉=0.1 volume % or 〉=0.5 volume %, often reach as high as the C of 6 volume % ₄Hydrocarbon (for example, 0.1 or 0.5 volume % is to 6 volume %).In addition and simultaneously, they can comprise 〉=5 volume ppm, often reach as high as the butylene (for example from 5 volume ppm to 0.5 volume %) of 0.5 volume %.And they also can comprise simultaneously 〉=5 volume ppm, often reach as high as the 1-butylene (for example from 5 volume ppm to 0.5 volume %) of 0.5 volume %.

The thick propane that is particularly suitable for the object of the invention also comprises and not only meets above-mentioned specification but also also meet those of following specification simultaneously:

Ag≤1 μ g/kg; Al≤10 μ g/kg; As≤1 μ g/kg; Au≤1 μ g/kg; Ba≤1 μ g/kg; Be≤1 μ g/kg; Bi≤1 μ g/kg; Ca≤2 μ g/kg; Cd≤1 μ g/kg; Co≤1 μ g/kg; Cr≤1 μ g/kg; Cu≤1 μ g/kg; Fe≤10 μ g/kg; Ga≤1 μ g/kg; Ge≤1 μ g/kg; Hg≤1 μ g/kg; In≤1 μ g/kg; Ir≤1 μ g/kg; K≤1 μ g/kg; Li≤1 μ g/kg; Mg≤1 μ g/kg; Mn≤1 μ g/kg; Mo≤1 μ g/kg; Na≤1 μ g/kg; Nb≤1 μ g/kg; Ni≤1 μ g/kg; Pb≤1 μ g/kg; Pd≤1 μ g/kg; Pt≤1 μ g/kg; Rh≤1 μ g/kg; Sb≤1 μ g/kg; Sn≤1 μ g/kg; Sr≤1 μ g/kg; Ta≤1 μ g/kg; Ti≤1 μ g/kg; Tl≤1 μ g/kg; V≤1 μ g/kg; Zn≤1 μ g/kg; And Zr≤1 μ g/kg.

The thick propane that is particularly suitable for very much the object of the invention is not only to meet above-mentioned specification but also also meet those of following specification simultaneously:

Density in the time of 20 ℃=500 ± 2.0kg/m ³

Vapour pressure in the time of 20 ℃=7.6 ± 0.2bar;

Water≤10mg/kg;

Evaporation residue≤2mg/kg.

Described specification is based upon on the mensuration of carrying out by vapor-phase chromatography with by atomic absorption spectrometry.Evaporation residue is based upon on the basis of gravimetric determination.It comprises high boiling hydrocarbon (for example amiantuhs) usually.

The component of not mentioning does not preferably exist in thick propane, promptly can not detect, and according to the present invention, this is suitable especially.

When using with recirculation mode, method of the present invention is a particularly important.

In this case, from the product gas mixture that derives from gas phase incomplete oxidation and/or ammonia oxidation, isolate required target product by the separation known method, and be present in unreacted propane in this product gas mixture, be recycled to oxydehydrogenation and/or dehydrogenation step with the unreacted propylene that wherein exists usually and/or be recycled in gas phase incomplete oxidation and/or the ammonia oxidation to the major general.With the target product after separating, usually by this way with the component recirculation of propane and propylene, and need not this tail gas is carried out intermediate treatment as residual exhaust, perhaps, (for example before recirculation, isolate the CO, the CO that wherein exist when carrying out intermediate treatment ₂, H ₂And/or O ₂) time, this intermediate treatment also only has limited effect.For example, even when used thick propane only contain very 1-butylene, other butylene and/or other C of small proportion ₄Hydrocarbon (C for example ₄The total content of hydrocarbon 〉=0.01 volume % the highlyest may reach 6 volume %) time, if adopt the gas re-circulation pattern, they can be accumulated in the gaseous mixture 2, and their concentration can surpass according to the present invention limit specified, unless take special measure.These measures for example can be included in and isolate after the target product, optionally isolate C by rectifying and/or by absorption/desorb and/or stripping and/or by adsorption/desorption and/or by condensation and/or by embrane method from remaining tail gas ₄Hydrocarbon, and only circulation contains the residual thereafter propane and the tail gas of propylene.

EP-A 938463 thinks that this separating step is unnecessary, though it recommends former state using gas mixture 1 to carry out incomplete oxidation, and the thick propane of any purity is used for the first step basically.

As the replacement scheme of gas re-circulation pattern, described tail gas can also be used for other purposes, to avoid undesirable C ₄The accumulation of hydrocarbon.For example they can be burnt with generation electric power with the propane and the propylene that are present in wherein, and/or make synthetic gas or the like with their.

Perhaps, can implement the inventive method according to different general planning described in the prior art.

In simple proposal, for example as following teach literature, in single reaction zone and be present in implement the inventive method on wherein the catalyst charge institute in steps: EP-A 608838, EP-A 529853, DE-A 19835247, EP-A 895809, JP-A 7-232071, JP-A11-169716, EP-A 1192987, JP-A 10-57813, JP-A 2000-37623, JP-A10-36311, WO 00/29105, EP-A 767164, DE-A 10029338, JP-A 8-57319, JP-A 10-28862, JP-A 11-43314, JP-A 11-574719, WO 00/29106, JP-A10-330343, JP-A 11-285637, JP-A 310539, JP-A 11-42434, JP-A 11-343261, JP-A 3423262, WO 99/03825, JP-A 7-53448, JP-A 2000-51693, JP-A11-263745, DE-A 10046672, DE-A 10118814, DE-A 10119933, JP-A2000/143244, EP-A 318295, EP-A 603836, DE-A 19832033, DE-A19836359, EP-A 962253, DE-A 10119933, DE-A 10051419, DE-A10046672, DE-A 10033121, DE-A 101 459 58, DE-A 10122027, draw reference in EP-A1193240 and these documents.

The active composition that is used for catalyst charge is essentially at least a, at least a multimetal oxide compositions that is selected from the element of the group of being made up of Nb, Ta, W, Ti, Al, Zr, Cr, Mn, Ga, Fe, Ru, Co, Rh, Ni, Pd, Pt, La, Bi, B, Ce, Sn, Zn, Si, Na, Li, K, Mg, Ag, Au and In that contains among the elements Mo that combines, V, two kinds of element T e and the Sb.

This combination preferably contains element nb, Ta, W and/or the Ti that is selected from back one element set, special preferred elements Nb.

Relevant active multimetal oxide compositions preferably contains the above-mentioned element combination of stoichiometry I:

Mo ₁V _bM ¹ _cM ² _d (I)，

Wherein

M ¹Be Te and/or Sb,

M ²Be at least a element that is selected from the group of forming by Nb, Ta, W, Ti, Al, Zr, Cr, Mn, Ga, Fe, Ru, Co, Rh, Ni, Pd, Pt, La, Bi, Ce, Sn, Zn, Si, Na, Li, K, Mg, Ag, Au and In,

B is 0.01 to 1,

C is＞0 to 1,

D is＞0 to 1.

According to the present invention, preferred M ¹Be Te and M ²Be Nb, Ta, W and/or Ti.M ²Be preferably Nb.

Stoichiometric coefficient b is preferably from 0.1 to 0.6.Correspondingly, the preferable range of stoichiometric coefficient c is from 0.01 to 1 or from 0.05 to 0.4, and the favourable value of d is from 0.01 to 1 or from 0.1 to 0.6.

If stoichiometric coefficient b, c and d are in above-mentioned preferred range simultaneously, then be particularly advantageous according to the present invention.

If be present in the element outside the deoxygenation in the active composition of catalyst charge and be fully above-mentioned element in conjunction with in a kind of, then the above is a particularly suitable.

Their active multimetal oxide compositions of formula II particularly so:

Mo ₁V _bM ¹ _cM ² _dO _n (II)，

Wherein variable has the specified implication for formula I, and n the serve as reasons valency of the element outside deoxygenation and the number of frequency of occurrences decision in (II).

And, when the inventive method is implemented under single district pattern, the preferred many metal composites of following activity that use: it at first or contain a kind of in the above-mentioned element combinations, perhaps, with regard to the element outside the deoxygenation, constitute and have following x-ray diffraction pattern simultaneously by it: have reflection h and i that maximum value is positioned at diffraction angle (2 θ) 22.2 ± 0.5 ° (h) and 27.3 ± 0.5 ° (i).X-ray diffraction pattern (the Siemens diffractometer θ-θ D-5000 that all data that relate to x-ray diffraction pattern herein all produce based on using the Cu-K alpha-ray to make the X-ray, tube voltage: 40kv, tube current: 40mA, aperture diaphragm V20 (variable), scattered radiation diaphragm V70 (variable), secondary monochromator diaphragm (0.1mm), detector diaphragm (0.6mm), measure (2 θ) at interval: 0.02 °, every pacing amount time: 2.4s, detector: scintillometer.

The halfwidth degree of these reflections can be very little or very obvious.

For the inventive method, in above-mentioned active multimetal oxide compositions, especially preferably except reflection h and i, its X-ray diffractogram also has those of reflection k that maximum value locates at 28.2 ± 0.5 ° (k).

In the latter, according to the present invention, preferred again in X-ray diffractogram its reflection h be that the strongest and halfwidth degree of intensity is no more than those of 0.5 °, and very preferably its reflection i and reflection k have respectively≤1 ° halfwidth degree and have intensity P _iAnd P _kThose, P _iAnd P _kMeet and concern 0.2≤R≤0.85, preferred 0.3≤R≤0.85, more preferably 0.4≤R≤0.85, preferred especially 0.65≤R≤0.85, even more preferably 0.67≤R≤0.75 and very particularly preferably R=0.70 to 0.75 or R=0.72, wherein R is the strength ratio by the following formula definition:

R＝P _i/(P _i+P _k)。

Above-mentioned X-ray diffractogram does not preferably have the reflection that its maximum value is positioned at 2 θ=50.0 ± 0.3 °.

With regard to this paper, the definition of reflection strength is the definition that provides among DE-A 19835247, DE-A 10122027, DE-A 10051419 and the DE-A 10046672 in the X-ray diffractogram.This is equally applicable to the definition of halfwidth degree.

Except reflection h, i and k, the above-mentioned X-ray diffractogram of active many metal composites that can advantageously use according to the present invention also has the reflection that its maximum value is positioned at following diffraction angle (2 θ):

9.0±0.4°(l)，

± 0.4 ° 6.7 (o) and

7.9±0.4°(p)。

X-ray diffractogram has the extra reflection that its maximum value is positioned at diffraction angle (2 θ) 45.2 ± 0.4 ° (q), so also is favourable.

X-ray diffractogram often also has the reflection that is positioned at 29.2 ± 0.4 ° (m) and 35.4 ± 0.4 ° (n).

It also is favourable that the element binding substances of formula I and formula II definition exists mutually with pure i.If the oxide composition of catalytic activity also comprises the k phase, its X-ray diffractogram comprises also that except that above-mentioned reflection its maximum value is positioned at the reflection of following diffraction angle (2 θ): 36.2 ± 0.4 ° and 50 ± 0.4 ° (in this article, term i mutually and k with the use of the definition among DE-A 10122027 and the DE-A 10119933).

Be appointed as intensity 100 if will reflect h, for the present invention, advantageously reflect i, l, m, n, o, p, q and under identical intensity scale, have following intensity:

I:5 to 95 is generally 5 to 80, often is 10 to 60;

L:1 to 30;

M:1 to 40;

N:1 to 40;

O:1 to 30;

P:1 to 30 and

Q:5 to 60.

If X-ray diffractogram also has other reflection those except that above-mentioned, then their half-peak width usually≤1 °.

The specific surface area of the active multimetal oxide compositions of formula II used according to the invention or the specific surface area of multimetal oxide compositions that contains the element combinations of formula I are generally 1 to 30 meters squared per gram (BET surface-area, nitrogen), particularly like this when they have aforesaid X-ray diffractogram especially.

Have open in the prior art that the preparation of described active multimetal oxide compositions is quoted in the context of these compositions.The prior art reference of this respect particularly including DE-A 10122027, DE-A 10119933, DE-A 10033121, EP-A 1192987, DE-A 10029338, JP-A2000-143244, EP-A 962253, EP-A 895809, DE-A 19835247, WO 00/29105, WO 00/29106, EP-A 529853, EP-A 608838 (in all embodiment of back two kinds of documents, use spraying drying as drying means, for example under the temperature out of 300 to 350 ℃ temperature in and 100 to 150 ℃, adverse current or and stream carry out).

Single district embodiment for the inventive method, described active multimetal oxide compositions can former state (promptly with powder type) uses, also can carry out moulding obtain suitable geometrical shape after use (referring to the coated catalysts among the DE-A 10051419 for example and the geometric shape scheme among the DE-A 10122027).They are particularly useful for preparing propenal and/or vinylformic acid and are used to prepare vinyl cyanide.

Single area scheme based on used, can catalysis the inventive method catalyzer in steps.

Reaction can be carried out on stationary catalyst bed, also can carry out on catalyst fluidized bed or moving-bed.Corresponding method explanation can be found in the prior art document.The acrylic acid fixed bed reaction of preparation carries out under single district operator scheme if the inventive method is for example to be used for, and reaction should have been loaded in pipe in the shell-tube type reactor of catalyzer and carried out.Usually with liquid (generally salt melt) as heat-transfer medium by around the catalyst tube.Perhaps, also can use the hot plate type reactor, wherein catalyst charge is present between the cooling plate with planar alignment.

Reaction gas mixtures with respect to salt bath and stream or adverse current by the catalyst tube in the reactor.Salt bath itself can have and the pure parallel stream of catalyst tube.But crossing current thereon can certainly superpose.In general, salt bath can flow around catalyst tube in the meander mode, when only observing above reactor, just sees this stream and reaction gas mixtures and stream or adverse current.The shell-tube type reactor that is suitable for the inventive method has open in for example EP-A 700714 and EP-A 700893.

For single area scheme of the inventive method, different may the forming of reactant gases starting mixt can obtain from the prior art that relevant this method is quoted.

Be preparation vinylformic acid, the composition of reactant gases starting mixt is usually in following ranges (mol ratio):

Propane: oxygen: H ₂O: other composition (mainly being inert dilution gas)=1: (0.1-10): (＞0-50): (＞0-50).

Above-mentioned ratio is preferably 1: (0.5-5): (1-30): (1-30).

When described other composition mainly was dinitrogen, above-mentioned scope was a particularly suitable.Temperature of reaction is generally 250 to 550 ℃ (if ignore extra ammonia content in the reaction gas mixtures, the condition of ammonia oxidation is quite (referring to for example EP-A 929853) therewith).

The space velocity of propane in the fixed bed catalyst charging of the single area scheme of the inventive method can be 10 to 500 standard liters/liter (fixed bed) hour for example.The space velocity of reactant gases starting mixt is usually in the scope of 100 to 10000 standard liter/liters per hours, through the scope of 500 to the 5000 standard liter/liters per hours of being everlasting.

Target product (for example vinylformic acid) can be in a manner known way, for example as described in the DE-A10122027, from the obtained product gaseous mixture, separate, promptly, be present in vinylformic acid in the product gas mixture can be for example by absorbing in the high boiling point inert hydrophobic organic solvent (for example the mixture of phenyl ether and biphenyl, it can also contain for example additive of dimethyl phthalate) and separate.Then the absorption agent and the acrylic acid mixture that obtain are handled by rectifying, extraction and/or crystallization in a manner known way, made pure acrylic acid.Perhaps, the initial gross separation of vinylformic acid and product gas mixture also can be undertaken by dephlegmation as described in for example DE-A 10053086, DE-A 19627847, DE-A19740253, DE-A 19740252, DE-A 19606877 and DE-A 19740253.Then, the vinylformic acid condensation product that obtains can be further purified, and is for example undertaken by fractional crystallization (for example suspension crystallization and/or layering crystallization).

Still residual tail gas mixture comprises unreacted propane and the unreacted propylene of possibility especially behind the initial gross separation vinylformic acid.

Depend on the content of 1-butylene in this tail gas mixture and the used oxygen source (no matter be pure oxygen, contain oxygen rare gas element or air), the total content and the C of butylene ₄The total content of hydrocarbon, this tail gas mixture recirculation like this.Also it can be divided into two parts of same composition, and, another part be blown out (for example it is sent to incinerate or do other purposes (as producing synthetic gas)) only with a part of recirculation.Can certainly carry out back one operation with the total amount of tail gas mixture.

If there is undesirable C according to the present invention of higher proportion in the tail gas mixture ₄The undesirable component of other of component and/or higher proportion, be present in propane in the tail gas mixture and any propylene and can for example purify (can select separation factor aptly) and isolate, and then be circulated in the method for the present invention and combine with thick propane and other component in the reactant gases starting mixt by dividing potential drop.But, for the present invention, make tail gas and preferential absorption C in extraction plant ₃The hydrophobic organic solvent contact (for example making it pass through this organic solvent) of hydrocarbon may be just enough.Then, the propane of absorption and possible propylene can discharge once more by desorb and/or with air (in any case all will need air as oxygen source) stripping, and are recycled to the inventive method.Certainly, also can use the method for describing among the DE-A10059122 from product mixtures, to isolate vinylformic acid.Can certainly recommend to be used for the active multimetal oxide compositions of single area scheme with (as colloidal) material in small, broken bits (for example silicon-dioxide, titanium dioxide, aluminum oxide, zirconium white and niobium oxides) dilution, to be used for method of the present invention.

The mass ratio of thinner and active composition reaches as high as 9 (thinners): 1 (active composition), that is, possible mass ratio has for example 6 (thinners): 1 (active composition) and 3 (thinners): 1 (active composition).Thinner can add before calcining or after the calcining as described in DE-A 10122027.Certainly, the single area scheme that also can be used for the inventive method as other catalyst system of describing among the JP-A 3-170445 for example.

When the inventive method realized in a reaction zone, this is equivalent to gaseous mixture 1 was identical with gaseous mixture 2.When according to the inventive method for the product gas mixture of the inventive method in 1-butylene and other C ₄When the content limit specified of hydrocarbon is exceeded, to utilize the inventive method especially.

According to the present invention, as described in for example EP-A 938463, EP-A 117146, DE-A 3313573, GB-A 2118939, US-A 3161670, WO 01/96270, EP-A 731077, DE-A19837520, DE-A 19837517, DE-A 19837519, DE-A 19837518, DE-A19837520, DE-A 10131297 and DE-A 10211275, this method is preferably being carried out in surpassing one reaction zone.

" surpassing one reaction zone " is meant, at first and main ground, at least one step of the inventive method is to carry out under the condition that can independently be selected from the condition of other step in the inventive method to small part, perhaps, only on lesser extent, these to the separate reaction conditions of small part be in one of reaction process and identical step, realize (latter is the situation that has adopted the multi-region pattern humidity province of separate setting (have can) for a step, as for example DE-A 19948241, DE-A19927624, DE-A 19910508, DE-A 19910506 and DE-A 19948248 describe).For example, if the inventive method comprises for example two steps, catalyzer that uses in the first step and catalyst charge can for example be different from catalyzer and the catalyst charge that uses in second step, perhaps two steps can be used identical catalyzer and catalyst charge, but the temperature of reaction in two steps can be selected or adjust independently.Naturally also can use the combination of the two.

The advantage of multi-region scheme is that it can make reaction conditions adapt to the needs of each step of the inventive method better in principle.

This advantage is known propylene heterogeneous catalyst gas phase incomplete oxidation from using molecular oxygen as vinylformic acid.

Be to prolong in the reaction coordinate step in succession at two to carry out on this reaction principle, the first step generates propenal, and second step generated vinylformic acid by propenal.

This reaction scheme provides in two placed in-line oxidation zones according to the present invention in a manner known way to being present in the possibility that propylene in the gaseous mixture 2 carries out incomplete oxidation, the oxide catalyst that uses in each of these two oxidation zones can be optimised (this handiness can also make the incomplete oxidation of propylene stop at the propenal stage, and makes the propenal can be separated).In first oxidation zone (propylene → propenal), usually be preferably based on the catalyzer of the poly-metal deoxide that contains element combinations Mo-Bi-Fe, and be preferred for second oxidation zone (propenal → vinylformic acid) usually based on the catalyzer of the poly-metal deoxide that contains element combinations Mo-V (for example recommend in this article be used for single area scheme those).But these two reactions steps also can be carried out on single catalyzer in the single reaction district in principle.

Generally speaking, in the methods of the invention, the first step should independently carried out in the reaction zone.

In the situation of oxidative dehydrogenation of propane, this can use molecular oxygen that propane homogeneous phase and/or heterogeneous catalyzed vapor-phase oxidation dehydrogenation are carried out as propylene.The air that can use air, pure molecular oxygen or be rich in molecular oxygen is as source of molecular oxygen.

If reaction zone is configured to the homogeneous oxidizing dehydrogenation, this in principle can be as for example US-A3,798,283, CN-A 1105352, Applied Catalysis, 70 (2) 1991, carry out as described in pp.175-187, the Catalysis Today 13,1992, pp.673-678 and DE-A 19622331.Suitable oxygen source is an air.The temperature of homogeneous oxidizing dehydrogenation should be chosen in 300 to 700 ℃ scope, is preferably 400 to 600 ℃, is preferably 400 to 500 ℃ especially.Operating pressure can be for 0.5 to 100bar, and particularly 1 to 10bar.The residence time is generally 0.1 or 0.5 to 20 seconds, is preferably 0.1 or 0.5 to 5 seconds.

As for reactor, can use for example tube furnace or shell-tube type reactor, for example use stack gas as the adverse current tube furnace of heat-transfer medium or use the shell-tube type reactor of salt melt as heat-transfer medium.The ratio of propane and oxygen is preferably 0.5: 1 to 40: 1 in the starting mixt, and particularly 1: 1 to 6: 1, more preferably 2: 1 to 5: 1.Starting mixt can further comprise other component, and (with regard to this paper, inert component is preferably reaction and proceeds to less than the degree of 5 moles of %, preferably less than 3 moles of % and the preferred especially component less than 1 mole of % preferred inert component; They very particularly preferably do not react), for example water, carbonic acid gas, carbon monoxide, nitrogen, rare gas, other hydrocarbon (for example being present in the accessory constituent in the thick propane) and/or propylene etc.These components can also comprise the component of recirculating gas.

If the oxydehydrogenation of propane is the heterogeneous catalytic oxidation dehydrogenation; it can carry out as described in following document for example in principle: US-A 4788371; CN-A 1073893; Catalysis Letters23 (1994); 103-106; W.Zhang; " SCI "; 14 (1993); 566; Z.Huang; " petrochemical complex "; 21 (1992) 592; WO 97/36849; DE-A 19753817; US-A3862256; US-A 3887631; DE-A 19530454; US-A 4341664; J.of Catalysis167; 560-569 (1997); J.of Catalysis 167; 550-559 (1997); Topics in Catalysis3 (1996) 265-275; US-A 5086032; Catalysis Letters 10 (1991); 181-192; Ind.Eng.Chem.Res.1996; 35; 14-18; US-A 4255284; Applied Catalysis A:General; 100 (1993); 111-130; J.of Catalysis 148; 56-67 (1994); V.Cort é sCorber á n and S.Vic Bell ó n (Ed.); New Developments in SelectiveOxidation II; 1994; Elsevier Science B.V.; pp.305-313; 3rd World Congresson Oxidation Catalysis; R.K.Grasselli; S.T.Oyama; A.M.Gaffney and J.E.Lyons (Ed.); 1997; Elsevier Science B.V., p.375 following or DE-A 19837520; DE-A 19837517; DE-A 19837519; DE-A 19837518.In this case, also can make oxygen source with air.But oxygen source often comprises the molecular oxygen of at least 90 moles of % herein, comprises the oxygen of at least 95 moles of % usually.

The catalyzer that is suitable for the heterogeneous catalytic oxidation dehydrogenation is had no particular limits.Well known by persons skilled in the art and can be that all oxy-dehydrogenation catalysts of propylene all are suitable with oxidation of propane.Especially, the oxy-dehydrogenation catalyst that can use all in above-mentioned document, to mention.Appropriate catalyst comprises the oxy-dehydrogenation catalyst that for example contains MoVNb oxide compound or Vanadyl pyrophosphate, if suitable, also contains promotor.An example of available oxy-dehydrogenation catalyst is the also recommended catalyzer that is used for single area scheme, its comprise have Mo, mixed metal oxide that V, Te, O and X make main composition, wherein X is at least a element (referring to EP-A 938463 and EP-A 167109) that is selected from niobium, tantalum, tungsten, titanium, aluminium, zirconium, chromium, manganese, gallium, iron, ruthenium, cobalt, rhodium, nickel, palladium, platinum, antimony, bismuth, boron, indium, silicon, lanthanum, sodium, lithium, potassium, magnesium, silver, gold and cerium.Other special available oxy-dehydrogenation catalyst is the catalyst A of multimetal oxide compositions or DE-A 19753817 and the catalyzer among the DE-A 19838312, and wherein multimetal oxide compositions or the catalyst A mentioned as preferred catalyst in first document are particularly advantageous.This means that special available active composition is the multimetal oxide compositions of formula III:

M ¹ _aMo _1-bM ² _bO _x (III)，

M wherein ¹=Co, Ni, Mg, Zn, Mn and/or Cu,

M ²=W, V, Te, Nb, P, Cr, Fe, Sb, Ce, Sn and/or La,

a＝0.5-1.5，

b＝0-0.5

And the number that x=is determined by the valency and the abundance of the element outside the deoxygenation in (III).

In principle, suitable active composition (III) can be prepared as follows in simple mode: make very uniform, preferred in small, broken bits having corresponding to they stoichiometric drying composites of forming by the suitable source of their basal components, and in 450 to 1000 ℃ are calcined to this mixture.May the originating of basal component of active multimetal oxide compositions (III) is oxide compound, and/or can be at least in the presence of oxygen, be the compound of oxide compound by thermal conversion.These compounds are particularly including halogenide, nitrate, formate, oxalate, Citrate trianion, acetate, carbonate, ammonia complex salt, ammonium salt and/or oxyhydroxide.The uniform mixing that is used to prepare the initial compounds of multimetal oxide compositions (III) can be realized (for example being prepared into powder in small, broken bits) with dry method, perhaps realizes (for example make and use water as liquid medium) with wet method.Multimetal oxide compositions (III) both can use with powder type, also can use after being shaped to the specific catalyst profile; Under a kind of situation in back, moulding can be carried out before or after final calcining.Can use full active catalyst, but the moulding of Powdered active composition or precursor composition can realize also by it being administered on the preformed inert catalyst carrier.As for solid support material, can use porous commonly used or non-porous aluminum oxide, silicon-dioxide, thorium dioxide, zirconium dioxide, silicon carbide or silicate, the body piece of carrier can have regular or irregular profile.

In the heterogeneous catalytic oxidation dehydrogenation of propane, temperature of reaction is preferably 200 to 600 ℃, and particularly 250 to 500 ℃, more preferably 350 to 440 ℃.Operating pressure is preferably 0.5 to 10bar, and particularly 1 to 10bar, and more preferably 1 to 5bar.Found to be higher than the operating pressure of 1bar, for example 1.5 to 10bar, is particularly advantageous.The heterogeneous catalytic oxidation dehydrogenation of propane is normally carried out on stationary catalyst bed.The latter should be installed in the pipe of shell-tube type reactor, as described in the reference of quoting in for example EP-A 0700893 and EP-A 0700714 and these documents.The mean residence time of reaction gas mixtures in catalyst bed is preferably 0.5 to 20 second.Propane is different with selectivity of catalyst because of required transformation efficiency with the ratio of oxygen, but should be 0.5: 1 to 40: 1 scope, and particularly 1: 1 to 6: 1, more preferably 2: 1 to 5: 1.The selectivity of propylene generally reduces with the increase of conversion of propane.Therefore, propane to the reaction of propylene is preferably carried out to such an extent that can realize lower conversion of propane under high propylene selectivity.The transformation efficiency of propane is particularly preferably in the scope of 5 to 40 moles of %, usually in the scope of 10 to 30 moles of %.Herein, term " transformation efficiency of propane " be meant added propane (be present in the propane in the thick propane and be present in propane in any recycle gas and) ratio of in one way, reacting.The selectivity that generates propylene is generally 50 to 98 moles of %, more preferably 80 to 98 moles of %.Term " selectivity " is meant the mole number of the propylene that the propane of every 1mol reaction of representing with molar percentage generates.

The starting mixt that uses in the oxydehydrogenation of propane generally comprises the propane (based on the starting mixt of 100 moles of %) of 5 to 95 moles of %.Except propane and oxygen, the starting mixt that is used for the heterogeneous catalytic oxidation dehydrogenation can further comprise other component, particularly inert component, for example carbonic acid gas, carbon monoxide, nitrogen, rare gas, other hydrocarbon (for example being present in the accessory constituent in the thick propane) and/or propylene.The heterogeneous oxidation dehydrogenation also can be carried out in the presence of the thinner of for example water vapour.

Any reactor order well known by persons skilled in the art all can be used for carrying out the homogeneous oxidizing dehydrogenation or the heterogeneous catalytic oxidation dehydrogenation of propane.For example, oxydehydrogenation can be carried out in single reactor or in placed in-line two or more reactors, if desired, can introduce oxygen between placed in-line reactor.Also homogeneous oxidizing dehydrogenation or heterogeneous catalytic oxidation dehydrogenation can be mutually combined.

As for possible component, the product mixtures that is obtained by the oxydehydrogenation of the propane that carries out according to the present invention can comprise for example following component: propylene, propane, carbonic acid gas, carbon monoxide, water, nitrogen, oxygen, ethane, ethene, methane, propenal, vinylformic acid, oxyethane, butane (as normal butane or Trimethylmethane), acetate, formaldehyde, formic acid, propylene oxide and butylene (as 1-butylene).The product mixtures that obtains in the oxydehydrogenation of propane of the present invention comprises usually: the oxygen of the carbon monoxide of the propylene of 5 to 10 moles of %, 0.1 to 2 mole of %, the carbonic acid gas of 1 to 3 mole of %, the water of 4 to 10 moles of %, the nitrogen of 0 to 1 mole of %, the propenal of 0.1 to 0.5 mole of %, the vinylformic acid of 0 to 1 mole of %, the acetate of 0.05 to 0.2 mole of %, the formaldehyde of 0.01 to 0.05 mole of %, 1 to 5 mole of %, described other component of 0.1 to 1.0 mole of %, all the other are the maximum propane of amount, more than respectively based on the product mixtures of 100 moles of %.

The dehydrogenation of the propane in first reaction zone generally also can be carried out the heterogeneous catalyst dehydrogenation for the propane of basic eliminating oxygen, as described in DE-A 3313573, WO 01/96270, DE-A 10131297 or the DE-A10211275, or as described below.

Because volume increased when the heterogeneous catalyst dehydrogenation reaction took place, thereby can improve transformation efficiency by the dividing potential drop that reduces product.This can realize in simple mode, for example carries out dehydrogenation under the pressure that reduces and/or by sneaking into basic inert diluent gas (being the water vapour of rare gas element to dehydrogenation reaction usually for example).Dilute usually another advantage in addition with water vapour, promptly reduced the carbonization of catalyst system therefor, because water vapour can react according to the carbon of coal gasification principle and generation.Water vapour also can be used as subsequently oxidation and/or the diluent gas in ammonia oxidation district (also abbreviating subregion in this article as).Water vapour can also partially or completely separate from the product mixtures that derives from dehydrogenation in simple mode (for example by condensation), if the modified product mixture that can obtain in this way is further used for subregion, just provides raising diluent gas N ₂The possibility of ratio.Other suitable diluent that can be used for the dehydrogenation of propane heterogeneous catalyst has, for example, and CO, methane, ethane, CO ₂, nitrogen and rare gas such as He, Ne and Ar.All described thinners all both can use independently, also can use with the form of different mixtures.Advantageously described thinner generally also is the suitable diluent in the subregion.As mentioned above, preferably in each reaction zone for inert (be that chemical transformation proceeds to the degree less than 5 moles of %, preferably less than 3 moles of % and be more preferably less than 1 mole of %) thinner.In principle, all are suitable for the heterogeneous catalyst dehydrogenation of propane by the known dehydrogenation catalyst of prior art.They are broadly divided into two groups, promptly are essentially the thinner (as chromic oxide and/or aluminum oxide) of oxidisability and contain at least a at the thinner of rarer metal (as platinum) usually that is generally on the oxidative vector.

Especially, for example can use all dehydrogenation catalysts of recommending among WO 01/96270, EP-A 731077, DE-A 10211275, DE-A 10131297, WO 99/46039, US-A 4788371, EP-A 0705136, WO99/29420, US-A 4220091, US-A 5430220, US-A 5877369, EP-A 0117146, DE-A 19937196, DE-A 19937105 and the DE-A 19937107.The catalyzer that can use embodiment 1 among the DE-A 19937107, embodiment 2, embodiment 3 and embodiment 4 to describe especially.

They are the dehydrogenation catalysts that contain following material: the zirconium dioxide of 10 to 99.9 weight %, the aluminum oxide of 0 to 60 weight %, silicon-dioxide and/or titanium dioxide, and the periodic table of elements main group I of 0.1 to 10 weight % or at least a element of II, the element of transition group III, element, lanthanum or the tin of transition group VIII, prerequisite be weight percent and be 100 weight %.

For carrying out the heterogeneous catalyst dehydrogenation of propane, all be feasible in principle by known all types of reactors of prior art and process program.In all prior art documents of these process programs citation aspect relevant dehydrogenation catalyst for example description is arranged all.

At " Catalytica ^Studies Division, Oxidative Dehydrogenation andAlternative Dehydrogenation Processes "; Study Number 4192 OD; 1993; 430 Ferguson Drive, Mountain View, California; among the 94043-5272 U.S.A, also carried out comparatively comprehensive description to being suitable for the object of the invention dehydrogenating technology.

The characteristics of the incomplete heterogeneous catalyst dehydrogenation of propane are that it is heat absorption.This just mean must be before the heterogeneous catalyst dehydrogenation and/or during will set the essential heat of desired reaction temperature (energy) and introduce in the reactant gases starting mixt.

In addition, owing to need high reaction temperature, the heterogeneous catalyst dehydrogenation of propane is usually because of generating a small amount of high boiling point macromolecular organic compound, being deposited on catalyst surface and thereby making the carbon sustain damage of catalyst deactivation until generation.For this unfavorable phenomenon is minimized, can the water vapor dilution will be in the heterogeneous catalyst dehydrogenation under the temperature that raises the reaction gas mixtures that contains propane by catalyst surface.Under obtaining condition, partly or entirely remove sedimentary carbon by the coal gasification principle.

Another kind remove the method for deposit carbon compound be every now and then with oxygen-containing gas in high temperature down by dehydrogenation catalyst, and thereby the effective sedimentary carbon of burn off.But also can the following generation that suppresses carbon laydown significantly: in that make will be at the propane of dehydrogenation on the heterogeneous catalyst in adding molecular hydrogen before by dehydrogenation catalyst in propane under the temperature that raises.

Certainly, also can be to the mixture that will in the propane of dehydrogenation in the presence of the heterogeneous catalyst, add water vapour and molecular hydrogen.In the heterogeneous catalyst dehydrogenation of propane, add the formation that molecular hydrogen can also reduce undesirable propadiene as by product, propine and acetylene.

The reactor types that is suitable for the dehydrogenation of propane heterogeneous catalyst is fixed-bed tube reactor or shell-tube type reactor, and promptly dehydrogenation catalyst exists with the fixed bed form in reaction tubes or a branch of reaction tubes.Gas by for example hydrocarbon (as methane) burns and the reacting by heating pipe around reaction tubes.Advantageously only catalyst tube is adopted this direct heating form, and be heated to required temperature of reaction in combustion processes by all the other length that the radiant heat that discharges will this bed in first about 20 to 30% parts of fixed bed.Like this, can realize roughly isothermal reaction conditions.The internal diameter that reaction tubes is suitable is about 10 to 15cm.Typical shell-tube type reactor has 300 to 1000 reaction tubess.Temperature in these reaction tubess is 300 to 700 ℃, preferred 400 to 700 ℃.Should before the reactant gases starting mixt is added tubular reactor, it be preheated to temperature of reaction.Product gas mixture can leave reaction tubes with low 50 to 100 ℃ temperature.But this temperature out also can exceed or equate.In above-mentioned steps, it is favourable using the oxy-dehydrogenation catalyst based on chromic oxide and/or aluminum oxide.It also is favourable not using diluent gas but beginning usually from only thick propane basically as initial action gas.Dehydrogenation catalyst also uses with undiluted form usually.

On big technical scale, can this shell-tube type reactor of parallel running a plurality of (as three).According to the present invention, in these reactors two can carry out dehydrogenation and catalyst bed in the 3rd reactor is regenerated, and the production in the subregion can not interrupted.

It is favourable that this technology in the BASF-Linde dehydrogenating propane method of for example being known by document is.But importantly,, use this shell-tube type reactor just enough according to the present invention.

In " active (STAR) method of reforming of water vapour " of Phillips Petroleum Co. exploitation, also used this technology (referring to for example US-A 4902849, US-A 4996387 and US-A5389342).About the dehydrogenation catalyst in the STAR method, should use the platinum that contains promotor (referring to for example US-A 5073662) on zinc (magnesium) spinel carrier.The difference of itself and BASF-Linde dehydrogenating propane method is to use the water vapour dilution to treat the propane of dehydrogenation in the STAR method.Typical mol ratio between water vapour and the propane is 4 to 6.Reactor outlet pressure is generally 3 to 8atm, and temperature of reaction is preferably 480 to 620 ℃.The typical space speed of total reaction gas mixtures on catalyzer is 0.5 to 10h ^-1(LHSV).

Also can use moving-bed to carry out the heterogeneous catalyst dehydrogenation of propane.For example, moving catalyst bed can be contained in the radial flow reactors.In radial flow reactors, catalyzer slowly moves down from the top, and the reaction gas mixtures radial flow.For example adopting this operator scheme in the UOP-Oleflex method of dehydrogenating.Because reactor is that puppet is carried out in the method, thereby should use a plurality of reactors (can reach four reactors usually at most) of series connection bunchiness adiabaticly.So just can avoid the temperature of reactor inlet place reaction gas mixtures and the excessive gap between the reactor exit temperature (in adiabatic operation, the reactant gases starting mixt plays a part heat-transfer medium, its heat content is depended in the decline of temperature of reaction), still can obtain attractive productive rate simultaneously.

When catalyst bed leaves flowing bed reactor, can be with its sent for regeneration, and then use.In this method, used dehydrogenation catalyst can be the spherical dehydrogenation catalyst of for example being made up of the platinum on the ball-aluminium oxide carrier substantially.In the UOP scheme,, in the propane for the treatment of dehydrogenation, add hydrogen for avoiding the catalyzer premature aging.Operating pressure is generally 2 to 5atm.The mol ratio of hydrogen and propane is preferably 0.1 to 1.Temperature of reaction is preferably 550 to 650 ℃, and the space velocity of reaction gas mixtures on catalyzer is about 2 to 6h ^-1

In described fixed-bed approach, catalyst appearance can also be a spheric, but also can be cylindrical (hollow or solid) or other shape.

As another process program of propane heterogeneous catalyst dehydrogenation, Proceedings De Witt, Petrochem.Review, Houston, Texas, 1992 a, N1 has described the possibility of propane being carried out the heterogeneous catalyst dehydrogenation in thermopnore, and propane is not diluted in the method.

According to the present invention, for example, two thermopnores can parallel operation, thereby makes one of them periodically to regenerate and can not have a negative impact to a total process.As for active composition, can use the chromic oxide on the aluminum oxide.Operating pressure is generally 1 to 2atm, and temperature of reaction is generally 550 to 600 ℃.By dehydrogenation catalyst being preheated to the temperature of reaction heat introducing reactive system that dehydrogenation is required.Above-mentioned method of carrying out dehydrogenation is also referred to as the Snamprogetti-Yarsintez method in the literature.

As the replacement scheme of said process, also can use the method for ABB Lummus Crest exploitation get rid of substantially the propane heterogeneous catalyst dehydrogenation of oxygen (referring to Proceedings De Witt, Petrochem.Review, Houston, Texas, 1992, P1).

The aforementioned heterogeneous catalytic method to dehydrogenating propane that is used for getting rid of substantially oxygen all is (general≤60 moles of %) (based on the one way by reaction zone) of carrying out with the conversion of propane of 〉=30 moles of %.Advantage of the present invention be reach 〉=5 moles of % to≤30 moles of % or≤conversion of propane of 25 moles of % is just enough.This heterogeneous catalyst dehydrogenation that just means propane also can be carried out (transformation efficiency is based on the one way by reaction zone) with the conversion of propane of 10 to 20 moles of %.This particularly plays a part inert dilution gas substantially because of the unreacted propane of residual content in the subregion of back, and can not be recycled to dehydrogenation zone and/or subregion then with losing substantially.

In order to realize the transformation efficiency of above-mentioned propane, the heterogeneous catalyst dehydrogenation of carrying out propane under 0.3 to 3atm operating pressure is favourable.The water vapor dilution will also be favourable at the propane of dehydrogenation in the presence of the heterogeneous catalyst.In this case, the thermal capacitance of water has partly compensated the influence that the heat absorption essence of dehydrogenation causes, and dilutes the dividing potential drop that has reduced raw material and product with water vapour, and this equilibrium theory of tide to dehydrogenation reaction has favourable influence.In addition, as mentioned above, use water vapour that the operation life of the dehydrogenation catalyst that contains precious metal is had favorable influence.If desired, also molecular hydrogen can be added as another kind of component.The ratio of molecular hydrogen and propane generally≤5.The mol ratio of water vapour and propane thereby can be (at this moment the transformation efficiency of propane is lower) 〉=0 to 30 is preferably 0.1 to 2 and be preferably 0.5 to 1.Another advantage of having found to have the operator scheme of low conversion of propane is, only consumed more a spot of heat at reactant gases in by the one way of reactor, and lower temperature of reaction just is enough to realize transforming in the one way by reactor.

Thereby the dehydrogenating propane (puppet) under the low conversion of propane is favourable adiabaticly.This means that general elder generation is heated to 500 to 700 ℃ (or 550 to 650 ℃) (for example by burning the direct of wall around it) all around with the reactant gases starting mixt.Single adiabatic process by catalyst bed just is enough to realize required conversion usually, and reaction gas mixtures is cooled about 30 ℃ to 200 ℃ (depending on transformation efficiency and extent of dilution) simultaneously.From the adiabatic operation pattern, exist water vapour also to have favourable influence as heat-transfer medium.Lower temperature of reaction can make the operation life of catalyst system therefor bed longer.

In principle, the propane heterogeneous catalyst dehydrogenation under the low conversion of propane can be carried out in fixed-bed reactor or in moving-bed or fluidized-bed reactor, and no matter dehydrogenation is adiabatic operation or isothermal operation.

The noticeable aspect of the inventive method is, single as fixed-bed reactor, reaction gas mixtures axially and/or the shaft furnace reactor crossed wherein of radial flow just be enough to carry out the inventive method, particularly in adiabatic operation.

Under the simplest situation, this is the reaction compartment of single sealing, and container for example, its internal diameter are 0.1 to 10m, can be for 0.5 to 5m, and wherein stationary catalyst bed is installed on the bracing or strutting arrangement (as grid).In this case, Re the reactant gases axial flow that contains propane cross catalyzer is housed and in adiabatic operation by heat-insulating reaction compartment.The profile of catalyzer can be the form of sphere or annular or extrudate.Because can obtain reaction compartment with the equipment that is dirt cheap in this case, so all catalyst appearances that produce low especially pressure drop all are preferred.They particularly produce big void volume or are configured to the catalyst appearance of for example only stone or honeycomb.In order to realize containing the radial flow of propane reaction gas, reactor can for example comprise two concentric mesh cylinders that are installed in the outer cylindrical wall, and catalyst bed is installed in the circular clearance between them.In the situation of adiabatic operation, outer cylindrical wall is thermal isolation aptly also.

Be used for having the suitable catalyst disclosed catalyzer among the DE-A 19937107 particularly of the propane heterogeneous catalyst dehydrogenation of low conversion of propane, particularly all those disclosed by way of example in one way.

After the operating period that prolongs, above-mentioned catalyzer can be regenerated in simple mode, for example, make earlier the air that dilutes with nitrogen and/or water vapour (preferably) pass through catalyst bed in the first regeneration stage with 300 to 600 ℃, the temperature in that is generally 400 to 550 ℃.The space velocity of resurgent gases on catalyst bed can be for example 50 to 10000h ^-1, and the oxygen level in the resurgent gases can be 0.5 to 20 volume %.

In another regeneration stage subsequently, can be with air as the resurgent gases under the same regeneration condition.In practice, usefulness rare gas element (N for example before regeneration advantageously ₂) the flushing catalyzer.

Then, molecular hydrogen (content of hydrogen answers 〉=1%) regenerated catalyst that can use pure molecular hydrogen usually under the same conditions or dilute with rare gas element (preferably water steam).

In all cases, have low conversion of propane (≤30 moles of %) the dehydrogenation of propane heterogeneous catalyst can with the scheme with high conversion of propane (＞30 moles of %) in space velocity (space velocity of total reaction gas and be present in the space velocity of propane wherein) operation on the identical catalyzer.This reaction gas space velocity can be for for example 100 to 10000h ^-1, be generally 300 to 5000h ^-1, promptly often be about 500 to 3000h ^-1

Propane heterogeneous catalyst dehydrogenation under the low conversion of propane can be carried out in the tower tray reactor especially aptly.

This comprises and surpasses a catalyst bed catalytic deoxidation reaction, that physically install continuously independently.The number of catalyst bed can be 1 to 20, is preferably 2 to 8, or 3 to 6.Catalyst bed should radially or axially installed one by one.In the practice, it is favourable using fixed-bed type catalyst in this tower tray reactor.

In the simplest situation, stationary catalyst bed axially is installed in the shaft furnace reactor or with one heart in the circular clearance between the mesh right cylinder.But also can be set to high section of a ratio in the circular clearance, and make gas radially by a section and enter the next one be higher than it or be lower than it the section.

Reaction gas mixtures should carry out centre heating at it in the tower tray reactor from a catalyst bed leads to the way of next catalyst bed, for example make it pass through heat exchanger comb with the hot gas heating, or make it pass through the pipeline that heats with hot burning gas.

If the tower tray reactor is adiabatic operation, for reaching desirable conversion of propane (≤30 moles of %), before reaction gas mixtures is introduced dehydrogenation reactor, it is preheated to 450 to 550 ℃ and to hold it in this temperature range in the tower tray reactor just enough, particularly like this when particularly using catalyzer described in the DE-A19937107 (embodiment of Miao Shuing especially by way of example).Like this, just can carry out total dehydrogenating propane with extremely low temperature, this is particularly advantageous with regard to the run duration between twice regeneration of stationary catalyst bed.

More suitable method is that catalytic dehydrogenation is autothermally carried out, and promptly for example carries out above-mentioned middle heating with direct mode (self-heating operation).For this reason, before reactive gas mixture current is crossed first catalyst bed and/or between the catalyst bed of back, limited amount molecular oxygen is added in the reaction gas mixtures.Depend on used dehydrogenation catalyst, this has caused being present in the hydrocarbon in the reaction gas mixtures, the limited burning that may be deposited on carbon on the catalyst surface or class carbon compound and/or generate in propane heterogeneous catalyst certain embodiments and/or add the hydrogen in the reaction gas mixtures (in the practice, is installed the catalyst bed that contains specifically hydrogen (and/or hydrocarbon) incendiary catalyzer in (optionally) catalysis tower tray reactor and also is that favourable (example of this catalyzer has US-A 4788371, US-A 4886928, US-A5430209, US-A 5530171, those that describe among US-A 5527979 and the US-A 5563314; For example, this catalyst bed can be contained in the tower tray reactor with the alternatively form between the bed that comprises dehydrogenation catalyst)).The reaction heat of Shi Fanging can make the propane heterogeneous catalyst in fact carry out on isothermal ground in the mode of pseudo-self-heating like this.Like this, if select the long time of reactant gases in catalyst bed, just can with reduce or substantially invariable temperature carry out dehydrogenating propane, this can obtain the run duration of growing especially between twice regeneration.

In general, the oxygen of introducing the above-mentioned type should make the oxygen level in the reaction gas mixtures be the propane of wherein existence and 0.5 to 30 volume % of propylene amount.About oxygen source, can use pure molecular oxygen or quilt for example CO, CO ₂, N ₂, rare gas the oxygen, particularly air of inert gas dilution.The burning gas that obtains generally has additional diluting effect, thereby has promoted the heterogeneous catalyst dehydrogenation of propane.

Airtight internals (as tubular inner member) are installed to space between the catalyst bed, the heterogeneous catalyst dehydrogenation of propane is more carried out on isothermal ground, these internals preferably were evacuated before the tower tray reactor of packing into, but this not necessarily.These internals can also be placed in each catalyst bed.These internals are equipped with suitable solid or liquid, and they are evaporation or fusion and absorption heat, condensation and rejected heat when temperature is lower than this specified temp then in this process when being higher than specified temp.

The method that the another kind of reactant gases starting mixt that will be used for the dehydrogenation of propane heterogeneous catalyst is heated to desired reaction temperature is to utilize the oxygen combustion parts to be present in wherein propane and/or H ₂(for example on specific combustioncatalysts, carrying out) as making reaction gas mixtures simply by on the catalyzer and/or in the catalyzer, and utilize the combustion heat that discharges like this that reaction gas mixtures is heated to desired reaction temperature.The products of combustion that obtains, for example CO ₂, H ₂O, and any N that follows the molecular oxygen of burning needs ₂Advantageously constituted rare gas element.

Above-mentioned hydrogen burning can carry out with the method for describing among the DE-A 10211275 especially aptly, promptly is used for the method for the incomplete dehydrogenation of continual multi-phase of gas phase propane, in the method:

-will wherein exist to remain the reactant gases of propane of dehydrogenation and add reaction zone continuously,

-in reaction zone, make reactant gases pass through at least one stationary catalyst bed, generating molecular hydrogen and the propylene at least incomplete degree on this catalyst bed by catalytic dehydrogenation,

-will contain molecular oxygen at least a gas before entering reaction zone and/or add afterwards in the reactant gases,

-in reaction zone, the molecular oxygen partial oxidation is present in the molecular hydrogen in the reactant gases, thus generate water vapour, and

-taking-up contains the product gas of molecular hydrogen, water vapour, propylene and propane from reaction zone,

The product gas that wherein will take from reaction zone is divided into the two portions with same composition, and one of these two portions are recycled in the dehydrogenation reaction zone as circulation gas, and according to the present invention another part further is used as gaseous mixture 1.

If outside thick propane, will contain propane and possible propylene and come from sectional circulation gas and (if desired, can therefrom remove accessory constituent (C for example ₄Hydrocarbon is as 1-butylene)) add dehydrogenation zone as another propane source, then this method is particularly preferred.If the circulation gas representative is used for the unique oxygen source of incendiary of this method hydrogen, this is a particularly suitable so.

In the methods of the invention, the product gas mixture that generates in the heterogeneous catalyst dehydrogenation of propane generally contains propane, propylene, molecular hydrogen, N ₂, H ₂O, methane, ethane, ethene, 1-butylene, other butylene and other C ₄Hydrocarbon (normal butane, Trimethylmethane, divinyl etc.), CO and CO ₂It generally is under 0.3 to 10atm the pressure, and often have 400 to 500 ℃, be 450 to 500 ℃ temperature under favourable situation.

Although EP-A 117146, DE-A 3313573 and US-A 3161670 recommend to use the product gas mixture (gaseous mixture 1) that generates in the dehydrogenation of propane heterogeneous catalyst as sending into sectional charging according to former state, but usually advantageously according to the present invention, with it further as before sending into sectional charging, isolate to small part and be present in any C in the product gas mixture (gaseous mixture 1) that comes from oxydehydrogenation and/or dehydrogenation ₄Hydrocarbon (for example 1-butylene, normal butane, Trimethylmethane, other butylene, divinyl etc.).If hydrogen is present in the gaseous mixture 1, above-mentioned separation can with hydrogen to the small part separation and combination, or carry out this hydrogen in advance and separate.

For example, the latter can followingly realize: make gaseous mixture 1 by only to molecular hydrogen be infiltrative, be generally the piped film, if suitable, in indirect heat exchanger, carry out (heat that reclaims should be used to heat the unstripped gas of the inventive method needs) after the cooling at it.Can perhaps it be sent to and make other purposes be returned to the heterogeneous catalyst dehydrogenation of propane by the isolating molecular hydrogen of this method (if desired) part.For example, can in fuel cell, burn.

Scheme as an alternative can be by partial condensation, absorption and/or purification cutting out partial or whole hydrogen (preferably be higher than under the atmospheric pressure carry out).In the methods of the invention, also can by with molecular oxygen with hydrogen optionally (for example heterogeneous catalyst) burning and from product gas mixture (gaseous mixture 1), remove part or all of molecular hydrogen.The water that reaction generates can partially or completely separate, and also can stay in the gaseous mixture, because it can play a part inert diluent in subregion.The catalyzer that is suitable for this purpose was for example disclosing among US-A 4788371, US-A 4886928, US-A 5430209, US-A 55530171, US-A 5527979 and the US-A 5563314.

Described in for example EP-A 832056, also can in the heterogeneous catalyst certain embodiments, carry out the selective combustion of molecular hydrogen then and there effectively for example by the oxidation at least a reducible metal oxide that except that dehydrogenation catalyst, adds again.

According to the present invention, advantageously with remaining product gas mixture (gaseous mixture 1 ') as delivering to before the sectional charging and/or simultaneously, isolate at least 10 moles of % or at least 25 moles of %, often at least 35 moles of % or at least 50 moles of %, at least 75 moles of % or the molecular hydrogen that in the heterogeneous catalyst dehydrogenation, generates all measured usually.If necessary, can isolating (as by condensation) before gaseous mixture is further used for subregion is present in any water in the gaseous mixture 1.Certainly, if desired, also molecular hydrogen and/or the C of 1-butylene etc. for example can isolated ₄In the time of hydrocarbon, isolate other component outside middle propane of product gas mixture (gaseous mixture 1) and the propylene.

The simple possible method that realizes this purpose is, for example, make preferably the gaseous mixture 1 of be cooled (preferably being cooled to 10 to 70 ℃), as under the temperature of 0.1 to 50atm pressure and 0 to 100 ℃, contact with propane and propylene preferentially absorbed therein (preferably high boiling) organic solvent (preferably hydrophobic), for example make described gas simply by this organic solvent.Desorb, purification by subsequently and/or use in subregion and need gas (as air) to carry out stripping as reagent as inert and/or in this reaction zone, propane and propylene are reclaimed with the form of purifying together, and as delivering to sectional charging (as mentioned above, using air to carry out under the steam stripped situation, the gaseous mixture 1 of Chan Shenging ' can be identical by this way with gaseous mixture 2, promptly directly former state as the charging that adds at least one incomplete oxidation reaction).Go out tail gas self-absorption, that may contain molecular hydrogen and can for example carry out membrane sepn, and if desired, isolated hydrogen can be used for the heterogeneous catalyst dehydrogenation of propane then.

But, in current separation method, C ₃Hydrocarbon/C ₄The separating factor of hydrocarbon is relatively limited, and is not enough to satisfy requirement of the present invention usually.

Thereby as the replacement scheme of the above-mentioned separating step that is undertaken by absorption, usually preferred applying pressure waves absorption or pressure is purified, to realize purpose of the present invention.

Being used for above-mentioned absorption isolating suitable absorbing medium is all absorbing mediums that can absorb propane and propylene in principle.The preferably preferred hydrophobic and/or high boiling organic solvent of absorbing medium.The boiling point of this solvent (under the barometric point of 1atm) is preferably at least 120 ℃, and preferably at least 180 ℃, more preferably 200 to 350 ℃, particularly 250 to 300 ℃, even more preferably 260 to 290 ℃.Its flash-point (under the barometric point of 1atm) should be higher than 110 ℃.In general, nonpolar relatively organic solvent, for example preferred aliphatic hydrocrbon that does not contain the polar group that externally works, perhaps aromatic hydrocarbon is suitable for usually as absorbing medium.Generally speaking, desirable is that absorbing medium has very high boiling point and simultaneously propane and propylene had very high dissolving power.The example of suitable absorbing medium has aliphatic hydrocrbon, as C ₈-C ₂₀Alkane and alkene; And aromatic hydrocarbons, for example from oil distillate in the paraffin distillatory; With the ether that huge group is arranged on the O atom; Perhaps they with can add in them, disclosed phthalic acid 1 among for example DE-A 4308087, the mixture of the polar solvent of 2-dimethyl ester.Other suitable absorbing medium has phenylformic acid and phthalic acid and contains the ester of the straight chain alkanol of 1 to 8 carbon atom, for example the positive butyl ester of phenylformic acid, methyl benzoate, ethyl benzoate, dimethyl phthalate, diethyl phthalate; And heat-transfer oil, for example mixture of biphenyl, phenyl ether and biphenyl and phenyl ether or their chlorinated derivative; And triaryl alkene, for example 4-methyl-4 '-benzyl ditan and isomer 2-methyl-2 '-benzyl ditan thereof, 2-methyl-4 '-benzyl ditan and 4-methyl-2 '-benzyl ditan and these mixture of isomers.Suitable absorbing medium is the solvent mixture of biphenyl and phenyl ether, preferably has the mixture that azeotropic is formed, the mixture of being made up of the phenyl ether of the biphenyl of about 25 weight % and about 75 weight % particularly, for example commercially available Diphyl ^(as available from Bayer Aktiengesellschaft).Usually with the amount that accounts for whole solvent mixture 0.1 to 25 weight % for example solvent of dimethyl phthalate is added this solvent mixture.Other special available absorbing medium has octane, nonane, decane, undecane, dodecane, tridecane, the tetradecane, pentadecane, n-Hexadecane, heptadecane and octadecane, has found that the tetradecane is specially suitable.Advantageously used absorbing medium meets above-mentioned boiling point requirement but has not too high molecular weight simultaneously.The molecular weight of absorbing medium is suitable≤300g/mol.The paraffinic hydrocarbons that has 8 to 6 carbon atoms described in the DE-A 3,313 573 also is suitable.The example of suitable commodity has the Haltermann product sold, and for example Halpasolsi as Halpasol 250/340 i and Halpasol 250/275 i, reaches the seal China ink oil of selling with the title of PKWF and Printosol.The preferred commodity that do not contain aromatics, for example commodity of PKWFaf type.

To the mode that absorbs without any special restriction.All methods and the condition that can use those skilled in the art to be familiar with.Gaseous mixture preferably contacts with absorbing medium under following condition: 1 to 50bar, preferred 2 to 20bar, more preferably 5 to 10bar pressure, 0 to 100 ℃, 30 to 50 ℃ temperature particularly.Absorption can be carried out in tower, also can carry out in sudden cool equipment.It can with and stream carry out, also can carry out with adverse current.The example on suitable absorption tower has tray column (having bubble cap plate and/or sieve plate), and (for example, specific surface area is 100 to 1000m to have structured packing ²/ m ³Or be up to 750m ²/ m ³The metal sheet filler, as Mellapak ^250 Y) tower, and comprise the packing tower (for example tower of filling) of random filler with Raschig ring.But, also can use surface absorber and tray scrubber, intersection spray scrubber and the rotary scrubber of dribble-feed tower and spray column, graphite block resorber, for example thick film and film absorption device.Make to be absorbed in and have or not with also being favourable in the bubble-plate column of internals.

Can from absorbing medium, isolate propane and propylene by stripping, flash distillation and/or distillation.

Preferably from absorbing medium, isolate propane and propylene by stripping and/or desorb.Can utilize pressure and/or variation of temperature preferably under 0.1 to 10bar, particularly 1 to 5bar, more preferably 1 to 3bar pressure and 0 to 200 ℃, particularly 20 to 100 ℃, more preferably 30 to 70 ℃, preferred especially 40 to 60 ℃ temperature, to carry out desorb in a usual manner.The example that is suitable for steam stripped gas is a water vapour, but special preferred oxygen/nitrogen mixture, as air.If use air or oxygen level to be higher than oxygen/nitrogen mixture of 10 volume %, can advantageously add before stripping process or in carrying out and dwindle the gas of explosive range.The gas that is particularly useful for this purpose is the gas of 20 ℃ of following specific heat 〉=29J/molK, for example methane, ethane, propane, propylene, benzene, methyl alcohol, ethanol and ammonia, carbonic acid gas and water.But, should avoid using C according to the present invention ₄Hydrocarbon is made this additive.Have or also be not particularly useful for stripping with the bubble-plate column of internals.

Can also or purify and from absorbing medium, to isolate propane and propylene by distillation, in this case, can use to comprise orderly filler, the conventional tower of filler or suitable internals at random.Distillation and purify in preferred condition be 0.01 to 5bar, particularly 0.1 to 4bar, more preferably 1 to 3bar pressure and 50 to 300 ℃, particularly 150 to 250 ℃ temperature (column bottom temperature).

The gaseous mixture 1 that obtains from absorbing medium by stripping ' can be as be sent to another before delivering to sectional charging the treatment stage; thereby for example reduce by the loss (as in scum dredger and/or deep bed filter, precipitating) of steam stripped absorbing medium altogether; and thereby protect subregion not to be subjected to the influence of absorbing medium simultaneously, perhaps further improve C ₃Hydrocarbon and C ₄The separation of hydrocarbon.Can carry out this removal of absorbing medium by all processing steps well known by persons skilled in the art.Preferred for the present invention this isolating embodiment is the sudden cold flow of feed gas that comes from stripper plant of water for example.In this case, utilize water that absorbing medium is washed out the flow of feed gas of this loading, and this flow of feed gas load simultaneously water.Described washing or sudden cold can for example carrying out above the liquid collecting column plate in the desorption tower top by the adverse current spray water, or in independent device, carry out.

In order to improve separating effect, can be in the sudden cold surface of sudden cold-zone installation can increase internals known to the skilled long-pending, in purification, absorption and desorption field.

Water is preferred washing medium, because it does not generally disturb the subregion of back.Water washed out absorbing medium from the flow of feed gas that is loaded with propane and propylene after, water/the absorbing medium mixture is sent to be separated, and treated flow of feed gas is as gaseous mixture 1 ' adding subregion.

Do not contained C by stripping ₃The absorbing medium of hydrocarbon and the absorbing medium that reclaims in being separated all can be reused for the absorption purpose.

Gaseous mixture 1 and/or by the gaseous mixture 1 of its manufacturing ' now can be used at least one reaction zone in a manner known way uses the propene to acrolein of feed gas mixtures 2 and/or the heterogeneous catalyzed vapor-phase oxidation and/or the ammonia oxidation of vinylformic acid and/or vinyl cyanide with supply.As for oxygenant, can add any other mixture of pure molecular oxygen, air, oxygen-rich air or oxygen and rare gas element.If incomplete oxidation is that propylene is converted into propylene oxide, then can adopt the step of describing among the EP-A 372972 for example.

If oxidizing reaction is the incomplete ammonia oxidation that is oxidized to vinyl cyanide, for example can as described in DE-A 2351151, carry out.If propene to acrolein and/or acrylic acid incomplete oxidation, then set in the method for the invention and follow using gas mixture 1 and/or 1 ' (also can use the mixture of these two, promptly separate and carry out from a part and do not carry out from another part) the composition of gaseous mixture 2, make it be in following molar ratio range:

Propane: propylene: N ₂: O ₂: H ₂O: other=0.5 to 20: 1: 0.1 to 40: 0.1 to 10: 0 to 20: 0 to 1.

According to the present invention, above-mentioned mol ratio is preferably 2 to 10: 1: 0.5 to 20: 0.5 to 5: 0.01 to 10: 0 to 1.

According to the present invention, above-mentioned mol ratio also is preferably 3 to 6: 1: 1 to 10: 1 to 3: 0.1 to 2: 0 to 0.5.

As mentioned above, propylene to acrylic acid heterogeneous catalyst gas phase incomplete oxidation of using molecular oxygen to carry out is carried out in two steps, these two steps are accepted on reaction coordinate mutually, and wherein first step generates propenal, and second step generates vinylformic acid by propenal.

This response hierarchy that is divided into two steps of accepting mutually in time, make the subregion of the inventive method can adopt the form of two successive oxidation zones in this case in a manner known way, thereby make the stand-by oxide catalyst can optimization in each of this two oxidation zones.For example, catalyzer based on the poly-metal deoxide of containing element combination Mo-Bi-Fe is preferred to first oxidation zone (propylene → propenal) generally, and is preferred to second oxidation zone (propenal → vinylformic acid) usually based on the catalyzer of the poly-metal deoxide of containing element combination Mo-V.

Many existing in the past descriptions of suitable multi-metal-oxide catalyst that are used for described two oxidation zones, and be well known to those skilled in the art.For example, EP A 253409 at page 5 with reference to suitable United States Patent (USP).

DE-A 4431957 and DE-A 4431949 also disclose the suitable multi-metal-oxide catalyst that is used for described two oxidation zones.Those of their particularly above-mentioned two document Chinese style I.

For the first step of incomplete oxidation, promptly the heterogeneous catalyst gas phase incomplete oxidation of propene to acrolein as mentioned above, can use all to comprise the multimetal oxide compositions of Mo, Bi and Fe in principle.

They are the active multimetal oxide compositions of DE-A 19955176 Chinese style I particularly, the active multimetal oxide compositions of DE-A 19948523 Chinese style I, the active multimetal oxide compositions of DE-A 19948523 Chinese style I, DE-A 10101695 Chinese style I, the active multimetal oxide compositions of II and III, DE-A 19948248 Chinese style I, the active multimetal oxide compositions of II and III, DE-A 19955168 Chinese style I, the active multimetal oxide compositions of describing among the active multimetal oxide compositions of II and III and the EP-A 700714.

Other comprises Mo, the multi-metal-oxide catalyst that is suitable for this oxidation step of Bi and Fe is at DE-A 10046957, DE-A 10063162, DE-C 3338380, DE-A 19902562, EP-A 15565, DE-C 2380765, EP-A 807465, EP-A 279374, DE-A 3300044, EP-A 575897, US-A 4438217, DE-A 19855913, WO 98/24746, DE-A 19746210 (those of formula II), JP-A 91/294239, those disclosed among EP-A 293224 and the EP-A 700714.The embodiment of mentioning by way of example in these documents particularly, wherein EP-A 15565, EP-A 575897, DE-A 19746210 and DE-A 19855913 are particularly preferred.In this article, can should be mentioned that the catalyzer that embodiment 1c among the EP-A 15565 describes and can prepare in a similar fashion but its activity consists of formula Mo especially ₁₂Ni _6.5Zn ₂Fe ₂Bi ₁P _0.0065K _0.06O _x10SiO ₂Catalyzer.Other catalyzer that is worth mentioning especially is embodiment a 3 (stoichiometry: Mo among the DE-A 19855913 ₁₂Co ₇Fe ₃Bi _0.6K _0.08Si _1.6O _x) profile be the complete active hollow circuit cylinder body catalyst of 5mm * 3mm * 2mm (external diameter * height * internal diameter), and the full active catalyst described of the embodiment 1 of poly-metal deoxide II--DE-A 19746210.Can also mention the multi-metal-oxide catalyst of US-A 4438217.When these hollow circular cylinders have the profile of 5.5mm * 3mm * 3.5mm or 5mm * 2mm * 2mm or 5mm * 3mm * 2mm or 6mm * 3mm * 3mm or 7mm * 3mm * 4mm (being respectively external diameter * height * internal diameter), the latter is a particularly suitable.

Many multimetal oxide compositions that are suitable for the propene to acrolein step can be described with formula IV:

Mo ₁₂Bi _aFe _bX ¹ _cX ² _dX ³ _eX ⁴ _fO _n (IV)，

Wherein variable has following implication:

X ¹=nickel and/or cobalt,

X ²=thallium, basic metal and/or alkaline-earth metal,

X ³=zinc, phosphorus, arsenic, boron, antimony, tin, cerium, lead and/or tungsten,

X ⁴=silicon, aluminium, titanium and/or zirconium,

A=0.5 to 5,

B=0.01 to 5, preferred 2 to 4,

C=0 to 10, preferred 3 to 10,

D=0 to 2, preferred 0.02 to 2,

E=0 to 8, preferred 0 to 5,

F=0 to 10 and

The number that n=is determined by the chemical valence and the abundance of the element outside the oxygen among the IV.

They can itself make (referring to for example DE-A 4023239) in the mode of knowing, usually be shaped to undiluted form to make sphere, annular or cylindrical, or use with the form of coated catalysts, promptly be coated with the preformed inert support of active composition.Certainly, they also can be used as the catalyzer of powder type.

In principle, the active composition of formula IV can be prepared as follows in simple mode: make very uniform, preferred in small, broken bits having corresponding to they stoichiometric drying composites of forming by the suitable source of their basal components, and in 350 to 650 ℃ are calcined to this mixture.Calcining can be carried out in rare gas element, also can be in the oxidizing atmosphere of for example air (mixture of rare gas element and oxygen) or reducing atmosphere (for example rare gas element, NH ₃, CO and/or H ₂Mixture) carry out.Calcination time can be from several minutes to a few hours, and generally rise and shorten with temperature.May the originating of basal component of active multimetal oxide compositions IV is oxide compound, and/or can be at least in the presence of oxygen, be the compound of oxide compound by thermal conversion.

Except that oxide compound, other suitable initial compounds (can evenly sneaked into following compound in the dry mixture: decompose and/or can be broken down into the compound of the compound that discharges with gaseous state at the latest during the calcining in the back, for example NH in addition particularly including halogenide, nitrate, formate, oxalate, Citrate trianion, acetate, carbonate, ammonia complex salt, ammonium salt and/or oxyhydroxide ₄OH, (NH ₄) ₂CO ₃, NH ₄NO ₃, NH ₄CHO ₂, CH ₃COOH, NH ₄CH ₃CO ₂And/or ammonium oxalate).

The uniform mixing that is used to prepare the initial compounds of multimetal oxide compositions IV can carry out or carry out with wet method with dry method.If carry out with dry method, initial compounds should be used as fine powder, and after mixing, calcine, if suitable, also suppress.But uniform mixing preferably carries out with wet method.In this case, starting mixt mixes mutually with the form of the aqueous solution and/or aqeous suspension usually.Drying composite obtains in described mixing process when the basal component source all is in solubilized form especially uniformly.Preferred water is as solvent.The dry then aqueous composition that obtains preferably passes through the described aqueous mixture of spraying drying with 100 to 150 ℃ temperature out.

The active multimetal oxide compositions of formula IV can be used for " propylene → propenal " step with powder type or after being shaped to the specific catalyst profile.Moulding can be carried out before or after final calcining.For example, can be by compacting by the active composition of powder type or its not incinerating and/or the full active catalyst of part incinerating precursor manufacturing, to produce desirable catalyst appearance (for example by suppress in flakes, extrude or plunger is extruded), if desired, auxiliary agent such as graphite or stearic acid be can add and lubricant and/or shaping assistant made; And strongthener, as glass microfiber, asbestos, silicon carbide or potassium titanate.Suitable full active catalyst profile has, and for example, external diameter and length are 2 to 10mm solid cylindrical or hollow cylinder.Under the situation that is hollow cylinder, wall thickness is preferably 1 to 3mm.Certainly, full active catalyst can also be spherical, and this moment, its diameter can be 2 to 10mm.

Special available hollow cylinder profile is 5mm * 3mm * 2mm (external diameter * length * internal diameter), particularly under the situation of full active catalyst.

Certainly, also can be by being administered to the moulding that realizes Powdered active composition on the preformed inert catalyst carrier, or its not moulding of incinerating and/or the Powdered precursor composition of part incinerating as yet.The catalyzer that applies for making, coated carrier in suitable rotatable container usually, this is known by for example DE-A 2909671, EP-A 293859 or EP-A 714700.Be coated carrier, powder composition to be administered should be drenched, and after using, for example pass through the warm air after drying.The thickness that is administered to the powder composition on the carrier is preferably 10 to 1000 μ m, is preferably 50 to 500 μ m, preferred especially 150 to 250 μ m.

As for solid support material, can use porous commonly used or non-porous aluminum oxide, silicon-dioxide, thorium dioxide, zirconium dioxide, silicon carbide or the silicate of Magnesium Silicate q-agent or pure aluminium silicate for example.For the described reaction in the inventive method, they generally are inert substantially.Carrier can have regular or irregular shape, but the carrier of the very large regular shape of preferred surface roughness, for example sphere or hollow cylindrical.It is 1 to 8mm, preferred 4 to 5mm suit for non-porous spherical talcum substantially that use has uneven surface and diameter.But use that length is 2 to 10mm, external diameter is that 4 to 10mm right cylinder also suits as carrier.Using under the suitable situation of ring as carrier, its wall thickness is generally 1 to 4mm.With regard to the inventive method, the length of preferred annular carrier is 2 to 6mm, and external diameter is 4 to 8mm, and wall thickness 1 is to 2mm.Profile is that the ring of 7mm * 3mm * 4mm (external diameter * length * internal diameter) also can be used as carrier of the present invention especially.Certainly, the thickness of the fineness of the catalytic activity oxide composition to carrier surface to be administered and required coating be complementary (referring to EP-A 714 700).

Other active multimetal oxide compositions that can be used for by propylene generation propenal is the composition of formula V:

[Y ¹ _a′Y ² _b′O _x′]p[Y ³ _c′Y ⁴ _d′Y ⁵ _e′Y ⁶ _f′Y7 _g′Y ² _h′O _y′] _q (V)

Wherein the implication of each variable is as follows:

Y ¹At least a in=independent bismuth or bismuth and tellurium, antimony, tin and the copper,

Y ²=molybdenum or molybdenum and tungsten,

Y ³=basic metal, thallium and/or samarium,

Y ⁴=alkaline-earth metal, nickel, cobalt, copper, manganese, zinc, tin, cadmium and/or mercury,

Y ⁵At least a in=iron or iron and elemental chromium and the cerium,

Y ⁶=phosphorus, arsenic, boron and/or antimony,

Y ⁷=rare earth element, titanium, zirconium, niobium, tantalum, rhenium, ruthenium, rhodium, silver, gold, aluminium, gallium, indium, silicon, germanium, lead, thorium and/or uranium,

A '=0.01 is to 8,

B '=0.1 is to 30,

C '=0 is to 4,

D '=0 is to 20,

E '＞0 is to 20,

F '=0 is to 6,

G '=0 is to 15,

H '=8 are to 16,

X ', y '=by the valency of the element outside the deoxygenation among the V and the number of abundance decision, and

P, q=ratio p/q are 0.1 to 10 number,

It has chemical composition Y ¹ _{A '}Y ² _{B '}Ox _'3D region, described 3D region comes with its local environment difference because of having the composition that is different from its local environment, and its maximum diameter (the longest wire between last 2 of this region surface (border) and centroidal) is 1nm to 100 μ m, often is 10nm to 500nm or 1 μ m to 50 or 25 μ m.

Shi Yi multimetal oxide compositions V is Y especially ¹Be those of independent bismuth.

Wherein, preferably have those that formula VI forms again:

[Bi _a”Z ² _b”O _x”] _p”[Z ² ₁₂Z ³ _c”Z ⁴ _d”Fe _e”Z ⁵ _f”Z ⁶ _g”Z ⁷ _h”O _y”] _q” (VI)

Wherein each variable has following implication:

Z ²=molybdenum or molybdenum and tungsten,

Z ³=nickel and/or cobalt,

Z ⁴=thallium, basic metal and/or alkaline-earth metal,

Z ⁵=phosphorus, arsenic, boron, antimony, tin, cerium and/or lead,

Z ⁶=silicon, aluminium, titanium and/or zirconium,

Z ⁷=copper, silver and/or golden,

A "=0.1 to 1,

B "=0.2 to 2,

C "=3 to 10,

D "=0.02 to 2,

E "=0.01 to 5, it is preferred 0.1 to 3,

F "=0 to 5,

G "=0 to 10,

H "=0 to 1,

X ", y "=by the number of the valency of the element outside the deoxygenation among the VI and abundance decision, and

P ", q "=ratio p "/q " be 0.1 to 5, be preferably 0.5 to 2 number,

Z very particularly preferably ² _{B "}=(tungsten) _{B "}And Z ² ₁₂=(molybdenum) ₁₂Composition VI.

Advantageously, be suitable for total [Y of the multimetal oxide compositions V (multimetal oxide compositions VI) of the object of the invention ¹ _{A '}Y ² _{B '}O _{X '}] _pContent ([Bi _{A "}Z ² _{B "}O _{X "}] _{P "}) at least 25 moles of % (preferably at least 50 moles of %) with the chemical composition Y of 3D region ¹ _{A '}Y ² _{B '}O _{X '}[Bi _{A "}Z ² _{B "}O _{X "}] _{P "}) form exist, described 3D region is distinguished with its local environment and is come because of having the composition that is different from its local environment, and its maximum diameter is 1nm to 100 μ m.

About moulding, be applicable to multimetallic catalyst V about the described content of the part of multi-metal-oxide catalyst IV.

The preparation of active multimetal oxide compositions V for example is described among the EP-A 575897 and DE-A 19855913.

Especially, above the inert support material of Tui Jianing also can be used as the suitable stationary catalyst bed of dilution and/or limits the inert material of its scope, or as guard catalyst and/upstream bed of heated air mixture.

At this, can be pointed out that, all be recommended as be suitable for by propylene generate the catalyzer of step of propenal and multimetal oxide compositions also all be in principle be suitable for by propylene generate vinyl cyanide incomplete ammonia oxidation.

For second step, promptly generate acrylic acid heterogeneous catalyst gas phase incomplete oxidation by vinyl cyanide, as mentioned above, can use all to comprise the multimetal oxide compositions that Mo and V make active composition in principle, for example those that know by DE-A 10046928.

Many this compositions, those among the DE-A 19815281 for example, can describe with formula VII:

Mo ₁₂V _aX ¹ _bX ² _cX ³ _dX ⁴ _eX ⁵ _fX ⁶ _gO _n (VII)

Wherein each variable has following implication:

X ¹=W, Nb, Ta, Cr and/or Ce,

X ²=Cu, Ni, Co, Fe, Mn and/or Zn,

X ³=Sb and/or Bi,

X ⁴=one or more basic metal,

X ⁵=one or more alkaline-earth metal,

X ⁶=Si, Al, Ti and/or Zr,

A=1 to 6,

B=0.2 to 4,

C=0.5 to 18,

D=0 to 40,

E=0 to 2,

F=0 to 4,

G=0 to 40 and

N=is by the valency of the element outside the deoxygenation among the VII and the number of abundance decision.

In active poly-metal deoxide VII, be that each variable has those of following implication among the formula VII according to the preferred embodiment of the invention:

X ¹=W, Nb and/or Cr,

X ²=Cu, Ni, Co and/or Fe,

X ³＝Sb，

X ⁴=Na and/or K,

X ⁵=Ca, Sr and/or Ba,

X ⁶=Si, Al and/or Ti,

A=1.5 to 5,

B=0.5 to 2,

C=0.5 to 3,

D=0 to 2,

E=0 to 0.2,

F=0 to 1 and

But very particularly preferably poly-metal deoxide VII is those shown in the formula VIII according to the present invention:

Mo ₁₂V _a′Y ¹ _b′Y ² _c′Y ⁵ _f′Y ⁶ _g′O _n′ (VIII)

Wherein

Y ¹=W and/or Nb,

Y ²=Cu and/or Ni,

Y ⁵=Ca and/or Sr,

Y ⁶=Si and/or Al,

A '=2 are to 4,

B '=1 is to 1.5,

C '=1 is to 3,

F '=0 is to 0.5,

G '=0 to 8 and

N '=by the valency of the element outside the deoxygenation among the VIII and the number of abundance decision.

The active multimetal oxide compositions (VII) that is suitable for the object of the invention can known method itself, for example disclosed method preparation among DE-A 4335973 or the EP-A 714700.

In principle, be suitable for the active multimetal oxide compositions of step " propenal → vinylformic acid ", those shown in the formula VII particularly, can be prepared as follows in simple mode: make very uniform, preferred in small, broken bits having by the suitable source of their basal components, and in 350 to 600 ℃ are calcined to this mixture corresponding to they stoichiometric drying composites of forming.Calcining can be carried out in rare gas element, also can be in the oxidizing atmosphere of for example air (mixture of rare gas element and oxygen) or at reducing atmosphere (for example rare gas element and for example H ₂, NH ₃, CO, methane and/or propenal reducing gas mixture, or described reducing gas self) in carry out.Calcination time can be from several minutes to a few hours, and generally rise and shorten with temperature.May the originating of basal component of active multimetal oxide compositions VII is oxide compound, and/or can be at least in the presence of oxygen, be the compound of oxide compound by thermal conversion.

The uniform mixing that is used to prepare the initial compounds of multimetal oxide compositions VII can carry out or carry out with wet method with dry method.If carry out with dry method, initial compounds should be used as fine powder, and after mixing, calcine, if suitable, also suppress.But uniform mixing preferably carries out with wet method.

In this case, starting mixt mixes mutually with the form of the aqueous solution and/or aqeous suspension usually.Drying composite obtains in described mixing process when the basal component source all is in solubilized form especially uniformly.Preferred water is as solvent.The dry then aqueous composition that obtains preferably passes through the described aqueous mixture of spraying drying with 100 to 150 ℃ temperature out.

The multimetal oxide compositions that obtains, particularly those shown in the formula VII can or be used for the oxidation of propenal with powder type after being shaped to the specific catalyst profile.Moulding can be carried out before or after final calcining.For example, can be by compacting by the active composition of powder type or its full active catalyst of incinerating precursor composition manufacturing not, to produce desirable catalyst appearance (for example by suppress in flakes, extrude or plunger is extruded), if desired, auxiliary agent such as graphite or stearic acid be can add and lubricant and/or shaping assistant made; And strongthener, as glass microfiber, asbestos, silicon carbide or potassium titanate.Suitable full active catalyst profile has, and for example, external diameter and length are 2 to 10mm solid cylindrical or hollow cylinder.Under the situation that is hollow cylinder, wall thickness is preferably 1 to 3mm.Certainly, full active catalyst can also be spherical, and this moment, its diameter can be 2 to 10mm.

Certainly, also can be by being administered to the moulding that realizes Powdered active composition on the preformed inert catalyst carrier, or its not moulding of the Powdered precursor composition of incinerating as yet.The catalyzer that applies for making, coated carrier in suitable rotatable container usually, this is known by for example DE-A 2909671, EP-A 293859 or EP-A 714700.

Be coated carrier, powder composition to be administered should be drenched, and after using for example by the warm air after drying.The thickness that is administered to the powder composition on the carrier is preferably 10 to 1000 μ m, is preferably 50 to 500 μ m, preferred especially 150 to 250 μ m.

As for solid support material, can use porous commonly used or non-porous aluminum oxide, silicon-dioxide, thorium dioxide, zirconium dioxide, silicon carbide or the silicate of Magnesium Silicate q-agent or pure aluminium silicate for example.Carrier can have regular or irregular shape, but the carrier of the very large regular shape of preferred surface roughness, the sphere or the hollow cylindrical that for example have the coarse sand coating.It is 1 to 8mm, preferred 4 to 5mm suit for non-porous spherical talcum substantially that use has uneven surface and diameter.But use that length is 2 to 10mm, external diameter is that 4 to 10mm right cylinder also suits as carrier.Under the situation of using ring as carrier, its wall thickness is generally 1 to 4mm.Annular carrier preferably has 2 to 6mm length, 4 to 8mm external diameter and 1 to 2mm wall thickness.Profile is that the ring of 7mm * 3mm * 4mm (external diameter * length * internal diameter) also can be used as carrier especially.Certainly, the thickness of the fineness of the catalytic activity oxide composition to carrier surface to be administered and required coating be complementary (referring to EP-A 714700).

The suitable active multimetal oxide compositions that is used for " propenal → vinylformic acid " step is suc as formula the composition shown in the IX:

[D] _p[E] _q (IX)

Wherein each variable has following implication:

D＝Mo ₁₂V _a”Z ¹ _b”Z ² _c”Z ³ _d”Z ⁴ _e”Z ⁵ _f“6 _g”O _x”，

E＝Z ⁷ ₁₂Cu _h”H _i”O _y”，

Z ¹=W, Nb, Ta, Cr and/or Ce,

Z ²=Cu, Ni, Co, Fe, Mn and/or Zn,

Z ³=Sb and/or Bi,

Z ⁴=Li, Na, K, Rb, Cs and/or H,

Z ⁵=Mg, Ca, Sr and/or Ba,

Z ⁶=Si, Al, Ti and/or Zr,

Z ⁷=Mo, W, V, Nb and/or Ta, preferred Mo and/or W,

A "=1 to 8,

B "=0.2 to 5,

C "=0 to 23,

d”＝0?to?50，

E "=0 to 2,

F "=0 to 5,

G "=0 to 50,

H "=4 to 30,

I "=0 to 20 and

X ", y "=by the number of the valency of the element outside the deoxygenation among the IX and abundance decision and

P, q=ratio p/q are the number of 160: 1 to 1: 1 non-zero,

And composition I X can followingly obtain: the pre-separately multimetal oxide compositions E (starting composition 1) that forms form in small, broken bits:

Z ⁷ ₁₂Cu _h”H _i”O _y” (E)

With required ratio p: q preformed solid starting composition 1 is sneaked into stoichiometry D containing element Mo, V, Z then ¹, Z ², Z ³, Z ⁴, Z ⁵And Z ⁶The aqueous solution, aqeous suspension or the drying composite in small, broken bits of source material of these elements in (starting composition 2):

Mo ₁₂V _a”Z ¹ _b”Z ² _c”Z ³ _d”Z ⁴ _e”Z ⁵ _f”Z ⁶ _g” (D)

If desired, can the dry aqueous mixture that obtains, and in 250 to 600 ℃ of calcinings dried precursor compositions of acquisition like this, to produce desirable catalyst appearance.

Preferred multimetal oxide compositions IX sneaks into preformed solid starting composition 1 in the moisture initial starting composition 2 and prepares in≤70 ℃.The detailed description of preparation multimetal oxide compositions IX is found in for example EP A 668104, DE-A 19736105, DE-A 10046928, DE-A 19740493 and DE-A 19528646.

About moulding, be applicable to multimetallic catalyst IX about the described content of the part of multi-metal-oxide catalyst VII.

Other multi-metal-oxide catalyst that is very suitable for step " propenal → vinylformic acid " be DE-A 19815281 described those, the active multimetal oxide compositions shown in the formula I that describes of the document particularly.

Advantageously, use full active catalyst ring for the step that generates propenal by propylene, and use the catalyst rings that applies for generate acrylic acid step by propenal.

Carry out in single district multitube fixed-bed reactor that the first step of incomplete oxidation (generating propenal by propylene) can use above-mentioned catalyzer to describe in DE-A 4431957 for example.

Use oxygen as oxygenant.If select N ₂As inert dilution gas, using air is suitable especially as oxygen source.

Incomplete oxidation is normally with 1: (1.0-3.0): (5-25), preferred 1: (1.7-2.3): propylene (10-15): oxygen: rare gas element (comprising water vapour) volume (standard liter) ratio carries out.Reaction pressure is generally 1 to 3 bar, and total space speed is preferably 1500 to 4000 standard liters/(liters per hour).The space velocity of propylene is generally 90 to 200 standard liters/(liters per hour).

Feed gas mixture preferably flows into single district multitube fixed-bed reactor from the top.As for heat-transfer medium, should use salt melt, preferably by the saltpetre (KNO of 60 weight % ₃) and the Sodium Nitrite (NaNO of 40 weight % ₂) form or by the saltpetre (KNO of 53 weight % ₃), the Sodium Nitrite (NaNO of 40 weight % ₂) and the SODIUMNITRATE (NaNO of 7 weight % ₃) salt melt formed.

During from the observation of reactor top, salt melt and reaction gas mixture can be so that also stream or adverse current are carried.Salt melt preferably passes through around catalyst tube with the form of meander.

If incoming mixture is to pass through catalyst tube downwards from the top, the following loading of catalyst tubes that then should make progress (if flow direction is to make progress from the bottom, the filling order is suitable opposite) from the bottom:

-at first, the catalyst tube length for 40 to 60% perhaps only has catalyzer, or the mixture (C part) of catalyzer and inert material (the highest 20 weight % that account for mixture of the latter);

-next, the total pipe range for 20 to 40% perhaps only has catalyzer, or the mixture (B part) of catalyzer and inert material (the highest 40 weight % that account for mixture of the latter); With

-last, the total pipe range for 10 to 20% is inert material bed (A part) that it preferably selects to such an extent that can produce very little pressure drop.

The C part is preferably without dilution.

If use catalyzer and the profile described among DE-A 10046957 embodiment 1 or DE-A 10046957 embodiment 3 describe to make inert material as the talcum ring of 7mm * 7mm * 4mm (external diameter * height * internal diameter), above-mentioned filling scheme is suitable especially.As for salt temperature, be suitable for content described in the DE-A 4431957.

But carry out in the two-region multitube fixed-bed reactor that the first step of incomplete oxidation (generating propenal by propylene) also can use described catalyzer to describe in DE-A 19910506 for example.In the above two kinds of cases, the propylene conversion of in one way, realizing usually all 〉=90 mole % or 〉=95 moles of %.Carry out in single district multitube fixed-bed reactor that second step (generating vinylformic acid by propenal) of incomplete oxidation can use described catalyzer to describe in DE-A 4431949 for example.Generate the general former state of product mixtures (promptly not isolating accessory constituent) that the oxidizing reaction of propenal produces by propylene and send into by propenal and generate acrylic acid oxidizing reaction, if desired, behind intercooling, carry out.

The required oxygen of second step of incomplete oxidation preferably adds with air, and in the product gas mixture of general direct adding from the propylene oxidation reaction.

The feed gas mixture that adds this acrolein oxidation reaction generally has following composition: propenal: oxygen: water vapour: the volumetric ratio of rare gas element (standard liter) is 1: (1-3): (0-20): (3-30), and preferred 1: (1-3): (0.5-10): (7-18).

Here, reaction pressure generally also is 1 to 3bar, and total space speed is preferably 1000 to 3800 standard liters/(liters per hour).The space velocity of propenal is generally 80 to 190 standard liters/(liters per hour).

Feed gas mixture equally preferably flows into single district multitube fixed-bed reactor from the top.In subordinate phase, used heat-transfer medium is preferably salt melt equally, preferably by the saltpetre (KNO of 60 weight % ₃) and the Sodium Nitrite (NaNO of 40 weight % ₂) form or by the saltpetre (KNO of 53 weight % ₃), the Sodium Nitrite (NaNO of 40 weight % ₂) and the SODIUMNITRATE (NaNO of 7 weight % ₃) salt melt formed.During from the observation of reactor top, salt melt and reaction gas mixture can be so that also stream or adverse current are carried.Salt melt preferably passes through around catalyst tube with the form of meander.

If incoming mixture is to pass through catalyst tube downwards from the top, following loading of catalyst tubes then should make progress from the bottom:

-at first, the catalyst tube length for 50 to 70% perhaps only has catalyzer, or the mixture (C part) of catalyzer and inert material (the highest 20 weight % that account for mixture of the latter);

-last, the total pipe range for 5 to 20% is inert material bed (A part) that it preferably selects to such an extent that can produce very little pressure drop.

The C part is preferably without dilution.

If flow direction is to make progress from the bottom, the filling order is suitable opposite.

Catalyzer and profiles that describe among the embodiment 5 or DE-A 19815281 descriptions are made inert material as the talcum ring of 7mm * 7mm * 4mm or 7mm * 7mm * 3mm (being external diameter * height * internal diameter) if use DE-A 10046958 to prepare, and above-mentioned filling scheme is suitable especially.As for salt temperature, be suitable for content described in the DE-A 4431949.Its generally select make the propenal of realizing in the one way transformation efficiency usually 〉=90 moles of % or 〉=95 moles of %.

But carry out in the two-region multitube fixed-bed reactor that second step (generating vinylformic acid by propenal) of incomplete oxidation also can use described catalyzer to describe in DE-A 19910508 for example.As for propylene conversion, be suitable for above-described scope.When this second step carries out in the multitube fixed-bed reactor of two-region, the product gas mixture of directly sending in the first step from incomplete oxidation (as mentioned above) should be directly used in manufacturing feed gas mixture (using if desired) equally behind intercooling.The required oxygen of second step of incomplete oxidation preferably adds with air, and directly in the product gas mixture of adding from the fs of incomplete oxidation.

In the two stages operating patterns of direct further use, generally two list district's multitube fixed-bed reactor or two two-region multitube fixed-bed reactor are connected from second step of the product gas mixture supply incomplete oxidation of the first step of incomplete oxidation.Hybrid series connection (single district/two-region or opposite) also is feasible.

Can the side cooler that can comprise inert bed when needing be installed between reactor, described inert bed plays filtering effect.The multitubular reactor salt temperature that is used for being generated by propylene the first step of acrylic acid incomplete oxidation is generally 300 to 400 ℃.Be used for generating the multitubular reactor salt temperature in second step (promptly generating acrylic acid incomplete oxidation) of acrylic acid incomplete oxidation and be generally 200 to 350 ℃ by propenal by propylene.In addition, with following amount heat-transfer medium (being preferably salt melt) is carried by relevant multitube fixed-bed reactor usually: the difference between their inflow temperature and their the outflow temperature generally≤5 ℃.As mentioned above, two steps that generate acrylic acid incomplete oxidation by propylene also can be as carrying out in the charging in a reactor as described in the DE-A 10121592.

Can be pointed out that once more that the part feed gas mixture (gaseous mixture 2) that is used for the first step (" propylene → propenal ") can be the circulation gas from incomplete oxidation.

This is to isolate the residual afterwards gas of target product (propenal and/or vinylformic acid separate) from the product gas mixture from incomplete oxidation, and can be used as inert diluent gas and be recycled to send into by propylene and generate in the first step and/or the charging in second step of propenal and/or acrylic acid incomplete oxidation.

But this circulation gas that comprises propane and possible propylene preferably is recycled in the charging of sending into the inventive method the first step.

Can also be pointed out that once more, incomplete oxidation of the present invention and/or ammonia oxidation can by at first make oxygen-free reaction gas mixture from the catalyst charge by preparing.In this case, the required oxygen of incomplete oxidation provides with lattice oxygen.Catalyst bed uses oxygen-containing gas (as air, oxygen-rich air or oxygen-denuded air) regeneration in the regeneration step of back, thereby makes it can be reused for oxygen-free reaction gas mixture, or the like.

In a word, wherein catalyst charge is prolonging the shell-tube type reactor that single catalyst tube changes (this propylene incomplete oxidation that is suitable for as reaction zone B of the present invention is for example EP-A 911313, EP-A 979813, EP-A 990636 and DE-A 2830765 instructions) and has represented the simplest mode that realizes being used for being generated by propylene two reaction zones of two steps of acrylic acid incomplete oxidation when first reactions steps finishes.If desired, the catalyst charge in the reaction tubes can be interrupted by inert bed.

But described two oxidation zones preferably realize with the form of two placed in-line shell-tube type systems.They can be installed in the reactor, are to form by the inert material bed (being preferably come-at-able) that is not contained in the catalyst tube by a beam tube to the transition of another beam tube wherein.Though heat-transfer medium generally flows around catalyst tube, it does not contact the inert bed of installing as mentioned above.Described two bundle catalyst tubes thereby should be contained in the reactor of physical sepn each other.In order to reduce any afterfire of propenal in the product gas mixture that leaves first oxidation zone, generally between two shell-tube type reactors, side cooler is installed.Can use for example have described in the DE-A 19929487 and DE-A 19952964 the salt cooling and/transpiration-cooled plate-type heat exchanger reactor replaces the shell-tube type reactor.

Temperature of reaction in first oxidation zone is generally 300 to 450 ℃, is preferably 320 to 390 ℃.Temperature of reaction in second oxidation zone is generally 200 to 300 ℃, is generally 220 to 290 ℃.Reaction pressure in two oxidation zones is preferably 0.5 to 5atm, and preferred 1 to 3atm.The space velocity (standard liter/liters per hour) of the reactant gases in two oxidation zones on the oxide catalyst often is 1500 to 2500h ^-1, or be up to 4000h ^-1The space velocity of propylene can be 100 to 200 standard liter/liters per hours or higher.

In principle, two reaction zones in the inventive method can be configured as described in for example DE-A 19837517, DE-A 19910506, DE-A 19910508 and DE-A 19837519.The outer heating of these two reaction zones (the multi-region reactor assembly when needing) usually is complementary with specific reaction gas mixture composition and catalyst charge in a manner known way.

Required whole molecular oxygens as oxygenant in the subregion of the needs according to the present invention can all add at the very start to be sent in the sectional feed gas mixture.But for example when preparation vinylformic acid, can certainly after first subregion, add extra oxygen.Under the acrylic acid situation of preparation, this back one step is preferred.

In first oxidation zone (propylene → propenal), propylene: the molar ratio of molecular oxygen is set to 1: 1-3 often is 1: 1.5-2.It is propenal in acrylic acid second oxidation zone that similar numerical value is suitable for the propenal incomplete oxidation: the molar ratio of molecular oxygen (preferred 1: 1.5-1.5).

In two oxidation zones, excessive molecular oxygen generally has useful effect for the kinetics of gaseous oxidation.Opposite with the ratio in the dehydrogenation reaction that adopts according to the present invention, the thermokinetics in the incomplete oxidation is subjected to the influence of reagent mol ratio not obvious, because generate acrylic acid heterogeneous catalyst gas phase incomplete oxidation by thermodynamic control by propylene.Thereby, for example in first oxidation zone, also can use propylene in principle with respect to the molecular oxygen molar excess.In this case, excessive propylene serves as carrier gas.

But, generate acrylic acid heterogeneous catalyst gas phase incomplete oxidation by propylene and also can in single oxidation zone, carry out in principle.In this case, two reactions steps all take place in the reactor that has loaded catalyzer that can these two reactions steps of catalysis.Certainly, catalyst charge also can prolong reaction coordinate and continuously or suddenly changing in oxidation zone.In sectional embodiment two placed in-line forms of oxidation zone, an employing according to the present invention, if desired, that generate as by product in first oxidation zone and be present in carbon oxides and water vapour in the product gas mixture that leaves first oxidation zone, nature can partly or entirely be separated from this product gas mixture before delivering to second oxidation zone.According to the present invention, preferably do not need this isolating operator scheme.

That incomplete oxidation and/or ammonia oxidation need, comprise pure molecular oxygen with the possible source of blended molecular oxygen of gaseous mixture 1 or 1 ' before the latter adds subregion and by for example CO ₂, CO, rare gas, N ₂And/or the molecular oxygen of the inert gas dilution of stable hydrocarbon.

Should use air as oxygen source to satisfy to the demand of small part to molecular oxygen.

In the methods of the invention, with freezing air introduce the gaseous mixture 1 or 1 of heat ', directly cooling gas mixture 1 or 1 '.

Under preparation propenal and/or acrylic acid situation, leave general main target product propenal or the vinylformic acid of comprising of sectional product gas mixture used according to the invention, or the mixture of the latter and following material: propenal, unreacted molecular oxygen, propane, unreacted propylene, dinitrogen, with the water vapour by product generation and/or that be used as carrier gas, with the carbon oxides by product generation and/or that be used as carrier gas and a small amount of other low grade aldehyde, the lower alkane carboxylic acid is (as acetate, formic acid and propionic acid) and maleic anhydride, phenyl aldehyde, aromatic carboxylic acid and aromatic tricarboxylic acid anhydride (as Tetra hydro Phthalic anhydride and phenylformic acid), possible other hydrocarbon such as C ₄Hydrocarbon (as 1-butylene and other possible butylene) and other inert diluent gas.

Target product can be separated from product gas mixture in a manner known way, for example by acrylic acid partial condensation or absorb vinylformic acid in the water inlet or in the high boiling point hydrophobic organic solvent or will propenal absorb in the water inlet or in low-grade carboxylic acid's the aqueous solution and subsequently absorbed material is handled; Perhaps, also can the fractional condensation product gas mixture; Referring to for example EP-A 117146, DE-A 4308087, DE-A 4335172, DE-A 4436243, DE-A 19924532 and DE-A 19924533.Also can as described in EP-A 982287, EP-A 982289, DE-A 19924532, DE-A 10115277, DE-A 19606877, DE-A 19740252, DE-A 19627847, DE-A 10053086 and EP-A 982288, isolate vinylformic acid.

If desired, also separablely go out unreacted propylene and/or propenal and be circulated to subregion.

Separate and preferably carry out as the shown in Figure 7 of WO/0196271.Equally, target product after isolating in the residual residual gas main ingredient, used thick propane and the used dehydrogenation/oxy-dehydrogenation catalyst except that vinylformic acid and propenal can isolate separately, and/or be recycled in the charging of adding the inventive method the first step with propane and circulation gas (recirculation flow).But unreacted propane can certainly mix (as feed cycle stream) with unreacted propylene and be recycled in this incoming flow.In the scheme of carrying out continuously of the inventive method, propane is converted into vinylformic acid and/or propenal like this continuously.

As mentioned above, propane and propylene can be separated by absorbing in the high boiling point hydrophobic organic solvent the residual gas residual after target product is isolated, and carry out desorb and/or stripping (with re-using of absorbing medium) then.Described residual gas generally comprises O ₂, CO, CO ₂, H ₂O, N ₂, rare gas and other low grade aldehyde, lower alkane carboxylic acid (as acetate, formic acid and propionic acid) and maleic anhydride, phenyl aldehyde, aromatic carboxylic acid and aromatic tricarboxylic acid anhydride (as Tetra hydro Phthalic anhydride and phenylformic acid) and hydrocarbon, as C ₄Hydrocarbon (as 1-butylene and other possible butylene).Realize that this isolating other possible mode has absorption, purification, embrane method and partial condensation.Described sepn process is preferably carried out being higher than under the atmospheric pressure.

If use dehydrogenation catalyst to oxygen or oxygenatedchemicals sensitivity, need with these oxygenatedchemicalss before circulation gas is recycled in the charging that adds the inventive method the first step from wherein removing.The removal of this oxygen also can be used for avoiding the total oxidation of propane at dehydrogenation stage.DE-A 19937107 described dehydrogenation catalysts are to oxygenatedchemicals insensitive (particularly for the first time disclosed embodiment of this DE 1 to 4 described those).

Similarly, as described above, carrying out this isolating another possibility mode be fractionation.Preferably carry out the dividing potential drop distillation at low temperatures.The pressure that adopts can be for example 10 to 100bar.As for purification tower, can use tower, tray column that is filled with filler at random or the tower that comprises orderly filler.Suitable tray column is the tower with double pass tray, bubble cap plate or valve tray.Reflux ratio can be for example 1 to 10.Carry out this isolating other and may for example pressure extraction, pressure-swing absorption, pressure washing, partial condensation and pressure extraction be arranged mode.

According to the present invention, for example, if after the first step of the inventive method, removed accessory constituent (as C ₄Hydrocarbon (as 1-butylene, normal butane, Trimethylmethane and other possible butylene)), perhaps interfering C ₄Hydrocarbon is accumulation (as when they burn on the appropriate catalyst in subregion) not, can certainly be with the residual gas recirculation (as recirculation flow) of all measuring to the charging that adds the inventive method the first step.In this case, the outlet that is used for the gaseous fraction except that propane, propylene and molecular oxygen can only be only second to gaseous mixture 1 and gaseous mixture 1 ' between.

Other outlet can certainly after isolating, target product be provided.Comprise carbon monoxide if be recycled to the circulation gas of dehydrogenating propane reaction, can be before adding fresh thick propane be CO with its catalyzed oxidation ₂The reaction heat that reaction discharges can be used for being heated to desorption temperature.

If tail gas is recycled to the dehydrogenation reaction of propane and/or oxidative dehydrogenation as circulation gas before, from tail gas, isolate carbon oxides, can be CO also with the CO catalytic postcombustion that is present in the tail gas ₂, because CO ₂Can separate (for example using alkali liquid washing) more simply.The catalytic postcombustion of this CO also can carry out in dehydrogenation zone, for example above-mentioned dehydrogenation catalyst (as DE-A 19937107 described those, this DE those described in the disclosed embodiment 1 to 4 for the first time particularly) on carry out.

Naturally also can be with the dehydrogenation reaction and/or the oxidative dehydrogenation of the unaltered exhaust gas recirculation of part to propane, and only from remainder, isolate the mixture of propane and propylene, and be recirculated to the dehydrogenation reaction and/or the oxidative dehydrogenation of propane equally and/or be recycled to subregion.Under latter event, the nubbin of tail gas should with gaseous mixture 1 or gaseous mixture 1 ' combine.

The fractionation of tail gas can for example be carried out in the following manner: all boiling points are lower than in the washing part that the component of the boiling point of propylene all rises in purification tower and separate basically, and remove at the top of tower.These components at first and mainly are carbon oxides CO and CO ₂Reach unreacted oxygen and ethene, methane, N ₂At the bottom of tower, separablely go out for example C of higher ₄Hydrocarbon.

If adopt the first step of the heterogeneous catalytic oxidation dehydrogenation of propane, when isolating dinitrogen, can also isolate accessory constituent according to DE-A 19837520, DE-A 19837517, DE-A 19837519 and DE-A 19837518 as the inventive method.

Embodiment

Use contains the heterogeneous catalyst gas phase incomplete oxidation of the propylene that the different gaseous mixture 2 of propylene and propane carries out in two placed in-line fixed-bed reactor

A) explanation of general treatment condition

1, is used for generating first fixed-bed reactor of the incomplete oxidation step of propenal by propylene

Used heat-transfer medium:

The salt melt of forming by the SODIUMNITRATE of the Sodium Nitrite of the saltpetre of 53 weight %, 40 weight % and 7 weight %.

The size of catalyst tube:

Length overall 4200mm, internal diameter 26mm, external diameter 30mm, wall thickness 2mm.

Reactor:

Comprise stainless steel double-walled cylinder (cylindrical conduit that cylindrical outer container surrounds).Wall thickness is 2 to 5mm everywhere.

The internal diameter of outside cylinder is 168mm.

The internal diameter of conduit is about 60mm.

The top and the bottom of double-walled cylinder are sealed with lid and bottom respectively.

Catalyst tube is housed in the cylindrical vessel, makes its top and bottom stretch out lid and bottom 250mm (and being sealed in the lid and bottom) respectively.

Heat-transfer medium is enclosed in the cylindrical vessel.On the outer wall of catalyst tube, guarantee the very thermal boundary condition of homogeneous for the whole catalyst tube length (3700mm) in cylindrical vessel goes up, heat-transfer medium to be circulated in the cylindrical vessel by bubbling nitrogen.

Heat-transfer medium upwards transmits from the bottom by the nitrogen that rises, and the intermediate space between cylindrical conduit and cylindrical outer container falls (similarly good circulation also can realize by pumping (as spiral pump)) downwards after rise then.Can the temperature of heat-transfer medium be adjusted to required level by the electrically heated that is applied on the outer wall.In addition, cool off by air.

The charging that adds reactor:

Observe from the reactor top, salt melt and reaction gas mixture (each gaseous mixture 2) adverse current transmits.Reaction gas mixture enters reactor from the top.Temperature when in all cases, it enters reaction tubes is 250 ℃.

Salt melt from the bottom with T ^{Go into}Temperature enter cylindrical conduit, and from the top with T ^{Go out}Temperature leave cylindrical conduit.T ^{Go into}With T ^{Go out}Between difference be about 2 ℃.

T ^{On average}=(T ^{Go into}+ T ^{Go out})/2.

Catalyst tube charging (downward) from the top:

The talcum ring external crucible that A part: 50cm is long, profile is 7mm * 7mm * 4mm (external diameter * length * internal diameter).

The catalyst tube charging that B part: 100cm is long is that the talcum ring of 5mm * 3mm * 2mm (external diameter * length * internal diameter) and the uniform mixture from C full active catalyst partly of 70 weight % are formed by the profile of 30 weight %.

The catalyst charge that C part: 170cm is long is by forming as the full active catalyst of DE-A 10046957 embodiment 1 described annulars (5mm * 3mm * 2mm, external diameter * length * internal diameter).

Bed behind the talcum ring of D part: 50cm length, profile is 7mm * 7mm * 4mm (external diameter * length * internal diameter).

Reaction gas starting mixt stream by reactor:

It all is the gaseous mixture 2 of 3860 grams per liters.

The space velocity of propylene on catalyst charge:

100 standard liter/liters per hours.

2, the middle explanation of introducing of intercooling and oxygen

The product gas mixture that leaves first fixed-bed reactor is used for the intercooled purpose (by the indirect cooling of oxygen) by pipe connecting.Connect pipe range 400mm, internal diameter 26mm, wall thickness 2mm, material are stainless steel, Bu Fen 200mm is filled with the inert bed that diameter is the talcum ball of 6mm therebetween, directly links to each other by the catalyst tube of flange with first fixed-bed reactor.

In all cases, gaseous mixture all enters pipe connecting with the temperature that is higher than 310 ℃, leaves with about 140 ℃ temperature.Then with 290 standard liters/hour pressurized air as in the oxygen source entrained gas mixture.

The feed gas mixture that obtains send into the fixed-bed reactor that are used for generating acrylic acid incomplete oxidation step by propenal with 220 ℃ temperature.

3, be used for generating second fixed-bed reactor of acrylic acid incomplete oxidation step by propenal

Use the configuration fixed-bed reactor identical with the reactor that is used for the first step.Observe from the reactor top, salt melt and reaction gas mixture and stream transmit.Salt melt and reaction gas mixture all enter from the bottom.

Catalyst tube charging (making progress from the bottom) is:

The talcum ring external crucible that A part: 20cm is long, profile is 7mm * 7mm * 4mm (external diameter * length * internal diameter).

The catalyst charge that B part: 100cm is long is that the talcum ring of 7mm * 3mm * 4mm (external diameter * length * internal diameter) and the uniform mixture from C coated catalysts partly of 70 weight % are formed by the profile of 30 weight %.

The catalyst charge that C part: 200cm is long is by forming as DE-A 10046928 preparation embodiment 5 described annulars (7mm * 3mm * 4mm, external diameter * length * internal diameter) coated catalysts.

In all cases, feed gas mixture is all passed through second reactor with datum speed 4240 grams per liters.T ^{On average}As definition for first fixed-bed reactor.

In following all embodiment, propylene conversion all is set to 97.7 moles of % in first reactor, and the transformation efficiency of propenal all is set to 99.3 moles of % in second reactor.

The T that needs ^{On average}(function of the composition of gaseous mixture 2), acrylic acid productive rate A ^AAThe selectivity S of (mole %) and formation carbon oxides ^COx(mole %) has following value in each embodiment.S wherein ^COxBased on the propylene that on two reactors, reacts, be to realize as the function of the composition of gaseous mixture 2.

B) embodiment 1

The composition of gaseous mixture 2 is:

6.18 the propylene of volume %,

33.1 the propane of volume %,

12.3 the oxygen of volume %,

0.15 the CO of volume % _x,

46.7 the N of volume % ₂With

1.63 volume %H ₂O.

A ^AA=86.1 moles of %, T ^{On average}, first reactor=316 ℃.

S ^COx=9.2 moles of %, T ^{On average}, second reactor=274 ℃.

C) embodiment 2

The composition of gaseous mixture 2 is:

6.04 the propylene of volume %,

42.3 the propane of volume %,

10.4 the oxygen of volume %,

0.15 the CO of volume % _x,

39.5 the N of volume % ₂With

1.60 volume %H ₂O.

A ^AA=85.2 moles of %, T ^{On average}, first reactor=322 ℃.

S ^COx=9.9 moles of %, T ^{On average}, second reactor=278 ℃.

D) embodiment 3

The composition of gaseous mixture 2 is:

0.20 the ethane of volume %,

6.14 the propylene of volume %,

33.0 the propane of volume %,

12.2 the oxygen of volume %,

0.16 the CO of volume % _x,

46.6 the N of volume % ₂With

1.65 volume %H ₂O.

A ^AA=86.1 moles of %, T ^{On average}, first reactor=316 ℃.

S ^COx=9.2 moles of %, T ^{On average}, second reactor=274 ℃.

E) embodiment 4

The composition of gaseous mixture 2 is:

0.22 the ethene of volume %,

6.13 the propylene of volume %,

33.0 the propane of volume %,

12.2 the oxygen of volume %,

0.16 the CO of volume % _x,

46.6 the N of volume % ₂With

1.64 volume %H ₂O.

A ^AA=86.1 moles of %, T ^{On average}, first reactor=316 ℃.

S ^COx=9.2 moles of %, T ^{On average}, second reactor=274 ℃.

F) embodiment 5

The composition of gaseous mixture 2 is:

0.20 the normal butane of volume %,

6.14 the propylene of volume %,

33.0 the propane of volume %,

12.2 the oxygen of volume %,

0.16 the CO of volume % _x,

46.6 the N of volume % ₂With

1.65 volume %H ₂O.

A ^AA=85.2 moles of %, T ^{On average}, first reactor=316.5 ℃.

S ^COx=9.9 moles of %, T ^{On average}, second reactor=274 ℃.

G) embodiment 6

The composition of gaseous mixture 2 is:

2.02 the normal butane of volume %,

5.98 the propylene of volume %,

32.4 the propane of volume %,

12.0 the oxygen of volume %,

0.16 the CO of volume % _x,

45.8 the N of volume % ₂With

1.64 volume %H ₂O.

Can not be again by improving T in the scope that can bear at catalyzer ^{On average}Keep required propylene conversion.

H) embodiment 7

The composition of gaseous mixture 2 is:

0.05 the 1-butylene of volume %,

6.16 the propylene of volume %,

33.0 the propane of volume %,

12.3 the oxygen of volume %,

0.16 the CO of volume % _x,

46.7 the N of volume % ₂With

1.70 volume %H ₂O.

A ^AA=85.1 moles of %, T ^{On average}, first reactor=318 ℃.

S ^COx=10 moles of %, T ^{On average}, second reactor=281 ℃.

I) embodiment 8

The composition of gaseous mixture 2 is:

0.09 the 1-butylene of volume %,

6.16 the propylene of volume %,

32.9 the propane of volume %,

12.3 the oxygen of volume %,

0.15 the CO of volume % _x,

46.8 the N of volume % ₂With

1.68 volume %H ₂O.

A ^AA=85.0 moles of %, T ^{On average}, first reactor=320 ℃.

S ^COx=10.2 moles of %, T ^{On average}, second reactor=287 ℃.

J) embodiment 9

The composition of gaseous mixture 2 is:

0.20 the 1-butylene of volume %,

6.19 the propylene of volume %,

32.7 the propane of volume %,

12.3 the oxygen of volume %,

0.18 the CO of volume % _x,

46.7 the N of volume % ₂With

1.71 volume %H ₂O.

Claims

1, the incomplete oxidation of at least a propylene of preparation and/or the method for ammoxidation product, in the method:

A) in the first step, the existence of oxygen with/thick propane is carried out homogeneous phase and becomes heterogeneous catalyst dehydrogenation and/or oxydehydrogenation in the presence of not, contain the gaseous mixture 1 of propane and propylene with production,

And

The content of the 1-butylene of gaseous mixture 2≤1 volume % wherein.

2, the method for claim 1, the wherein content of the 1-butylene of gaseous mixture 2≤0.75 volume %.

3, the method for claim 1, the wherein content of the 1-butylene of gaseous mixture 2≤0.5 volume %.

4, the method for claim 1, the wherein content of the 1-butylene of gaseous mixture 2≤0.3 volume %.

5, the method for claim 1, the wherein content of the 1-butylene of gaseous mixture 2≤0.1 volume %.

6, the method for claim 1, the wherein content of the 1-butylene of gaseous mixture 2＞0.003 volume %.

7, the method for claim 1, the wherein content of the 1-butylene of gaseous mixture 2＞0.001 volume %.

8, as each described method of claim 1 to 7, the content≤1 volume % of gaseous mixture 2 anti--2-butylene wherein.

9, as each described method of claim 1 to 7, the content≤0.5 volume % of gaseous mixture 2 anti--2-butylene wherein.

10, as each described method of claim 1 to 7, the content≤0.05 volume % of gaseous mixture 2 anti--2-butylene wherein.

11, as each described method of claim 1 to 7, the content≤1 volume % of gaseous mixture 2 suitable-2-butylene wherein.

12, as each described method of claim 1 to 7, the content≤0.5 volume % of gaseous mixture 2 suitable-2-butylene wherein.

13, as each described method of claim 1 to 7, the content≤0.05 volume % of gaseous mixture 2 suitable-2-butylene wherein.

14, as each described method of claim 1 to 7, the content of the iso-butylene of gaseous mixture 2≤1 volume % wherein.

15, as each described method of claim 1 to 7, the content of the iso-butylene of gaseous mixture 2≤0.5 volume % wherein.

16, as each described method of claim 1 to 7, the content of the iso-butylene of gaseous mixture 2≤0.05 volume % wherein.

17, as each described method of claim 1 to 7, the total content of butylene in the gaseous mixture 2≤1 volume % wherein.

18, as each described method of claim 1 to 7, the total content of butylene in the gaseous mixture 2≤0.5 volume % wherein.

19, as each described method of claim 1 to 7, the total content of butylene in the gaseous mixture 2≤0.05 volume % wherein.

20, as each described method of claim 1 to 7, wherein C in the gaseous mixture 2 ₄The total content of hydrocarbon≤3 volume %.

21, as each described method of claim 1 to 7, wherein C in the gaseous mixture 2 ₄The total content of hydrocarbon≤2 volume %.

22, as each described method of claim 1 to 7, wherein C in the gaseous mixture 2 ₄The total content of hydrocarbon≤1 volume %.

23, as each described method of claim 1 to 7, wherein C in the gaseous mixture 2 ₄The total content of hydrocarbon＞0.05 volume % and＜3 volume %.

24, as each described method of claim 1 to 7, the component except that propane, propylene and oxygen of gaseous mixture 1 ' comprise 〉=0.1 volume % wherein.

25, as each described method of claim 1 to 7, the component except that propane, propylene and oxygen of gaseous mixture 1 ' comprise 〉=0.2 volume % wherein.

26, as each described method of claim 1 to 7, the component except that propane, propylene and oxygen of gaseous mixture 1 ' comprise 〉=0.3 volume % wherein.

27, as each described method of claim 1 to 7, the component except that propane, propylene and oxygen of gaseous mixture 1 ' comprise 〉=0.5 volume % wherein.

28, as each described method of claim 1 to 7, the component except that propane, propylene and oxygen of gaseous mixture 1 ' comprise 〉=1 volume % wherein.

29, as each described method of claim 1 to 7, the component except that propane, propylene and oxygen of gaseous mixture 1 ' comprise 〉=3 volume % wherein.

30, as each described method of claim 1 to 7, the component except that propane, propylene and oxygen of gaseous mixture 1 ' comprise 〉=5 volume % wherein.

31, as each described method of claim 1 to 7, the component except that propane, propylene and oxygen of gaseous mixture 1 ' comprise 〉=10 volume % wherein.

32, as each described method of claim 1 to 7, the component except that propane, propylene and oxygen of gaseous mixture 1 ' comprise 〉=30 volume % wherein.

33, as each described method of claim 1 to 7, gaseous mixture 2 the highest propane that comprise 60 volume % wherein.

34, as each described method of claim 1 to 7, gaseous mixture 2 the highest propane that comprise 50 volume % wherein.

35, as each described method of claim 1 to 7, wherein gaseous mixture 2 comprises the propane of 20 volume % to 40 volume %.

36, as each described method of claim 1 to 7, wherein gaseous mixture 2 comprises:

The O of 7 to 15 volume % ₂,

The propylene of 5 to 10 volume %,

The propane of 15 to 40 volume %,

The nitrogen of 25 to 60 volume %,

Be total up to CO, the CO of 1 to 5 volume % ₂And H ₂O reaches

Other component of 0 to 5 volume %,

The ammonia of wherein having ignored any existence.

37, as each described method of claim 1 to 7, wherein gaseous mixture 2 comprises:

H ₂O≤60 volume %,

N ₂≤ 80 volume %,

O ₂＞0 ,≤20 volume %,

CO≤2 volume %,

CO ₂≤ 5 volume %,

Ethane≤10 volume %,

Ethene≤5 volume %,

Methane≤5 volume %,

Propane＞0 ,≤50 volume %,

Cyclopropane≤0.1 volume %,

Propine≤0.1 volume %,

Propadiene≤0.1 volume %,

Propylene＞0 ,≤30 volume %,

H ₂≤ 30 volume %,

Trimethylmethane≤3 volume %,

Normal butane≤3 volume %,

Instead-2-butylene≤1 volume %,

It is suitable-2-butylene≤1 volume %,

1-butylene≤1 volume %,

Iso-butylene≤1 volume %,

1,3-butadiene≤1 volume %,

1≤1 volume %,

Ethyl acetylene≤0.5 volume %,

2-butyne≤0.5 volume %,

The ammonia of wherein ignoring any existence.

38, as each described method of claim 1 to 7, wherein thick propane comprises 〉=component except that propane and propylene of 0.25 volume %.

39, as each described method of claim 1 to 7, wherein thick propane comprises 〉=component except that propane and propylene of 1 volume %.

40, as each described method of claim 1 to 7, wherein thick propane comprises 〉=component except that propane and propylene of 2 volume %.

41, as each described method of claim 1 to 7, wherein thick propane comprises 〉=component except that propane and propylene of 3 volume %.

42, as each described method of claim 1 to 7, the wherein thick the highest C that comprises 6 volume % of propane ₄Hydrocarbon.

43, as each described method of claim 1 to 7, wherein thick propane comprises the C of 0.1 to 6 volume % ₄Hydrocarbon.

44, as each described method of claim 1 to 7, the wherein thick the highest 1-butylene that comprises 0.5 volume % of propane.

45, as each described method of claim 1 to 7, wherein thick propane comprises the 1-butylene of 5 volume ppm to 0.5 volume %.

46, as each described method of claim 1 to 7, wherein thick propane comprises the butylene that total amount reaches as high as 0.5 volume %.

47, as each described method of claim 1 to 7, wherein thick propane comprises the butylene that total amount is 5 volume ppm to 0.5 volume %.

48, as each described method of claim 1 to 7, wherein thick propane meets following specification:

The content of propane 〉=90 volume %,

The total content of propane and propylene≤99 volume %,

C ₄Always containing of hydrocarbon be heavy≤6 volume %,

The content of 1-butylene≤0.5 volume %,

The total content of butylene≤0.5 volume %,

The content of ethane≤10 volume %,

The content of ethene≤5 volume %,

The content of methane≤5 volume %,

The content of cyclopropane≤0.1 volume %,

The content of propylene≤10 volume %,

C outside propane and the propylene ₃The total content of hydrocarbon≤0.3 volume %,

C ₅The total content of hydrocarbon≤0.3 volume %,

And C ₆-C ₈The total content of hydrocarbon≤600 volume ppm.

49, as each described method of claim 1 to 7, wherein in the first step transformation efficiency of propane 〉=5 mole % to≤30 moles of %.

50, as each described method of claim 1 to 7, wherein from deriving from the gas phase incomplete oxidation and/or not exclusively isolate at least a incomplete oxidation of propylene and/or the product of ammonia oxidation the product gas mixture of gas phase ammonoxidation, and be recycled to the first step and/or be recycled to the gas phase incomplete oxidation and/or incomplete gas phase ammonoxidation to the unreacted propane of major general and propylene.

51, as each described method of claim 1 to 7, wherein said method is carried out on catalyst charge in reaction zone, the active composition of described catalyst charge is made up of at least a multimetal oxide compositions, and described multimetal oxide compositions contains the elements Mo that combines, V, at least a among two kinds of element T e and the Sb, at least a being selected from by Nb, Ta, W, Ti, Al, Zr, Cr, Mn, Ga, Fe, Ru, Co, Rh, Ni, Pd, Pt, La, Bi, B, Ce, Sn, Zn, Si, Na, Li, K, Mg, Ag, the element of the group that Au and In form.

52, method as claimed in claim 51, wherein said active composition is made up of at least a multimetal oxide compositions, and described multimetal oxide compositions has element chemistry metering I:

Mo ₁V _bM ¹ _cM ² _d (I)

Wherein

M ¹Be Te and/or Sb,

B is 0.01 to 1,

C is＞0 to 1, and

D is＞0 to 1.

53, method as claimed in claim 52, wherein M ¹Be Te and M ²Be Nb, Ta, W and/or Ti.

54, method as claimed in claim 52, wherein M ²Be Nb.

55, method as claimed in claim 51, the X-ray diffractogram of wherein said active poly-metal deoxide have reflection h and the i that maximum value is positioned at diffraction angle (2 θ) 22.2 ± 0.5 ° (h) and 27.3 ± 0.5 ° (i).

56, method as claimed in claim 55, wherein said X ray diffraction line chart have maximum value in addition and are positioned at 28.2 ± 0.5 ° reflection k.

57, method as claimed in claim 55 wherein reflect h intensity maximum in the X ray diffraction line chart, and its halfwidth degree is no more than 0.5 °.

58, method as claimed in claim 57 wherein reflects i and≤1 ° respectively of the halfwidth degree that reflects k, and the intensity P of reflection k _kIntensity P with reflection i _iSatisfied 0.2≤R≤0.85 that concerns, wherein R is the strength ratio by the following formula definition:

R＝P _i/(P _i+P _k)

59, method as claimed in claim 51, the X-ray diffractogram of wherein said active poly-metal deoxide do not have the reflection that maximum value is positioned at 2 θ=50 ± 0.3 °.

60, as each described method of claim 1 to 7, wherein the first step is to carry out in independent reaction zone.

61, method as claimed in claim 60, the wherein said the first step are the heterogeneous catalyst dehydrogenations.

62, method as claimed in claim 60 is wherein isolated from gaseous mixture 1 in the component except that propane and propylene that is present in the gaseous mixture 1 and is comprised at least a C ₄The part of hydrocarbon.

63, method as claimed in claim 60 is wherein isolated the part that contains at least a butylene in the component except that propane and propylene that is present in the gaseous mixture 1 from gaseous mixture 1.

64, method as claimed in claim 60 is wherein isolated the part that contains 1-butylene in the component except that propane and propylene that is present in the gaseous mixture 1 at least from gaseous mixture 1.

65, method as claimed in claim 60 wherein uses the catalyzer that active ingredient contains elements Mo, Bi and Fe to carry out heterogeneous catalyst gas phase incomplete oxidation and/or incomplete gas phase ammonoxidation.

66, method as claimed in claim 60, wherein use active ingredient to carry out heterogeneous catalyst gas phase incomplete oxidation and/or incomplete gas phase ammonoxidation as the catalyzer of the poly-metal deoxide shown in the formula IV:

Mo ₁₂Bi _aFe _bX ¹ _cX ² _dX ³ _eX ⁴ _fO _n (IV)

Wherein each variable has following implication:

X ¹=nickel and/or cobalt,

X ²=thallium, basic metal and/or alkaline-earth metal,

X ⁴=silicon, aluminium, titanium and/or zirconium,

A=0 to 5,

B=0.01 to 5,

C=0 to 10,

D=0 to 2,

E=0 to 8,

F=0 to 10 and

The number that n=is determined by the chemical valence and the abundance of the element outside the oxygen in (IV).

67, method as claimed in claim 60 wherein uses the catalyzer that active ingredient contains elements Mo and V to carry out heterogeneous catalyst gas phase incomplete oxidation.

68, method as claimed in claim 60, wherein use active ingredient to carry out heterogeneous catalyst gas phase incomplete oxidation as the catalyzer of the poly-metal deoxide shown in the formula VII:

Mo ₁₂V _aX ¹ _bX ² _cX ³ _dX ⁴ _eX ⁵ _fX ⁶ _gO _n (VII)

Wherein each variable has following implication:

X ¹=W, Nb, Ta, Cr and/or Ce,

X ²=Cu, Ni, Co, Fe, Mn and/or Zn,

X ³=Sb and/or Bi,

X ⁴=one or more basic metal,

X ⁵=one or more alkaline-earth metal,

X ⁶=Si, Al, Ti and/or Zr,

A=1 to 6,

B=0.2 to 4,

C=0.5 to 18,

D=0 to 40,

E=0 to 2,

F=0 to 4,

G=0 to 40 and

69, as each described method of claim 1 to 7, wherein the product of propylene incomplete oxidation and/or ammonia oxidation comprises at least a compound that is selected from the group of being made up of propylene oxide, propenal, vinylformic acid and vinyl cyanide.

70, as each described method of claim 1 to 7, wherein the first step be included in oxygen existence and/do not exist and down thick propane do not carried out the heterogeneous catalyst dehydrogenation, and gaseous mixture 1 is present in the heterogeneous catalyst gas phase ammonoxidation of the propylene in the gaseous mixture 1.

71, as each described method of claim 1 to 7, wherein the first step be included in exist and/do not have oxygen, exist under the condition of water vapour thick propane is carried out the heterogeneous catalyst dehydrogenation, and from the gaseous mixture 1 that the first step, generates condensation go out all or part of water vapour with obtain gaseous mixture 1 ', to gaseous mixture 1 ' be present in gaseous mixture 1 ' in propylene heterogeneous catalyst gas phase incomplete oxidation and/incomplete gas phase ammonoxidation.

72, as each described method of claim 1 to 7, wherein the first step comprises thick propane is carried out the dehydrogenation of autothermal heterogeneous catalyst.

73, as each described method of claim 1 to 7, wherein with gaseous mixture 1 and/or gaseous mixture 1 ' as the component of gaseous mixture 2 be present in gaseous mixture 1 and/or gaseous mixture 1 ' in the incomplete gas phase ammonoxidation of heterogeneous catalyst of propylene.