CN1310855C

CN1310855C - Method for the production of at least one partial propylene oxidation and/or ammoxidation product

Info

Publication number: CN1310855C
Application number: CNB038254093A
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: 2007-04-18
Anticipated expiration: 2023-09-18
Also published as: CN1703387A; ZA200503358B; CN1305817C; CN1701054A; DE10245585A1

Abstract

Disclosed is a method for producing at least one partial propylene oxidation and/or ammoxidation product, according to which the propylene is produced from raw propane by means of dehydration and is subjected to a heterogeneously catalyzed partial gas phase oxidation and/or partial gas phase ammoxidation in the presence of unreacted propane as a component of a gas mixture 2 having a total C4 hydrocarbon content of = 3 percent by volume.

Description

At least the partial oxidation of propylene and/or the preparation method of ammoxidation product

The present invention relates to a kind of partial oxidation at least of propylene and/or method of ammoxidation product of preparing, comprising:

A) in the first step with thick propane in the presence of the oxygen and/or getting rid of under the oxygen and carrying out homogeneous phase and/or heterogeneous catalysis dehydrogenation and/or oxydehydrogenation, obtain containing propane and propylene gaseous mixture 1 and

B) optionally take out propane and the composition beyond the propylene that exists in the gaseous mixture 1 that a part forms and/or be translated into other compounds in the first step, obtain comprising the gaseous mixture 1 ' of propane and propylene and oxygen, propane and propylene compound in addition by this gaseous mixture 1, and at least one other step

C) gaseous mixture 1 and/or gaseous mixture 1 ' are carried out the heterogeneous catalyzed gas phase partial oxidation and/or the part gas phase ammonoxidation of the propylene that exists in gaseous mixture 1 and/or the gaseous mixture 1 ' as the composition of gaseous mixture 2.

In this article, thick propane is meant except propane and existence, outside the propylene, also comprises the compound beyond at least a propane and the propylene, normally at least two or three and be in many cases at least four or five kind of compound contain propane gas.The latter can pass through chromatography at this compounds, for example vapor-phase chromatography detected situation in thick propane.

In this article, the oxydehydrogenation of propane is meant by the oxygen that exists and promotes and wherein do not form as the free hydrogen of intermediate or detect dehydrogenation less than free hydrogen.What the conventional dehydrogenation of carrying out with heat absorption was opposite is the exothermic heat of reaction of oxydehydrogenation.The oxydehydrogenation of propane can be carried out under the effect of elevated temperature, (does not promptly have for example solid catalyst with homogeneous phase; For example referring to US-A3 798 283) or heterogeneous (for example on solid catalyst; Referring to DE-A 2058054 and DE-A 19530494) mode catalysis.

Same situation is applied to the conventional dehydrogenation (for example referring to EP-A 731 077 and WO 01/96270) that dehydrogenation step wherein carries out substantially under the playing an active part in that does not have oxygen.In other words, the main by product that forms this moment is hydrogen but not water under the oxydehydrogenation situation.

In this article, the complete oxidation of propylene is meant that the carbon of the whole amounts that exist in the propylene changes into carbon oxides (CO, CO ₂).All differential responses of the reactive propylene that participates in of molecular oxygen are included in herein with the term partial oxidation.Extra reactive participation of ammonia characterizes with ammonia oxidation.

Preferably propenal, vinylformic acid, propylene oxide and vinyl cyanide of the partial oxidation of propylene and/or ammoxidation product in this article.

The partial oxidation of propylene and/or ammoxidation product for example are the important intermediate of preparation polymkeric substance.

The enforcement of this partial oxidation and/or ammonia oxidation (in reaction gas mixtures, select the ammonia content of control in a manner known way to allow this reactive group the design is become only partial oxidation, or only part ammonia oxidation, or the stack of two kinds of reactions) itself be known.These reactions are at solid, are generally the heterogeneous catalysis gas-phase reaction on the catalyzer of oxidisability.

Quote DE-A 2 351 151 (propylene changes into the example that propenal and/or vinylformic acid and propylene change into vinyl cyanide) and EP-A 372 972 (propylene changes into the example of propylene oxide) as an example.

Used oxygenant is generally can be with respective pure form or to add molecular oxygen in the reaction gas mixtures with mixture (for example air) form that partial oxidation/ammonia oxidation is substantially inert gasses.Usually, the reactant in the reaction gas mixtures also because of depyrogenation because of and security reaction control is former thereby by at least a rare gas element (N for example ₂, H ₂O, CO, CO ₂, for example C ₁-C ₅Stable hydrocarbon (for example according to DE-A 1924431 and EP-A 293224), He and/or Ar etc.) dilution.A kind of inert dilution gas that DE-B 2251364 recommends to use is a butane.As mentioned above, the difference of ammonia oxidation is additionally to exist ammonia.

Opposite with laboratory and pilot-plant test, the initial propylene that uses with technical scale is not chemical pure, but has impurity but have the crude propylene (for example " polymerization-grade " or " chemical pure " of higher degree; Referring to DE-A10131297).

Providing of this purer crude propylene is comparatively inconvenient and expensive.Usually begin by thick paraffinic hydrocarbons and generally include at least one purification step, in this step, from the propylene that forms, remove unconverted paraffinic hydrocarbons (referring to for example DE-A3 521 458) by physical method.Usually, this at least one purification step also comprises the propylene alkene in addition and the separation of the by product beyond the propylene, and described by product comprises the secondary component in the Already in thick paraffinic hydrocarbons.

Above-mentioned removing has high fund cost and the very power consumption owing to the similarity of olefin/paraff iotan usually.Therefore, they only are applied in the system with the associating of refining cracker and steam cracker and only require the crude propylenes that great majority obtain in this way because of subsequently polymerization (for example preparing polypropylene) (scale economics) on the one hand is a large amount of and high value-added occurs on the other hand in these polymerizations produce effects usually.

The ratio of partial oxidation and/or ammonia oxidation of flowing in these crude propylenes is unimportant and be unworthy secondary consumption materials flow, and the crude propylene why Here it is obtains in this way still has the reason of acceptable cost of material for partial oxidation and/or ammonia oxidation.

Cost of material may only just significantly reduce in the time can omitting at least some above-mentioned separation or all these separation.

The solution to this problem that EP-B 938463 proposes is for example to make the dehydrogenation of thick propane part with heterogeneous catalysis in the presence of oxygen in the first step, obtain comprising first gaseous mixture of propylene and propane, this mixture is direct, promptly do not carry out intermediate treatment, composition as second gaseous mixture carries out heterogeneous catalyzed gas phase partial oxidation, and the propylene oxidation that is contained in first gaseous mixture is become propenal and/or vinylformic acid.

About the purity problem of the thick propane that will use, EP-B 938463 especially the 3rd hurdle the 40th row and following each mention in capable: " purity of raw material alkane is not limited especially "." in addition, raw material alkane can be the mixture of various alkane.Usually, this raw material comprises 30mol% at least, preferred 50mol% at least, the more preferably propane of 80mol% at least.The source that is used for the alkane of the inventive method, for example propane feed is unimportant ".

In addition, EP-B 938463 instruction in each row below the 3rd hurdle the 17th row reaches: " therefore, after reclaiming propenal, can not having the uncooled gas that contains propane of recirculation under the significant additional purification steps ".

The instruction of EP-A 117146 corresponds essentially to EP-B 938463, and different is that EP-A 117146 is recommended in the heterogeneous catalysis dehydrogenation of getting rid of enforcement propane under the oxygen.

For above-mentioned recycle stream, further instruction in each row below the 11st page of the 14th row reaches of EP-A 117146: " because lightweight and heavy hydrocarbon by product significantly are being different from propenal or C as methane, ethane, ethene, butane and butylene ₃Seethe with excitement under the temperature of hydrocarbon, they can pass through fractionation by distillation.Perhaps, can wash to concentrate the materials flow that amount contains by product." possibility of flushing materials flow of this recycle gas also sees EP-B 938463 the 11st hurdle the 10th row.

Mention the necessity of before partial oxidation and/or ammonia oxidation, removing above-mentioned secondary component without any document.

The instruction that provides is followed in the instruction of WO 01/96270 in EP-B938463 and EP-A 117 146.For example, it is mentioned in each row below page 4 the 10th row reaches: " certainly, the feed gas mixtures of the oxidation step B in this new procedure can also comprise other components except said components, as CO, CO ₂, H ₂O, rare gas such as He and/or Ar, hydrogen, methane, ethene, butane, butylene, butine, pentane, propine, propadiene class and/or propenal ".

For the thick propane that is ready to use in dehydrogenation step, WO 01/96270 is instruction in each row below the 15th page of the 26th row reaches: " according to the present invention, the propane that is used for steps A needs not to be pure propane.On the contrary, used propane can contain other gases of 50 volume % at the most, as ethane, methane, ethene, butane, butylene, propine, acetylene, H ₂S, SO ₂, pentane etc. ".

WO 01/96270 also recommends to remove at least a portion and is contained in the hydrogen in first gaseous mixture that contains propane and propylene that forms and removes also optional other optional all basically compositions except that propane and propylene of removing in the process at this from this first gaseous mixture in dehydrogenation step, then it is further used for being contained in the partial oxidation of propylene wherein, and EP-B 731077 even think therefrom quantitatively removed propane, propylene before this first gaseous mixture further uses and if exist, all the components beyond the molecular oxygen is particularly preferred.Yet on the one hand, the separation method that is ready to use in this purpose has reduced the economic vitality of entire method, and on the other hand, the certain methods proof of recommending in above-mentioned document is not suitable for this and quantitatively removes.For example, back one situation for example is applied to the 16th page of absorption/desorption method that recommend the bottom of WO 01/96270, and this proves in nearer check and is unsuitable for for example from C ₃Separation of C in the hydrocarbon ₄Hydrocarbon.

In the prior art of being quoted, do not see when raw material is become thick propane by crude propylene after dehydrogenation and/or oxydehydrogenation step or even removing some secondary component before this step at least one oxidation and/or ammonia oxidation step, to reduce the necessity that forms and form required target product of by product.Although think that the change raw material can change the formation of by product and (according to WO 01/96270, for example exist propane to cause the formation of propionic aldehyde and/or propionic acid to increase in partial oxidation; Yet the advantage of not removing propane dehydrogenation from the propylene that forms is possessed of higher values), but do not think that this is crucial especially because aforementioned remove more more expensive and inconvenient than separating of target product and by product usually.This in addition with under any circumstance all the background that target product is removed from the secondary component that forms must be runed counter to.

This suggestion is resembled EP-A 1192987 or DE-A 10122027 obviously, or EP-A 608838, or EP-A 529853, or DE-A 10051419, or DE-A 10119933 equally is recommended in and (carries out) carrying out the people that this paper starts defined method in the single reaction district usually hold at least two reaction zones on catalyst charge, the activating oxide component of described catalyst charge is at least a poly-metal deoxide, this poly-metal deoxide containing element Mo, V and Te and/or Sb.The basis of this program is that the related activity oxide component on the one hand can the catalysis oxidative dehydrogenation of propane becomes propylene (for example referring to EP-B 938463 the 4th hurdle the 37th row and following each row) and partial oxidation and/or ammonia oxidation that on the other hand can catalyzing propone.Be understood that gaseous mixture 1 in this program is directly used in partial oxidation at least and/or ammonia oxidation step subsequently.

Yet EP-A 1192987 is recommendation in the 9th page of the 26th row and following each row for example: " similarly, to the source of alkane without any restriction.It can be bought, and directly or with alkene and/or other impurity mixes use.In addition, no matter how it originates the blend as required of alkane and alkene." correspondence is fully, DE-A 10122027 instructs at page 3 the 35/36th row: " propane that is ready to use in the inventive method needn't satisfy any extra high requirement on purity ".

WO 0196271 thinks that equally the thick propane of different purity is useful.

The shortcoming of above-mentioned prior art suggested design is that they are not analyzed any composition of being present in the cheap thick propane or are formed by this constituents in the first step and be present in compound in first gaseous mixture subsequently (described compound is as if the words that have, only be present in the normally used crude propylene with trace, thereby its negative interaction is not noted up to now as yet) in any can be as subsequently the heterogeneously catalyzed partial oxidation and/or the catalyzer poison of ammonia oxidation, thereby reduce the required partial oxidation of propylene and/or the activity and/or the selectivity of ammonia oxidation.

As result detailed and that scrutinize, have now found that C ₄Hydrocarbon (compound of being made up of 4 carbon atoms and hydrogen) forms such catalyzer poison usually and wherein especially with alkene (butene-1, anti--butene-2, suitable-butene-2 and iso-butylene), especially butene-1 is representative.Yet, be that those of representative also have unfavorable effect with stable hydrocarbon (normal butane and Trimethylmethane) and other unsaturated hydrocarbons.

Yet, say it is C exactly ₄Hydrocarbon (for example normal butane, Trimethylmethane, anti--butene-2, suitable-butene-2, iso-butylene, divinyl-1,3, divinyl-1,2, butine-1 and/or crotonylene) forms the general accompaniment of propane and therefore is present in the cheap thick propane with significant quantity usually.This statement very specifically is applied to saturated C ₄Hydrocarbon, however it forms olefinic C to small part under the condition of dehydrogenation of propane part and/or oxydehydrogenation ₄Hydrocarbon, the butene-1 of especially special trouble.

The purpose of this invention is to provide and a kind ofly be used to prepare the partial oxidation at least of propylene and/or the method for ammoxidation product as described in starting, what this method was opposite with art methods is to have considered the above-mentioned fact.

We find this purpose by a kind of method realization for preparing the partial oxidation at least and/or the ammoxidation product of propylene, and this method comprises:

C) gaseous mixture 1 and/or gaseous mixture 1 ' are carried out the heterogeneous catalyzed gas phase partial oxidation and/or the part gas phase ammonoxidation of the propylene that exists in gaseous mixture 1 and/or the gaseous mixture 1 ' as the composition of gaseous mixture 2,

The C of gaseous mixture 2 wherein ₄Hydrocarbon total content≤3 volume %.

The amount that becomes component to be present in these compositions in the gaseous mixture 1 in based on the inventive method beyond the propane that takes out and/or be converted into other compounds from gaseous mixture 1 during obtaining the process of gaseous mixture 1 ' and the propylene can be 5 weight % at the most, or 10 weight % at the most, or 20 weight % at the most, or 30 or 40 weight % at the most, or 60 weight % at the most, or 70 or 80 weight % at the most, or 85 or 90 weight % at the most, or 94 weight % at the most, or 96 or 98 weight % at the most, or 99 weight % or more at the most.

According to the present invention, the C of gaseous mixture 2 ₄The hydrocarbon total content is preferred≤2.5 volume %, and be more preferably≤2.0 volume %, even be more preferably≤1.5 volume %, or≤1.0 volume %, or≤0.50 volume %, volume % most preferably≤0.30, or≤0.10 volume %.

No longer containing any C ₄Under the situation of the gaseous mixture 2 of hydrocarbon, be understood that their negative interaction no longer occurs at all.Yet,, may reasonably be to accept C in the gaseous mixture 2 for economic evaluation on the whole ₄The unfavorable effect of some of hydrocarbon and to make its total content in gaseous mixture 2 be 〉=0.05 volume %, or 〉=0.07 volume %, or 〉=0.09 volume %, or 〉=0.1 volume % or under extreme case 〉=0.2 volume %.

According to the present invention, with above-mentioned C ₄The hydrocarbon total content while is the butene-1 content of gaseous mixture 2≤1 volume % preferably, or≤0.9 volume %, or≤0.75 volume %, or≤0.6 volume %, or≤0.5 volume %, or≤0.4 volume %, more preferably≤0.3 volume %, even more preferably≤0.2 volume %, even be more preferably≤0.1 volume % or≤0.05 volume %, or≤0.03 volume % or≤0.01 volume %.Under the situation of the gaseous mixture 2 that at all no longer contains any butene-1, be understood that their negative interaction no longer occurs at all.Yet, for economic evaluation on the whole, may reasonably be that to accept some unfavorable effect of butene-1 in the gaseous mixture 2 and make its total content in gaseous mixture 2 be 〉=0.001 volume %, or 〉=0.003 volume %, or 〉=0.006 volume %, or under extreme case 〉=0.009 volume %.

For the purpose of the present invention, preferred above-mentioned restricted value and aforementioned C ₄The hydrocarbon total content not only is applied to the amount of butene-1 in the gaseous mixture 2 together, and being applied to each other possible representative in the butylene (promptly being applied to anti--butene-2, suitable-butene-2 and iso-butylene) independently simultaneously, very particularly preferably above-mentioned restricted value also is applied to the total amount of butylene in the gaseous mixture 2 simultaneously.In other words, the example that is suitable for gaseous mixture 2 of the present invention be following those:

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

-C ₄The total content of the total content of hydrocarbon≤2.5 volume % and butylene≤1 volume %; Or

-C ₄The total content of the total content of hydrocarbon≤2.0 volume % and butylene≤1 volume %; Or

-C ₄The total content of the total content of hydrocarbon≤1.5 volume % and butylene≤1 volume %; Or

-C ₄The total content of the total content of hydrocarbon≤1.0 volume % and butylene≤0.75 volume %; Or

-C ₄The total content of the total content of hydrocarbon≤1.0 volume % and butylene≤0.50 volume %; Or

-C ₄The total content of the total content of hydrocarbon≤0.5 volume % and butylene≤0.30 volume %; Or

-C ₄The total content of the total content of hydrocarbon≤0.3 volume % and butylene≤0.1 volume % etc.

In order to keep above-mentioned restricted value, the inventive method mainly provides two kinds of possibilities, wherein can only use one of them or use these two.

A kind of possibility is by no longer contain any C at all ₄The thick propane of hydrocarbon begins, or only contains C with following amount ₄The thick propane of hydrocarbon begins: satisfy according to the present invention the C in the gaseous mixture 2 ₄The restriction of hydrocarbon, total butylene and the observed total content of butene-1.The possible C compatible in the thick propane with the inventive method ₄The concrete content of hydrocarbon especially depends on the specific border condition of the first step that is used for this method and can be determined by several tentative experiments by those skilled in the art, is suitable for the specific border condition in each case.

Necessary removes C from commercially available thick propane ₄Hydrocarbon can for example be undertaken by rectifying in a manner known way.Be understood that and additionally consider every other separation method, as adsorption/desorption (for example transformation absorption), extraction and/or absorption/desorb.

As a supplement and/or as other selection, can further gaseous mixture 1 therefrom removed C before as gaseous mixture 1 ' according to the present invention usually ₄Hydrocarbon, especially butene-1 or butylene, the degree of removing should make its content reach the observed maximum constraints according to the present invention, or are lower than these maximum constraints.For example ought only in oxydehydrogenation or dehydrogenation step process, for example form the C of trouble by propane by disproportionation and/or transposition ₄During hydrocarbon, this measure is suitable.A factor that increases its possibility is the first step (under the catalytic dehydrogenation situation) that the part recycle gas method of DE-A 10211275 is used for the inventive method.The example of useful separation method comprises absorption and desorption or steam stripped combination (preferably with pressurizing absorption), as described in DE-A 10131297, and transformation absorption, rectifying and/or extracting process.Under the stripping situation, must carefully not introduce C via used stripping gas ₄Hydrocarbon.

When by air from be accumulated in absorption agent propane and propylene (for example absorb and remove) from the product gas mixture of catalytic dehydrogenation stripping when removing absorption agent, this combination can be one of process combination of the present invention, wherein removes gaseous mixture 1 ' that absorption agent obtains by stripping and can be used for part gas-phase partial oxidation and/or part gas phase ammonoxidation and therefore can be identical with gaseous mixture 2 immediately when suitably selecting the amount of stripping gas.The components contents beyond propane, propylene and the oxygen is generally 35-55 volume % in the gaseous mixture 1 ' at this moment.Under propenal produced according to the present invention and/or acrylic acid situation, preferred this program.

Be understood that the C that is discussed ₄Removing of hydrocarbon also can be accompanied by removing of propane and propylene other compositions in addition.Part propane and/or propylene also can be removed certainly separately simultaneously.

According to the present invention, the separation method of being discussed advantageously will be removed C ₄Hydrocarbon is with restriction separation costs and desired on the whole inconvenience and therefore limit infringement to economic vitality.

In other words, gaseous mixture 1 ' still contains at least 〉=0.1 volume % usually in the methods of the invention, usually 〉=0.2 volume %, or 〉=0.3 volume % or 〉=0.4 volume %, or 〉=0.5 volume %, volume % in many cases 〉=0.6, or 〉=0.8 volume %, or 〉=1 volume %, usually 〉=2 volume %, or 〉=3 volume % or 〉=5 volume %, on the whole usually 〉=10 volume %, or 〉=15 volume % or 〉=20 volume %, or 〉=25 volume %, or 〉=30 volume %, or 〉=composition beyond propane, propylene and the oxygen of 35 volume %.

Yet, under normal conditions, components in proportions≤80 volume % beyond the propane in the gaseous mixture 1 ', propylene and the oxygen in the methods of the invention, or≤70 volume %, or≤60 volume %, or≤50 volume %, or≤40 volume %.

As previously mentioned, advantageously aforementioned removing so that gaseous mixture 2 not only has is suitable for C of the present invention according to the present invention ₄Hydrocarbon total content and having simultaneously≤1 volume %, or≤mode of the butene-1 content of 0.9 volume % etc. carries out.

In other words, the purpose of program of the present invention especially for gaseous mixture 2, satisfies the present invention to C ₄At least one restriction that the hydrocarbon total content is set also realizes when satisfying in this article restriction that butene-1 content is set simultaneously.

In other words, the example that is suitable for gaseous mixture 2 of the present invention is to satisfy those of following condition simultaneously:

-C ₄Hydrocarbon total content≤3 volume % and butene-1 content≤1 volume %; Or

-C ₄Hydrocarbon total content≤2 volume % and butene-1 content≤1 volume %; Or

-C ₄Hydrocarbon total content≤3 volume % and butene-1 content≤0.5 volume %; Or

-C ₄Hydrocarbon total content≤2 volume % and butene-1 content≤0.5 volume %; Or

-C ₄Hydrocarbon total content≤3 volume % and butene-1 content≤0.75 volume %; Or

-C ₄Hydrocarbon total content≤2 volume % and butene-1 content≤0.75 volume %; Or

-C ₄Hydrocarbon total content≤3 volume % and butene-1 content≤0.4 volume %; Or

-C ₄Hydrocarbon total content≤2 volume % and butene-1 content≤0.4 volume %; Or

-C ₄Hydrocarbon total content≤1 volume % and butene-1 content≤0.4 volume %; Or

-C ₄Hydrocarbon total content≤3 volume % and butene-1 content≤0.3 volume %; Or

-C ₄Hydrocarbon total content≤2 volume % and butene-1 content≤0.3 volume %; Or

-C ₄Hydrocarbon total content≤1 volume % and butene-1 content≤0.3 volume % etc.

To the particularly advantageous gaseous mixture 2 of the inventive method is wherein to satisfy those of at least one restriction that this paper sets butylene total content in the gaseous mixture 2 simultaneously.

In other words, be suitable for gaseous mixture 2 of the present invention and especially wherein satisfy those of following condition simultaneously:

-C ₄Hydrocarbon total content≤3 volume %, butylene total content≤1 volume % and butene-1 content≤1 volume %; Or

-C ₄Hydrocarbon total content≤3 volume %, butylene total content≤1 volume % and butene-1 content≤0.75 volume %; Or

-C ₄Hydrocarbon total content≤3 volume %, butylene total content≤1 volume % and butene-1 content≤0.5 volume %; Or

-C ₄Hydrocarbon total content≤3 volume %, butylene total content≤1 volume % and butene-1 content≤0.3 volume %; Or

-C ₄Hydrocarbon total content≤3 volume %, butylene total content≤0.75 volume % and butene-1 content≤0.5 volume %; Or

-C ₄Hydrocarbon total content≤3 volume %, butylene total content≤0.5 volume % and butene-1 content≤0.5 volume %; Or

-C ₄Hydrocarbon total content≤2 volume %, butylene total content≤0.5 volume % and butene-1 content≤0.5 volume % etc.

According to the present invention, particularly advantageous method be following those: wherein not only satisfy C in the gaseous mixture 2 ₄The aforesaid combination of hydrocarbon total content and butylene total content and optional butene-1 content, and use still contains at least 〉=0.1 volume % simultaneously, 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 usually≤80 volume %, or≤70 volume %, or≤60 volume %, or≤50 volume %) propane and the gaseous mixture 1 ' of the composition beyond propylene and the oxygen.

The research that the present invention is carried out further shows for fear of propylene undesirable perfect combustion in partial oxidation and/or ammonia oxidation, advantageously limits the propane content in the gaseous mixture 2 usually a little.According to the present invention, the propane content in the preferred gas mixture 2≤60 volume %, or≤50 volume %.Particularly advantageous propane content is 20-40 volume % in the gaseous mixture 2, for example about 30 volume %.

When not considering to be used for any ammonia content (promptly also not considering the basis of percent by volume) that nitrile generates, be suitable for the gaseous mixture 2 of the inventive method normally following those: they satisfy according to the present invention on the one hand to its C ₄The restriction of hydrocarbon total content, preferred additionally to its butene-1 content and more preferably additionally to the restriction of its butylene total content, have following content on the other hand:

The O of 7-15 volume % ₂,

The propylene of 5-10 volume %,

The propane of 15-40 volume % is generally 25-35 volume %,

The nitrogen of 25-60 volume % is generally 40-60 volume %,

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

Other compositions of 0-5 volume %.

Above-mentioned explanation especially is suitable for when gaseous mixture 2 that heterogeneously catalyzed partial oxidation is contained in the propylene of gaseous mixture 2 is used to prepare propenal and/or vinylformic acid will being used for.

In addition, the gaseous mixture 2 that can be used for all propylene heterogeneously catalyzed partial oxidations that comprised by the inventive method and/or ammonia oxidation is not considered any nitrile to be formed existing NH especially once more ₃Have those of following composition during content (also being in the reference basis):

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

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

O ₂20 volume % are generally 2-20 volume % at the most, are generally 5-15 volume %;

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

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

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

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

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

Propane＞0 ,≤50 volume % are generally 10-50 volume %, are generally 20-40 volume %;

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

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

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

Propylene＞0 ,≤30 volume %, usually 〉=and 2 ,≤20 volume %, be generally 5-10 volume %;

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

Trimethylmethane≤3 volume %, preferred≤2 volume %, be generally 0.1-1 volume %;

Normal butane≤3 volume %, preferred≤2 volume %, be generally 0.1-1 volume %;

Instead-and butene-2≤1 volume %, preferred≤0.5 volume %, usually 〉=and 0.003 volume % ,≤0.1 volume %;

Suitable-butene-2≤1 volume %, preferred≤0.5 volume %, usually 〉=0.003 volume % ,≤0.1 volume %;

Butene-1≤1 volume %, preferred≤0.5 volume %, usually 〉=and 0.003 volume % ,≤0.1 body

Long-pending %;

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

Long-pending %;

Divinyl-1,3≤1 volume %, preferred≤0.5 volume %, usually 〉=and 0.003 volume % ,≤0.1

Volume %;

Divinyl-1,2≤1 volume %, preferred≤0.5 volume %, be generally 〉=0-0.1 volume %;

Butine-1≤0.5 volume %, preferred≤0.3 volume %, be generally 0-0.1 volume %; With

Crotonylene≤0.5 volume %, preferred≤0.3 volume %, be generally 0-0.1 volume %.

Being suitable for gaseous mixture 2 of the present invention still not only satisfies above-mentioned technical requirements but also satisfies those of following technical requirements simultaneously:

Other unsaturated C ₄Hydrocarbon is volume % altogether≤0.5, and is preferred≤0.3 volume %, is generally 0-0.1 volume %;

C ₅Hydrocarbon is volume % altogether≤0.1, usually≤0.05 volume %, be generally the 0-300ppm volume;

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

Acetone≤100ppm volume;

C ₁-C ₄Alcohol≤100ppm volume;

C ₂-C ₄Aldehyde≤100ppm volume;

Acetylene≤10ppm volume;

Carbonyl containing compound is (with Ni (CO) ₄Calculate) altogether≤the 100ppm volume;

Ion chlorine≤1mg/kg is generally 0-0.2mg/kg;

Contain the Cl compound and represent altogether≤1mg/kg, be generally 0-0.2mg/kg with Cl;

Contain the F compound and represent altogether≤1mg/kg, be generally 0-0.2mg/kg with F; With contain the S compound and represent altogether≤10mg/kg with S, be generally 0-1mg/kg, be generally 0-0.1mg/kg;

Condition is under all above-mentioned situations, all C ₄The total content of total content of hydrocarbon≤3 volume % (more preferably≤2 volume %, most preferably≤1 volume %) and while butylene is volume % (preferred≤0.75 volume %, more preferably≤0.5 volume %) more preferably≤1.

Not clear and definite component (composition) preferably is not present in the gaseous mixture 2 of the present invention, promptly can not detect.

For the purpose of the present invention, especially when using when gaseous mixture 1 being changed into the separation method that gaseous mixture 1 ' of the present invention mentions, this gaseous mixture 2 also can obtain by use following thick propane in the first step usually, this thick propane contains 〉=100ppm weight, or 〉=150ppm weight, or 〉=C of 200ppm weight ₄Hydrocarbon, or 6 volume % (for example 0.1 volume % or 0.5-6 volume %) at the most for example, especially when they satisfy following technical requirements:

Propane content 〉=90 volume %, usually 〉=93 volume %, general 〉=95 volume %;

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

C ₄Hydrocarbon total content≤6 volume %, usually≤5 volume %, general≤4 volume %; But usually 〉=0.5 volume %, or 〉=1 volume %, volume % sometimes 〉=2, or volume % in some cases 〉=3;

Butene-1 content≤0.5 volume %, usually≤0.3 volume %, general≤0.1 volume %; But usually 〉=the 5ppm volume, sometimes 〉=the 10ppm volume, or in some cases 〉=the 20ppm volume;

Butylene total content≤0.5 volume %, usually≤0.3 volume %, general≤0.1 volume %; But usually 〉=the 10ppm volume, sometimes 〉=the 20ppm volume, or in some cases 〉=the 30ppm volume;

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

Ethylene content≤5 volume %, usually≤2 volume %, be generally 0-0.5 volume %;

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

Cyclopropane≤0.1 volume %;

Propylene content≤10 volume %, usually≤5 volume %, general≤2 volume %;

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

C ₅Hydrocarbon total content≤0.3 volume %; With

C ₆-C ₈Hydrocarbon total content≤600ppm volume.

Be suitable for thick propane of the present invention and still not only satisfy above-mentioned technical requirements, and satisfy following technical requirements those simultaneously:

The total content of oxygenatedchemicals≤300ppm volume;

Acetylene content≤30ppm volume;

Ion cl content≤1mg/kg;

Contain total content≤1mg/kg that the Cl compound is represented with Cl;

Contain total content≤1mg/kg that the F compound is represented with F;

(under the catalytic dehydrogenation situation, maybe advantageously reaction mixture contains the 1-1000ppm volume based on the propane that wherein exists, the sulfocompound of preferred 1-100ppm volume (H for example to contain total content≤10mg/kg that the S compound represents with S ₂S and/or dimethyl sulphide), because these compounds are passivation (reactor) steel constituents such as Ni, Cr and Fe (reducing undesirable cracking of propane) and can activate catalyst system therefor on the other hand (referring to " catalytic dehydrogenation of lower alkane " on the one hand, Resasco, Daniel E.; Haller, Gary L., University of Oklahoma, USA, Catalysis (1994), 11,379-411);

Condition is C ₄The total content of hydrocarbon is preferred≤3 volume %, or≤2.5 volume %, or≤2 volume %, and the total content of butylene more preferably is 0.1 volume % simultaneously.

When the gaseous mixture 1 as the composition of gaseous mixture 2 directly carries out the heterogeneous catalyzed gas phase partial oxidation of the propylene in this gaseous mixture 1 and/or part gas phase ammonoxidation, generally be suitable for the inventive method in the technical requirements of the undefined thick propane of this prerequisite.Thus, advantageously in the first step according to the inventive method limited oxydehydrogenation and/or dehydrogenation transform favourable on the whole according to the present invention.Usually, this transforms concerning existing each independent stable hydrocarbon 〉=5mol%, but≤30mol%, common≤25mol% and in many cases≤20mol%.

Usually, above-mentioned and the every other thick propane that is suitable for the inventive method contains at least 0.25 volume %, or at least 0.5 volume %, or at least 1 volume %, usually at least 1.5 volume % or at least 2 volume % and in many cases the propane of at least 2.5 volume % or at least 3 volume % and the composition beyond the propylene (but usually≤10 volume %, usually≤these compositions of 7 volume % and general≤5 volume %).These additional content also are applied to be suitable for other thick propane of the inventive method usually, for example do not contain C ₄Those of hydrocarbon.Yet these thick propane also can contain 〉=0.1 volume %, or 〉=0.5 volume %, the common C of 6 volume % at the most ₄Hydrocarbon (for example 0.1 or 0.5 volume %-6 volume %).These thick propane can contain 〉=the 5ppm volume simultaneously in addition, the common butylene of 0.5 volume % (for example 5ppm volume-0.5 volume %) at the most.In addition, they can also contain 〉=the 5ppm volume simultaneously, the common butene-1 of 0.5 volume % (for example 5ppm volume-0.5 volume %) at the most.

According to the present invention, specially suitable thick propane still not only satisfies above-mentioned technical requirements but also satisfies those of following technical requirements simultaneously:

Ag≤1μg/kg；

Al≤10μg/kg；

As≤1μg/kg；

Au≤1μg/kg；

Ba≤1μg/kg；

Be≤1μg/kg；

Bi≤1μg/kg；

Ca≤2μg/kg；

Cd≤1μg/kg；

Co≤1μg/kg；

Cr≤1μg/kg；

Cu≤1μg/kg；

Fe≤10μg/kg；

Ga≤1μg/kg；

Ge≤1μg/kg；

Hg≤1μg/kg；

In≤1μg/kg；

Ir≤1μg/kg；

K≤1μg/kg；

Li≤1μg/kg；

Mg≤1μg/kg；

Mn≤1μg/kg；

Mo≤1μg/kg；

Na≤1μg/lg；

Nb≤1μg/kg；

Ni≤1μg/kg；

Pb≤1μg/kg；

Pd≤1μg/kg；

Pt≤1μg/kg；

Rh≤1μg/kg；

Sb≤1μg/kg；

Sn≤1μg/kg；

Sr≤1μg/kg；

Ta≤1μg/kg；

Ti≤1μg/kg；

Tl≤1μg/kg；

V≤1μg/kg；

Zn≤1 μ g/kg; With

Zr≤1μg/kg。

According to the present invention, thick propane very particularly preferably is not only to satisfy above-mentioned technical requirements but also satisfy those of following technical requirements simultaneously:

Density under 20 ℃=500 ± 2.0kg/m ³

Vapour pressure under 20 ℃=7.6 ± 0.2 crust;

Water≤10mg/kg;

Evaporation residue≤2mg/kg.

Described technical requirements relates to the mensuration by vapor-phase chromatography and atomic absorption spectrometry.Evaporation residue relates to weight determination.This resistates generally is made up of high boiling hydrocarbon (for example green oil).

In preferably being suitable for thick propane of the present invention, not clear and definite composition does not preferably exist, and promptly can not detect.

Program of the present invention particularly important in being applied to method for recycling the time.

At this moment, required target product takes out from gas-phase partial oxidation and/or ammoxidation product gaseous mixture by one of known separation method, and will be present in unconverted at least propane in this product gas mixture, general with the unconverted propylene that is present in wherein, be recycled in oxydehydrogenation and/or the dehydrogenation step and/or in gas-phase partial oxidation and/or the ammonia oxidation.Usually, carry out not handling immediately under this residual gas as this recirculation (circulation) of propane that takes out the composition of remaining residual gas after the target product and propylene, maybe (for example before recirculation, remove CO, the CO of wherein existence when it is handled immediately ₂, H ₂And/or O ₂) time, this is only handled immediately and carries out with limited cost and inconvenience.In other words, even when used thick propane only contain a small amount of C ₄Hydrocarbon, for example normal butane, Trimethylmethane, butene-1 or other butylene (C for example ₄Hydrocarbon total content 〉=0.01 volume % is 6 volume % at the most if possible) time, they may be gathered in the gaseous mixture 2 in the recirculating gas body method and exceed restriction of the present invention, unless take special measure.These methods for example may relate to specifically by rectifying and/or by absorption/desorb and/or stripping and/or by adsorption/desorption and/or by condensation and/or by membrane method removes C the remaining residual gas after taking out target product ₄Hydrocarbon, and the remaining thereafter residual gas that contains propane and propylene of recirculation at this moment only.

EP-A 938463 thinks that this separating step is unnecessary, although the thick propane that its is recommended that gaseous mixture 1 is directly used in partial oxidation and will have any required purity basically is used for the first step.

As the replacement method of method for recycling, residual gas can also infeed in other application to avoid unwanted C ₄Hydrocarbon is assembled.For example, they can burn to generate electricity and/or to be particularly useful for preparing synthetic gas with propane that wherein exists and propylene.

In addition, the inventive method can be carried out in the mode that is similar to different general plannings described in the prior art.

In other words, in simple proposal, the inventive method in the single reaction district, be present in steps on wherein the catalyst charge and carrying out, for example as document EP-A 608838, EP-A529853, DE-A 19835247, EP-A 895809, JP-A 7-232071, JP-A 11-169716, EP-A 1192987, JP-A 10-57813, JP-A 2000-37623, JP-A 10-36311, WO00/29105, 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-A 10-330343, JP-A11-285637, 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-A 11-263745, DE-A10046672, DE-A 10118814, DE-A 10119933, JP-A 2000/143244, EP-A318295, EP-A 603836, DE-A 19832033, DE-A 19836359, EP-A 962253, DE-A 10119933, DE-A 10051419, DE-A 10046672, DE-A 10033121, DE-A101 459 58, DE-A 10122027, the document of being quoted in EP-A 1193240 and these documents is instructed.

The active composition of catalyst charge to be used mainly is a multimetal oxide compositions, at least a among its combination containing element Mo and V, two kinds of element T e and the Sb and be selected from least a among element 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 the In.

Combination containing element Nb, Ta, W and/or Ti, the more preferably element nb of preferred back one element set.

Preferred relevant poly-metal deoxide active composition comprises above-mentioned element combinations with stoichiometric equation I:

Mo ₁V _bM ¹ _cM ² _d(I)，

M wherein ¹=Te and/or Sb,

M ²=at least a the element that is selected among 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 the In,

b＝0.01-1，

C=＞0-1 and

d＝＞0-1。

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

Stoichiometric coefficient b advantageously is 0.1-0.6.Correspondingly, the preferable range of stoichiometric coefficient c is 0.01-1 or 0.05-0.4, and the favorable values of d is 0.01-1 or 0.1-0.6.

According to the present invention, particularly advantageous is that stoichiometric coefficient b, c and d are positioned at above-mentioned preferable range simultaneously.

Above-mentioned situation is especially suitable when the active composition of catalyst charge is made up of one of above-mentioned element combinations for the element beyond its oxygen.

The poly-metal deoxide active composition of the especially general stoichiometric equation II of these compositions:

Mo ₁V _bM ¹ _cM ² _dO _n(II)

Wherein each variable each freely stoichiometric equation I is defined and number that n=is determined by the valency and the occurrence rate of the element beyond oxygen in (II).

In the single reaction district of the inventive method method, following those poly-metal deoxide active compositions of further preferred use, they contain one of above-mentioned element combinations on the one hand or are made up of these for the element beyond the oxygen, and the X-ray diffractogram that has simultaneously has reflection peak h and i, the peak position at described peak locates at the reflection angle (2 θ) of 22.2 ± 0.5 ° (h) and 27.3 ± 0.5 ° (i) that (all information relevant with X-ray diffractogram relate to X-ray diffractogram (the theta-theta D-5000 Siemens diffractometer that uses the Cu-Ka radiation to obtain as X-radiation in this article, tube voltage: 40kV, tube current: 40mA, hole V20 (variable), collimator tube V20 (variable), secondary monochromator hole (0.1mm), detector aperture (0.6mm), measure (2 θ) at interval: 0.02 °, the Measuring Time of every stepping: 2.4s, detector: scintillation counter).

The halfwidth degree of these reflections can very little or highly significant.

For the inventive method, those of preferred especially above-mentioned poly-metal deoxide active composition, the reflection k that its X-ray diffractogram also has peak position to locate at 28.2 ± 0.5 ° (k) except reflection h and i.

In the latter, preferably wherein reflect h again to have maximum intensity and maximum half high width in X-ray diffractogram be those of 0.5 ° according to the present invention, the halfwidth degree that very particularly preferably wherein reflects i and reflection k simultaneously≤the intensity P of 1 ° and reflection k _kIntensity P with reflection i _iSatisfy and concern 0.2≤R≤0.85, be more preferably 0.3≤R≤0.85, preferred 0.4≤R≤0.85, preferred especially 0.65≤R≤0.85, even more preferably 0.67≤R≤0.75 and very particularly preferably those of R=0.70-0.75 or R=0.72, wherein R is the strength ratio by the following formula definition:

R＝P _i/(P _i+P _k)

Preferred above-mentioned X-ray diffractogram ° is not located the reflection that is maximum in 2 θ=50 ± 0.3.

The intensity definition reference of reflecting in the X-ray diffractogram in this article, is in the definition described in DE-A 19835247, DE-A 10122027 and DE-A 10051419 and the DE-A 10046672.The definition of halfwidth degree is also like this.

Except reflection h, i and k, the above-mentioned X-ray diffractogram of advantageously stand-by poly-metal deoxide active composition still contains other reflections according to the present invention, and the peak position of these reflections is in following reflection angle (2 θ):

9.0±0.4°(l)

± 0.4 ° 6.7 (o) and

7.9±0.4°(p)。

Further advantageously X-ray diffractogram additionally contains peak position in reflection angle (2 θ)=45.2 ± 0.4 ° of reflections that (q) locates.

Usually, X-ray diffractogram also contains 29.2 ± 0.4 ° (m) and 35.4 ± 0.4 ° (n) of reflection.

Further the element combinations that advantageously defines in formula I and II exists mutually with pure i-.When the catalytic activity oxide composition also contains the k-phase time, its X-ray diffractogram also contains other peak positions at following reflection angle (2 θ) except above-mentioned reflection: 36.2 ± 0.4 ° with 50 ± 0.4 ° of reflections of locating (term " i-with k-mutually " is used for herein with the definition among DE-A 10122027 and the DE-A 10119933).

In the time will reflecting h and be appointed as intensity 100, advantageously reflect i, l, m, n, o, p and q according to the present invention and have following intensity with identical intensity dimension:

I:5-95 is generally 5-80, is 10-60 sometimes;

l：1-30；

m：1-40；

n：1-40；

o：1-30；

P:1-30 and

q：5-60。

When the X-ray diffractogram of above-mentioned composition contains extra reflex time, their halfwidth degree is general≤and 1 °.

The poly-metal deoxide active composition of general formula I I used according to the invention or the specific surface area of poly-metal deoxide active composition of element combinations that comprises general formula I are in many cases for 1-30m ²/ g (BET specific surface area, nitrogen) is especially when their X-ray diffractogram as previously mentioned the time.

The preparation of described poly-metal deoxide active composition can be found in the prior art of being quoted.This comprises that especially (in the end among all embodiment of two pieces of documents, drying means to be used is a spraying drying for DE-A 10122027, DE-A 10119933, DE-A 10033121, EP-A1192987, DE-A 10029338, JP-A 2000-143244, EP-A 962253, EP-A 895809, DE-A 19835247, WO 00/29105, WO 00/29106, EP-A 529853 and EP-A608838; For example being 300-350 ℃ in temperature in is under 100-150 ℃ with temperature out; And stream or adverse current).

Described poly-metal deoxide active composition can directly use (promptly with powder type) or be shaped to suitable geometrical shape (referring to the coating catalyst of for example DE-A 10051419 and how much variants of DE-A 10122027) to be used for the single district structure of the inventive method.They are particularly suited for preparing propenal and/or vinylformic acid and preparation vinyl cyanide.

The basis of single district method be institute that stand-by catalyzer can catalysis the inventive method in steps.

They can carry out in stationary catalyst bed or fluid catalyst beds (moving-bed).Suitable method is described and can be found in the prior art document.When the inventive method is implemented with fixed bed reaction, for example be used for preparing vinylformic acid in single district method, advantageously in being equipped with the tube bundle reactor of catalyzer, its catalyst tube carries out.Usually,, be generally salt-melting, transmit as the thermal barrier around the catalyst tube with liquid.Perhaps, can use the hot plate reactor, lie against catalyst charge between the cooling plate this moment.

Catalyst tube from the reactor, reaction gas mixtures and salt bath are and stream or adverse current transmit.This salt bath itself can be pure parallel-flow with respect to catalyst tube.Yet, be understood that the cross-stream that also can superpose thereon.In a word, salt bath can only be with reaction gas mixtures when catalyst tube be tortuous stream on every side and observe on reactor and stream or adverse current transmission.The tube bundle reactor that is suitable for the inventive method is for example open by document EP-A 700714 and EP-A 700893.

May form the difference of the reaction gas mixtures of the single area scheme of the inventive method can be by the prior art collection of quoting with regard to this method scheme.

In order to prepare vinylformic acid, the composition of initial action gaseous mixture changes in following scope (mol ratio) usually:

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

Preferred aforementioned proportion is 1: (0.5-5): (1-30): (1-30).

Above-mentioned scope especially is suitable for when used other compositions mainly are dinitrogen.Temperature of reaction is generally 250-550 ℃ (condition of ammonia oxidation is suitable, and different is that reaction gas mixtures additionally comprises ammonia (for example referring to EP-A 929853)).

Propane can be for example 10-500 (STP)/l (fixed bed) h to the load of fixed bed catalyst charging in that the single area scheme situation of the inventive method is following.The load of initial action gaseous mixture is generally 100-10000L (STP)/Lh, is 500-5000L (STP)/Lh in many cases.

Target product, for example vinylformic acid can take out from the products therefrom gaseous mixture in a manner known way, for example as described in the DE-A 10122027.In other words, the vinylformic acid of existence can be for example by absorbing with high boiling point inert hydrophobic organic solvent (for example the mixture of phenyl ether and biphenyl, it can also be chosen wantonly and contain additive such as dimethyl phthalate) and from product gas mixture, drawing.Gained absorption agent and acrylic acid mixture can carry out rectifying, extraction and/or crystallization treatment subsequently in a manner known way, obtain glacial acrylic acid.Perhaps, vinylformic acid removing substantially also from product gas mixture can be undertaken by partial condensation, for example as described in DE-A 10053086, DE-A 19627847, DE-A 19740253, DE-A 19740252, DE-A 19606877 and the DE-A 19740253.Gained vinylformic acid phlegma can for example pass through fractional crystallization (for example suspension crystallization and/or layer crystallization) and further purify.

Remaining residual gas mixture especially comprises unconverted propane after removing vinylformic acid substantially, contains or do not contain unconverted propylene.

The butene-1 content and butylene and the C that depend on this residual gas mixture ₄Hydrocarbon total content and depend on used oxygen source (no matter be purity oxygen, contain oxygen rare gas element or air), the directly recirculation of this reaction mixture.If need, can also be divided into two portions and only wash (for example infeeding its burning or another purposes (for example preparing synthetic gas)) with a part of recirculation and with another part with same composition.Be understood that the latter can also use whole residual gas mixture to carry out.

At undesirable C according to the present invention ₄Under the situation that other unwanted component ratios increase in component ratio increase and/or the residual gas mixture, for example can remove propane and any propylene that is contained in the residual gas mixture, then it is recycled in the inventive method and and combine with other compositions of thick propane and initial action gaseous mixture by dividing potential drop rectifying (can suitably select separation factor).Yet, from the present invention, the words that need only make this residual gas in extraction plant with preferred C ₃Hydrocarbon absorptivity hydrophobic organic solvent contact (for example by making this gas by this organic solvent) is just enough.By desorb subsequently and/or with air (under any circumstance requiring) stripping, can discharge the propane of absorption and any propylene once more and it is recycled in the inventive method as oxygen source.Be understood that vinylformic acid can also take out by the program described in the DE-A 10059122 from product mixtures.Be understood that many metal actives composition that single district method is recommended also can dilute form be used for the inventive method, it is with in small, broken bits, and for example colloidal material such as silicon-dioxide, titanium dioxide, aluminum oxide, zirconium white and niobium oxides dilute.

The dilution mass ratio can be 9 (thinners) at the most: 1 (active composition).In other words, the example of possible dilution mass ratio comprises 6 (thinners): 1 (active composition) and 3 (thinners): 1 (active composition).Thinner can mix before or after calcining according to DE-A 10122027.Yet, be understood that other catalyst systems to be used for method, for example as described in the JP-A 3-170445 according to single district of the present invention.

When the inventive method was implemented in the single reaction district, a kind of situation was that wherein gaseous mixture 1 is identical with 0 gaseous mixture 2.The inventive method especially according to the present invention to the product gas mixture of the inventive method in C ₄When being exceeded, the content restriction of hydrocarbon uses.

According to the present invention, preferably in a more than reaction zone, implement the inventive method, for example as described in EP-A 938463, EP-A 117146, DE-A 3313573, GB-A 2118939, US-A3161670, WO 01/96270, EP-A 731077, DE-A 19837520, DE-A 19837517, DE-A 19837519, DE-A 19837518, DE-A 19837520, DE-A 10131297 and the DE-A 10211275.

A more than reaction zone is meant that mainly at least one step of the inventive method carries out under can being chosen as the condition that is independent of at least one other step in the inventive method to small part, although perhaps only be accessory, be meant to small part independently reaction conditions can in one of reaction path and identical step, realize (when multi-zone process being used for a step (this step have can independent regulation humidity province), being exactly like this for example, for example as DE-A 19948241, DE-A 19927624, DE-A 19910508, DE-A 19910506 and DE-A 19948248 are described).In other words, when the inventive method for example comprised for two steps, the first step for example can use another catalyzer or another catalyst charge that were different from for second step to carry out.Perhaps, another program can be that two steps are adopted identical catalyzer or catalyst charge, but these two steps are selected and the conditioned reaction temperature independently of each other.Be understood that these two kinds of measures also can superpose.

The advantage of multi-zone process allows to improve reaction conditions based on it in principle so that it adapts to this fact that requires of each step of the inventive method.

This advantage is by using molecular oxygen to become vinylformic acid known the propylene heterogeneous catalyzed gas phase partial oxidation.

In principle, this reaction is carried out in two step in succession along reaction coordinate, at first obtains propenal, obtains vinylformic acid by propenal then.

The propylene that this reaction sequence has existed in having started according to the present invention in two oxidation zones that are arranged in order gaseous mixture 2 in a manner known way carries out the possibility of partial oxidation, and the oxide catalyst that allows to be ready to use in each of this two oxidation zones is regulated (this optimizing chance also allows the partial oxidation of propylene to stop on the propenal and allows separation of propylene aldehyde) in the best way.For example, the catalyzer that is preferred for first oxidation zone (propylene → propenal) is generally the poly-metal deoxide based on element combinations Mo-Bi-Fe, and the catalyzer that is preferred for second oxidation zone (propenal → vinylformic acid) is generally poly-metal deoxide based on element combinations Mo-V (for example recommended in this article in addition be used for single district method those).Yet these two reactions steps can also be carried out on single catalyst in the single reaction district in principle.

Very general is that the first step in the inventive method is advantageously carried out in independent reaction zone.

Under the situation of oxidative dehydrogenation of propane, this can use molecular oxygen to carry out to the homogeneous phase and/or the heterogeneous catalytic oxidation dehydrogenation of propylene with propane in gas phase.The source of used molecular oxygen can be air, pure molecular oxygen or the air that is rich in molecular oxygen.

When reaction zone is configured to the homogeneous oxidizing dehydrogenation, this can be with for example at document US-A 3 in principle, 798,283, CN-A 1,105 352, applied catalysis (APPlied Catalysis), 70 (2) 1991,175-187 page or leaf, Catalysis Today (catalysis today) 13, mode described in 1992, the 673-678 pages or leaves and the application DE-A 19 622 331 is carried out.Favourable oxygen source is an air.The temperature of homogeneous oxidizing dehydrogenation advantageously is chosen as 300-700 ℃, and preferred 400-600 ℃, more preferably 400-500 ℃.Operating pressure can be clung to for 0.5-100, especially the 1-10 crust.The residence time is generally 0.1 or 0.5-20 second, preferred 0.1 or 0.5-5 second.

Reactor used can be for example tube furnace or tube bundle reactor, for example uses stack gas as the adverse current tube furnace of thermal barrier or use the tube bundle reactor of salt-melting as thermal barrier.The ratio of propane and oxygen is preferably 0.5 in the starting mixt: 1-40: 1, and especially be 1: 1-6: 1, more preferably 2: 1-5: 1.Starting mixt can also comprise other and preferably be inert (inert fraction preferably very usually refers to be less than 5mol% in this article, preferably is less than 3mol%, those compositions that react in the correlated response step more preferably less than 1mol%; More preferably they do not react) composition such as water, carbonic acid gas, carbon monoxide, nitrogen, rare gas, other hydrocarbon (for example being present in the secondary component in the thick propane) and/or propylene etc., also comprise (circulation gas) composition of recirculation.

When dehydrogenating propane is configured to the oxydehydrogenation of heterogeneous catalysis; this can be for example as document US-A 4 788 371 in principle; CN-A 1073893; Catalysis Letters (catalysis circular) 23 (1994); 103-106; W.Zhang; SCI; 14 (1993) 566; Z.Huang; petrochemical complex; 21 (1992) 592; WO 97/36849; DE-A 197 53 817; US-A 3 862 256; US-A 3 887 631; DE-A 195 30 454; US-A 4 341 664; J.of Catalysis (catalysis magazine) 167; 560-569 (1997); J.of Catalysis 167; 550-559 (1997); Topics inCatalysis (catalytic motif) 3 (1996) 265-275; US-A 5 086 032; Catalysis Letters10 (1991); 181-192; Ind.Eng.Chem.Res.1996; 35; 14-18; US-A 4 255 284; Applied Caralysis A (applied catalysis A): General; 100 (1993); 111-130; J.ofCatalysis 148; 56-67 (1994); V.Cort é s Corber á n and S.Vic Bell ó n (Ed.); NewDevelopments in Selective Oxidation II (the new development II of selective oxidation); 1994; Elsevier Science B.V., the 305-313 page or leaf; 3 ^RdWorld Congress on OxidationCatalysis (world's oxidation catalysis meeting for the third time), R.K.Grasselli, S.T.Oyama, A.M.Gaffney and J.E.Lyons (Ed.), 1997, carry out described in the Elsevier Science B.V., the 375th page and following pages or DE-A 19837520, DE-A 19837517, DE-A 19837519 and DE-A 19837518.Used oxygen source can also be an air.Yet oxygen source is made up of 90mol% molecular oxygen at least usually, and is made up of 95mol% oxygen at least in many cases.

To the catalyzer that is suitable for the heterogeneous catalytic oxidation dehydrogenation without any particular restriction.Useful catalysts is the known oxy-dehydrogenation catalysts that oxidation of propane can be become propylene of any those skilled in the art.Particularly, can use any oxy-dehydrogenation catalyst of in above-mentioned document, mentioning.The appropriate catalyst example comprises the oxy-dehydrogenation catalyst that comprises MoVNb oxide compound or Vanadyl pyrophosphate, chooses wantonly to contain promotor.This favourable oxy-dehydrogenation catalyst example is a catalyzer of also recommending to be used for single district method, its comprise contain Mo, V, Te, O and X mixed metal oxide as basal component, wherein X is at least a element 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 (can also be referring to EP-A 938463 and EP-A 167109 about this theme).The catalyzer of multimetal oxide compositions that other specially suitable oxy-dehydrogenation catalysts are DE-A-197 53 817 or catalyst A and DE-A 19838312, very particularly advantageous is as multimetal oxide compositions or the catalyst A preferably mentioned in last document.In other words, the useful active composition multimetal oxide compositions of general formula III especially:

M ¹ _aMo _1-bM ² _bO _x (III)

Wherein

M 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 occurrence rate of the element beyond the oxygen in (III).

In principle, suitable active composition (III) can plain mode by being prepared as follows: produce corresponding to its stoichiometric very uniformly, preferred in small, broken bits drying composite and at 450-1000 ℃ temperature lower calcination by its elementary composition suitable source.The elementary composition source that can be used for poly-metal deoxide active composition (III) be for those compounds of oxide compound and/or can by at least in the presence of oxygen thermal conversion become those compounds of oxide compound.These compounds are halogenide, nitrate, formate, oxalate, Citrate trianion, acetate, carbonate, amine complex salt, ammonium salt and/or oxyhydroxide normally.The initial compounds that is used to prepare multimetal oxide compositions (III) can dry form uniform mixing, for example mixes with fine-powder, or with the hygrometric state uniform mixing, for example mixes with water as solvent.Multimetal oxide compositions (III) can powder type uses or be shaped to some catalyzer geometrical shape and moulding can be carried out before or after last calcining.Can also use the catalyzer of not load.Yet, can also be by imposing on the preformed inert catalyst carrier and moulding powder activity composition or precursor composition.The useful catalysts carrier is conventional porous or non-porous aluminas, silicon-dioxide, thorium dioxide, zirconium dioxide, silicon carbide or silicate, and carrier can conventional or unconventional moulding.

For the heterogeneous catalytic oxidation dehydrogenation of propane, temperature of reaction is preferably 200-600 ℃, especially 250-500 ℃, is more preferably 350-440 ℃.Operating pressure is preferably the 0.5-10 crust, especially 1-10 crust, more preferably 1-5 crust.The verified operating pressure that surpasses 1 crust, for example the 1.5-10 crust is particularly advantageous.Usually, the heterogeneous catalytic oxidation dehydrogenation of propane is carried out on stationary catalyst bed.The latter advantageously adds in the pipe of tube bundle reactor, as described in the document of being quoted in EP-A-0 700 893 and EP-A-0 700714 and these files.The mean residence time of reaction gas mixtures in catalyst bed advantageously is 0.5-20 second.The ratio of propane and oxygen is with required transformation efficiency and selectivity of catalyst becomes and advantageously be 0.5: 1-40: 1, especially 1: 1-6: 1, more preferably 2: 1-5: 1.Usually, the propylene selectivity raises with conversion of propane and reduces.Propane is to the carrying out of the reaction of propylene so preferably should make the lower conversion of propane of acquisition under high propylene selectivity.The transformation efficiency of propane is 5-40mol% more preferably, is generally 10-30mol%.Thus, term " conversion of propane " is meant the ratio that the propane that infeeds (being present in the propane summation in the recirculating gas of thick propane and any recirculation) transforms in one way.Usually, the selectivity that forms propylene is 50-98mol%, 80-98mol% more preferably, and wherein term " selectivity " refers to the propylene mole number that the propane of every molar reactive produces, and represents with molecular fraction.

Usually, the starting mixt that is used for the oxidisability dehydrogenating propane comprises the propane of 5-95mol% (based on the 100mol% starting mixt).Except propane and oxygen, the starting mixt that is used for the heterogeneous catalytic oxidation dehydrogenation also can comprise other, especially inert composition, as carbonic acid gas, carbon monoxide, nitrogen, rare gas, other hydrocarbon as being present in secondary component and/or the propylene in the thick propane.Heterogeneous oxydehydrogenation also can be at thinner, and for example steam carries out under existing.

Can use known to those skilled in the art any required reactor sequences to carry out the homogeneous oxidizing dehydrogenation or the heterogeneous catalytic oxidation dehydrogenation of propane.For example, oxydehydrogenation can be carried out in single reaction vessel or carry out in the group (choose wantonly between each reactor and introduce oxygen) of two or more reactors.Also there is the possibility of implementing homogeneous phase and heterogeneous catalytic oxidation dehydrogenation with mutually combining.

The example that is present in according to the possible composition in the product mixtures of oxidative dehydrogenation of propane of the present invention comprises following component: propylene, propane, carbonic acid gas, carbon monoxide, water, nitrogen, oxygen, ethane, ethene, methane, propenal, vinylformic acid, ethylene oxide, butane (for example normal butane or Trimethylmethane), acetate, formaldehyde, formic acid, propylene oxide and butylene (for example butene-1).Usually, the product mixtures that obtains in oxidative dehydrogenation of propane according to the present invention comprises: the 5-10mol% propylene, the 0.1-2mol% carbon monoxide, the 1-3mol% carbonic acid gas, 4-10mol% water, 0-1mol% nitrogen, the 0.1-0.5mol% propenal, 0-1mol% vinylformic acid, 0.05-0.2mol% acetate, 0.01-0.05mol% formaldehyde, 1-5mol% oxygen, other said components of 0.1-1.0mol%, and the remaining propane that is essentially are in each case based on the 100mol% product mixtures.

Usually, dehydrogenating propane in first reaction zone also can carry out with the heterogeneous catalysis dehydrogenating propane in basic the eliminating under the oxygen, for example as described in DE-A 3313573, WO 01/96270, DE-A 10131297 or the DE-A 10211275, or be performed as follows:

Because the volume of following of heterogeneous catalysis dehydrogenation reaction increases, so can increase transformation efficiency by the dividing potential drop that reduces product.This can realize by plain mode that for example by dehydrogenation under reduced pressure and/or by mixing basic inert diluent gas, for example steam is realized, described gas is configured for the rare gas element of dehydrogenation reaction usually.Usually the further advantage that causes with the steam dilution is the carbonization reduction of catalyst system therefor, because steam is by the carbon reaction of gasification principle and formation.In addition, steam can be used as diluent gas in subsequently at least one oxidation and/or ammonia oxidation district (also abbreviating at least one part district in this article as).Yet, also can plain mode (for example by condensation) with vapor portion or from the dehydrogenation product mixture, remove fully, this has started increase diluent gas N ₂The possibility of the ratio of in the modified product mixture that at least one part district, obtains in this way, further using.The example that is used for other suitable diluents of heterogeneous catalysis dehydrogenating propane comprises CO, methane, ethane, CO ₂, nitrogen and rare gas such as He, Ne and Ar.All thinners of mentioning can use separately or use with highly different form of mixtures.Advantageously described thinner also is suitable diluent at least one part district usually.Usually, just as has been described, preferred diluent is inertia (promptly be lower than 5mol%, preferably be lower than 3mol% and even be more preferably the thinner generation chemical transformation that is lower than 1mol%) in concrete reaction zone.In principle, be that all are by the known dehydrogenation catalyst of prior art to heterogeneous catalysis dehydrogenating propane useful catalysts.They can be divided into two groups roughly, promptly have those (for example chromic oxide and/or aluminum oxide) of oxidisability and are generally those that at least a usually comparatively expensive metal (for example platinum) on the oxidative vector forms by being deposited on.

More operable dehydrogenation catalysts be all in following document, recommend those: WO01/96270, EP-A 731077, DE-A 10211275, DE-A 10131297, WO 99/46039, US-A 4 788 371, EP-A-0 705 136, WO 99/29420, US-A 4 220 091, US-A 5,430 220, US-A 5 877 369, EP-A-0 117 146, DE-A 199 37 196, DE-A 199 37105 and DE-A 199 37 107.Particularly, can use catalyzer among the embodiment 1-4 of DE-A 199 37 107.

These catalyzer are the dehydrogenation catalysts that comprise following composition: at least a element of periodictable the 1st or 2 main groups, the element of the 3rd transition group, element, lanthanum and/or the tin of the 8th transition group of being selected from of 10-99.9 weight % zirconium dioxide, 0-60 weight % aluminum oxide, silicon-dioxide and/or titanium dioxide and 0.1-10 weight %, condition is that the weight percentage sum is 100 weight %.

In order to carry out the heterogeneous catalysis dehydrogenating propane, useful type of reactor and process program be all by prior art known those.These process programs for example are described in all prior art documents of quoting with regard to dehydrogenation catalyst.

The comparatively comprehensive description that is suitable for method of dehydrogenating of the present invention also can be at " Catalytica ^Studies Division, oxydehydrogenation and other method of dehydrogenating ", Study Number 4192 OD, 1993,430 Ferguson Drive, Mountain View, California finds among the 94043-5272 U.S.A.

The feature of propane part heterogeneous catalysis dehydrogenation is to carry out in the heat absorption mode.This means and to obtain the required heat (energy) of necessary temperature of reaction in advance and/or in the heterogeneous catalysis certain embodiments, infeed in the initial action gaseous mixture.

Because the temperature of reaction height that requires, especially the heterogeneous catalysis dehydrogenation of propane further is typically and forms a small amount of high boiling point high molecular organic compound, until carbon and comprise carbon, it is deposited on the catalyst surface and therefore makes its inactivation.Reduce to minimumly for the shortcoming that will follow this phenomenon, can treat at high temperature to contain the propane reaction gas mixtures with what carry out the heterogeneous catalysis dehydrogenation with steam dilution by catalyst surface.Deposit carbon is partially or completely eliminated by the gasification principle under the condition that is produced.

The possibility that another kind is removed the deposit carbon compound relates to be made oxygen-containing gas at high temperature flow through dehydrogenation catalyst frequently and therefore effectively burns deposit carbon.Yet, can also treat by significantly suppressing the formation of carbon deposits in the propane of heterogeneous catalysis dehydrogenation by at high temperature on dehydrogenation catalyst, carrying out before the dehydrogenation molecular hydrogen added.

Be understood that also to exist steam and molecular hydrogen are treated by the possibility in the propane of heterogeneous catalysis dehydrogenation with the mixture adding.Molecular hydrogen is added the generation that also reduces unwanted by product propadiene, propine and acetylene in the heterogeneous catalysis dehydrogenation of propane.

The suitable reactors that is used for the heterogeneous catalysis dehydrogenating propane is fixed bed tubular type or tube bundle reactor.This means that dehydrogenation catalyst places a reaction tubes or bundle of reaction tubes with the fixed bed form.Reaction tubes is by combustion gases in the space around the reaction tubes, for example hydro carbons such as methane and heat.Advantageously the catalyst tube heating with this direct form only is used for fixing beginning about 20-30% place most and heat remaining length to desired reaction temperature by the radiant heat that discharges in combustion processes of bed.This realizes isothermal substantially reaction control in mode.Suitable tube inner diameter is about 10-15cm.Typical dehydrogenation tube bundle reactor comprises 300-1000 root reaction tubes.The reaction tubes temperature inside changes in the preferred 400-700 ℃ of scope at 300-700 ℃.Advantageously the initial action gaseous mixture is infeeded in the tubular reactor that is preheating to temperature of reaction.Possible is that product gas mixture leaves reaction tubes under low 50-100 ℃ temperature.Yet this starting temperature can also be in higher or par.For said procedure, advantageously use oxy-dehydrogenation catalyst based on chromic oxide and/or aluminum oxide.Usually, do not use diluent gas and initial action gas substantially only to be thick propane.Dehydrogenation catalyst also uses with undiluted form usually.

Can this type of tube bundle reactor of parallel running a plurality of (for example 3) on technical scale.According to the present invention, two in these reactors can be in the dehydrogenated operation, and catalyst charge is regenerated in the 3rd reactor, does not carry out the operation at least one part district.

This program is favourable in the known BASF-Linde dehydrogenating propane method by document for example.Yet, importantly use this tube bundle reactor just enough according to the present invention.

This program can also be used for " steam activation reformation (STAR) method ", and this method is by PhillipsPetroleum Co. exploitation (for example referring to US-A 4 902 849, US-A 4 996 387 and US-A5 389 342).The dehydrogenation catalyst that is used for this STAR method is advantageously for containing the platinum (for example referring to US-A 5 073 662) of promotor on zinc (magnesium) spinel as carrier.Opposite with BASF-Linde dehydrogenating propane method is to treat the propane of dehydrogenation in the STAR method with the steam dilution.It is typical that steam/the propane mol ratio is 4-6.Initial reactor pressure is generally 3-8atm and temperature of reaction advantageously is chosen as 480-620 ℃.The typical liquid gas hourly space velocity (LHSV) of entire reaction gaseous mixture is 0.5-10h ^-1

The heterogeneous catalysis dehydrogenating propane can also carry out in moving-bed.For example, moving catalyst bed can be set in radial flow reactors.In this reactor, catalyzer slowly moves to the bottom by the top, simultaneously the reaction gas mixtures radial flow.This program for example is applied in the UOP-Oleflex method of dehydrogenating.Because the basic adiabatic operation of the reactor in this method, therefore advantageously operate a plurality of tandem reactors (usually at the most 4) with one group.This can be avoided reaction gas mixtures in the excessive temperature contrast of reactor inlet and reactor exit (in the operation at adiabatic model, the initial action gaseous mixture is as thermal barrier, its thermal content is depended in the reduction of temperature of reaction), but still can obtain tempting total conversion rate.

When catalyst bed leaves moving-burden bed reactor, it is infeeded regeneration and utilization more subsequently.The dehydrogenation catalyst that is used for this method for example can be spherical dehydrogenation catalyst, and it is made up of the platinum that is carried on the ball-aluminium oxide carrier substantially.In the UOP scheme, the hydrogen adding is treated in the propane of dehydrogenation, to avoid the catalyzer premature aging.Operating pressure is generally 2-5atm.Hydrogen/propane (mole) is 0.1-1 than advantageously.Be chosen as about 2-6h the duration of contact that temperature of reaction is preferably 550-650 ℃ and catalyzer and reaction gas mixtures ^-1

In the said fixing bed process, the catalyzer geometrical shape can be spheric equally, but also can or have different geometrical shapies for cylindrical (hollow or solid).

By Proceedings De Witt, Petrochem.Review, Houston, Texas, another process program of the heterogeneous catalysis dehydrogenating propane that 1992a, N1 describe do not dilute propane and the possibility of carrying out the heterogeneous catalysis dehydrogenating propane in fluidized-bed.

According to the present invention, for example can two fluidized-beds of parallel running, one of them can be in reproduced state frequently and entire method not had a negative impact.Used active composition is chromic oxide or aluminum oxide.Operating pressure is generally 1-2atm and desorption temperature is generally 550-600 ℃.The required heat of dehydrogenation is introduced in the reaction system by dehydrogenation catalyst is preheating to temperature of reaction.Above-mentioned method of dehydrogenating is known as the Snamprogetti-Yarsintez method in the literature.

As the replacement of said procedure, and the method that the heterogeneous catalysis dehydrogenating propane can also be developed by ABB Lummus Crest under basic eliminating oxygen (referring to Proceedings De Witt, Petrochem.Review, Houston, Texas, 1992, P1) realize.

To up to now described basic get rid of under the oxygen propane heterogeneous catalysis method of dehydrogenating commonly they in (the operation down of (passing through reaction zone) usually≤60mol%) of the conversion of propane of 〉=30mol% based on one way.Advantageously realize according to the present invention 〉=5mol%-≤30mol% or≤conversion of propane of 25mol% is just enough.This means that the heterogeneous catalysis dehydrogenating propane also can operate (transformation efficiency passes through reaction zone based on one way) under the conversion of propane of 10-20mol%.This is especially basic as inert dilution gas and the latter be can't harm the lost territory substantially be recycled in dehydrogenation zone and/or at least one the part district at least one part district subsequently based on the unconverted propane of residual content.

In order to obtain above-mentioned conversion of propane, advantageously under the operating pressure of 0.3-3atm, carry out the heterogeneous catalysis dehydrogenating propane.Advantageously under heterogeneous catalysis, treat the propane of dehydrogenation in addition with diluted in hydrogen.For example, the thermal capacitance of water can compensate the endothermic effect of a part of dehydrogenation on the one hand, and the steam dilution has reduced reactant and product dividing potential drop on the other hand, and this equilibrium theory of tide to dehydrogenation has beneficial effect.As previously mentioned, use steam also the on-stream time of the dehydrogenation catalyst that contains precious metal to be had advantageous effect.If need, also molecular hydrogen can be added as another composition.The mol ratio of molecular hydrogen and propane generally≤5.Therefore, under low conversion of propane the mol ratio of hydrogen and propane can for 〉=0-30, advantageously 0.1-2, especially 0.5-1.The program of low conversion of propane only also proved advantageously in one way consume more a spot of heat during by reactor and lower temperature of reaction just is enough to realize the transformation efficiency of this one way by reactor.

Therefore, maybe advantageously carry out dehydrogenating propane with low conversion of propane (substantially) adiabaticly.This means the temperature (for example by its wall on every side of direct heating) that at first the initial action gaseous mixture is heated to 500-700 ℃ (or 550-650 ℃) usually.Usually, in order to realize required transformation efficiency, the one way thermal insulation is just enough by catalyst bed, and reaction gas mixtures about 30-200 ℃ (depending on transformation efficiency and extent of dilution) of cooling.Steam sees it also is significantly favourable as the existence of thermal barrier from the insulation method angle.Lower temperature of reaction allows the catalyst system therefor bed accessory that the longer on-stream time is arranged.

In principle, the heterogeneous catalysis dehydrogenating propane under low conversion of propane is that thermal insulation or isothermal carry out all can carrying out in fixed-bed reactor or moving-bed or fluidized-bed reactor.

Be,, especially implement that reaction gas mixtures single shaft furnace reactor axial and/or that radial flow is crossed wherein is enough as fixed-bed reactor significantly with adiabatic operation in order to implement the inventive method.

Under the simplest situation, this reactor is single capping volume, container for example, and its internal diameter is 0.1-10m, also is 0.5-5m if possible, and wherein stationary catalyst bed is applied on the bracing or strutting arrangement (for example barrier).Make the propane reactant gases axial flow that contains of heat cross and catalyzer is housed and with the adiabatic reaction volume of adiabatic operation.The catalyzer geometrical shape can be sphere or annular or bar shaped.Because reaction volume can realize that preferably all have the catalyzer geometrical shape of special low pressure drop by the equipment that is dirt cheap in this case.These especially cause big cavity volume or by structurized catalyzer geometrical shape, for example one-piece construction or honeycomb structure.In order to realize containing the radial flow of propane reactant gases, reactor for example can be made up of and catalyst bed can be arranged on annular space two concentric column grids that place shell.Under adiabatic condition, metal casing also is heat-insulating.

Can be used for catalyst charge that one way has the heterogeneous catalysis dehydrogenating propane under the low conversion of propane and especially be disclosed in catalyzer among the DE-A 199 37 107, particularly those disclosed for example.

After the operating time that prolongs, above-mentioned catalyzer can be regenerated by plain mode, for example by at first in first RS Regenerator Section, make (preferably) with the air of nitrogen and/or steam dilution at 300-600 ℃, be generally under 400-550 ℃ the temperature in and regenerate by catalyst bed.The gas hourly space velocity of regeneration gas for example can be 50-10000h ^-1And the oxygen level of regeneration gas can be 0.5-20 volume %.

In further RS Regenerator Section subsequently, the regeneration gas that identical in other respects regeneration condition uses down can be an air.From application point, advantageously before regeneration with rare gas element (N for example ₂) the flushing catalyzer.

Usually recommend subsequently with pure molecular hydrogen or with regenerating under the identical in other respects condition of the molecular hydrogen (hydrogen richness is answered 〉=1 volume %) of rare gas element (preferred steam) dilution.

In all cases, low conversion of propane (≤30mol%) down the heterogeneous catalysis dehydrogenating propane can with high conversion of propane (gas hourly space velocity that＞scheme under 30mol%) is identical (and for entire reaction gas be present in wherein propane for the two) under carry out.This gas hourly space velocity of reactant gases for example can be 100-10000h ^-1, be generally 300-5000h ^-1, promptly be about 500-3000h in many cases ^-1

In particularly advantageous mode, the heterogeneous catalysis dehydrogenating propane under the low conversion of propane can be implemented in the column plate reactor.

This reactor spatially comprises the catalyst bed of more than this dehydrogenation of catalysis successively.The catalyst bed number can be 1-20,2-8 advantageously, or be 3-6.Catalyst bed preferably is arranged in order diametrically or axially.From application point, advantageously in this column plate reactor, use fixed bed catalyst.

Under the simplest situation, the stationary catalyst bed axial array in the shaft furnace reactor or be arranged in the annular space of concentric column grid.Yet, can also one section be arranged in and arrange annular space on another section and make gas after radially by one section, send into another section on it or under it.

Advantageously reaction gas mixtures is carried out the centre heating at it in the process of another catalyst bed by a catalyst bed in the column plate reactor, for example by making this mixture by by the interchanger fin of hot gas heating or make it pass through pipeline by the hot combustion gas heating.

When this column plate reactor adiabatic operation, for required conversion of propane (≤30mol%), especially when using the catalyzer described in the DE-A 199 37 107, especially during those of exemplary, reaction gas mixtures is sent in the dehydrogenation reactor that is preheating to 450-550 ℃ and it is remained in this temperature range in this column plate reactor is enough.This means whole dehydrogenating propane so can realize under low-down temperature that this on-stream time to the fixed bed catalyst bed between twice regeneration is particularly advantageous.

Even more advantageously carry out the self-heating catalytic dehydrogenation, promptly for example carry out above-mentioned middle heating with direct mode (autothermal process).For this reason, before being flowed before reactive gas mixture current is crossed first catalyst bed and/or between ensuing catalyst bed, limited amount molecular oxygen adds in this reaction gas mixtures.Depend on used dehydrogenation catalyst, therefore be present in the hydrocarbon in the reaction gas mixtures, any limited burning that has been deposited on coke on the catalyst surface or coke shape compound and/or has formed in heterogeneous catalysis dehydrogenating propane process and/or add the hydrogen in the reaction mixture (is seen from application point and also maybe advantageously to be introduced the catalyst bed that specificity (selectivity) hydrogen catalyzed (and/or hydrocarbon) incendiary catalyzer is housed the column plate reactor (example of useful catalyzer comprises document US-A 4,788 371, US-A 4 886 928, US-A 5 430 209, US-A 5 530 171, those of US-A 5 527 979 and US-A 5 563 314; For example such catalyst bed can alternately be contained in the column plate reactor with the bed that contains dehydrogenation catalyst)).Therefore, the reaction heat of release allows with standard from the basic isothermal operation heterogeneous catalysis of hot mode dehydrogenating propane.The residence time of selecting in catalyst bed along with reactant gases increases, and therefore dehydrogenating propane is possible under temperature reduction or substantially constant, and this allows the on-stream time between the regeneration long especially.

Usually, aforesaid oxygen feeding should be carried out as follows, and the oxygen content of reaction gas mixtures is based on wherein contained propane and propylene amount are 0.5-30 volume %.Useful oxygen source comprises pure molecular oxygen and with rare gas element such as CO, CO ₂, N ₂Or the oxygen of rare gas dilution, but especially also has air.The gained combustion gases have extra dilution effect usually and therefore support the heterogeneous catalysis dehydrogenating propane.

The isothermal of heterogeneous catalysis dehydrogenating propane can further improve by (for example tubular type) internals of mixing sealing, and these internals advantageously but optionally be evacuated before the space between the catalyst bed in being filled in the column plate reactor.These internals can also place each catalyst bed.These internals contain suitable solid or liquid, and these solids or liquid evaporate on a certain temperature or melts, thus hectic fever, and drop to the condensation and therefore rejected heat once more when following of this value when temperature.

Another possibility method that the initial action gaseous mixture that will be used for the heterogeneous catalysis dehydrogenating propane is heated to desired reaction temperature relate to by molecular oxygen (for example at suitable specific combustioncatalysts, for example by simply on catalyzer and/or in the catalyzer by) a burning part is present in propane and/or hydrogen wherein and is heated to desired reaction temperature by the combustion heat that discharges in this way.Gained products of combustion such as CO ₂And H ₂O and also have any N that follows burning desired molecule oxygen ₂Advantageously constitute inert dilution gas.

Above-mentioned combustion of hydrogen can be particularly advantageously as enforcement as described in the DE-A 10211275.This be a kind of under heterogeneous catalysis in gas phase in the following way to the method for propane sequential portion dehydrogenation:

To contain and remain the reactant gases of dehydrogenation propane and infeed reaction zone continuously,

In this reaction zone, reactant gases is drawn at least one stationary catalyst bed, thereon by catalytic dehydrogenation formation molecular hydrogen with to small part formation propylene,

Before reactant gases enters reaction zone and/or afterwards the gas with at least a molecule-containing keto adds in the reactant gases,

In reaction zone with the molecular hydrogen that exists in the molecular oxygen partial oxidation reaction gas, obtain steam and

From reaction zone, take out the product gas that comprises molecular hydrogen, steam, propylene and propane, this method comprises that the product gas that will take out is divided into the two portions with same composition from reaction zone, one of these two portions are recycled to dehydrogenation reaction zone and further another part are used as gaseous mixture 1 according to the present invention.

This process program is especially when comprising propane and optional propylene and (can choosing wantonly and carry out secondary component and remove (C for example from the sectional recycle gas of at least one ₄Hydrocarbon such as butene-1)) be preferred when introducing in the dehydrogenation zone as other propane source except thick propane.Especially like this really when recycle gas constitutes hydrogen burning in this process program with unique oxygen source.

The product gas mixture that forms in the heterogeneous catalysis dehydrogenating propane of the inventive method comprises propane, propylene, molecular hydrogen, N usually ₂, H ₂O, methane, ethane, ethene, butene-1, other butylene and other C ₄Hydrocarbon (normal butane, Trimethylmethane, divinyl etc.), CO and CO ₂Its pressure is generally 0.3-10atm and temperature is generally 400-500 ℃, is 450-500 ℃ under favourable situation.

Although EP-A 117 146, DE-A 3 313 573 and US-A 3 161 670 recommends directly to use the product gas mixture (gaseous mixture 1) that forms to be fed in raw material at least one part district, advantageously be further used at least one part district from the product gas mixture (gaseous mixture 1) of oxydehydrogenation and/or dehydrogenation, removing any C that is present in wherein of at least a portion before reinforced usually according to the present invention in the heterogeneous catalysis dehydrogenating propane ₄Hydrocarbon (as normal butane, Trimethylmethane, butene-1, other butylene, divinyl etc.).When gaseous mixture 1 contained hydrogen, above-mentioned separation can follow the part of this hydrogen to remove at least or this hydrogen is removed and can be carried out in advance.

For example the latter can be undertaken by film after the cooling at indirect heat exchanger (advantageously the heat that will remove is used for heating the required feed gas of the inventive method) in advance by gaseous mixture 1 is chosen wantonly at it, and this film is generally configured to pipe and only sees through molecular hydrogen.The molecular hydrogen of removing in this way is if the words that need can partly be recycled in the heterogeneous catalysis dehydrogenation of propane or infeed during other use.For example, can in fuel cell, burn.

Perhaps, hydrogen is partially or completely removed also and can be undertaken by partial condensation, absorption and/or rectifying (preferably add depress).Partially or completely removing molecular hydrogen in the product gas mixture from the inventive method (gaseous mixture 1) also can be undertaken by make its selectivity (for example heterogeneous catalysis) burning with molecular oxygen.The reaction water that forms can partially or completely remove or stay in the gaseous mixture, because it can be used as inert dilution gas at least one part district.The catalyzer that is suitable for this respect for example is disclosed among US-A 4 788 371, US-A 4 886 928, US-A 5 430 209, US-A 5530171, US-A 5 527 979 and the US-A 5 563 314.

The selective combustion of molecular hydrogen can also be carried out in the heterogeneous catalysis certain embodiments as soon as possible effectively on the spot, and for example oxidation by being undertaken by the reducible metal oxide at least a extra adding dehydrogenation catalyst is for example as described in the EP-A 832056.

Advantageously, according to the present invention, at least 10mol%, or 25mol% at least, usually 35mol% at least, or 50mol% at least, in many cases at least 75mol% and usually whole molecular hydrogens that in the heterogeneous catalysis dehydrogenation, forms remove in advance and/or simultaneously, then remaining gaseous mixture (gaseous mixture 1 ') is used at least one part district reinforced.If need, can before it is further used at least one part district, from gaseous mixture 1, remove the water (for example condensation goes out this water) of any existence.The words that it should be understood that needs can also removed molecular hydrogen and/or C ₄Remove propane and propylene other compositions in addition in the product gas mixture (gaseous mixture 1) when hydrocarbon such as butene-1 etc.

The example that is used for this simple measures of removing relates to the gaseous mixture 1 that makes preferred cooling (preferably arriving 10-70 ℃ temperature) and contact (for example by passing through wherein simply) with (preferred high boiling point) organic solvent (preferred hydrophobicity) of wherein propane and propylene preferentially adsorbed, and this contact is for example carried out under the temperature of the pressure of 0.1-50atm and 0-100 ℃.Desorb subsequently, rectifying and/or stripping (use at least one part district is inertia and/or is required gas (for example air) as reactant in this reaction zone) reclaim the mixture of propane and propylene with the purification form, this mixture can be used at least one part district reinforced (as already mentioned, under with the steam stripped situation of air, the gaseous mixture 1 ' that produces can be identical with gaseous mixture 2, promptly can be directly used at least one part district reinforced immediately).Any absorption waste gas that contains molecular hydrogen for example can carry out membrane sepn and need subsequently the hydrogen of removing being used for the heterogeneous catalysis dehydrogenating propane once more.

Yet, the C in the above-mentioned separation method ₃Hydrocarbon/C ₄The hydrocarbon separation factor is comparatively limited and not enough usually to requirement of the present invention.

Therefore, to preferred alternative via the separating step that absorbs described in the invention normally transformation absorption or compression rectification.

Can be used for the absorption agent that above-mentioned absorption removes is any absorption agent that can absorb propane and propylene in principle.This absorption agent is preferably and preferably is hydrophobicity and/or high boiling organic solvent.Advantageously, the boiling point of this solvent (under the barometric point of 1atm) is at least 120 ℃, preferably at least 180 ℃, and more preferably 200-350 ℃, especially 250-300 ℃, greatly preferably 260-290 ℃.Advantageously, flash-point (under the barometric point of 1atm) is higher than 110 ℃.Usually, useful absorption agent comprises nonpolar relatively organic solvent, and is for example preferred not with the aliphatic hydrocrbon and the aromatic hydrocarbon of exterior active polar group.Usually, wish that absorption agent has very high boiling point and simultaneously propane and propylene had very high solubleness.The example of useful absorption agent comprises aliphatic hydrocrbon, for example C ₈-C ₂₀Alkane or alkene; Or aromatic hydrocarbon, for example middle runnings of paraffinic hydrocarbons distillatory; Or on Sauerstoffatom, have ethers or its mixture of huge (space requirement) group, and can be to wherein adding polar solvent, disclosed dimethyl phthalate among the DE-A 43 08 087 for example.Other suitable absorption agents comprise phenylformic acid and phthalic acid and contain the ester of the straight chain alkanol of 1-8 carbon atom, as the phenylformic acid n-butyl, methyl benzoate, ethyl benzoate, dimethyl phthalate and diethyl phthalate, and heat medium oil such as biphenyl, the mixture of phenyl ether and biphenyl and phenyl ether or its chlorine derivative, also have 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.Useful absorption agent is biphenyl and phenyl ether, preferably has the solvent mixture that azeotropic is formed, the mixture of especially about 25 weight % biphenyl and about 75 weight % phenyl ether, for example commercially available Diphyl ^(for example obtaining) by Bayer Aktiengesellschaft.Usually, this solvent mixture comprises solvent such as the dimethyl phthalate of 0.1-25 weight % based on whole solvent mixture.Useful especially absorption agent also comprises octane, nonane, decane, undecane, dodecane, tridecane, the tetradecane, pentadecane, n-Hexadecane, heptadecane and octadecane, and verified useful especially be the tetradecane.Advantageously used absorption agent has above-mentioned boiling point on the one hand and does not have too high molecular weight on the other hand simultaneously.Molecular weight≤the 300g/mol of absorption agent advantageously.Same suitable is the paraffin oil that has 8-10 carbon atom described in the DE-A 33 13 573.The example of useful commodity comprises the product sold by Haltermann, comprises Halpasols i, for example Halpasol 250/340i and Halpasol 250/275i, and the printing ink distillment of selling with PKWF and Printosol.The preferred not commodity of aromatic-containing compound, for example those of PKWFaf type.

To the carrying out that absorb without any particular restriction.Can use all method well known to those skilled in the art and conditions.Gaseous mixture and absorption agent are clung at 1-50, preferred 2-20 crust, more preferably the pressure of 5-10 crust and 0-100 ℃ especially contact under 30-50 ℃ the temperature.Absorption can be carried out in tower or in chilled equipment.Can and flow or counter-current operation.The example on useful absorption tower comprises tray column (having bubble cap plate and/or sieve plate), (for example specific surface area is 100-1000m to have structured packing ²/ m ³, or 100-750m ²/ m ³The sheet metal filler, Mellapak for example ^Tower 250Y) and random packed tower (for example with drawing western random packing to fill).Can also use spray column and spray tower, graphite coarse fodder resorber, surface absorber such as thick film and film absorption device and board-like scrubber, cross spray scrubber and rotary scrubber.Also maybe advantageously in bubble-plate column, absorb with or without internals.

Propane and/or propylene can be removed from absorption agent by stripping, decompression-evaporation (flash distillation) and/or distillation.

Propane and propylene are preferably removed from absorption agent by stripping and/or desorb.Desorb can be in a usual manner be undertaken by changing pressure and/or temperature, preferably at the 0.1-10 crust, and 1-5 crust especially, more preferably the pressure of 1-3 crust and 0-200 ℃, more preferably 30-70 ℃, carry out under preferred 40-60 ℃ the temperature especially by especially 20-100 ℃.Being suitable for steam stripped examples of gases is steam, but especially preferred oxygen/nitrogen mixture, for example air.When using oxygen content wherein to surpass the air or oxygen of 10 volume %/nitrogen mixture, may be suitable be before the gas stripping process or among add the gas that reduces explosive range.The specific heat capacity that is particularly suitable for this gas at 20 ℃ is down 〉=29J/molK, for example methane, ethane, propane, propylene, benzene, methyl alcohol, ethanol and ammonia, carbonic acid gas and water.Yet, to avoid C as examples of such additives according to the present invention ₄Hydrocarbon.Be particularly suitable for that steam stripped equipment also comprises band and not with the bubble-plate column of internals.

Propane and propylene can also by distillation or rectifying be removed from absorption agent and used tower can be that those skilled in the art know and have those of structured packing, random packing or suitable internals.Preferred condition is that pressure is that 0.01-5 crust, especially 0.1-4 cling in distillation or rectifying, and more preferably 1-3 crust, and temperature (in the bottom) is 50-300 ℃, especially 150-250 ℃.

Be used at least one part district reinforced before; the gaseous mixture 1 ' that obtains by stripping from absorption agent can infeed in another process section; for example also protect this at least one part district simultaneously, or further improve C in case damaged by absorption agent to reduce the loss (for example in scum dredger and/or deep filter, separating) of steam stripped absorption agent simultaneously ₃Hydrocarbon/C ₄Centrifugation between the hydrocarbon.This of absorption agent removed and can be undertaken by the known processing step of any those skilled in the art.The example that is used for this preferred embodiment of removing of the inventive method is that water is from the initial materials flow of stripping apparatus quenching.This moment, water washed absorption agent to come out and simultaneously with this initial materials flow of water load from the initial materials flow of this load.This washing or quenching for example can be used the liquid collecting column plate to carry out at the desorption tower top by reverse spray water or carry out in its oneself equipment.

In order to support separating effect, the internals of those skilled in the art by rectifying, the known increase quenching of absorption and desorption surface-area can be installed in the quenching space.

Water is preferred washing medium, because it does not disturb at least one part district subsequently usually.After water has absorption agent the initial materials flow of propane and propylene from load, washing out, water/absorber blend can be infeeded be separated in and the initial materials flow of handling can be infeeded in this part district as gaseous mixture 1 '.

Stripping is to remove C ₃Absorption agent and the absorption agent that in being separated, reclaims all can be used further to absorb.

Consequent gaseous mixture 1 and/or gaseous mixture 1 ' can be used at least one other reaction zone in a manner known way with reinforced to the heterogeneous catalysis gaseous oxidation and/or the ammonia oxidation of propenal and/or vinylformic acid and/or vinyl cyanide with 2 pairs of propylene of feed gas mixtures then.Used oxygenant can be pure molecular oxygen, air, be rich in the air of oxygen or other mixtures of any oxygen and rare gas element.When partial oxidation when being propylene to the conversion of propylene oxide, this program for example can be as described in the EP-A372972.

When partial oxidation was part ammonia oxidation to vinyl cyanide, this program for example can be the program of DE-A2351151.Arrive under propenal and/or the acrylic acid partial oxidation situation at propylene, when going back using gas mixture 1 and/or 1 ' (also can use the mixture of the two, promptly from a part and from another part, do not remove) composition of gaseous mixture 2 regulates in the mode that satisfies following mol ratio in the methods of the invention:

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

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

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

As already mentioned, use molecular oxygen that the propylene heterogeneous catalyzed gas phase partial oxidation is carried out along reaction coordinate in two successive steps to vinylformic acid, wherein at first obtain propenal, obtain vinylformic acid by propenal then.

This reaction sequence in two consecutive steps that stagger has in time been started in this case and implemented the sectional possibility of at least one of the inventive method in a manner known way in the oxidation zone of two arranged in series, and can optimize the oxide catalyst that is ready to use in each (two) oxidation zone.For example, for 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 preferably based on the catalyzer of the poly-metal deoxide that contains element combinations Mo-V usually for second oxidation zone (propenal → vinylformic acid).

Be used for that the corresponding multi-metal-oxide catalyst of two oxidation zones is former have been described many times and be well-known to those skilled in the art.For example, EP-A 253 409 has quoted suitable US patent at page 5.

Also open to two oxidation zone advantageous catalysts by DE-A 4 431 957 and DE-A 4431949.This especially is applied to the two formula of I of above-mentioned document those.

For the partial oxidation of the first step, promptly heterogeneous catalyzed gas phase partial oxidation or propylene are to the oxidation of propenal, and useful catalysts is all multimetal oxide compositions that contain Mo, Bi and Fe as previously mentioned in principle.

These catalyzer are the poly-metal deoxide active composition of the general formula I of DE-A 19955176 especially, the poly-metal deoxide active composition of the general formula I of DE-A 19948523, the poly-metal deoxide active composition of the general formula I of DE-A 10101695, II and III, the poly-metal deoxide active composition of the poly-metal deoxide active composition of the general formula I of DE-A 19948248, II and III and general formula I, II and the III of DE-A 19955168, the multimetal oxide compositions of in EP-A 700714, mentioning in addition.

Other catalyzer that are suitable for this oxidation step are the multi-metal-oxide catalysts that contain Mo, Bi and Fe, and they are disclosed in the following document: 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 general formula I I), JP-A 91/294239, EP-A 293224 and EP-A 700714.Especially for the exemplary in these documents really so, and those of wherein preferred especially EP-A 15565, EP-A 575897, DE-A 19746210 and DE-A 19855913.Thus, be stressed that especially EP-A 15565 embodiment 1c catalyzer and will be with the catalyzer of corresponded manner preparation, but its active composition have consist of Mo ₁₂Ni _6.5Zn ₂Fe ₂Bi ₁P _0.0065K _0.06O _x10SiO ₂Be stressed that also (stoichiometric equation is Mo for embodiment 3 among the DE-A 19855913 ₁₂Co ₇Fe ₃Bi _0.6K _0.08Si _1.6O _x), it is the not load hollow circuit cylinder body catalyst of 5mm * 3mm * 2mm (external diameter * highly * internal diameter) for geometrical dimension, and the poly-metal deoxide II of the embodiment 1 of DE-A 19746210 supported catalyst not.Also should mention the multi-metal-oxide catalyst of US-A 4438217, especially the geometrical dimension that has when these hollow circular cylinders is 5.5mm * 3mm * 3.5mm, or 5mm * 2mm * 2mm, or 5mm * 3mm * 2mm, or 6mm * 3mm * 3mm, or 7mm * 3mm * 4mm (external diameter of respectively doing for oneself * highly * internal diameter) time.

The multiple propylene that is suitable for can be included in the general formula I V to the poly-metal deoxide active composition of this step of propenal:

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

Wherein each variable is as giving a definition:

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＝0.5-5，

B=0.01-5, preferred 2-4,

C=0-10, preferred 3-10,

D=0-2, preferred 0.02-2,

E=0-8, preferred 0-5,

F=0-10 and

N=is by the valency of the element beyond the oxygen in (IV) and the number of occurrence rate decision.

They can obtain (for example referring to DE-A 4023239) in a known way and be shaped to ball, ring or right cylinder with undiluted form usually or use with the coating catalyst form, promptly use with the premolding inert support that is coated with active composition.Be understood that they can also be used as catalyzer by powder type.

In principle, the active composition of general formula I V can plain mode obtains very even corresponding to its stoichiometric equation by the suitable source by its elemental composition, and drying composite preferred in small, broken bits also prepares it at 350-650 ℃ temperature lower calcination.Calcining can be under rare gas element or under oxidizing atmosphere, air (mixture of rare gas element and oxygen) for example, or at reducing atmosphere (for example rare gas element, NH ₃, CO and/or H ₂Mixture) under carry out.Calcination time can for several minutes to several hours and reduce with temperature usually.The useful source of the elemental composition of multimetal oxide compositions IV is for those compounds of oxide compound and/or by heat those compounds that can change into oxide compound at least in the presence of oxygen.

Except oxide compound, the useful initial compounds of this class especially halogenide, nitrate, formate, oxalate, Citrate trianion, acetate, carbonate, amine complex, ammonium salt and/or oxyhydroxide (can additionally mix such as NH in uniform drying composite ₄OH, (NH ₄) ₂CO ₃, NH ₄NO ₃, NH ₄CHO ₂, CH ₃COOH, NH ₄CH ₃CO ₂And/or the compound of ammonium oxalate, they resolve into the compound that discharges and/or decompose with gaseous form at the latest when calcining subsequently).

The uniform mixing that is used to prepare the initial compounds of poly-metal deoxide active composition IV can carry out with dry state or hygrometric state.When carrying out with dry state, initial compounds advantageously uses with fine-powder and calcines after mixing and choosing compression wantonly.Yet uniform mixing preferably carries out with hygrometric state.Usually with the aqueous solution and/or form of suspension initial compounds is mixed mutually.When raw material during, in described blending means, obtain drying composite especially uniformly only for the source of the elemental composition that exists with solubilized form.Solvent for use is preferably water.Dry then gained aqueous composition and drying means are preferably undertaken by spraying drying aqueous mixture under 100-150 ℃ temperature out.

The poly-metal deoxide active composition of general formula I V can powder type or be shaped to certain catalyzer geometrical shape after be used for " propylene → propenal " this step, and moulding can be carried out before or after final calcining.For example, the catalyzer of load can by the active composition of powder type or it is not calcined and/or part incinerating precursor composition prepares in the following way: be compressed into required catalyzer geometrical shape (for example by film-making or extrude), the optional auxiliary agent such as graphite or stearic acid of adding is as lubricant and/or shaping assistant, and the primitive fiber of toughener such as glass, asbestos, silicon carbide or potassium titanate.The example of suitable not supported catalyst geometrical shape comprises that external diameter and length are solid cylinder or the hollow circular cylinder of 2-10mm.Under the hollow circular cylinder situation, wall thickness is that 1-3mm is favourable.The catalyzer that is understood that not load can also have spherical geometries and spherical diameter can be 2-10mm.

Particularly advantageous hollow circular cylinder geometrical shape is 5mm * 3mm * 2mm (external diameter * length * internal diameter), especially under supported catalyst situation not.

The moulding that is understood that as yet not calcining and/or part incinerating powder activity composition or its powder precursor composition also can be undertaken by putting on the preformed inert catalyst carrier.The coating of carrier of preparation coating catalyst is carried out in suitable rotary container usually, for example as DE-A 2909671, EP-A 293859 or EP-A 714700 are disclosed.In order to apply carrier, advantageously wetting powder composition to be administered and after using after drying, for example by hot-air dry.The coat-thickness that is applied to the powder composition on the carrier advantageously is chosen as 10-1000 μ m, preferred 50-500 μ m, more preferably 150-250 μ m.

The used carrier material can be conventional porous or non-porous aluminas, silicon-dioxide, thorium dioxide, zirconium dioxide, silicon carbide or silicate such as Magnesium Silicate q-agent or pure aluminium silicate.They are inertia substantially to the goal response of carrying out under the inventive method usually.Carrier can have rule or irregularly shaped, but preferably has the carrier of the regular moulding of obvious surfaceness, for example ball or hollow circular cylinder.The carrier that be fit to use comprises the ball type carrier of basic atresia, and it has surfaceness and is 1-8mm by diameter, and the talcum of preferred 4-5mm is made.Yet to be length be 2-10mm and the external diameter right cylinder as 4-10mm to other carriers that are fit to use.In addition, ring be suitable as according to the present invention carrier situation under, wall thickness is generally 1-4mm.Annular carrier preferably used according to the invention has the length of 2-6mm, the external diameter of 4-8mm and the wall thickness of 1-2mm.According to the present invention suitable carriers especially geometrical dimension be the ring of 7mm * 3mm * 4mm (external diameter * length * internal diameter).Be understood that the fineness and the required coat-thickness coupling (referring to EP-A 714 700) of the catalytic activity oxide composition on carrier surface to be administered.

Being used for propylene still is the composition of general formula V to the poly-metal deoxide active composition of this step of propenal:

[Y ¹ _a’Y ² _b’O _x’] _p[Y ³ _c’Y ⁴ _d’Y ⁵ _e’Y ⁶ _f’Y ⁷ _g’Y ² _h’O _y’] _q (V)

Wherein each variable is as giving a definition:

Y ¹=only be bismuth or at least a in bismuth and elemental 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 metal, titanium, zirconium, niobium, tantalum, rhenium, ruthenium, rhodium, silver, gold, aluminium, gallium, indium, silicon, germanium, lead, thorium and/or uranium,

a’＝0.01-8，

b’＝0.1-30，

c’＝0-4，

d’＝0-20，

e’＞0-20，

f’＝0-6，

g’＝0-15，

h’＝8-16，

X ', the number of y '=determined by the valency and the occurrence rate of the element beyond the oxygen among the V, and p, its P/q of q=be than being the number of 0.1-10,

Comprise and have chemical constitution Y ¹ _{A '}Y ² _{B '}O _{X '}3D region, described zone is different from because of its composition that local environment is demarcated by local environment and its maximum diameter (being present between 2 on the surface (interface) in this zone and the longest distance by this regional center) is 1nm-100 μ m, is generally 10nm-500nm or 1 μ m-50 or 25 μ m.

Particularly advantageous multimetal oxide compositions V is Y wherein according to the present invention ¹Only be those of bismuth.

Wherein again preferably corresponding to those of general formula VI:

[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 is as giving a definition:

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”＝0.1-1，

b”＝0.2-2，

c”＝3-10，

d”＝0.02-2，

E "=0.01-5, preferred 0.1-3,

f”＝0-5，

g”＝0-10，

h”＝0-1，

X ", y "=number determined by the valency and the occurrence rate of the element beyond the oxygen among the VI,

P ", q "=its p "/q " than for 0.1-5, the number of preferred 0.5-2,

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

Be suitable for [the Y of whole ratios among the multimetal oxide compositions V of the present invention (multimetal oxide compositions VI) also advantageously ¹ _{A '}Y ² _{B '}O _{X '}] _p([Bi _{A "}Z ² _{B "}O _{X "}] _{P "}) in 25mol% (preferably 50mol% and more preferably 100mol% at least at least) is arranged at least to have chemical constitution Y ¹ _{A '}Y ² _{B '}O _{X '}[Bi _{A "}Z ² _{B "}O _{X "}] the form of 3D region be present in multimetal oxide compositions V (multimetal oxide compositions VI), local environment is demarcated by its local environment and its maximum diameter is 1nm-100 μ m because of its chemical constitution is different from described zone.

For moulding, the situation of multimetal oxide compositions V catalyzer is with described identical to multimetal oxide compositions IV catalyzer.

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

In other materials, above the inert support material recommended also be to be used to dilute and/or to divide the useful inert material of suitable stationary catalyst bed or as the upstream bed of protection they and/or heated air mixture.

It is to be noted in this that all recommendations are applicable to by propylene also is applicable to the part ammonia oxidation of propylene to vinyl cyanide in principle to the catalyzer and the multimetal oxide compositions of this step of propenal.

For second step, promptly propenal is to acrylic acid heterogeneous catalyzed gas phase partial oxidation, and useful active composition is all multimetal oxide compositions that contain Mo and V, for example those of DE-A 10046928 as mentioned above in principle.

Multiple these compositions, those of DE-A 19815281 for example can be comprised by general formula VII:

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

Wherein each variable is as giving a definition:

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＝1-6，

b＝0.2-4，

c＝0.5-18，

d＝0-40，

e＝0-2，

f＝0-4，

G=0-40 and

The number that n=is determined by the valency and the occurrence rate of the element beyond the oxygen among the VI.

Embodiment preferred is by included those of the following definition of each variable of general formula VII in active poly-metal deoxide VII according to the present 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＝1.5-5，

b＝0.5-2，

c＝0.5-3，

d＝0-2，

e＝0-0.2，

F=0-1 and

The number that n=is determined by the valency and the occurrence rate of the element beyond the oxygen among the VII.

Yet very particularly preferably poly-metal deoxide VII is those of general 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’＝2-4，

b’＝1-1.5，

c’＝1-3，

f’＝0-0.5

G '=0-8 and

The number of n '=determine by the valency and the occurrence rate of the element beyond the oxygen among the VIII.

Suitable poly-metal deoxide active composition (VII) can known method itself obtain according to the present invention, for example as DE-A 4335973 or EP-A 714700 are disclosed.

In principle, be suitable for the poly-metal deoxide active composition of step " propenal → vinylformic acid ", especially those of general formula VII, can obtain very even corresponding to its stoichiometric equation by the suitable source by its elemental composition with plain mode, drying composite preferred in small, broken bits also prepares it at 350-600 ℃ temperature lower calcination.Calcining can be under rare gas element or under oxidizing atmosphere such as the air (mixture of rare gas element and oxygen), or at reducing atmosphere (for example rare gas element and reducing gas such as H ₂, NH ₃, CO, methane and/or propenal mixture or above-mentioned reducing gas itself) under carry out.Calcination time can for several minutes by several hours and reduce with temperature usually.The suitable source of the elemental composition of multimetal oxide compositions VII be for those compounds of oxide compound and/or can by at least in the presence of oxygen heating change into those compounds of oxide compound.

The uniform mixing that is used to prepare the initial compounds of multimetal oxide compositions VII can carry out with dry state or hygrometric state.When carrying out with dry state, initial compounds advantageously uses with fine-powder and after mixing and choosing compression wantonly, calcines.Yet uniform mixing preferably carries out with hygrometric state.

Usually with the aqueous solution and/or form of suspension initial compounds is mixed mutually.When raw material during, in described blending means, obtain drying composite especially uniformly only for the source of the elemental composition that exists with solubilized form.Solvent for use is preferably water.Dry then gained aqueous composition and drying means are preferably undertaken by spraying drying aqueous mixture under 100-150 ℃ temperature out.

Gained multimetal oxide compositions, especially those of general formula VII, can powder type or be shaped to certain catalyzer geometrical shape after be used for acrolein oxidation, and moulding can be carried out before or after final calcining.For example, not the catalyzer of load can by the active composition of powder type or its not the calcined precursors composition prepare in the following way: be compressed into required catalyzer geometrical shape (for example by film-making or extrude), the optional auxiliary agent such as graphite or stearic acid of adding is as lubricant and/or shaping assistant, and the primitive fiber of toughener such as glass, asbestos, silicon carbide or potassium titanate.The example of suitable not supported catalyst geometrical shape comprises that external diameter and length are solid cylinder or the hollow circular cylinder of 2-10mm.Under the hollow circular cylinder situation, wall thickness is that 1-3mm is favourable.The catalyzer that is understood that not load can also have spherical geometries and spherical diameter can be 2-10mm.

Be understood that as yet the moulding of incinerating powder activity composition or its powder precursor composition can not undertaken by putting on the preformed inert catalyst carrier yet.The carrier coating of preparation coating catalyst is carried out in suitable rotary container usually, for example as DE-A 2909671, EP-A 293859 or EP-A 714700 are disclosed.

In order to apply carrier, advantageously wetting powder composition to be administered and after using after drying, for example by hot-air dry.The coat-thickness that is applied to the powder composition on the carrier advantageously is chosen as 10-1000 μ m, preferred 50-500 μ m, more preferably 150-250 μ m.

The used carrier material can be conventional porous or non-porous aluminas, silicon-dioxide, thorium dioxide, zirconium dioxide, silicon carbide or silicate such as Magnesium Silicate q-agent or pure aluminium silicate.Carrier can have rule or irregularly shaped, but preferably has the carrier of the regular moulding of obvious surfaceness, for example has the ball or the hollow circular cylinder of coarse sands layer.The carrier that be fit to use comprises the ball type carrier of basic atresia, and it has surfaceness and is 1-8mm by diameter, and the talcum of preferred 4-5mm is made.Yet to be length be 2-10mm and the external diameter right cylinder as 4-10mm to other carriers that are fit to use.In addition, under the situation as the ring of carrier, wall thickness is generally 1-4mm.Preferred annular carrier to be used has the length of 2-6mm, the external diameter of 4-8mm and the wall thickness of 1-2mm.Suitable carriers especially geometrical dimension is the ring of 7mm * 3mm * 4mm (external diameter * length * internal diameter).Be understood that the fineness and the required coat-thickness coupling (referring to EP-A 714 700) of the catalytic activity oxide composition on carrier surface to be administered.

The favourable poly-metal deoxide active composition that is ready to use in step " propenal → vinylformic acid " also has the composition of general formula I X:

[D] _p[E] _q (IX)

Wherein each variable is as giving a definition:

D＝Mo ₁₂V _a”Z ¹ _b”Z ² _c”Z ³ _d”Z ⁴ _e”Z ⁵ _f“Z 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”＝1-8，

b”＝0.2-5，

c”＝0-23，

d”＝0-50，

e”＝0-2，

f”＝0-5，

g”＝0-50，

h”＝4-30，

I "=0-20 and

X ", y "=number determined by the valency and the occurrence rate of the element beyond the oxygen among the IX and

Number beyond the p, q=0, its p/q ratio is 160: 1-1: 1,

And said composition can obtain in the following way: the multimetal oxide compositions E (starting composition 1) that forms form in small, broken bits at first separately:

Z ⁷ ₁₂Cu _{H "}H _{I "}O _{Y "}The solid starting composition 1 that (E) will at first form then with required p: q than doping element Mo, V, Z ¹, Z ², Z ³, Z ⁴, Z ⁵And Z ⁶The aqueous solution, aq suspension or drying composite in small, broken bits in source in, its each self-contained stoichiometric equation is the above-mentioned element of D (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)

The dry gained aqueous mixture of suitable words, and the dried precursor composition that before or after being shaped to required catalyzer geometrical shape, obtains in this way 250-600 ℃ of following calcining.

The preferred solid starting composition 1 that wherein will at first form under≤70 ℃ temperature mixes the multimetal oxide compositions IX of moisture starting composition 2.The detailed description of multimetal oxide compositions VI Preparation of catalysts for example is included among EP-A 668104, DE-A 19736105, DE-A 10046928, DE-A 19740493 and the DE-A 19528646.

For moulding, the situation of poly-metal deoxide IX catalyzer is with described identical to multimetal oxide compositions VII catalyzer.

The multi-metal-oxide catalyst that is particularly suited for step " propenal → vinylformic acid " still is those of DE-A19815281, especially has those of poly-metal deoxide active composition of the general formula I of the document.

Advantageously the catalyst rings of load is not used for propylene and is used for propenal to this step of vinylformic acid to this step of propenal and with the catalyst rings that applies.

The first step of partial oxidation, promptly propylene can use the catalyzer described in a plurality of catalyst tube fixed-bed reactor in for example single district to carry out, as described in DE-A 4431957 to propenal.

Used oxygenant is an oxygen.When with N ₂When being chosen as inert dilution gas, air is proved particularly advantageous as oxygen source.

Usually, at propylene: oxygen: rare gas element (comprising steam) volume (L (STP)) is than being 1: (1.0-3.0): (5-25), and preferred 1: (1.7-2.3): operate (10-15).Reaction pressure is generally the 1-3 crust and whole gas hourly space velocity is preferably 1500-4000L (STP)/(Lh).The propylene gas hourly space velocity is generally 90-200L (STP)/(Lh).

Feed gas mixtures is preferably from a plurality of catalyst tube fixed-bed reactor in the single district of top inflow.Used heat exchange medium is salt-melting advantageously, preferably by 60 weight % saltpetre (KNO ₃) and 40 weight % Sodium Nitrite (NaNO ₂) form or by 53 weight % saltpetre (KNO ₃), 40 weight % Sodium Nitrite (NaNO ₂) and 7 weight % SODIUMNITRATE (NaNO ₃) form.

See that on reactor salt-melting and reaction gas mixtures can and flow or adverse current transmits.Salt-melting itself preferably transmits around catalyst tube in tortuous mode.

When from the top to the bottom, flowing through catalyst tube, advantageously press following to catalyst tube reinforced from bottom to top (when flowing from bottom to top) advantageously with the order of addition(of ingredients) counter-rotating:

At first only be dosed to the 40-60% length place of catalyst tube length with catalyzer or with the mixture of catalyzer and inert material, the weight ratio of inert material is based on the 20 weight % (C section) at the most of being of this mixture under the mixture situation;

The then mixture of only reinforced catalyzer or reinforced catalyzer and inert material on the 20-40% of whole length of tube length, the weight ratio of inert material is 40 weight % (B section) at the most based on this mixture under the mixture situation; With

The last inert material bed (A section) that feeds in raw material on the 10-20% of whole length of tube length, this selection should make the pressure drop that causes very low.

Preferred C section is undiluted.

Above-mentioned reinforced scheme is that those and the used inert material of embodiment 3 of the embodiment 1 of DE-A 10046957 or DE-A 10046957 is favourable during for the talcum ring of geometrical dimension with 7mm * 7mm * 4mm (external diameter * highly * internal diameter) at catalyst system therefor especially.For salt temperature, identical with described in the DE-A 4431957.

Yet, the first step of partial oxidation, promptly propylene for example also can use and carry out at the catalyzer described in a plurality of catalyst tube fixed-bed reactor in two-region, as described in DE-A 19910506 to propenal.In the above two kinds of cases, the propylene conversion that one way obtains usually 〉=90mol%, or 〉=95mol%.In second step of partial oxidation, promptly propenal for example can use and carry out at the catalyzer described in a plurality of catalyst tube fixed-bed reactor in single district, as described in DE-A 4431949 to vinylformic acid.Usually, propylene oxidation becomes the product mixtures direct (choosing wantonly after the intercooling of finishing this mixture) of propenal to be sent to acrolein oxidation and becomes acrylic acid step, does not promptly carry out removing of secondary component.

Required oxygen preferably added and directly added usually in the product gas mixture of propylene oxidation with air second step of partial oxidation.

Usually, the feed gas mixtures of this acrolein oxidation has following composition: propenal: oxygen: steam: rare gas element volume ratio (L (STP)) is 1: (1-3): (0-20): (3-30), be preferably 1: (1-3): (0.5-10): (7-18).

The reaction pressure of this moment is also clung to for 1-3 usually and whole gas hourly space velocity is preferably 1000-3800 L (STP)/(Lh).The propenal gas hourly space velocity is generally 80-190 L (STP)/(Lh).

Feed gas mixtures is preferably equally from a plurality of catalyst tube fixed-bed reactor in the single district of top inflow.The heat exchange medium that uses in second step advantageously also is salt-melting, preferably by 60 weight % saltpetre (KNO ₃) and 40 weight % Sodium Nitrite (NaNO ₂) form or by 53 weight % saltpetre (KNO ₃), 40 weight % Sodium Nitrite (NaNO ₂) and 7 weight % SODIUMNITRATE (NaNO ₃) form.See that on reactor salt-melting and reaction gas mixtures can and flow or adverse current transmits.Salt-melting itself preferably transmits around catalyst tube in tortuous mode.

When from the top to the bottom, flowing through catalyst tube, advantageously by following reinforced from bottom to top to catalyst tube:

At first only be dosed to the 50-70% length place of catalyst tube length with catalyzer or with the mixture of catalyzer and inert material, the weight ratio of inert material is 20 weight % (C section) at the most based on this mixture under the mixture situation;

The last inert material bed (A section) that feeds in raw material on the 5-20% of whole length of tube length, this selection should make the pressure drop that causes very low.

Preferred C section is undiluted.

When flowing through catalyst tube from bottom to top, advantageously with the reinforced counter-rotating of catalyst tube.

Above-mentioned reinforced scheme is that those and the inert material of those or DE-A 19815281 of preparation embodiment 5 of DE-A 10046928 is favourable during for the talcum ring of geometrical dimension with 7mm * 7mm * 4mm or 7mm * 7mm * 3mm (external diameter of respectively doing for oneself * highly * internal diameter) at catalyst system therefor especially.For salt temperature, identical with described in the DE-A 44 319 49.Common selection mode is to make the acrolein conversion rate of one way acquisition common 〉=90mol%, or 〉=95mol%.

Yet in second step of partial oxidation, promptly propenal for example also can use and carry out at the catalyzer described in a plurality of catalyst tube fixed-bed reactor in two-region, as described in DE-19910508 to vinylformic acid.For acrolein conversion rate, said circumstances is suitable for.In this second step when also in a plurality of catalyst tube fixed-bed reactor in two-region, carrying out, the feed gas mixtures advantageously product gas mixture generation (choosing wantonly after intercooling) of the partial oxidation by directly using the first step (as mistake described above).The required oxygen of partial oxidation in second step preferably adds with air and under this second kind of situation directly in the product gas mixture of the partial oxidation of the adding the first step.

Under being used further to the product gas mixture of the partial oxidation of the first step to the reinforced two-stage method situation of the partial oxidation in second step immediately, two a plurality of catalyst tube fixed-bed reactor in single district or two a plurality of catalyst tube fixed-bed reactor in two-region are connected in series usually.Also can compounding in series connect (single district/two-region or vice versa).

Between reactor side cooler can be set, it can be chosen wantonly and comprise the inert bed with filtering function.To the acrylate moiety oxidation, the salt temperature of a plurality of catalyst tube reactors is generally 300-400 ℃ for the propylene of the first step.For second the step propylene to acrylate moiety oxidation, propenal to the acrylate moiety oxidation, the salt temperature of a plurality of catalyst tube reactors is generally 200-350 ℃.In addition, heat exchange medium (preferably salt melt) usually so that the difference of temperature in and temperature out usually≤5 ℃ amount transmits by relevant a plurality of catalyst tube fixed-bed reactor.Yet as already mentioned, propylene also can carry out on a kind of feeding in raw material in a reactor as described in DE-A 10121592 to two steps of acrylate moiety oxidation.

To should be mentioned that again a part of feed gas mixtures (gaseous mixture 2) that is used for the first step (" propylene → propenal ") can be the recycle gas from partial oxidation.

This recycle gas is that to take out target product (propenal and/or vinylformic acid take out) from the partial oxidation products gaseous mixture remaining afterwards and be recycled to by the gas of propylene in propenal and/or the acrylic acid the first step and/or the second step partial oxidation reinforced as inert dilution gas.

Yet the recycle gas that preferably this is comprised propane and comprise or do not contain propylene is recycled in the first step reinforced of the inventive method.

Also should be mentioned that according to partial oxidation of the present invention and/or ammonia oxidation can so that the reaction gas mixtures of oxygen-free gas at first undertaken by the mode of catalyst charge.The required oxygen of partial oxidation this moment provides with lattice oxygen.In the regeneration step of using oxygen-containing gas (for example air, oxygen-rich air or oxygen-denuded air) subsequently, the regenerated catalyst bed is can be used for anaerobic reaction gas mixtures or the like once more.

In a word, tube bundle reactor constitute to be realized the plain mode of propylene to two oxidation zones of acrylic acid two partial oxidation steps, wherein along catalyst charge appropriate change (this propylene partial oxidation that is suitable as reaction zone B of the present invention is for example instructed by EP-A 911313, EP-A 979813, EP-A 990636 and DE-A 2830765) when first reactions steps finishes of single catalyst tube.Randomly, catalyzer is interrupted by inert bed the reinforced of catalyst tube.

Yet, preferably realize two oxidation zones with two tube bundle system forms that are connected in series.These systems can be arranged in the reactor, so that a path of restraining another tube bank forms (advantageously underway realization) by the inert material bed that is not contained in the catalyst tube.Although flow through thermal barrier usually around the catalyst tube, the inert bed that does not reach as above to be constructed.Advantageously, therefore two catalyzer tube banks are contained in the reactor that separates on the space.Usually, between two tube bundle reactors, there is side cooler, to reduce any lasting propenal burning in the product gas mixture that leaves first oxidation zone.Replace tube bundle reactor, can also use to have salt and/or transpiration-cooled plate-type heat exchanger reactor, for example as described in DE-A 19 929 487 and the DE-A 19 952 964.

Temperature of reaction in first oxidation zone is generally 300-450 ℃, preferred 320-390 ℃.Temperature of reaction in second oxidation zone is generally 200-300 ℃, is generally 220-290 ℃.Reaction pressure in two oxidation zones advantageously is 0.5-5atm, more advantageously is 1-3atm.(L (STP)/Lh) is generally 1500-2500 h to reactant gases to the gas hourly space velocity of oxide catalyst in two oxidation zones ^-1Or 1500-4000h ^-1The gas hourly space velocity of propylene can be 100-200 L (STP)/Lh and bigger.

In principle, two oxidation zones in the inventive method can be for example as structure as described in DE-A 19 837 517, DE-A 19 910 506, DE-A 19 910 508 and the DE-A 19 837 519.Usually, the indirect heating in two oxidation zones, suitable words are in the multi-region reactor assembly, are complementary with specific reaction gas mixtures composition and catalyst charge in a manner known way.

Integral body can all add in the sectional feed gas mixtures of at least one in advance as the desired molecular oxygen of the sectional oxygenant of at least one required for the present invention.Yet, for example be understood that in acrylic acid preparation can also be in the first part district after supplemental oxygen.Preferably in acrylic acid preparation, carry out back one operation.

In first oxidation zone (propylene → propenal), preferably with propylene: the molecular oxygen mol ratio is set at 1: 1-3 is generally 1: 1.5-2.Similarly numerical value also is applicable to the propenal of propenal in second oxidation zone of acrylic acid partial oxidation: molecular oxygen mol ratio (preferred 1: 0.5-1.5).

In two oxidation zones, excessive molecular oxygen has advantageous effect to the kinetics of gaseous oxidation usually.With according to of the present invention treat the condition in the dehydrogenation opposite be that the ratio of the thermodynamics in the partial oxidation is not subjected to the influence of reactant molar ratio substantially at least, because propylene is under the kinetic control to acrylic acid heterogeneous catalyzed gas phase partial oxidation.Therefore, for example can also at first in first oxidation zone, add propylene with molar excess in principle based on molecular oxygen.This moment, in fact excessive propylene played diluent gas.

Yet, can also realize in single oxidation zone that in principle propylene is to acrylic acid heterogeneous catalyzed gas phase partial oxidation.This moment, two reactions steps were carried out in oxidation reactor, were added with the catalyzer of conversion that can two reactions steps of catalysis in this reactor.Be understood that catalyst charge can continuously change or flip-flop along reaction coordinate in oxidation zone.Certainly, be ready to use in the sectional embodiment of at least one of the present invention an oxidation zone form that is connected in series with two, be present in first oxidation zone, forming and leave the oxycarbide of first oxidation zone and the words of steam needs can partially or completely be removed before sending into second oxidation zone in the product gas mixture as by product.According to the present invention, preferably do not require the program that this is removed.

The source of desired molecular oxygen in partial oxidation and/or ammonia oxidation at least (being used for this part district mixing before reinforced with gaseous mixture 1 or 1 ') can be a pure molecular oxygen or with rare gas element such as CO ₂, CO, rare gas, N ₂And/or the molecular oxygen of stable hydrocarbon dilution.

Advantageously air is used as and covers to the oxygen source of small part molecular oxygen demand.

For the purpose of the present invention, freezing air is metered in hot gas mixture 1 or 1 ' and can passes through direct way cooling gas mixture 1 or 1 '.

Under preparation propenal and/or acrylic acid situation, the stand-by sectional product gas mixture of this that leaves is generally by the mixture of target product propenal or vinylformic acid or itself and propenal according to the present invention, unconverted molecular oxygen, propane, unconverted propylene, dinitrogen, by product steam and/or as the steam of diluent gas, by product oxycarbide and/or as the oxycarbide of diluent gas and other low-grade aldehydes on a small quantity, lower alkane carboxylic acid (acetate for example, formic acid and propionic acid) and maleic anhydride, phenyl aldehyde, aromatic carboxylic acid and aromatic carboxylic acid's acid anhydride (for example Tetra hydro Phthalic anhydride and phenylformic acid), other hydro carbons such as C if possible ₄Hydrocarbon (for example butene-1 and other butylene if possible) and other inert dilution gas are formed.

Target product can be in a manner known way from product gas mixture, take out (for example by partial condensation vinylformic acid or in water or high boiling point hydrophobic organic solvent absorbing propenoic acid or by in water or low-grade carboxylic acid's the aqueous solution, absorbing propenal and with the post-treatment absorption liquid; Perhaps, also can be with the product gas mixture partial condensation; For example referring to EP-A 117146, DE-A 4308087, and DE-A 4335172, DE-A 4436243, DE-A 19 924 532 and DE-A 19 924 533).Vinylformic acid takes out and also can carry out 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.

Optional remove unconverted propylene and/or propenal equally and be recycled in the part district.

Preferably remove as the shown in Figure 7 of WO/0196271.Otherwise, after taking out target product in the remaining residual gas basal component beyond vinylformic acid and the propenal can be as required, used thick propane and used dehydrogenation/oxy-dehydrogenation catalyst is removed separately separately and/or be recycled to as recycle gas (recycle stream) with propane in the feeding in raw material of the first step of the inventive method.Yet, be understood that unconverted propane only can also be mixed with unconverted propylene (as recycle stream) be recycled to this reinforced in.When the inventive method was carried out continuously, this allowed the continuous conversion of propane to vinylformic acid and/or propenal.

Propane and propylene remaining residual gas after taking out target product (comprises O usually ₂, CO, CO ₂, H ₂O, N ₂, rare gas and other low grade aldehydes, lower alkane carboxylic acid (for example acetate, formic acid and propionic acid) and maleic anhydride, phenyl aldehyde, aromatic carboxylic acid and aromatic carboxylic acid's acid anhydride (Tetra hydro Phthalic anhydride and phenylformic acid) and hydro carbons such as C ₄Hydrocarbon (for example butene-1 and any other butylene)) removes and to be undertaken by absorption in the high boiling point hydrophobic organic solvent and subsequently desorb and/or stripping (and utilizing absorption agent in addition again) as already described in.Other separate possibility is absorption, rectifying, membrane method and partial condensation.Preferably under elevated pressure, carry out described separation method.

When the dehydrogenation catalyst that uses oxygen or oxygenatedchemicals sensitivity, these oxygenate are removed from this recycle gas before in the first step that recycle gas is recycled to the inventive method reinforced.It may also be suitable that this oxygen is removed, to avoid propane exhaustive oxidation in dehydrogenation section.The dehydrogenation catalyst of DE-A 19 937107 is to oxygenate insensitive (especially those of embodiment 1-4).

As already mentioned equally, the another kind of possibility of taking out is provided by fractionation.Preferably carry out fractionation at low temperatures.Pressure to be applied for example can cling to for 10-100.Used rectifying tower can be the tower that looses and pile packed tower, tray column or have structured packing.Useful tray column is to have those of double pass tray, bubble cap plate or valve tray.Reflux ratio for example can be 1-10.Other examples that separate possibility comprise pressure extraction, transformation absorption, pressurization scrubbing, partial condensation and pressure extraction.

Be understood that in the first step that the residual gas of all measuring (as recycle stream) can also be recycled to the inventive method according to the present invention reinforced, for example as secondary component (C for example ₄Hydrocarbon (for example normal butane, Trimethylmethane, butene-1 and other butylene if possible)) remove when after the first step of the inventive method, integrating maybe C when trouble ₄When hydrocarbon is not assembled (for example if they in this part district on appropriate catalyst incendiary words).Unique outlet of the gaseous constituent beyond propane, propylene and the molecular oxygen at this moment may be arranged between gaseous mixture 1 and the gaseous mixture 1 '.

Be understood that and after target product takes out, another outlet be installed.If the recycle gas that is recycled in the dehydrogenating propane comprises carbon monoxide, then can before replenishing this gas, its catalyticcombustion be become CO with fresh thick propane ₂The reaction heat that discharges can be used to be heated to desorption temperature.

In the time need before being recycled to residual gas in dehydrogenating propane and/or the oxydehydrogenation as recycle gas, therefrom removing oxycarbide, also can recommend to be present in the residual gas CO subsequently catalyticcombustion become CO ₂, and can more easily remove CO ₂(for example by using the alkaline liquid scrubbing).This catalysis CO burning subsequently also can for example be carried out on above-mentioned dehydrogenation catalyst (for example those of DE-A 19937107, especially those of embodiment 1-4) in dehydrogenation zone.

Yes with the unconverted residual gas of a part is recycled in dehydrogenating propane and/or the oxydehydrogenation and only removes propane and propylene with mixture from remainder and equally they are recycled in dehydrogenating propane and/or the oxydehydrogenation and/or at least one part district for another possible program.Under one situation of back, the residual gas of remainder advantageously combines with gaseous mixture 1 or gaseous mixture 1 '.

For the fractionation residual gas, for example separator tube can be defined as: removing basically in the rectifying section of rectifying tower, all boiling points are lower than the component of propylene boiling point and can take out at the top of this tower.These components mainly are oxycarbide CO and CO ₂And unconverted oxygen and ethene, also have methane and N ₂At the bottom of tower, for example can take out the C of higher ₄Hydrocarbon.

When with the heterogeneous catalytic oxidation dehydrogenation of propane during, also always may when removing of dinitrogen undertaken by document DE-A 19837520, DE-A 19837517, DE-A 19837519 and DE-A 19837518, carry out secondary component and remove as the first step of the inventive method.

Embodiment

Use the different gaseous mixture that contains propylene and propane 2 heterogeneous catalyzed gas phase partial oxidation propylene in two fixed-bed reactor that are connected in series

A) description of common processes condition

1. be used for first fixed-bed reactor of propylene to the partial oxidation step of propenal

Used heat exchange medium: the salt-melting of forming by 53 weight % saltpetre, 40 weight % Sodium Nitrites and 7 weight % SODIUMNITRATE.

The size of catalyst tube: total length 4200mm, internal diameter 26mm, external diameter 30mm, wall thickness 2mm.

Reactor: form by chuck stainless steel right cylinder (the cylinder conduit that is surrounded by the cylindrical outer container).

Wall thickness is always 2-5mm.

The internal diameter of exterior circular column is 168mm.The internal diameter of conduit is about 60mm.

Seal by lid and bottom respectively with following above chuck is cylindrical.

Catalyst tube surpasses lid in each case with its projection at (sealing) upper end or hypomere

The mode of son or bottom 250mm is contained in the cylindrical vessel.

Heat exchange medium is enclosed in the cylindrical vessel.In order to guarantee on the whole catalyst tube length (3700mm) of cylindrical vessel that the catalyst tube outer wall has very thermal boundary condition uniformly, the circulating heat exchange medium by blast nitrogen in cylindrical vessel placing.

The nitrogen that rises is transported to the top with heat exchange medium from the bottom in cylindrical conduit, flow back to (same good circulation also can be realized by the circulation by pumping (for example spiral pump)) downwards with the intermediate space between cylindrical conduit and cylindrical outer container.Be installed in electrically heated on the external jacket and allow temperature with desired level control heat exchange medium.Also there is air cooling.

Reactor is reinforced: from reactor, salt-melting and reaction gas mixtures (being gaseous mixture 2 under every kind of situation) transmit with adverse current.Reaction gas mixtures enters reactor from above.

Under 250 ℃ temperature, send in the reaction tubes in each case.

Salt-melting is at T ^InTemperature under enter cylindrical conduit from below and at T ^OutTemperature under leave cylindrical conduit from above.T ^InAnd T ^OutBetween difference be about 2 ℃.

T ^ave＝(T ⁱⁿ+T ^out)/2。

The catalyst tube charging: the A section: length is 50cm

(from the top to the bottom) geometrical dimension is the initial bed of the talcum ring of 7mm * 7mm * 4mm (external diameter * length * internal diameter).

The B section: length is 100cm

Catalyst tube charging is that 30 weight % geometrical dimensions are the talcum ring of 5mm * 3mm * 2mm (external diameter * length * internal diameter) and the 70 weight % uniform mixture from the not supported catalyst of C section.

The C section: length is 170cm

Catalyst charge is annular (5mm * 3mm * 2mm=external diameter * length * internal diameter) supported catalyst not of the embodiment 1 of DE-A 10046957.

The D section: length is 50cm

Geometrical dimension is the last bed of the talcum ring of 7mm * 7mm * 4mm (external diameter * length * internal diameter).

Reaction gas mixtures is to the load of reactor: be 3860g/h gaseous mixture 2 in all cases.The propylene gas hourly space velocity of catalyst charge: 100L ((STP)/Lh).

2. the description of intercooling and oxygen intermediate feed

The product gas mixture that leaves first fixed-bed reactor is by pipe connecting (length=400mm, internal diameter=26mm, wall thickness=2mm, material=stainless steel) transmits to carry out intercooling (carrying out indirectly) by air, this pipe connecting is installed in 200mm place and placed in the middle, and diameter is housed is the talcum ball inert bed of 6mm and directly be installed on the catalyst tube of first fixed-bed reactor with flange.

In all cases, gaseous mixture enters pipe connecting under 310 ℃ the temperature and leaves under about 140 ℃ temperature surpassing.((STP)/h) mixes as the pressurized air of oxygen source with 290 L with this gaseous mixture then.

The gaseous mixture of under 220 ℃ temperature gained being feeded infeeds and is used for propenal moiety is oxidized to acrylic acid fixed-bed reactor.

3. be used for propenal moiety is oxidized to acrylic acid second fixed-bed reactor

The fixed-bed reactor that use are identical with the first step.Salt-melting and reaction gas mixtures are from reactor and flow transmission.Salt-melting enters from below, and reaction gas mixtures enters from below equally.

Catalyst tube charging (from bottom to top) is:

The A section: length is 20cm

Geometrical dimension is the talcum ring initial bed of 7mm * 7mm * 4mm (external diameter * length * internal diameter).

The B section: length is 100cm

Catalyst charge is that 30 weight % geometrical dimensions are the talcum ring of 7mm * 3mm * 4mm (external diameter * length * internal diameter) and the 70 weight % uniform mixture from the coating catalyst of C section.

The C section: length is 200cm

Catalyst charge is annular (7mm * 3mm * 4mm=external diameter * length * internal diameter) coating catalyst of the preparation embodiment 5 of DE-A 10046928.

The D section: length is 50cm

In all cases, nominally second reactor loads about 4240g/h feed gas mixtures.Tave defines as first fixed-bed reactor.

In all the following example, the propylene conversion in first reactor is set at 97.7mol% and the acrolein conversion rate in second reactor is set at 99.3mol%.

In each embodiment, depend on the desired T of composition of gaseous mixture 2 ^Ave, depend on the composition of gaseous mixture 2 and the vinylformic acid yield Y that obtains based on the propylene that in two reactors, transforms ^AA(mol%) and the selectivity S that forms of oxycarbide ^COx(mol%) has following train value.

B) embodiment 1

The propylene that consists of 6.18 volume % of gaseous mixture 2, the propane of 33.1 volume %, the oxygen of 12.3 volume %, the CO of 0.15 volume % _x, the N of 46.7 volume % ₂H with 1.63 volume % ₂O.

Y ^AA=86.1mol% T ^AveFirst reactor=316 ℃.

S ^COx=9.2mol% T ^AveSecond reactor=274 ℃.

C) embodiment 2

The propylene that consists of 6.04 volume % of gaseous mixture 2, the propane of 42.3 volume %, the oxygen of 10.4 volume %, the CO of 0.15 volume % _x, the N of 39.5 volume % ₂H with 1.60 volume % ₂O.

Y ^AA=85.2mol% T ^AveFirst reactor=322 ℃.

S ^COx=9.9mol% T ^AveSecond reactor=278 ℃.

D) embodiment 3

The ethane that consists of 0.20 volume % of gaseous mixture 2, the propylene of 6.14 volume %, the propane of 33.0 volume %, the oxygen of 12.2 volume %, the CO of 0.16 volume % _x, the N of 46.6 volume % ₂H with 1.65 volume % ₂O.

Y ^AA=86.1mol% T ^AveFirst reactor=316 ℃.

S ^COx=9.2mol% T ^AveSecond reactor=274 ℃.

E) embodiment 4

The ethene that consists of 0.22 volume % of gaseous mixture 2, the propylene of 6.13 volume %, the propane of 33.0 volume %, the oxygen of 12.2 volume %, the CO of 0.16 volume % _x, the N of 46.6 volume % ₂H with 1.64 volume % ₂O.

Y ^AA=86.1mol% T ^AveFirst reactor=316 ℃.

S ^COx=9.2mol% T ^AveSecond reactor=274 ℃.

F) embodiment 5

The normal butane that consists of 0.20 volume % of gaseous mixture 2, the propylene of 6.14 volume %, the propane of 33.0 volume %, the oxygen of 12.2 volume %, the CO of 0.16 volume % _x, the N of 46.6 volume % ₂H with 1.65 volume % ₂O.

Y ^AA=85.2mol% T ^AveFirst reactor=316.5 ℃.

S ^COx=9.9mol% T ^AveSecond reactor=274 ℃.

G) embodiment 6

The normal butane that consists of 2.02 volume % of gaseous mixture 2, the propylene of 5.98 volume %, the propane of 32.4 volume %, the oxygen of 12.0 volume %, the CO of 0.16 volume % _x, the N of 45.8 volume % ₂H with 1.64 volume % ₂O.

Required propylene conversion is because of the former of catalyzer consistency thereby can not pass through to increase T again ^AveBe maintained.

H) embodiment 7

The butene-1 that consists of 0.05 volume % of gaseous mixture 2, the propylene of 6.16 volume %, the propane of 33.0 volume %, the oxygen of 12.3 volume %, the CO of 0.16 volume % _x, the N of 46.7 volume % ₂H with 1.70 volume % ₂O.

Y ^AA=85.1mol% T ^AveFirst reactor=318 ℃.

S ^COx=10mol% T ^AveSecond reactor=281 ℃.

I) embodiment 8

The butene-1 that consists of 0.09 volume % of gaseous mixture 2, the propylene of 6.16 volume %, the propane of 32.9 volume %, the oxygen of 12.3 volume %, the CO of 0.15 volume % _x, the N of 46.8 volume % ₂H with 1.68 volume % ₂O.

Y ^AA=85.0mol% T ^AveFirst reactor=320 ℃.

S ^COx=10.2mol% T ^AveSecond reactor=287 ℃.

J) embodiment 9

Consisting of of gas mixing 2: the butene-1 of 0.20 volume %, the propylene of 6.19 volume %, the propane of 32.7 volume %, the oxygen of 12.3 volume %, the CO of 0.18 volume % _x, the N of 46.7 volume % ₂H with 1.71 volume % ₂O.

Claims

1. one kind prepares the partial oxidation at least of propylene and/or the method for ammoxidation product, comprising:

The C of gaseous mixture 2 wherein ₄Hydrocarbon total content≤3 volume %.

2. as the desired method of claim 1, the wherein C of gaseous mixture 2 ₄Hydrocarbon total content≤2.5 volume %.

3. as the desired method of claim 1, the wherein C of gaseous mixture 2 ₄Hydrocarbon total content≤2.0 volume %.

4. as the desired method of claim 1, the wherein C of gaseous mixture 2 ₄Hydrocarbon total content≤1.5 volume %.

5. as the desired method of claim 1, the wherein C of gaseous mixture 2 ₄Hydrocarbon total content≤1.0 volume %.

6. as the desired method of claim 1, the wherein C of gaseous mixture 2 ₄Hydrocarbon total content≤0.5 volume %.

7. as the desired method of claim 1, the wherein C of gaseous mixture 2 ₄Hydrocarbon total content 〉=0.07 volume %.

8. as the desired method of claim 1, the wherein C of gaseous mixture 2 ₄Hydrocarbon total content 〉=0.05 volume %.

9. as each desired method among the claim 1-8, wherein gaseous mixture 1 ' comprises 〉=propane of 0.1 volume % and the composition beyond propylene and the oxygen.

10. as each desired method among the claim 1-8, wherein gaseous mixture 1 ' comprises 〉=propane of 0.2 volume % and the composition beyond propylene and the oxygen.

11. as each desired method among the claim 1-8, wherein gaseous mixture 1 ' comprises 〉=composition beyond the propane of 0.3 volume % and propylene and the oxygen.

12. as each desired method among the claim 1-8, wherein gaseous mixture 1 ' comprises 〉=composition beyond the propane of 0.5 volume % and propylene and the oxygen.

13. as each desired method among the claim 1-8, wherein gaseous mixture 1 ' comprises 〉=composition beyond the propane of 1 volume % and propylene and the oxygen.

14. as each desired method among the claim 1-8, wherein gaseous mixture 1 ' comprises 〉=composition beyond the propane of 3 volume % and propylene and the oxygen.

15. as each desired method among the claim 1-8, wherein gaseous mixture 1 ' comprises 〉=composition beyond the propane of 5 volume % and propylene and the oxygen.

16. as each desired method among the claim 1-8, wherein gaseous mixture 1 ' comprises 〉=composition beyond the propane of 10 volume % and propylene and the oxygen.

17. as each desired method among the claim 1-8, wherein gaseous mixture 1 ' comprises 〉=composition beyond the propane of 30 volume % and propylene and the oxygen.

18. as each desired method among the claim 1-8, wherein gaseous mixture 2 comprises the propane of 60 volume % at the most.

19. as each desired method among the claim 1-8, wherein gaseous mixture 2 comprises the propane of 50 volume % at the most.

20. as each desired method among the claim 1-8, wherein gaseous mixture 2 comprises the propane of 20-40 volume %.

21. as each desired method among the claim 1-8, wherein gaseous mixture 2 has following content:

The O of 7-15 volume % ₂,

The propylene of 5-10 volume %,

The propane of 15-40 volume %,

The nitrogen of 25-60 volume %,

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

Other compositions of 0-5 volume %,

The ammonia of ignoring any existence.

22. as each desired method among the claim 1-8, wherein gaseous mixture 2 has following content:

H ₂O≤60 volume %,

N ₂≤ 80 volume %,

O ₂＞0 ,≤20 volume %,

CO≤2 volume %,

CO ₂＞0 ,≤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-butene-2≤1 volume %,

It is suitable-butene-2≤1 volume %,

Butene-1≤1 volume %,

Iso-butylene≤1 volume %,

Divinyl-1,3≤1 volume %,

Divinyl-1,2≤1 volume %,

Butine-1≤0.5 volume % and

Butine≤0.5 volume %,

The ammonia of ignoring any existence.

23. as each desired method among the claim 1-8, wherein thick propane comprises 〉=propane of 0.25 volume % and the composition beyond the propylene.

24. as each desired method among the claim 1-8, wherein thick propane comprises 〉=propane of 1 volume % and the composition beyond the propylene.

25. as each desired method among the claim 1-8, wherein thick propane comprises 〉=propane of 2 volume % and the composition beyond the propylene.

26. as each desired method among the claim 1-8, wherein thick propane comprises 〉=propane of 3 volume % and the composition beyond the propylene.

27. as each desired method among the claim 1-8, wherein thick propane comprises the C of 6 volume % at the most ₄Hydrocarbon.

28. as each desired method among the claim 1-8, wherein thick propane comprises the C of 0.1-6 volume % ₄Hydrocarbon.

29. as each desired method among the claim 1-8, wherein thick propane satisfies following technical requirements:

Propane content 〉=90 volume %,

Propane and propylene total content≤99 volume %,

C ₄Hydrocarbon total content≤6 volume %,

Butene-1 content≤0.5 volume %,

Butylene total content≤0.5 volume %,

Ethane content≤10 volume %,

Ethylene content≤5 volume %,

Methane content≤5 volume %,

Cyclopropane content≤0.1 volume %,

Propylene content≤10 volume %,

C beyond propane and the propylene ₃Hydrocarbon total content≤0.3 volume %,

C ₅Hydrocarbon total content≤0.3 volume % and

C ₆-C ₈Hydrocarbon total content≤600ppm volume.

30. as each desired method among the claim 1-8, wherein the conversion of propane in the first step is 〉=5mol%-≤30mol%.

31. as each desired method among the claim 1-8, wherein from the product gas mixture of gas-phase partial oxidation and/or part gas phase ammonoxidation, take out the partial oxidation at least and/or the ammoxidation product of propylene and will be present at least unconverted propane in this product gas mixture be recycled in the first step and/or be recycled to gas-phase partial oxidation and/or the part gas phase ammonoxidation in.

32. as each desired method among the claim 1-8, wherein said method is carried out on its active composition is the catalyst charge of at least a multimetal oxide compositions in reaction zone, and this oxide composition is with at least a among combination containing element Mo and V, two kinds of element T e and the Sb and be selected from least a among element 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 the In.

33. as the desired method of claim 32, wherein active composition is the multimetal oxide compositions of at least a containing element stoichiometric equation I:

Mo ₁V _bM ¹ _cM ² _d (I)

M wherein ¹=Te and/or Sb,

M ²=be selected from element nb, Ta, W, Ti, Al, Zr, Cr, Mn, Ga, Fe, Ru, Co, Rh, at least a among Ni, Pd, Pt, La, Bi, Ce, Sn, Zn, Si, Na, Li, K, Mg, Ag, Au and the In,

b＝0.01-1，

C=＞0-1 and

d＝＞0-1。

34. as the desired method of claim 33, wherein M ¹=Te and M ²=Nb, Ta, W and/or Ti.

35. as the desired method of claim 33, wherein M ²=Nb.

36. as the desired method of claim 32, the X-ray diffractogram of wherein at least a poly-metal deoxide active composition has reflection h and the i that its peak position is located at reflection angle 22.2 ± 0.5 ° (h) and 27.3 ± 0.5 ° (i).

37. as the desired method of claim 36, wherein X-ray diffractogram additionally has its peak at 28.2 ± 0.5 ° of reflection k that locate.

38., reflect wherein that h has maximum intensity in X-ray diffractogram and maximum half high width is 0.5 ° as the desired method of claim 36.

39. as the desired method of claim 38, the halfwidth degree that wherein reflects i and reflection k is extra separately simultaneously≤the intensity P of 1 ° and reflection k _kIntensity P with reflection i _i0.20≤R≤0.85 that satisfies condition, wherein R is the strength ratio that is limited by following formula:

R＝P _i/(P _i+P _k)。

40. as the desired method of claim 32, the X-ray diffractogram of wherein at least a poly-metal deoxide active composition does not have maximum value and is positioned at 2 θ=50 ± 0.3 ° reflection of locating.

41. as each desired method among the claim 1-8, wherein the first step is carried out in independent reaction zone.

42. as the desired method of claim 41, wherein the first step is the heterogeneous catalysis dehydrogenation.

43., wherein take out a part and be present in the gaseous mixture 1 and comprise at least a C as the desired method of claim 41 ₄Composition beyond the propane of hydrocarbon and the propylene.

44. as the desired method of claim 41, wherein also use catalyzer in heterogeneous catalyzed gas phase partial oxidation and/or part gas phase ammonoxidation, described catalyzer has the active composition of containing element Mo, Bi and Fe.

45. as the desired method of claim 41, wherein also use catalyzer in heterogeneous catalyzed gas phase partial oxidation and/or part gas phase ammonoxidation, described activity of such catalysts composition is the poly-metal deoxide of general formula I V:

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

Wherein each variable is as giving a definition:

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＝0-5，

b＝0.01-5，

c＝0-10，

d＝0-2，

e＝0-8，

F=0-10 and

46. as the desired method of claim 41, wherein in heterogeneous catalyzed gas phase partial oxidation, also use catalyzer, described activity of such catalysts composition containing element Mo and V.

47. as the desired method of claim 41, wherein also use catalyzer in heterogeneous catalyzed gas phase partial oxidation, described activity of such catalysts composition is the poly-metal deoxide of general formula VII:

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

Wherein each variable is as giving a definition:

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＝1-6，

b＝0.2-4，

c＝0.5-18，

d＝0-40，

e＝0-2，

f＝0-4，

G=0-40 and

N=is by the valency of the element beyond the oxygen among the VII and the number of occurrence rate decision.

48. as each desired method among the claim 1-8, wherein the partial oxidation at least of propylene and/or ammoxidation product are at least a compounds that is selected from propylene oxide, propenal, vinylformic acid and vinyl cyanide.

49. as each desired method among the claim 1-8, wherein in the first step with thick propane in the presence of the oxygen and/or getting rid of the heterogeneous catalyzed gas phase partial oxidation and/or the part gas phase ammonoxidation of the propylene that carries out the heterogeneous catalysis dehydrogenation under the oxygen and gaseous mixture 1 carried out exist in the gaseous mixture 1.

50. as each desired method among the claim 1-8, wherein in the first step with thick propane in the presence of the oxygen and/or getting rid of under the oxygen and in the presence of steam, carry out the heterogeneous catalysis dehydrogenation, partly or entirely remove devaporation by condensation from the gaseous mixture 1 that the first step, forms and gained gaseous mixture 1 ' carried out the heterogeneous catalyzed gas phase partial oxidation and/or the part gas phase ammonoxidation of the propylene of existence in the gaseous mixture 1.

51., wherein in the first step, thick propane carried out self-heating heterogeneous catalysis dehydrogenation as each desired method among the claim 1-8.

52., wherein will carry out the heterogeneous catalysis part gas phase ammonoxidation of the propylene that exists in gaseous mixture 1 and/or the gaseous mixture 1 ' as the gaseous mixture 1 of the composition of gaseous mixture 2 and/or gaseous mixture 1 ' as each desired method among the claim 1-8.