CN100390126C - Heterogeneously catalyzed partial direct oxidation of propane and/or isobutane - Google Patents

Abstract

Disclosed is a method for the heterogeneously catalyzed partial direct oxidation of propane and/or isobutane. According to said method, target product is separated from the product gas mixture obtained in the reaction stage in a reprocessing stage, the remaining product gas mixture is divided into two partial quantities having the same composition, one partial quantity is redirected into the reaction stage while the other partial quantity is discharged, and both the reaction stage and the reprocessing stage are operated at an increased pressure.

Description

The partial direct oxidation of the heterogeneous catalysis of propane and/or Trimethylmethane

The present invention relates to a kind of method, be used for propane and/or Trimethylmethane partial direct oxidation at least a heterogeneous catalysis of target product vinylformic acid and methacrylic acid, this method is initial action gaseous mixture supply response section, and the initial action gas mixture comprises propane and/or Trimethylmethane, molecular oxygen and at least a inert dilution gas and has inlet pressure P ¹Except initial action gaseous mixture outlet, nonessential other auxiliary gas entry and product gas mixture outlet, conversion zone seals at gas side, in conversion zone, by making the initial action gaseous mixture pass solid catalyst under elevated temperature, the propane and/or the Trimethylmethane that will be present in the initial action gaseous mixture become direct part to be oxidized at least a target product; To introduce the aftertreatment section as the reactant gas mixtures of product gas mixture then, product gas mixture comprises at least a target product and with top hole pressure P ²Leave conversion zone, and with this pressure P ²Enter into the aftertreatment section, except product gas mixture inlet, nonessential other auxiliary gas entry and the outlet of bottom product gaseous mixture, the aftertreatment section seals at gas side, in the aftertreatment section, the target product that will be present in the conversion zone product gas mixture segregates into the liquid phase from this product gas mixture substantially, and the remaining residue product gas mixture drawn the aftertreatment section, this remaining residue product gas mixture not only comprises propane and/or Trimethylmethane, sometimes propylene and/or iso-butylene is arranged also, and has top hole pressure P ³, P wherein ³＜P ¹And will be present in the propane in the bottom product gaseous mixture and/or be that Trimethylmethane is recycled to conversion zone.

Vinylformic acid and methacrylic acid are important intermediate, for example are used to prepare polymkeric substance.

The heterogeneous catalysis partial direct oxidation in conversion zone reacts to such an extent that preparation is known (referring to for example: EP-A 529853, EP-A 603836, EP-A 608838, EP-A 895809, DE-A 19835247, DE-A 10051419, DE-A 10122027, EP-A1254707, EP-A 1254709, EP-A 1192987, EP-A 1090684, DE-A 10254279 and the document of being quoted from these files by propane and/or Trimethylmethane for they.)

Used oxygenant is generally oxygen molecule, for example can with respective pure form or with gas (for example airborne N to the basic non-activity of partial oxidation ₂) the form of mixture it is joined in the initial action gaseous mixture.Such as N ₂, H ₂O, CO, CO ₂, He and/or Ar etc. inert dilution gas absorption reaction heat and reaction gas mixtures remained on outside the explosive range.Herein, inert dilution gas is generally in the one way of reaction gas mixtures and is less than 5mol% through partial oxidation, preferably is less than 3mol%, those gases that transformed more preferably less than 2mol%.Catalyst system therefor is generally solid-state multivariant oxide.Can solid-state, on the multivariant oxide of stationary catalyst bed, fluidized catalyst bed or moving-bed, carry out step of reaction.

According to the instruction of prior art, the operating pressure in conversion zone can be lower than normal atmosphere (=1 crust) or be higher than 1 crust (referring to, for example DE-A 19835247, EP-A 895809 and DE-A 10261186).Generally speaking, for overcoming the resistance to flow in the conversion zone, a little higher than barometric point of this pressure.

The shortcoming of propane and/or Trimethylmethane at least a heterogeneous catalysis partial direct oxidation to target product vinylformic acid and the methacrylic acid is the comparatively significant inertia of propane and Trimethylmethane.Even this is that reaction gas mixtures passes the reason that the part that also only realizes propane and/or Trimethylmethane in the one way of appropriate reaction section usually transforms at elevated temperatures.

Thereby, the heterogeneous catalysis partial direct oxidation of propane and/or Trimethylmethane at least a purpose to target product vinylformic acid and the methacrylic acid is that reaction gas mixtures passes the very high transformation efficiency of realizing propane and/or Trimethylmethane in the one way of conversion zone under low-down temperature, in conjunction with the very high selectivity that forms target product, promptly the very high space-time yield of target product combines with low-down energy requirement simultaneously.

The further demand that the heterogeneous catalysis partial direct oxidation of propane and/or Trimethylmethane is become the economic performance of at least a desired destination product is to be recycled in the conversion zone substantially being present in the product gas mixture unconverted propane and/or Trimethylmethane.For this purpose, prior art proposes following suggestion.

Prepare in the vinylformic acid at heterogeneous catalysis partial direct oxidation by propane, DE-A 10119933 suggestion by absorb in the liquid-absorbant, the absorption agent with gained becomes glacial acrylic acid with acrylic acid liquid mixture with known mode rectifying own, extraction and/or crystallization treatment subsequently, and the vinylformic acid that is present in the product gas mixture is separated substantially with this product gas mixture; Or by fractional condensation vinylformic acid is separated in the liquid phase from product oxysome mixture substantially, for example described in DE-A19924532, and be further purified gained water soluble acrylic acid enriched material, for example by the fractionation crystallization.

About the bottom product gaseous mixture that comprises unconverted propane in the basic sepn process that enters liquid phase at this vinylformic acid, in DE-A 10119933 suggestions remove propane and will remove from the bottom product gaseous mixture the acrylic acid partial direct oxidation of the back-shaped one-tenth of propane recirculation.For this purpose and the method that removes of suggestion for example for dividing potential drop rectifying, perhaps with hydrophobic organic solvent (can preferential absorption propane) extraction, serve as that release propane carries out desorb and/or carries with air gas subsequently.

In full accord with it, partial direct oxidation reaction for alkane such as propane, the unconverted alkanes that EP-A 1193240 suggestions will be present in the bottom product gaseous mixture removes from this bottom product gaseous mixture (as in above prior art document, preferably with the alkene that forms as by product) (for example absorptivity or adsorptivity mode), and be recirculated in the partial oxidation.

Yet, according to the suggestion of prior art and with unconverted alkane and any olefin recycle to shortcoming in the conversion zone that forms as by product is to be present in wherein the residual product gas mixture alkane and any alkene removed with high relatively dilution usually from unconverted alkane to take cost and inconvenience, and with extra high pressure drop associated.The latter does not encourage to adopt elevated pressure in conversion zone, because in the recirculation of the propane that has removed, must recompress usually to reach these pressure.

Another shortcoming be to be present in the bottom product gaseous mixture and to the heterogeneous catalysis partial direct oxidation have favourable influence other component (steam for example, it supports the activity and the selectivity of catalytic activity composition usually; Or residual oxygen, it needs not to be high compression) be not circulated in the conversion zone (but being drained) and, when needed, must add fresh composition once more usually.

Suggestion will be present in another reason that the no conversion hydrocarbon in the resultant product gaseous mixture is recycled to respectively in the conversion zone, especially, consider to remain on gas volume to be recycled (and also being initial action gaseous mixture amount therefore) very low, (recycle gas must recompress before entering conversion zone to the reaction gas mixtures inlet pressure to make the forwarder treating for this reason and adopt and the output of compressor in this way, because it is passing through conversion zone, in aftertreatment section and the process that from the bottom product gaseous mixture, removes, can fall by experience pressure, this pressure falls in order to overcome resistance to flow and must be resumed) and volume required be reduced to minimum.Further purpose also may be that significant loss is remained on minimum.

An object of the present invention is to provide a kind of method, be used for propane and/or Trimethylmethane to target product vinylformic acid and at least a heterogeneous catalysis partial direct oxidation reaction of methacrylic acid, wherein make compressor output and charging minimization of loss to be adopted with another kind of more favourable mode, the energy requirement with minimum makes the space-time yield optimization simultaneously.

We have found that this purpose reacts by a kind of propane and/or Trimethylmethane heterogeneous catalysis partial direct oxidation that at least a method realizes to target product vinylformic acid and the methacrylic acid, this method is initial action gaseous mixture supply response section, and the initial action gas mixture comprises propane and/or Trimethylmethane, molecular oxygen and at least a inert dilution gas and has initial pressure P ¹Except initial action gaseous mixture inlet, nonessential other auxiliary gas entry and product gas mixture outlet, conversion zone seals at gas side, in conversion zone, by making the initial action gaseous mixture pass solid catalyst under elevated temperature, the propane and/or the Trimethylmethane that will be present in the initial action gaseous mixture become direct part to be oxidized at least a target product; To introduce the aftertreatment section as the reactant gas mixtures of product gas mixture then, product gas mixture comprises at least a target product and with top hole pressure P ²Leave conversion zone, and with this pressure P ²Enter into the aftertreatment section, except product gas mixture inlet, nonessential other auxiliary gas entry and the outlet of bottom product gaseous mixture, the aftertreatment section seals at gas side, in the aftertreatment section, the target product that will be present in the conversion zone product gas mixture segregates into the liquid phase from this product gas mixture substantially, and the remaining residue product gas mixture drawn the aftertreatment section, this remaining residue product gas mixture not only comprises propane and/or Trimethylmethane, sometimes propylene and/or iso-butylene is arranged also, and has top hole pressure P ³, P wherein ³＜P ¹And will be present in the propane in the bottom product gaseous mixture and/or be that Trimethylmethane is recycled to conversion zone; It comprises selects P ¹So that P ³〉=1.5 crust, and the bottom product gaseous mixture is divided into two portions of same composition, a part is discharged as output, and another part is compressed to inlet pressure P as recycle gas recirculation with this part ¹And return to conversion zone as the component of initial action gaseous mixture.Outside other, the method according to this invention is different from the process that discloses among the EP-A 495504, does not have catalytic carbon monoxide oxygenizement in the method for the present invention in the aftertreatment section and/or afterwards and before output.The method according to this invention is also washed the step of bottom product gaseous mixture without any need for carbonic acid gas.

When propylene and/or iso-butylene were by product in the conversion zone, the general combination with propane and/or Trimethylmethane maintenance of these compounds passed the aftertreatment section, and one coexists and is recycled to conversion zone in the recycle gas.

Unless otherwise specifically indicated, all pressure values are meant absolute pressure herein.

Usually, the bottom product gaseous mixture comprises at least 2 volume %, or at least 5 volume %, usually at least 10 volume % except propane and/or Trimethylmethane, propylene and/or iso-butylene and the component the oxygen when existing (for example CO, CO ₂, H ₂O and/or N ₂Deng) (these are the components that are present in the product gas mixture that boiling point (under atmospheric pressure) is lower than target product usually).

The organic precursor compound of partial oxidation (being propane and/or Trimethylmethane) in fact often stores with liquid form when desiring in the method according to the invention, but when it was gaseous state under standard temperature and pressure, usually simple Evaporation just was enough to make the organic precursor compound to bring to the conversion zone inlet pressure.Not necessarily the steam that uses as inert dilution gas can obtain from multiple source, the same usually normal atmosphere that enough surpasses.

Yet this is not suitable for usually for oxygen source (for example air or oxygen-denuded air), any other inert dilution gas at least, and (this recycle gas generally has the conversion zone inlet pressure, and this pressure is P to be unsuitable for containing the recycle gas of propane especially ¹Deduct and falling by conversion zone, aftertreatment section and the pressure that is divided on the path of two-part splitter; Usually it is not recirculated into conversion zone with the pipeline of internals via no obvious additional voltage drop in the method according to the invention).

Therefore need to take higher terminal pressure to from lower initial pressure in fact usually and (enter the inlet pressure P of conversion zone with the near small part of compressor (recycle gas at least) initial action gaseous mixture component ¹).

Can be in the compressor unit of spatial isolation or single compressed machine compression these components (for example oxygen source air and recycle gas).

In principle, being used for the compressor unit of described gas compression can be for various dissimilar.Citation is positive-displacement compressor group (for example piston type compressed unit as an example, screw-type compressor group and rolling piston compressor group), flowing-type compressor (flow compressor) group (turbo-driven compressor group for example, centrifugal compressor units, axial-flow compressor group and radial flow compressor group) and the jet compression unit.According to the present invention, preferred radial flow compressor group is for example described in DE-A 10259023.

According to the present invention, also preferably carry out by this way: will at first in mixing tank such as static mixer, mix (chamber from the initial action gaseous mixture each several part of different sources earlier usually with internals, compare with blank pipe described member have strengthen the blended effect), this initial action gaseous mixture is derived from various pipelines and is in conversion zone inlet pressure (or it is reached at this) substantially; Not necessarily be heated to temperature in subsequently and be supplied to conversion zone.

The mode that suitable selection all gases enters to the pipeline of static mixer feed generates (in the situation of partial oxidation reaction of the present invention to prevent explosive mixture, the for example following order that enters suits: at first be recycle gas and/or steam, then being air, is the organic precursor compound at last).The adding mode of the steam composition of initial action gaseous mixture can certainly be this mode: the liquid water droplets of fine segmentation is entered in the initial action gaseous precursors mixture after measuring, and this precursor mixture has been heated to temperature of reaction substantially by the indirect heat exchange with product gas stream; Described water droplet forms the initial action gaseous mixture by the heat absorption spontaneous evaporation.In addition, through the initial action gaseous precursors mixture of preheating can feed via the gas saturex (with gaseous mixture and water with and stream or reflux type pass through high surface area).

The top hole pressure P that selects according to the present invention ³, influence the output that compressor is compression cycle gas and oxygen source thus substantially.

From the viewpoint of using, in the method according to the invention, the pressure P that the bottom product gaseous mixture is had when leaving the aftertreatment section ³Generally be no more than 30 or 25 crust, often be no more than 20 crust.According to the present invention, top hole pressure P ³〉=1.5 crust and≤10 crust are favourable, preferred 〉=2 crust and≤8 crust, usually 〉=3 crust and≤6 crust or≤5 crust (for example 4 crust).

In other words, the method according to this invention be characterized as conversion zone and the aftertreatment section all is to operate under elevated pressure.

This kind treating processes has advantage because of underlying cause:

-heterogeneous catalysis partial direct oxidation the reaction of having made us finding uncannily under elevated pressure propane and/or Trimethylmethane makes not to be followed target product to form and optionally obviously reduces at other identical reaction conditions and based on increasing transformation efficiency under the one way;

-thus also under elevated pressure operation aftertreatment section make even the circulation gas of the amount that increases can transmit with less relatively volume required and relatively low caused pressure drop because the transmission volume of specified rate gas and follow transmit this gas pressure drop both all increase and reduce usually along with pressure; The latter has reduced recycle gas has been compressed to conversion zone inlet pressure P ¹Required compressor output; Simultaneously, compared to work output, the increasing amount of recycle gas makes the unconverted propane that is present in the output and/or the minimization of loss of Trimethylmethane.

-propane do not removed from the bottom product gaseous mixture and recirculation has prevented to follow this pressure drop of shifting out and guaranteed that other component is simultaneously and the recirculation of energy-conservation ground, this other component is present in the bottom product gaseous mixture sometimes, for example steam and O ₂

In other words, can realize all favorable characteristics of existing method equally similarly according to the measure of simple relatively pressure boost of the present invention, and need not expensive for this purpose and remove unconverted alkane and any alkene from the bottom product gaseous mixture inconveniently (this has further been avoided the shortcoming do not expected, for example steam does not circulate fully or needs the recirculation of energy), simultaneously, the measure of pressure boost makes based on the selectivity that does not significantly reduce target product by the once-through reaction-ure conversion-age increase of conversion zone.

Herein, term " conversion zone " or " the aftertreatment section " refer in particular to one or more device units that are connected in series, this device unit is except entrance and exit and nonessential any other auxiliary gas entry, seal at gas side, thereby to overcome resistance to flow required being restricted to by this device unit or the pressure drop experienced in the placed in-line device unit group way by this with gaseous mixture.

For example, this device unit (this unit group that perhaps is connected in series) can be bundled tube reactor, fluidized-bed reactor, this class set of reactors, absorption tower, rectifying tower, the condensing tower that are connected in series or this class tower or the single quench section that are connected in series.Aforesaid reactor can certainly be included in the possibility that when implementing the method according to this invention for example catalyst activator is joined reactor, and for example WO 02/081421 is described.In the method according to the invention, the term assist gas is intended to comprise: in the situation with the set of reactors that is connected in series, and the possibility of topping up and/or oxygen between reactor (for example air); , for example be polymerization retardation reason perhaps, the gas (for example air) of molecule-containing keto is guided possibility by the aftertreatment section with product gas mixture in the aftertreatment section.Generally speaking, in the method according to the invention, the pressure drop of entire reaction section is the 0.1-3 crust, usually is 0.3-1 or-0.5 crust; The pressure drop of whole aftertreatment section is the 0.5-3 crust, usually is the 1-2 crust.

When carrying out in the zone of the method according to this invention at extra-lnigh tension, the pressure drop in conversion zone and the aftertreatment section may be all obviously lower and be reached for example 0.05 Palestine and Israel and littler.

In the method according to the invention, the pressure P that enters the conversion zone ingress that depends on used aftertreatment segment type ¹To be higher than aftertreatment section outlet pressure P ³0.5 or 1-4 crust, the 1.5-3.5 crust clings to for 2-3 in many situations usually.

When carrying out in the zone of the method according to this invention at extra-lnigh tension, enter conversion zone ingress pressure P ¹Generally than aftertreatment section outlet pressure P ³Height is less than 0.5 crust (for example 0.1 or 0.01 crust).

Enter the typical pressure P of conversion zone ingress ¹Be the 2.5-25 crust thus.Generally speaking, enter the pressure P of the ingress of conversion zone ¹To be the 3-10 crust, and the 4-8 crust be more suitable according to the present invention.

Enter the typical pressure P of aftertreatment section ingress ²Be the 3-25 crust, usually be the 3-20 crust, or the 3-15 crust, or the 3-8 crust.

In the method according to the invention, can control compression ratio, for example be used for the throttle valve gear in the exit of discharge section bottom product gaseous mixture with simple method.In the method according to the invention, except the advantage of having narrated, when by until the part of atmospheric controlled decompression process discharging bottom product gaseous mixture when recovering the compressor output, also can be with the expander that is connected in series (anti-compressor, discharge with it) the replacement throttle valve gear, this output is required for other of compression bottom product gaseous mixture and/or oxygen source (for example air), and this another part has been circulated to inlet pressure P ¹

In the method according to the invention as the bottom product gaseous mixture part of recycle gas recirculation and the composition that in every kind of situation, all depends on the initial action gaseous mixture as the bottom product gaseous mixture ratio partly of output discharge.Yet R generally is 〉=0.5 or 〉=1, usually 〉=1.5, preferred 〉=2, more preferably 〉=3.Can recognize in the method according to the invention, R also can 〉=8 or 〉=10.Generally speaking, in the method according to the invention, R will be≤30, usually≤25, usually≤20.Usually, R will be≤15 or≤10, preferred 2-8.

In addition, the method according to this invention can be to carry out with partial oxidation to the similar mode of prior art of at least a target product of the heterogeneous catalysis that is used for propane and/or Trimethylmethane.

In other words, be molecular oxygen source or air that the purpose of the method according to this invention is required, or removed the air (O of volume % for example 〉=90 of nitrogen molecule ₂, the N of≤10 volume % ₂), the mixture of perhaps pure molecular oxygen or molecular oxygen and other rare gas element.

Useful catalysts is that the heterogeneous catalysis partial direct oxidation that is used for propane and/or Trimethylmethane becomes all that the prior art of at least a target product is advised in principle in the method according to the invention.

For example, these are the catalyzer among document JP-A 3-170445, EP-A 609122 and the EP-A 747349.

For the present invention, requirement can be used the basic every kind of heterogeneous catalysis partial direct oxidation catalyst for reaction that original creation is feasible that is useful on.

These activity of such catalysts compositions are generally multivariant oxide, normally poly-metal deoxide.

Be suitable for the poly-metal deoxide in the particularly following document of poly-metal deoxide of the method according to this invention: EP-A 608838, EP-A 529853, DE-A 10254279, DE-A 19835247, EP-A 895809, JP-A 7-232071, JP-A 11-169716, DE-A 10261186, EP-A1192987, JP-A 10-57813, JP-A 2000-37623, JP-A 10-36311, WO 00/29105, EP-A 767164, DE-A 10029338, JP-A 8-57319, JP-A 10-28862, JP-A11-43314, JP-A 11-574719, WO 00/29106, JP-A 10-330343, JP-A 11-285637, JP-A 3 10539, JP-A 11-42434, JP-A 11-343261, JP-A 3423262, WO99/03825, 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-A3 18295, 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 quoting from EP-A 1193240 and these files.

The active composition of waiting to be used in the catalyst charge in the aforementioned circumstances is multimetal oxide compositions substantially, and said composition is with at least a element among two kinds of array mode containing element Mo, V, Te and the Sb and at least a element among Nb, Ta, W, Ti, Al, Zr, Cr, Mn, Ga, Fe, Ru, Co, Cs, Ca, Sr, Ba, Rh, Ni, Pd, Pt, La, Pb, Cu, Re, Ir, Y, Pr, Nd, Tb, Bi, B, Ce, Sn, Zn, Si, Na, Li, K, Mg, Ag, Au and the In.

From this last element set, preferred described combination containing element Nb, Ta, W and/or Ti, more preferably element nb.

Relevant poly-metal deoxide active composition preferably comprises the combination of aforementioned elements with stoichiometric equation I:

Mo ₁V _bM ¹ _cM ² _d (I)

Wherein

M ¹=Te and/or Sb,

M ²At least a element among=Nb, Ta, W, Ti, Al, Zr, Cs, Ca, Sr, Ba, Cr, Mn, Ga, Fe, Ru, Co, Rh, Ni, Pd, Pt, La, Bi, Pb, Cu, Re, Ir, V, Pr, Nd, Tb, Ce, Sn, Zn, Si, Na, Li, K, Mg, Ag, Au and the In

B=from 0.01 to 1,

C=from＞0 to 1, and

D=from＞0 to 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 is that 0.1-0.6 is favourable.Correspondingly, the preferable range of stoichiometric coefficient c extends to 1 or from 0.05 to 0.4 from 0.01, and the preferred values of d is from 0.001 to 1 or from 0.01 to 0.6.

According to the present invention, especially favourable when stoichiometric coefficient b, c and d are in the aforementioned preferable range simultaneously.

When the active composition in the catalyst charge was constituted by aforementioned elements with regard to the element beyond the deoxygenation, the narration of front was especially suitable.

Thus, these poly-metal deoxide active compositions are specially stoichiometry general formula I I:

Mo ₁V _bM ¹ _cM ² _dO _n (II)

Wherein variable is as the definition to stoichiometry I, and n is the numeral by the valence mumber of the element outside the deoxygenation in the formula (II) and occurrence number decision.

Relevant poly-metal deoxide active composition preferably comprises the element combinations that the beginning among the stoichiometric equation III is quoted from:

Mo ₁V _a′M ⁴ _b′M ⁵ _c′M ⁶ _d′ (III)

Wherein

M ⁴At least a element among=Te and the Sb;

M ⁵At least a element among=Nb, Ti, W, Ta and the Ce;

M ⁶At least a element among=Pb, Ni, Co, Bi, Pd, Cs, Ca, Sr, Ba, Ag, Pt, Cu, Au, Ga, Zn, Sn, In, Re, Ir, Sm, Sc, Y, Pr, Nd and the Tb;

A '=from 0.01 to 1;

B '=from＞0 to 1;

C '=from＞0 to 1; And

D '=from 0 to 0.5;

A ' preferably from 0.05 to 0.6, and more preferably from 0.1 to 0.6 or 0.5.

B ' preferably from 0.01 to 1, more preferably from 0.01 or 0.1 to 0.5 or 0.4.

C ' preferably from 0.01 to 1, more preferably from 0.01 or 0.1 to 0.5 or 0.4.

D ' is preferably from 0.00005 or 0.0005 to 0.5, and more preferably from 0.001 to 0.5, usually for from 0.002 to 0.3 and be generally from 0.005 or 0.01 to 0.1.

M ⁴Be preferably Te.

M ⁵Be Nb, be preferably and account for its total amount 50mol% at least, and be preferably 75mol% at least, most preferably 100mol% at least.

M ⁶Be preferably at least a element among Ni, Co, Bi, Pd, Ag, Au, Pb and the Ga, more preferably at least a element among Ni, Co, Pd and the Bi.

The 50mol% at least of M5 total amount very particularly preferably, or 75mol% at least, or 100mol% is Nb, and M6 is at least a element among Ni, Co, Pd and the Bi.

The best is M according to the present invention ⁴=Te, M ⁵=Nb and M ⁶Be at least a element among Ni, Co and the Pd.

When the element beyond the active composition deoxygenation in the catalyst charge was made of the element combinations in the stoichiometric equation (III), aforementioned range was especially suitable.Thus, these poly-metal deoxide active compositions are specially stoichiometry general formula (IV):

Mo ₁V _a′M ⁴ _b′M ⁵ _c′M ⁶ _d′O _n′ (IV)

Wherein each variable is as the definition to stoichiometry III, and n ' is the numeral by the valence mumber of the element outside the deoxygenation in the formula (IV) and occurrence number decision.

In the method according to the invention, the such poly-metal deoxide active composition of further preferred use, on the one hand, this active composition or comprise above-mentioned element combinations (I) and (III) in a kind of, perhaps form by them about the element outside its deoxygenation; This active composition has the X-ray diffractogram that presents reflection h and I simultaneously, (all information about X-ray diffractogram all is X-ray diffractogram (the siemens Theta-Theta D-5000 diffractometer that obtains as X-radiation with respect to Cu-K α radiation herein at reflection angle (2 θ) 22.2 ± 0.5 ° (h) and 27.3 ± 0.5 ° (I) in its peak position, tube voltage: 40kV, tube current: 40mA, aperture V20 (variable), collimator V20 (variable), the second monochromator aperture (0.1mm), detector aperture (0.6mm), measure (2 θ) at interval: 0.02 °, every pacing amount time: 2.4 seconds, detector: scintillation counter).

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

For the method according to this invention, those above-mentioned poly-metal deoxide active compositions advantageously, its X-ray diffractogram also has the peak of peak position at the reflection k of 28.2 ± 0.5 ° (k) except reflection h and i.

Among the latter, also preferred those poly-metal deoxide active compositions according to the present invention, wherein reflection h has maximum intensity, also has maximum half high width of 0.5 ° at the most in X-ray diffractogram; And very particularly preferably such poly-metal deoxide active composition, the halfwidth degree of its reflection i and reflection k simultaneously≤1 °, and the intensity P of reflection k _kIntensity P with reflection i _iMeeting relational expression 0.2≤R≤0.85, is 0.3≤R≤0.85 preferably, preferred 0.4≤R≤0.85, preferred especially 0.65≤R≤0.85, even more preferably 0.67≤R≤0.75, very particularly preferably R=0.70-0.75 or R=0.72, wherein the R strength ratio of following formula definition of serving as reasons:

R＝P _i/(P _i+P _k)

Preferably, above-mentioned X-ray diffractogram does not have the reflection of maximum value in 2 θ=50 ± 0.3 °.

Herein, in the X-ray diffractogram definition of reflection strength with reference to described in DE-A 19835247, DE-A10122027 and DE-A 10051419 and the DE-A 10046672 definition.These files are equally applicable to the half-and-half definition of high width.

Except reflection h, i and k, the above-mentioned X-ray diffractogram of the poly-metal deoxide active composition that can advantageously use according to the present invention also further comprises the reflection of peak position at following reflection angle (2 θ):

9.0±0.4°(l)

6.7 ± 0.4 ° (o) reaches

7.9±0.4°(p)。

Also to comprise the peak position more favourable at the reflex time of reflection angle (2 θ)=45.2 ± 0.4 ° (q) when X-ray diffractogram.

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

As molecular formula (I), (II), (III) and (IV) in the element combinations of definition more favourable when existing mutually with pure i-.When the catalytic activity oxide composition also comprises the k-phase time, its X-ray diffractogram also comprises peak position other reflection of locating of reflection angle (2 θ) below except above-mentioned reflection: 36.2 ± 0.4 ° and 50 ± 0.4 ° (term i-and k-mutually as defined use in this article among DE-A 10122027 and the DE-A 10119933).

When intensity 100 being appointed as reflection h,, when reflection i, l, m, n, o, p and q have following intensity, be favourable according to the present invention with identical intensity dimension:

I: from 5 to 95, Chang Weicong 5 to 80, are from 10 to 60 sometimes;

L: from 1 to 30;

M: from 1 to 40;

N: from 1 to 40;

O: from 1 to 30;

P: from 1 to 30 reaches

Q: from 5 to 60.

When x-ray diffraction pattern comprises above-mentioned other reflex time, the halfwidth degree usually≤1 °.

The specific surface area of multi-element metal oxide active composition for the treatment of the specific surface area of general formula used according to the invention (II) or poly-metal deoxide active composition (IV) or comprising general formula (I) or element combinations (III) is 1-40m in many situations ²/ g or 10-30m ²/ g (BET surface-area, nitrogen) is particularly when its X-ray diffractogram is as narrates.

Can find the preparation of described poly-metal deoxide active composition in conjunction with the prior art of being quoted from.These prior aries comprise that specifically (in the end among all embodiment of two pieces of files, used drying means is a spraying drying for DE-A 10303526, DE-A 10261186, DE-A10254279, DE-A 10254278, DE-A 10122027, DE-A 10119933, DE-A10033121, EP-A 1192987, DE-A 10029338, JP-A 2000-143244, EP-A962253, EP-A 895809, DE-A 19835247, WO 00/29105, WO 00/29106, EP-A 529853 and EP-A 608838; For example, with 300-350 ℃ temperature in and 100-150 ℃ temperature out; And stream or adverse current are carried out).

Described poly-metal deoxide active composition can use (promptly with powder type) at this point, perhaps is configured as the geometrical shape that is suitable for according to the inventive method (referring to the catalyzer through applying of for example DE-A 10051419 and the geometrical shape of DE-A 10122027) and uses.They are particularly suitable for preparing vinylformic acid by propane, but also are suitable for preparing methacrylic acid by Trimethylmethane.

Be to implement the method according to this invention, the catalyzer that all are mentioned or dilute and use without dilution or with inert particle and/or molding (it does not have any active composition).The suitable dilution material for example is a steatite.

Being shaped, preferably the geometrical shape with the formed catalyst body is identical for the geometrical shape of diluting body.

As described in the document of the multi-element metal oxide active composition catalyzer that is applicable to the method according to this invention, the method according to this invention can be carried out in charging on the fixed bed catalyst or on the fluid catalyst charging.The conversion zone inlet pressure that can adopt according to the present invention was described.

Temperature of reaction especially when adopting the catalyzer of suggestion herein, can be 200-700 ℃, preferred 200-550 ℃ or 230-480 ℃ or 300-440 ℃.

Propane and/or the Trimethylmethane space-time speed on catalyst charge can be 50-3000 liter (STP)/liter (catalyst charge)/h, or 80-1500 liter (STP)/liter/h, or 100-1000 liter (STP)/liter/h, or 120-600 liter (STP)/liter/h, or 140-300 liter (STP)/liter/h.

The space-time speed of initial action gaseous mixture on catalyst charge can be 100-10000 liter (STP)/liter/h, or 300-6000 liter (STP)/liter/h, or 300-2000 liter (STP)/liter/h.Mean residence time in the catalyst charge can be 0.01-10 second, or 0.1-10 second, or 2-6 second.

Prepared vinylformic acid by propane or prepared by Trimethylmethane in the situation of methacrylic acid, the initial action gaseous mixture for example can comprise:

0.5-15 volume %, usually be propane or the Trimethylmethane of 1-7 volume %,

10-90 volume %, usually be the air of 20-50 volume %,

The steam of 0-50 volume %, and

The residuum of recycle gas.

Yet, preparing vinylformic acid with method of the present invention by propane or preparing by Trimethylmethane in the situation of methacrylic acid, the initial action gaseous mixture also can comprise:

0.6-1.2 the propane of volume % or Trimethylmethane,

The air of 65-95 volume %,

The nitrogen of 2-30 volume %,

0.05-0.8 the CO of volume % _x, and

The steam of 2-3 volume %.

The initial action gaseous mixture that preferably comprises 10-50 volume % steam (fresh).

Another possible composition of initial action gaseous mixture for example can comprise:

Propane or the Trimethylmethane of 70-90 volume %,

The molecular oxygen of 5-25 volume %,

The steam of 0-25 volume % reaches

The residuum of recycle gas.

Also preferably comprise the initial gaseous mixture of 10-50 volume % steam altogether at this.In other words, in the situation of propane or Trimethylmethane partial oxidation, the composition that is used for the initial action gaseous mixture of the method according to this invention changes (mol ratio) in following scope usually:

Trimethylmethane or propane: oxygen: H ₂O: other diluent gas=

1∶(0.1-10)∶(0-50)∶(0-50)

Preferred 1: (0.1-10): (0.1-50): (1-50)

More preferably 1: (0.5-5): (1-30): (1-30)

Above-mentioned scope is applied in used other diluent gas when being mainly dinitrogen especially.Other available diluent gas for example is He, Ar, CO and/or CO ₂Deng.

Quite at large, the composition of initial action gaseous mixture is so selected so that it is preferably outside the explosion gases scope.

When the method according to this invention is carried out as partial oxidation reaction, can implement for example single the district in the bundled tube reactor, described in EP-A 700714 and EP-A 700893.Yet this method also can be carried out in the multi-region bundled tube reactor, described in DE-A 19927624, DE-A 19948242, DE-A 19948241, DE-A 19910508 and DE-A 19910506.The method according to this invention can be carried out in fluidized-bed, for example described in the WO 02/0811421.

Based on the propane and/or the Trimethylmethane that are present in the initial action gaseous mixture, in the method according to the invention, propane and/or Trimethylmethane will be 10 or 20-70mol% based on reaction gas mixtures by the once-through transformation efficiency of conversion zone usually, usually be 30-60mol%, and be 40-60mol% or 45-55mol% in many situations.The selectivity that target product forms will be 50-80mol% usually for 40 to 98 or to 95 or to 90mol% usually, be generally 60-80mol%.

Basic separation in the product gas mixture that at least a in principle target product produces from the conversion zone of the method according to this invention can be carried out in the mode that can know from prior art in aftertreatment section of the present invention.Especially, according to the present invention, also can adopt being used for same target product of disclosing in the prior art, as known to the propylene by heterogeneous catalysis and/or iso-butylene partial oxidation prepare in the target product from the isolating substantially last handling process of product gas mixture.

Generally speaking, in the time of in entering aftertreatment section of the present invention, the product gas mixture experience that produces in the conversion zone according to the inventive method is cooled off indirectly and/or directly.

For the target product that will be present in the product gas mixture is separated in the liquid phase substantially, can with in this way the refrigerative product gas mixture (for example in acrylic acid situation, be typically and be chilled to 150-250 ℃) or for example introduce in the absorption tower with the defluent liquid-absorbant of reflux type without the refrigerative product gas mixture, this absorption agent substantially optionally absorbs at least a target product from product gas mixture, for example, as JP-A 2001/0026269, EP-A 990636, JP-A2000/327651, EP-A 925272, EP-A 695736, EP-A 778255, DE-A 2136396, DE-A 2449780, DE-A 4308087, EP-A 982287, EP-A 982289, the description of 19631645 pairs of target products of E P-A 982288 and DE-A and different absorbents.

Substantially absorption agent that two kinds of target products all are suitable for or water (or aqueous mixture, for example aqueous sodium hydroxide solution or water-containing acrylic acid or methacrylic acid), in order to alcohol such as the 2-Ethylhexyl Alcohol or the higher relatively organic solvent of boiling point of esterification of acrylic and methacrylic acid.The boiling point of preferred organic solvent is higher than at least 20 ℃ of boiling points treating the target product that removes from product gas mixture, particularly at least 50 ℃ and more preferably at least 70 ℃ of boiling points that are higher than the target product that desire removes (vinylformic acid and/or be methacrylic acid) from product gas mixture according to the present invention.Preferred organic absorbent has 180-400 ℃ boiling point (under the normal atmosphere), particularly 220-360 ℃ according to the present invention.In the situation of target product vinylformic acid and methacrylic acid, suitable especially absorption agent is the high boiling point that do not contain the external action polar group, hydrophobic solvent extremely according to the present invention, for example aliphatic series or aromatic hydrocarbons, as derive from paraffinic hydrocarbon distillatory intermediate distillates; The ether that perhaps on Sauerstoffatom, has big functional group; Or its mixture; Polar solvent is favourable to wherein adding, as the phthalic acid-1 that discloses among the DE-A 4308087,2-dimethyl ester.Same what be fit to is phenylformic acid and phthalic acid and the ester that contains the straight chain alcohol of 1-8 carbon atom, the positive butyl ester of phenylformic acid for example, methyl benzoate, ethyl benzoate, dimethyl phthalate, diethyl phthalate; And known oil as thermal barrier, the for example mixture of biphenyl, phenyl ether and biphenyl and diphenyl ether or its chlorinated derivative, and triaryl alkane, for example 4-methyl-4 '-benzyl ditane and isomer 2-methyl-2 thereof '-the benzyl ditane, 2-methyl-4 '-benzyl ditane and 4-methyl-2 '-mixture of benzyl ditane and this type of isomer.

The solvent mixture (preferably methacrylic acid being absorbed water) that to be used for acrylic acid particularly preferred absorption agent be biphenyl and phenyl ether, preferably with azeotropic form, particularly based on biphenyl and the phenyl ether of 100 weight %, the phenyl ether of the biphenyl of about 25 weight % (hexichol) and about 75 weight %, for example commercially available

Based on whole solvent mixture, preferred this solvent mixture also comprises polar solvent such as dimethyl phthalate with the amount of 0.1-25 weight %.Advantageously, when with high boiling organic solvent during as absorption agent, with before absorbing in direct-cooled device or in the chilling apparatus part evaporation by absorption agent product gas mixture is cooled to favourable.What be fit to this purpose is specially Venturi scrubber, bubble column or spray condenser.

Herein, the term high boiling material, in boil thing and low-boiling-point substance refer to the boiling point compound higher (high boiling material) respectively than target compound, compound that boiling point and target compound are approximately identical (in boil thing) and the boiling point compound (low-boiling-point substance) lower than target compound are especially when target compound is vinylformic acid.

Quite at large, counter-current absorption is preferably carried out in the tower with structuring filling or random packing or in the tower tray tower, and this tower tray tower preferred fit has double-pass tray and/or valve tray and the solvent of packing into from the top.Product gas mixture (and the solvent from chilling apparatus that not necessarily evaporates) enters the tower from the below, is cooled to absorption temperature subsequently.Advantageously carry out this cooling by cooling loop.In other words, the absorption agent through heating that rises in the tower is removed from tower, cooling and the site recirculation that is being higher than the leading point are returned in the absorption tower in interchanger.After the absorption, all high boiling material, most target compound (for example vinylformic acid) and part low-boiling-point substance are in the absorption agent substantially.Can further target product be removed the absorbate through isolating substantially target compound (for example vinylformic acid) from comprising with any desired purity (for example in DE-A 19606877 or DE-A 19838845) then, this removes method can be described in prior art (for example for absorbing the part of being quoted from), and the absorption agent that does not contain target product can be used further to (for example absorb, utilization will remove and further carries out purifying with rectifying mode and/or crystallization mode (for example suspension crystallization and in the melt cleaning tower crystallisate is removed) in cat head in the organic absorbent of vinylformic acid from organic absorbate, perhaps utilize organic entrainer from the water-based absorbate, further to remove water, and vinylformic acid is removed from containing acrylic acid liquid phase with any desired purity with rectifying mode and/or crystallization mode in cat head in the rectifying mode; In latter's situation, usually overhead product is divided into two-phase (by cooling); Rectifying tower is returned in organic phase recirculation, and water then enters absorption tower (every kind of situation kind all is at cat head)).

Can with remaining unabsorbed bottom product gaseous mixture further cooling to remove easily condensing part in the lower boiling secondary components (for example water, formaldehyde and acetic acid) (being commonly referred to as sour water).According to the present invention, can be with remaining bottom product gaseous mixture separated into two parts, the part in these two portions can be used as recycle gas recirculation (entering conversion zone), and another part is then discharged.According to the present invention, preferably do not have sour water and remove.Especially when in the conversion zone that steam is used in the method according to this invention as diluent gas (when using multi-element metal oxide composition (I), (II), (III) or (IV) time, this is normally favourable for the selectivity that target product forms), to be present in target product in the conversion zone product gas mixture enters liquid phase through basic separation of the present invention and (no matter adopts which kind of separation method, in particular for herein described those) preferably so carry out: loop back according to the present invention in the conversion zone to small part remaining residue product gas mixture, the steam and the mol ratio W that is present in propane wherein that are present in wherein are littler by at the most 50% than the corresponding mol ratio W ' in the conversion zone product gas mixture, preferably at the most 40% or 30%, even at the most 20 or 10%.Under egregious cases, also can be identical according to above-mentioned ratio W in the inventive method and W '.

Attempt steam is stayed in the remaining residue product gas mixture as much as possible is to infeed (or condensation and revaporization) live steam charging in order to exempt very fully in the initial action gaseous mixture herein.

Yet, for anti-sealing is accumulated in reaction gas mixtures, in the method according to the invention the bottom product gaseous mixture of discharging as output partly have to comprise at least with conversion zone in the as many water of water (it is higher to be reflected at the selectivity of carrying out in the conversion zone, and the water yield to be discharged is just fewer) of by-product.This also correspondingly is applicable to other secondary composition that forms in the conversion zone.When air used in the method according to the invention as oxygen source, the work output of bottom product gaseous mixture also must be so simultaneously: the nitrogen amount that is present in wherein is suitable corresponding to the nitrogen amount that is present in the air feed at least.

When used absorption agent was one of high boiling organic solvent, the absorption in situation of the present invention (special in the situation of absorbing propenoic acid) is preferably carried out by this way: the effluent on absorption tower was monophasic.If not so, selected absorption agent no matter, the steam content that remains in the bottom product gaseous mixture in the absorption can be adjusted by the absorption temperature of suitable selection.

As the another kind that target product is separated in the liquid phase substantially being selected by being absorbed into solvent, can also be undertaken this by condensation, particularly fractional condensation and separate (particularly under acrylic acid situation) substantially, for example, as described in DE-A 19924532, DE-A 10200583, DE-A 10053086, DE-A19627847, DE-A 19740253, DE-A 19740252, DE-A 19740253, DE-A19814387 and the DE-A 10247240.

In this condensation, after direct and/or indirect precooling not necessarily, make the conversion zone product gas mixture experience fractional condensation in the knockout tower of being furnished with the separating member that upwards enters itself, target product experiences further crystallization and/or rectifying separation step via the extraction of knockout tower side line and described in prior art.

The condensing tower that preferably comprises separating member is the tower tray tower, and it begins to be double-pass tray from the bottom to vertical separating member, is hydraulic seal cross flow tower tray then, as described above described in the prior art.

Preferably carry out aforementioned fractional condensation by this way according to the present invention: do not remove the water that is present in the product gas mixture substantially.In other words, not having sour water at this removes.

Yet,, still can before with its output, clean the bottom product gaseous mixture part of discharging for water as output for preventing methacrylic acid or loss of acrylic acid.Acrylic or methacrylic acid and any other valuable organic product can be from the containing methacrylic acid or contain acrylic acid sour water and take out of gained, and for example are used to the organic absorbent that absorbs and combine with absorbate.

In order to prevent that pressure drop from increasing, both can replace absorption tower and partial condensation tower with the quench section with absorption agent or condensation product operation that is connected in series in principle.

Quite at large, as about described in the prior art of suitable stopper, inhibition carries out target product is separated to liquid phase substantially from product gas mixture during.

For the present invention, need remain on bottom product gaseous mixture in the isolating substantially target product not only comprises propane and/or Trimethylmethane, also comprises propylene and/or iso-butylene sometimes, and generally also comprise at least 5 volume %, the component of common at least 10 volume %, these components under atmospheric pressure have the boiling point lower than target product.These components particularly are lower than the component (N for example of water for the boiling point under normal pressure in the product gas mixture ₂, CO, CO ₂), also preferably water itself.

According to the advantage of the inventive method be common available gas blower with recycle gas (near top hole pressure P ³) recompress to inlet pressure P ¹In the case, the compressor (be generally axial compressor) of gas blower for having low compression ratio (final pressure for example is 1.1: 1 to 3: 1 than top hole pressure).On the contrary, will be compressed to inlet pressure P as the air (near environmental stress) of oxygen source with radial compressor usually ¹In principle, indication compression herein can be carried out with isothermal mode or multiple temperature mode.The preferred latter according to the present invention.

Even therefrom remove and recompress to inlet pressure P when being present in the propane waiting to discharge in the resultant product gaseous mixture part and/or Trimethylmethane and any propylene and/or iso-butylene ¹And recirculation is when returning conversion zone, not necessarily removes the moisture content (can be recycled in the conversion zone) that is present in wherein afterwards in condensation in advance, and some advantages of the inventive method still keep.

This removes (for the bottom product gaseous mixture all in the prior aries of amount suggestion and also can adopt (specific as follows described) in principle) for example can followingly carry out (with reference to WO 0196271): be present in the propane waiting to discharge in the resultant product gaseous mixture part and/or Trimethylmethane and any propylene and/or iso-butylene to absorb and/or absorption removes and discharges once more by desorb and/or desorption substantially.For example, can implement this release by carrying with air gas from absorbate, for example, described in WO0196271.Also can and be recycled in the conversion zone subsequently this air compression.

In addition, not necessarily after supplemental oxygen, also bottom product gaseous mixture to be discharged partly can be supplied with other oxidation reactor, to improve the transformation efficiency of carbonic acid gas.

Usually, as stating, gas blower is enough to be used in and will recompresses according to the recycle gas in the inventive method.

Appended herein Fig. 1 represents the illustrative embodiments according to the inventive method.

In this figure, different numerals are defined as follows:

The 1=conversion zone

2=aftertreatment section

3=circulating air compressor (gas blower)

4=exports expander

5=output

6=is as the air of oxygen source

The 7=air compressor

Fresh propane of 8=and/or Trimethylmethane and nonessential steam

The recycle gas of 9=recompression

Embodiment

1. has poly-metal deoxide active composition Mo ₁V _0.29Te _0.13Nb _0.13O _xThe Preparation of catalysts of (pure i phase)

With the 87.61g ammonium meta-vanadate (V of 78.55 weight % ₂O ₅, derive from G.f.E., the Nuremburge) and under 80 ℃, be dissolved in (three-necked flask of being furnished with agitator, thermometer and reflux exchanger) in the 3040ml water.Form transparent pale yellow solution.This solution is cooled to 60 ℃, is remaining in 60 ℃ then, stir into the 117.03g telluric acid (H of 99 weight % in succession ₆TeO ₆, derive from Aldrich) and 400.00g Ammonium Heptamolybdate (82.52% MoO by weight ₃, derive from Starck, Goslar).The gained dark red solution is cooled to 30 ℃ (solution A).

In beaker, (Nb of 20.8 weight % derives from Starck, Goslar) is dissolved under 60 ℃ (solution B) in the 500ml water with the 112.67g ammonium niobium oxalate separately.

Solution B is cooled to 30 ℃ and combine with solution A by solution B is joined in the solution A under this temperature.Carried out continuously general 5 minutes.Formation has the orange waterborne suspension of suspended sediment.Subsequently with this spray dried ( _{The T storage tank}=30 ℃, T ^{Go into}=320 ℃, T ^{Go out}=110 ℃, t=1.5h, spray tower derive from Niro type spraying gun).Gained is similarly orange and comprises experience stoichiometric equation Mo through the material of spraying ₁V _0.33Te _0.22Nb _0.11

In according to the spherical baking oven of the revolution of DE-A 10119933 Fig. 1 (1l internal volume), 2 * 100g is heat-treated through the powder of spraying, at first under the airflow of 50 liters of (STP)/h, be heated to 275 ℃ from 25 ℃ through 27.5 minutes, keep this temperature 1h subsequently by linear temperature increase.Afterwards, within 32.5 minutes, this baking oven is heated to 600 ℃ from 275 ℃, during this period, replaces airflow with the nitrogen gas stream of 50 liters of (STP)/h by linear temperature increase.When continuing logical nitrogen gas stream, with 600 ℃ of maintenance 2h, subsequently with whole baking oven cool to room temperature.With 100g gained oxide composition in 70 ℃ refluxing under at HNO at 1000ml 10 weight % ₃Stirred in the aqueous solution 7 hours, and remaining solid was leached from the gained slip and water (25 ℃) is washed till and does not contain nitrate.With the gained filter cake under air in retort furnace 110 ℃ of following dried overnight.

Gained solid chemical analysis is obtained forming Mo ₁V _0.29Te _0.13Nb _0.13O _xAppended X-ray diffractogram has shown pure i phase.

Then, described in DE-A 10119933, this dried material is ground in Retsch mill (granular size≤0.12mm) and, as example A) at DE-A 10119933 a) in, its processing is obtained catalyzer through applying:

With the active composition of 38g grinding, the ball type carrier (solid support material=Steatite C-220 that the 150g diameter is 2.2-3.2mm, derive from CeramTec, Germany, surfaceness Rz is 45 μ m), the mixture of tackifier=30ml glycerine and water (glycerine: water weight ratio=1: 3), time of drying=150 ℃ following 16h; The activity of such catalysts component of gained through applying is 20 weight % (based on the catalyst weights through applying).

2. under the different pressures, propane is to acrylic acid heterogeneous catalysis partial direct oxidation.

The catalyzer through applying that derives from 1 is used to load the stainless steel reaction tubes of V2A (pipe range 140cm) (external diameter=60mm, internal diameter=8.5mm).Selected filling length is 53cm (=about 35.0g is through the catalyzer of coating).Preparation bed as the long 30cm of the steatite ball of solid support material is used to locate the catalyzer band.Use identical steatite ball catalyst filling band reaction tubes (being used to heat the preheating zone of initial action gaseous mixture) afterwards at last.This reaction tubes on its whole length with electric pad from indirect heating.The mole of initial action gaseous mixture consists of propane: air: water=1: 15: 14.Express the per pass conversion (C of gained propane down ^PAN, mol%), follow the vinylformic acid of the selected inlet pressure function of conduct of this transformation efficiency to form selectivity (S ^ACA, mol%) and the heating cushion relevant temperature.The residence time (based on the catalyst bed volume) is 2.4 seconds in all scenario.In addition, this table is with S ^PEBThe selectivity of propylene by product is shown.

Table

Inlet pressure [crust, absolute]	T [℃]	C PAN (mol％)	S ACA (mol％)	S PEB (mol％)
					1.3	390	28	70	10
1.3	440	53	39	5
					6	330	32	69	5
6	350	50	70	3
					6	390	77	60	1

Under higher working pressure, when not changing the target product compound selective substantially, obtaining higher conversion of propane under the lower temperature.In addition, this product gas mixture comprises a small amount of other acid as acetic acid and CO in all scenario _x

3. under the given recycle gas ratio, as top hole pressure P ³The output according to isothermal compressor in the inventive method of function.

Process 2 is carried out in the device of arranging according to Fig. 2.Transformation efficiency that its basis is 40mol% and the vinylformic acid of 70mol% form selectivity.Propane: oxygen: the water mole is formed suitable with 2 composition.Recycle gas control influences nitrogen content.Different numerals are defined as follows:

The 1=conversion zone

2=aftertreatment section

The discharge section of 3=bottom product gaseous mixture

4=circulating air compressor (gas blower)

The 5=air compressor

6=is as the air of oxygen source

Fresh propane of 7=and live steam

The recycle gas of 8=recompression

9=is used to adjust mouth pressure P ³Throttling set

10=has inlet pressure P ¹The initial action gaseous mixture.

Fresh propane and live steam can obtain with required inlet pressure in every kind of situation.

In other words, P ³Change only can influence the output of circulating air compressor and the output of air compressor.

For simplicity, suppose that two kinds of compressors all are isothermal compression.

According to Verlag des Vereins Deutscher Ingenieure, Dusseldorf, the 5th ^ThVersion, 1988,1 page of La, air compressor (V ^L) isothermal compressor be output as:

$V^L=\frac{\stackrel{\&CenterDot;}{m_L}}{n_L}\&CenterDot;Z_L\&CenterDot;R\&CenterDot;T_L\&CenterDot;\ln \left(\frac{{\mathrm{<figure-callout\; id="1"\; label="P"\; filenames="C20048000951700351.png,C20048000951700361.png"\; state="\{\{state\}\}">P</figure-callout>}}^1}{1}\right)$

Wherein

n _L=air compressor efficient

Z _LThe real gas factor of=air;

R=specific gas constant=ideal gas constant is divided by molar mass;

T _LThe temperature of=the fresh air that sucks from environment;

Barometric point (environmental stress)=1 crust that the l=air sucks;

P ¹=entering the inlet pressure of conversion zone, the air compression enters this conversion zone;

In other words, $V^L=\stackrel{\&CenterDot;}{m_L}\&CenterDot;A\&CenterDot;\ln \&CenterDot;{\mathrm{<figure-callout\; id="1"\; label="P"\; filenames="C20048000951700351.png,C20048000951700361.png"\; state="\{\{state\}\}">P</figure-callout>}}^1,$ Wherein A is a constant;

In correlation method, circulating air compressor V ^KIsothermal compressor be output as:

$V^K=\frac{\stackrel{\&CenterDot;}{m_K}}{n_K}\&CenterDot;Z_K\&CenterDot;R\&CenterDot;T_K\&CenterDot;\ln \frac{P^1}{{\mathrm{<figure-callout\; id="3"\; label="P"\; filenames="C20048000951700351.png,C20048000951700361.png"\; state="\{\{state\}\}">P</figure-callout>}}^3}.$

In other words $V^K=\stackrel{\&CenterDot;}{m_K}\&CenterDot;A^{\&prime;}\&CenterDot;\ln \frac{P^1}{{\mathrm{<figure-callout\; id="3"\; label="P"\; filenames="C20048000951700351.png,C20048000951700361.png"\; state="\{\{state\}\}">P</figure-callout>}}^3},$ Wherein A ' is a constant, wherein: A ' ≈ A.

Therefore, for total compressor output V to be adopted _Ges=V ^L+ V ^K:

$V_{\mathrm{ges}}=\stackrel{\&CenterDot;}{m_L}\&CenterDot;A\&CenterDot;\ln \&CenterDot;{\mathrm{<figure-callout\; id="1"\; label="P"\; filenames="C20048000951700351.png,C20048000951700361.png"\; state="\{\{state\}\}">P</figure-callout>}}^1+\stackrel{\&CenterDot;}{m_K}\&CenterDot;A^{\&prime;}\ln \frac{P^1}{{\mathrm{<figure-callout\; id="3"\; label="P"\; filenames="C20048000951700351.png,C20048000951700361.png"\; state="\{\{state\}\}">P</figure-callout>}}^3}.$

$P^1-{\mathrm{<figure-callout\; id="3"\; label="P"\; filenames="C20048000951700351.png,C20048000951700361.png"\; state="\{\{state\}\}">P</figure-callout>}}^3=C\&CenterDot;\frac{1}{{\mathrm{<figure-callout\; id="1"\; label="P"\; filenames="C20048000951700351.png,C20048000951700361.png"\; state="\{\{state\}\}">P</figure-callout>}}^1},$ Wherein C is a constant, characterizes used reaction and after-treatment device, and

$V_{\mathrm{ges}}=\stackrel{\&CenterDot;}{m_K}\&CenterDot;A\&CenterDot;[(1+\frac{1}{K_r})\ln (\frac{{\mathrm{<figure-callout\; id="3"\; label="P"\; filenames="C20048000951700351.png,C20048000951700361.png"\; state="\{\{state\}\}">P</figure-callout>}}^3}{2}+\sqrt{{\left(\frac{{\mathrm{<figure-callout\; id="3"\; label="P"\; filenames="C20048000951700351.png,C20048000951700361.png"\; state="\{\{state\}\}">P</figure-callout>}}^3}{2}\right)}^2+C})-\ln P^3].$

When the recycle gas ratio one is chosen to be 2.5 and when once being 3.5, constant C is defined as C=(1.5 crust+Δ P _1.5) Δ P _1.5,

Δ P wherein _1.5Be top hole pressure (outlet of aftertreatment section) be 1.5 crust down through the total pressure drop of entire reaction section and aftertreatment section, be 2 crust and specify C=(1.5 crust+2 crust) 2 crust=7 to cling in the pressure drop according to the inventive method of its representative ²The time, with the recycle gas flow velocity $\stackrel{\&CenterDot;}{m_K}=166\mathrm{kg}/\sec$ K _f=2.5 and with the recycle gas flow velocity $\stackrel{\&CenterDot;}{m_K}=213\mathrm{kg}/\sec$ K _f=3.5 times, for two kinds of selected recycle gas ratios, obtain (selecting

Value so that in two kinds of situations acrylic acid Space Time productive rate identical) shown in Fig. 3 as P ³The V of function _GesGraphic representation (suppose along with pressure increase transformation efficiency and selectivity constant, according to 2 this sets up as a result).

From P ³=1.5 crust beginnings, compressor to be adopted is exported in two kinds of situations generally speaking all with P ³Increase and increase, proved the advantage of process of the present invention.

Claims (59)

1. propane and/or Trimethylmethane heterogeneous catalysis partial direct oxidation react at least a method to target product vinylformic acid and the methacrylic acid, with initial action gaseous mixture supply response section, this initial action gas mixture comprises propane and/or Trimethylmethane, molecular oxygen and at least a inert dilution gas and has inlet pressure P in this method ¹Except the outlet of initial action gaseous mixture, outside other nonessential auxiliary gas entry and the product gas mixture outlet, this conversion zone seals at gas side, in conversion zone, by the initial action gaseous mixture is passed on solid catalyst, the propane and/or the Trimethylmethane direct part that will be present in the initial action gaseous mixture are oxidized at least a target product, to introduce the aftertreatment section as the reactant gas mixtures of product gas mixture then, this product gas mixture comprises at least a target product and with top hole pressure P ²Leave conversion zone, and with this pressure P ²Enter into the aftertreatment section, except product gas mixture inlet, nonessential other auxiliary gas entry and the outlet of bottom product gaseous mixture, this aftertreatment section seals at gas side, in the aftertreatment section, the target product that will be present in the conversion zone product gas mixture segregates into the liquid phase from this product gas mixture substantially, and the remaining residue product gas mixture drawn the aftertreatment section, this remaining residue product gas mixture not only comprises propane and/or Trimethylmethane, sometimes propylene and/or iso-butylene is arranged also, and has top hole pressure P ³, P wherein ³＜P ¹, and will be present in the propane in the bottom product gaseous mixture and/or be that Trimethylmethane is recycled to conversion zone; It comprises selects P ¹So that P ³〉=1.5 crust, and the bottom product gaseous mixture is divided into two portions of same composition, a part is discharged as product, and another part is as recycle gas recirculation and will be compressed to inlet pressure P ¹This part and return to conversion zone as the component of initial action gaseous mixture.

2. the process of claim 1 wherein that the bottom product gaseous mixture comprises the component of at least 5 volume % except that propane and/or Trimethylmethane and propylene and/or iso-butylene.

3. the process of claim 1 wherein that the bottom product gaseous mixture comprises the component of at least 10 volume % except that propane and/or Trimethylmethane and propylene and/or iso-butylene.

4. each method, wherein P in the claim 1 to 3 ³〉=1.5 the crust and≤25 the crust.

5. each method, wherein P in the claim 1 to 3 ³〉=1.5 the crust and≤20 the crust.

6. each method, wherein P in the claim 1 to 3 ³〉=1.5 the crust and≤10 the crust.

7. each method, wherein P in the claim 1 to 3 ³〉=2 the crust and≤8 the crust.

8. each method, wherein P in the claim 1 to 3 ¹Compare P ³High 1-4 crust.

9. the method for claim 7, wherein P ¹Compare P ³High 1-4 crust.

10. each method, wherein P in the claim 1 to 3 ¹Compare P ³High 1.5-3.5 crust.

11. the method for claim 7, wherein P ¹Compare P ³High 1-4 crust.

12. each method, wherein P in the claim 1 to 3 ¹Be the 3-10 crust.

13. the method for claim 4, wherein P ¹Be the 3-10 crust.

14. the method for claim 11, wherein P ¹Be the 3-10 crust.

15. each method, wherein P in the claim 1 to 3 ¹Be the 4-8 crust.

16. the method for claim 4, wherein P ¹Be the 4-8 crust.

17. the method for claim 11, wherein P ¹Be the 4-8 crust.

18. each method in the claim 1 to 3 is wherein discharged via expander as the bottom product gaseous mixture part that output is discharged.

19. the method for claim 17 is wherein discharged via expander as the bottom product gaseous mixture part that output is discharged.

20. each method in the claim 1 to 3, wherein conversion zone is tube bundle reactor or the fluidized-bed reactor that is filled with catalyzer.

21. the method for claim 19, wherein conversion zone is tube bundle reactor or the fluidized-bed reactor that is filled with catalyzer.

22. each method in the claim 1 to 3, wherein aftertreatment section are the quench section of absorption tower or partial condensation tower or series arrangement.

23. the method for claim 21, wherein aftertreatment section are the quench section of absorption tower or partial condensation tower or series arrangement.

24. each method in the claim 1 to 3, wherein the catalyst activity composition is a multimetal oxide compositions, its containing element Mo, V, with at least a in Te and two kinds of elements of Sb, and the combination of at least a element among Nb, Ta, W, Ti, Al, Zr, Cr, Mn, Ga, Fe, Ru, Co, Cs, Ca, Sr, Ba, Rh, Ni, Pd, Pt, La, Pb, Cu, Re, Ir, Y, Pr, Nd, Tb, Bi, B, Ce, Sn, Zn, Si, Na, Li, K, Mg, Ag, Au and the In.

25. the method for claim 23, wherein the catalyst activity composition is a multimetal oxide compositions, its containing element Mo, V, with at least a in Te and two kinds of elements of Sb, and the combination of at least a element among Nb, Ta, W, Ti, Al, Zr, Cr, Mn, Ga, Fe, Ru, Co, Cs, Ca, Sr, Ba, Rh, Ni, Pd, Pt, La, Pb, Cu, Re, Ir, Y, Pr, Nd, Tb, Bi, B, Ce, Sn, Zn, Si, Na, Li, K, Mg, Ag, Au and the In.

26. each method in the claim 1 to 3, wherein the activity of such catalysts composition is for comprising the multimetal oxide compositions of stoichiometric equation (I) element combinations:

Mo ₁V _bM ¹ _cM ² _d (I)

Wherein

M ¹=Te and/or Sb,

M ²At least a element among=Nb, Ta, W, Ti, Al, Zr, Cs, Ca, Sr, Ba, Cr, Mn, Ga, Fe, Ru, Co, Rh, Ni, Pd, Pt, La, Bi, Pb, Cu, Re, Ir, Y, Pr, Nd, Tb, Ce, Sn, Zn, Si, Na, Li, K, Mg, Ag, Au and the In

B=from 0.01 to 1,

C=from＞0 to 1, and

D=from＞0 to 1.

27. the method for claim 23, wherein the activity of such catalysts composition is for comprising the multimetal oxide compositions of stoichiometric equation (I) element combinations:

Mo ₁V _bM ¹ _cM ² _d (I)

Wherein

M ¹=Te and/or Sb,

M ²At least a element among=Nb, Ta, W, Ti, Al, Zr, Cs, Ca, Sr, Ba, Cr, Mn, Ga, Fe, Ru, Co, Rh, Ni, Pd, Pt, La, Bi, Pb, Cu, Re, Ir, Y, Pr, Nd, Tb, Ce, Sn, Zn, Si, Na, Li, K, Mg, Ag, Au and the In

B=from 0.01 to 1,

C=from＞0 to 1, and

D=from＞0 to 1.

28. each method in the claim 1 to 3, wherein used oxygen source is an air.

29. the method for claim 27, wherein used oxygen source is an air.

30. each method in the claim 1 to 3, wherein temperature of reaction is 200-700 ℃.

31. the method for claim 29, wherein temperature of reaction is 200-700 ℃.

32. each method in the claim 1 to 3, wherein the initial action gaseous mixture comprises:

0.5-15 the propane of volume % or Trimethylmethane,

The air of 10-90 volume %,

The steam of 0-50 volume %, and

The recycle gas of residual content.

33. the method for claim 31, wherein the initial action gaseous mixture comprises:

0.5-15 the propane of volume % or Trimethylmethane,

The air of 10-90 volume %,

The steam of 0-50 volume %, and

The recycle gas of residual content.

34. each method in the claim 1 to 3, wherein the initial action gaseous mixture comprises:

0.6-1.2 the propane of volume % or Trimethylmethane,

The air of 65-95 volume %,

The nitrogen of 2-30 volume %,

0.05-0.8 the CO of volume % _x, and

The steam of 2-3 volume %.

35. the method for claim 31, wherein the initial action gaseous mixture comprises:

0.6-1.2 the propane of volume % or Trimethylmethane,

The air of 65-95 volume %,

The nitrogen of 2-30 volume %,

0.05-0.8 the CO of volume % _x, and

The steam of 2-3 volume %.

36. each method in the claim 1 to 3, wherein the initial action gaseous mixture comprises:

Propane or the Trimethylmethane of 70-90 volume %,

The molecular oxygen of 5-25 volume %,

The steam of 0-25 volume % reaches

The recycle gas of residual content.

37. the method for claim 31, wherein the initial action gaseous mixture comprises:

Propane or the Trimethylmethane of 70-90 volume %,

The molecular oxygen of 5-25 volume %,

The steam of 0-25 volume % reaches

The recycle gas of residual content.

38. each method in the claim 1 to 3 is wherein passed conversion zone based on the reaction gas mixtures one way, the transformation efficiency of propane and/or Trimethylmethane is 10-70mol%.

39. the method for claim 37 is wherein passed conversion zone based on the reaction gas mixtures one way, the transformation efficiency of propane and/or Trimethylmethane is 10-70mol%.

40. the method for claim 38, wherein the selectivity of target product formation is 40-98mol%.

41. the method for claim 39, wherein the selectivity of target product formation is 40-98mol%.

42. each method in the claim 1 to 3, wherein will be present in target product in the conversion zone product gas mixture and separate substantially by this way and enter in the liquid phase, promptly be present in steam and the mol ratio W that is present in propane wherein in the remaining residue product gas mixture than the corresponding mol ratio W ' in the conversion zone product gas mixture little at least 50%.

43. the method for claim 41, wherein will be present in target product in the conversion zone product gas mixture and separate substantially by this way and enter in the liquid phase, promptly be present in steam and the mol ratio W that is present in propane wherein in the remaining residue product gas mixture than the corresponding mol ratio W ' in the conversion zone product gas mixture little at least 50%.

44. each method in the claim 1 to 3, wherein will be present in target product in the conversion zone product gas mixture by being absorbed in the organic solvent and separate substantially by this way and enter in the liquid phase in the absorption tower, promptly the effluent on absorption tower is monophasic.

45. the method for claim 43 wherein will be present in target product in the conversion zone product gas mixture and separate substantially by this way and enter in the liquid phase by being absorbed in the organic solvent in the absorption tower, promptly the effluent on absorption tower is monophasic.

46. each method in the claim 1 to 3 will be present in propane in the bottom product gaseous mixture part of discharging as output and/or Trimethylmethane and any propylene and/or iso-butylene and shift out and recompress to inlet pressure P from described bottom product gaseous mixture ¹And conversion zone is returned in recirculation.

47. the method for claim 45 will be present in propane in the bottom product gaseous mixture part of discharging as output and/or Trimethylmethane and any propylene and/or iso-butylene and shift out and recompress to inlet pressure P from described bottom product gaseous mixture ¹And conversion zone is returned in recirculation.

48. each method in the claim 1 to 3, wherein as the ratio V of the bottom product gaseous mixture of recycle gas recirculation part and the entrap bubble mixture part of discharging as output be 〉=0.5 and≤30.

49. the method for claim 47, wherein as the ratio V of the bottom product gaseous mixture of recycle gas recirculation part and the entrap bubble mixture part of discharging as output be 〉=0.5 and≤30.

50. each method in the claim 1 to 3, wherein as the ratio V of the bottom product gaseous mixture of recycle gas recirculation part and the entrap bubble mixture part of discharging as output be 〉=2 and≤25.

51. the method for claim 47, wherein as the ratio V of the bottom product gaseous mixture of recycle gas recirculation part and the entrap bubble mixture part of discharging as output be 〉=2 and≤25.

52. each method in the claim 1 to 3, wherein as the ratio V of the bottom product gaseous mixture of recycle gas recirculation part and the entrap bubble mixture part of discharging as output be 〉=3 and≤20.

53. the method for claim 47, wherein as the ratio V of the bottom product gaseous mixture of recycle gas recirculation part and the entrap bubble mixture part of discharging as output be 〉=2 and≤25.

54. each method in the claim 1 to 3 wherein recompresses recycle gas to inlet pressure P with gas blower ¹

55. the method for claim 53 wherein recompresses recycle gas to inlet pressure P with gas blower ¹。

56. each method in the claim 1 to 3, wherein used oxygen source is for to be compressed to inlet pressure P with radial compressor ¹Air.

57. the method for claim 55, wherein used oxygen source is for to be compressed to inlet pressure P with radial compressor ¹Air.

58. each method in the claim 1 to 3, be a kind of with the propane partial direct oxidation to acrylic acid.

59. the method for claim 57, be a kind of with the propane partial direct oxidation to acrylic acid.

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