CN104649875B - Propylene selective oxidation method - Google Patents

Abstract

The invention relates to a method for preparing acrolein by propylene oxidation, wherein reaction raw materials of propylene, water and air enter a fixed bed single-tube reactor after being preheated by a preheater at a temperature of more than 120 ℃, and are heated by a salt bath, wherein the volume percent of the propylene is 8-14%, the volume percent of the air is 70-74%, and the water vapor is 15-20%; an oxidation catalyst is filled in the fixed bed reactor, the catalyst contains molybdenum, bismuth, iron, cobalt, tungsten and potassium elements, the catalyst also contains strontium titanate, and the finished catalyst is obtained after the molybdenum and bismuth-containing (I) and the strontium titanate are mixed according to the mass percent of 90-98% and 0.4-10%, kneaded, formed, dried and roasted. The catalyst has stable structure, active components such as molybdenum and the like are not easy to lose, the active phase is not easy to generate phase transformation, and the selectivity and the yield of target products are improved. Acrolein and acrylic acid can be stably produced for a long period.

Description

A kind of Propylene Selectivity method for oxidation

Technical field

The present invention relates to a kind of Propylene Selectivity method for oxidation, be particularly suited for Propylene Selectivity oxidation preparation third Olefine aldehydr.

Background technology

The reaction unit that methacrylaldehyde is prepared in industrial propylene oxidation is mainly many reaction tubes, is ensureing catalyst not It is sintered, on the premise of service life length, improves as far as possible selectively and purpose product yield, conservation, Even if if feed stock conversion, methacrylaldehyde acrylic acid yield improve 0.1～0.5 percentage point, the amount of the product obtained Increasing with hundreds of～thousands of tons of level, its economic benefit is also the most considerable.

It is mainly molybdenum system multicomponent catalyst about propylene fraction oxidation acrolein, acrylic acid catalyst.Due to It is strong exothermal reaction that the acrylic acid reaction of methacrylaldehyde is prepared in Propylene Selectivity oxidation, so being passed through ratio in course of reaction The steam that heat is big, effectively to remove reaction heat, but the active component molybdenum in catalyst etc. are at gas such as steam Easy loss under the washing away of stream.And, under the high temperature conditions, in catalyst, part active component molybdenum is from catalyst Surface loses because of distillation.The loss of active component molybdenum cause reduce the activity of catalyst, selectivity, intensity and Service life, and molybdenum is in the deposition in reaction system downstream, and blocking pipeline affects the long-term operation of system.

It addition, the active component molybdenum etc. in catalyst i.e. enables and keeps not running off, basic before and after the reaction of molybdenum equal size Change is little, but through long-term operation activity compatible, phase in version easily occurs.Key component bag in catalyst Include Fe₂(MoO₄)₃、α-Bi₂(MoO₄)₃、CoMoO₄And NiMoO₄, wherein α-Bi₂(MoO₄)₃It is to live in surface Property center, plays selective oxidation effect；Fe₂(MoO₄)₃Play redox facilitation；CoMoO₄With NiMoO₄Play Stability Analysis of Structures effect.But, catalyst prepared by employing coprecipitation method is many due to component, mistake Journey is complicated, and catalyst stabilization differs, although initial activity is the highest, but inactivation is fast.Cause many components It is a lot, wherein because have that Mo-Bi-Co-Fe-O catalyst and Mo-V-O catalysqt deactivation and stability decline Change including sublimation and the irreversible crystalline phase because of local abnormal high temperature (focus) caused Mo component Deng.These factors all can cause the change of specificity of catalyst, causes the reduction of catalyst activity and shortens catalysis The service life of agent.By decaying catalyst being carried out phenetic analysis, find Fe₂(MoO₄)₃It is reduced into FeMoO₄, and α-Bi₂(MoO₄)₃It is changed into γ-Bi₂MoO₆。

Solving the problems referred to above, the patent related to is the most, such as, for suppressing the loss of molybdenum, CN1583261 Disclose a kind of gas for the gas containing unsaturated aldehyde Yu a kind of molecule-containing keto and carry out selective oxygen in the gas phase Changing the O composite metallic oxide catalyst of reaction, its catalyst consists of: [Mo_aV_bCu_cX_d] 1Y_m[Sb_eZ¹ _fZ² _g]_nO_xWherein Mo is molybdenum, and V is vanadium, and Cu is copper, and Sb is antimony, X be at least selected from tungsten and A kind of element of niobium, Y is at least selected from titanium, a kind of element of antimony, Z₁It it is the one unit of at least chosen from Fe and nickel Element, Z₂At least selected from silicon, aluminium, a kind of element of alkali and alkaline earth metal ions, a, b, c, d, e, f, G and x represents the atomic ratio number of its element, and time on the basis of a=12, b is a number of 1 to 6, and c is 0.5 To a number of 4, d is a number of 0.05 to 4, and e is a number of 0.1 to 30, and f is 0 to 25 A number, g is a number of 0.01 to 20；Needed for x is by meeting each metallic element combined oxidation state One number；Catalyst is made up of its each element oxide or composite oxides.

In order to improve the stability of catalyst, the open a kind of acrylic acid catalyst of CN1130172, respectively with partially Ammonium vanadate and copper nitrate, and with Low Valent Vanadium oxide and/or at a low price Cu oxide part replace ammonium metavanadate and/or Copper nitrate makees the catalyst obtained by the raw material of vanadium metal and copper or in addition to above-mentioned raw materials, uses antimony oxidation at a low price Thing and/or the catalyst that tin-oxide obtains at a low price demonstrate there is a strengthened peak (vanadium-molybdenum at d=4.00 Reactive compound is peculiar) and the V of a remitted its fury is had at d=4.38_₂O₅Specific peak.So, above-mentioned The catalyst obtained has the catalysis activity of raising, and long-term performance can go out stability.Similar also has patent Document 1: Japanese Unexamined Patent Publication 2002-233757 publication, patent document 2: Japanese Unexamined Patent Publication 8-299797 public affairs Report, patent document 3: Japanese Unexamined Patent Publication 9-194213 publication, patent document 4: Japanese Unexamined Patent Application Publication 2004-504288 Number publication；CN102066000A.

For improving the activity of catalyst, selectivity and catalyst life, CN200980112659.3 discloses one Kind comprise the coating catalyst of following components: (a) carrier, before (b) comprises molybdenum oxide or form molybdenum oxide The ground floor of body compound, (c) comprises the second layer containing molybdenum He the poly-metal deoxide of at least one other metal. The preferably molybdenum oxide of ground floor is MoO₃, the poly-metal deoxide of the second layer is many metals that formula II represents Oxide: Mo₁₂Bi_aCr_bX¹ _cFe_dX² _eX³ _fO_y.This catalyst is the application type catalyst including carrier.Invention Purpose be suppression heterogeneously catalysed partial gas phase oxidation methacrylaldehyde be acrylic acid coating catalysqt deactivation, have and change The inactivation performance entered.This invention is not expressly recited catalyst for being catalyzed propylene oxidation acrolein, propylene The reactivity worth evaluating data of acid, such as conversion ratio, selectivity, yield etc..The open one of CN87103192 The method producing composite oxide catalysts, the Mo-Bi composite oxide catalytic wherein represented with following chemical formula The production method of agent includes coherent element source compound to mix form compound in Aquo System and be combined this Thing is heat-treated, and uses the one of the waltherite compound of (a) Bi and Na or (b) Bi, Na and X or (c) Bi and X Compound, as Bi source, at least contains required Na and/or X of part wherein in this compound: X represent Mg, Ca, Zn, Ce and/or Sm；Y represents K, Rb, Cs and/or Tl；Z represents B, P, As and/or W；A-K represents Respective atomic ratio, as a=12, b=0.5-7, c=0-10, d=0-10, c+d=1-10, e=0.05-3, f=0.01-1, G=0-1, h=0.04-0.4, i=0-3, j=0-48, k is a number meeting other element oxide state.Solve Bi Can in composite oxide catalysts homodisperse problem.Containing α-Bi in catalyst₂(MoO₄)₃、MoO₃Fe₂ (MoO₄)₃With β-CoMoO₄、y-Bi₂MoO₆And γ-Bi₂MoO₆.The open one of CN101690900A Preparing the preparation method of methacrylaldehyde and acrylic acid catalyst, catalyst is supported thing and inert alumina by active component Carrier forms；Active component mainly comprises element, selected from Mo, Bi, Co and/or Ni and Fe, also comprises The trace elements such as K, Na, Rb, Cs, Mg, Ca, Zn, B, P, W；The wherein following table of active component The formula of stating represents: Mo_aBi_bCo_cNi_dFe_eX_fY_gZ_hO_iIn formula, X represents at least one of K, Na, Rb and Cs, Y represents that at least one in B, P and W, Z represent at least one in Mg, Ca, Zn.Live The ratio that property component is supported on carrier accounts for the 5-70% of overall catalyst weight；Active component is uneven distribution, CoMoO₄、NiMoO₄Aluminate Deng divalent metal is positioned at the kernel of catalyst activity component；Fe₂(MoO₄)₃ And the MoO of free state₃Invest the outer layer of kernel；And the outermost layer of active component is bismuth molybdate, formation core- The state of shell layer distributed.In active component, divalence molybdate is mainly beta phase structure, and α phase structure is in active component Middle content is the lowest or does not exists.Catalyst has high activity and high stability.CN1280036 mono-kind produces not Saturated aldehyde and the catalyst of unsaturated carboxylic acid, described production be by make at least one be selected from propylene, isobutene, The compound of the tert-butyl alcohol and methyl tertiary butyl ether(MTBE) and oxygen molecule or the gas containing oxygen molecule carry out vapour-phase oxidation and Realize, it is characterised in that this catalyst is a kind of combined oxidation compositions, contains: (A) containing molybdenum, bismuth and Iron, as the composite oxides of key component, itself is known for urging that described vapor phase catalytic oxidation reacts Agent, and (B) containing cerium and zirconium as the composite oxides of key component.Catalyst has long catalytic life also Make to operate steadily in the long term to be possibly realized.Wherein component (B), is the composite oxides represented by below general formula (2): Ce_pZr_qF_rO_y.The zirconium oxide of high degree of dispersion inhibits the gathering of cerium oxide, to keep the latter in course of reaction In to absorbing and discharge the promotion functions of oxygen significantly, thus accelerate the oxidation reaction of isobutene, therefore improve Catalysis activity.Additionally, further suppress component (A) composite oxides that cause because of over reduction in time Irreversible activity reduces (i.e. the stability of composite oxides improves), so that catalytic life extends.This The catalysis activity that improve and the catalytic life extended inhibit reaction temperature to raise in time, thus reduce Molybdenum is in the distillation of hot spot.This catalyst is used for isobutylene oxidation.

CN102489309A discloses a kind of catalyst preparation for producing methacrylaldehyde and renovation process.Catalyst For having the composite oxides of following atomic ratio: Mo: Bi: Co: Ni: Fe=10-14: 1.2-2.0: 4.8-5.6∶2-3∶1-2；This catalyst has a pore size distribution more concentrated, moderate total pore volume, wherein The mesopore of about 5-10nm accounts for more than the 70% of total pore size distribution, forms short and thick pore passage structure, this feature Give the anti-carbon deposition ability that catalyst is stronger, catalyst surface not easy-sintering, it is possible to extend the use longevity of catalyst Life.And the renovation process provided by the present invention, decaying catalyst carries out calcining in 1-3 days in an oxidizing atmosphere Processing, catalyst activity is suitable with fresh catalyst.CN87103192 produces Mo-Bi-Na composite oxides The method of catalyst prod, the method includes that mixing coherent element source compound forms compound, then carries out at heat Reason, the basic bismuth carbonate of the required Na of part is as Bi source compound using the most solid solution.Catalyst Activity imports the catalyst of specific water-insoluble compound formation by means of Bi and Na and is improved greatly. CN101850259A discloses propylene oxidation under a kind of high-speed and prepares the preparation method of the catalyst of methacrylaldehyde, should Catalyst is based on Mo-Bi-Fe-Co metal composite oxide, and formula is； MoaBibFecCodXeYfZgOh, wherein Mo represents that molybdenum, Bi represent that bismuth, Fe represent that iron, Co represent cobalt, X be in W, Sb, As, P, Ni, Sn and Pb at least one element, Y be selected from Zn, At least one element in Cr, Mn, Ru, Ag, Pd and Ru, Z be selected from Na, K, Li, Rb, Cs, At least one element in Ca, Mg, Sr and Ba；A, b, c, d, e, f and g represent the former of each element Sub-ratio, i.e. as a=12, b is 0.1～7, and c is 0.5～8, and d+e is 0.5～20, and f is 0～1, and g is 0～2, h are the numeral determined by the oxidation state of above-mentioned each element；This catalyst is obtained by coprecipitation method, Used by will, the precursor compound of component obtains the pulpous state liquid that pH is 1.5～3.0 under co-precipitation, should Pulpous state liquid is dried rapidly, add dilution thermal conducting agent shaping, roasting and obtain catalyst；Or at above-mentioned gained In pulpous state liquid add dilution thermal conducting agent, the most after drying, shaping, roasting and obtain catalyst.This catalyst selects Being incorporated in catalyst with the dilution thermal conducting agent with excellent heat conductivity performance, dilution thermal conducting agent is silica flour, solves The rendezvous problem of focus under high-speed, makes catalyst have selectivity excellent.This invention mainly by Catalyst preparation process adds dilution thermal conducting agent silica flour and improves the selectivity of catalyst.Silica flour is at methacrylaldehyde third Olefin(e) acid catalyst is relatively common in preparing.

CN1109803 relates to multimetal oxide compositions, and they have two phase structure and comprise molybdenum, hydrogen, and one Individual or multiple element phosphor, arsenic, boron, germanium and silicon；And relate to described composition and prepared by catalytic gas phase oxidation Purposes in terms of methacrylic acid, improves activity and selectivity.The open a kind of poly-metal deoxide of CN1109802 Composition, they have two phase structure and comprise molybdenum, hydrogen, one or more element phosphors, arsenic, boron, germanium and silicon And copper, improve base acrylic acid activity and selectivity.CN1298861A is then to use to add magnesium, aluminium and silicon Composite oxides.CN1321110A is the most respectively using antimony oxide and antimony acetate as activity metal composite oxide Antimony source.To solve under high-load condition, catalytic mechanical intensity is good, the problem that activity is high. The open a kind of O composite metallic oxide catalyst of CN200410048021.7, catalyst is by 1. molybdenum, vanadium, copper Main active component and the most requisite at least by antimony and the stable component of titanium and 3. nickel, iron, silicon, aluminium, The composite oxides of alkali metal, alkaline-earth metal composition.The most 2. and 3. it is can be in the range of 120 DEG C to 900 DEG C Composite oxides prepared by roasting.This catalyst shows the permanent stability under high activity and good selectivity. CN1121441 discloses a kind of for being existed by methacrylaldehyde or the gas containing acrolein gas and a kind of molecule-containing keto Carrying out oxidation reaction in vapour phase and produce acrylic acid catalyst, this catalyst includes (A) a kind of composite oxides, There is molybdenum and vanadium as base stock, and be suitable to by vapor phase catalytic oxidation methacrylaldehyde to produce acrylic acid, and (B) A kind of solid peracid, its acid strength (Ho) is not more than-11.93 (Ho≤-11.93).This invention uses molybdenum vanadium type composite oxygen Compound combines with a kind of acid strength solid acid less than-11.93, improves the low temperature high activity of catalyst. The open a kind of acrylic acid catalyst for producing of CN200510059468.9, is characterized in that, at following formula The oxide of the metallic element composition that MoaVbWcCudOx (1) represents and/or composite oxides are for being catalyzed In the acrylic acid catalyst for producing of agent composition, need to control tungsten and be partially the face side of this catalyst, and/or Copper is the core side of this catalyst partially, to improve catalyst activity.Tungsten is the face side of this catalyst partially, and / or copper be partially the core side of this catalyst to be difficult to accurately to control.The open a kind of propylene formoxy-of CN102039143A Change and prepare the preparation method of acrylic acid catalyst, a) preparation method of composite oxide coating: will containing Mo, The water-soluble metal salt of V, W, Cu, Sb composition is dispersed in water/organic phase mixed system in 30-100 DEG C； Keeping organic solvent and water weight ratio is 5～50%；Reaction generates composite oxides presoma slurries；Pass through again Distillation, drying, roasting prepare catalyst activity component；B) above-mentioned active component mainly comprises element, is selected from Mo, V, Cu, W, Sb one of which or several；Wherein active component following formula represents: Mo_aV_bCu_cW_dSb_eO_f, this catalyst uses the mixed system of water and lower alcohol to prepare, and catalyst has higher Specific surface area and special microstructure, there is relatively high-ratio surface and difficult drop-off, and bearing capacity can reach To 50% and more than, solve shorter problem in application type catalyst service life.

The open a kind of MAL acrylic acid catalyst of selective oxidation synthesizing methyl of CN1647854, this is urged The composition formula of agent is: x (Mo₁₂P_aK_bSb_cCu_dAs_eA_fD_gQ_hO_iMo_j)/yZ, Z are that carrier dilutes heat conduction Agent；Mo, P, K, Sb, Cu and As are respectively molybdenum, phosphorus, potassium, antimony, copper and arsenic；A represent tungsten W, At least one element in vanadium V, niobium Nb, iron Fe and lead Pb；D represents boron, gallium Ga, indium In, germanium At least one element in Ge and silicon Si；Q represents at least one element in rubidium Rb, caesium Cs and thallium Tl, this Bright one side improves the activity and selectivity of catalyst by adding Sb, Cu and As；On the other hand pass through Add MoO₃The heat endurance of catalyst, heat conductivility and mechanical strength is improved with carrier heat conduction diluent, Effectively inhibitory activity component heteropolyacid salt decomposition and reduce beds hot(test)-spot temperature, it is to avoid Mo and The loss of As, extends catalyst service life.

The open a kind of polymetal oxide materials of CN1109800: in formula, A is Mo₁₂V_aX_b ¹X_c ² X_d ³X_e ⁴X_f ⁵X_g ⁶O_x(coexisting phase), its part B comprises and has the X-ray of at least one following copper molybdate and spread out Penetrate the crystallite (giving the firsthand information about X-ray diffraction fingerprint in round parentheses) of pattern: Cu₃(MoO₄)₂(OH)₂(lindgrenite, the card index 36-405 of JCPDS-ICDD index (1991)), Cu₄Mo₆O₂₀(A.Moini et al., Inorg.Chem.25(21) (1986), 3782-3785), Cu₄Mo₅O₁₇ (the card index 39-181 of JCPDS-ICDD index (1991)), etc..CN1462211 relates to a kind of system Standby containing Mo, V, Cu and the method for the multiple-phase multi-metal oxide materials of other optional element.According to this Invention, at least one phase is pre-formed independently, and in the precursor material of the plastically deformable being dispersed in another phase. Then this mixture is dried and calcines.Polymetal oxide materials is suitable as at catalytic gas phase oxidation organic Compound, particularly acrolein oxidation is being become in acrylic acid the active material of catalyst used. [A] p [B] q [C] r (I), phase A in multimetal oxide compositions, B and C can be unbodied and/or Crystallization.Phase B is advantageously made up of the crystallite of oxometallate, or comprises there is X-ray diffraction Pattern and and then the crystalline substance of oxometallate crystallite copper molybdate of crystal structure types of at least one following copper molybdate Body structure class α-CuMo₄[the registration card 22-242 of JCPDS-ICDD card index, (1991)], Cu₆Mo₅O₁₈[the registration card 40-865 of JCPCS-ICDD card index, (1991)], Cu_4-xMo₃O₁₂, its Middle x=0-0.25 [registration card 24-56 and 26-547 of JCPCS-ICDD card index, (1991)], etc..Should Catalyst is to improve selectivity.

Polymetal oxide materials [A] p [B] q [C] r (I) of the open a kind of formula of CN1295499 (I), with containing molybdenum, Vanadium, copper and antimony and one or more other metals specific also have the polymetal oxide materials of multicomponent structure Acrylic acid catalyst is prepared as with the gas phase catalytic oxidation reaction of methacrylaldehyde.In formula, A is Mo₁₂V_aX¹bX² _cX³ _dX⁴ _eX⁵ _fX⁶ _gO_x, B is X¹ ₇Cu_hH_iO_y, C is X₁ ⁸Sb_jH_kO_z, X₁For W, Nb, Ta, Cr and/or Ce.Co-catalyst phase B is made up of the crystallite of these copper molybdate or micro-containing such copper molybdate Brilliant: α-CuMoO₄[the reference diffraction pattern in the index card 22-242 of JCPDS-ICDD retrieval 1991], Cu₆Mo₅O₁₈[the reference diffraction pattern in the index card 40-865 of JCPDS-ICDD retrieval 1991], Cu_4-x Mo₃O₁₂Wherein, x is the 0-0.25 [reference in index card 24-56 and 26-547 of JCPDS-ICDD retrieval 1991 Diffraction pattern], etc..Region C can have metaantimmonic acid copper Cu₉Sb₄O₁₉The crystallite of structure or Cu₄SbO_4.5Structure micro- Brilliant.CN1093950 discloses the composition of one kind of multiple metal oxides, including the oxidation shape as basis Mo, V, W, Cu, Ni of formula, its premise is to there is following ratio: Mo:V=12:1 between each elemental composition To 2:1, Mo:W=60:1 to 3:1, Mo:Cu=24:1 to 2:1, Cu:Ni=5:1 to 1:3.X₁It is one or more Alkali metal；X₂It is one or more alkaline-earth metal；X₃It is Cr, Mn, Ce and/or Nb；X₄It is Sb and/or Bi； X₅It is Si, Al, Ti and/or Zr.CN1387945 relate to containing Cu, Mo and at least one selected from element W, The oxo metal compound of the HT copper molybdate structure type of the element in V, Nb and Ta, its preparation method, and they In preparation, containing molybdenum, vanadium, copper and to contain having of one or more elements in elemental tungsten, niobium, tantalum, chromium and cerium many Application in the composite metal oxide material of phase structure.CN1394812 is at the catalysis gas for organic compound Phase oxidation reaction catalyst in use poly-metal deoxide, described poly-metal deoxide contain Mo, V and At least one in element W, Nb, Ti, Zr, Hf, Ta, Cr, Si and Ge, and it is former to have special three-dimensional Son arrangement.CN1500770 contains molybdenum, vanadium, copper and contains in elemental tungsten, niobium, tantalum, chromium and cerium a kind of or many Planting the composite metal oxide material having heterogeneous structure of element, they are by catalytic gas phase oxidation of acrolein system third Application in olefin(e) acid, and containing Cu, Mo and at least one element in element W, V, Nb and Ta The oxo metal compound of HT copper molybdate structure type.

It addition, under the high temperature conditions, in catalyst, part active component molybdenum loses because of distillation from catalyst surface. The mixed airflows such as methacrylaldehyde, air (oxygen), nitrogen and steam wash away the activity that also can make in catalyst Component runs off.For suppression molybdenum distillation loss cause activity decay, CN1121504 by mix copper component and There is specified particle diameter and the zirconium of specific surface area and/or titanium and/or cerium, dissipation effect and the mistake of molybdenum composition can be suppressed Degree reduction.Catalyst includes by lower formula (I) MO_aV_bW_cCu_dX_eY_f(I) oxygen of the metallic element composition represented Compound or composite oxides.CN1445020 adds a small amount of tellurium and plays stably free molybdenum trioxide and copper molybdate The effect of crystal structure, sublimation and the over reduction of molybdenum have suppressed；CN1583261 with molybdenum, vanadium, Copper, tungsten and/or niobium are key component, the composite oxides constituted with other element or its hopcalite The loss of composition catalyst suppression molybdenum.

Accordingly, it is desirable to provide methacrylaldehyde, acrylic acid catalyst are prepared in Propylene Selectivity oxidation, anti-in propylene oxidation Should carry out under low temperature, high-load condition.Temperature of reactor distribution is more reasonable, and active component molybdenum etc. is difficult to Because of sublimation, and activity is not susceptible to phase in version, purpose selectivity of product and yield height mutually.

Propylene Selectivity is aoxidized, first has to select the oxidation catalyst of function admirable, secondly also will be in gentleness Operating condition under react, to adapt to industrial high-speed, high selective requirement.Accordingly, it would be desirable to open The Propylene Selectivity oxidation technology sent out reaction condition a kind of and relax.On the premise of suppression focus, improve as far as possible The selectivity of purpose product and yield, to obtain bigger economic benefit.

Summary of the invention

The present invention provides a kind of method that Propylene Selectivity aoxidizes, mainly Propylene Selectivity oxidation to prepare propylene Aldehyde, acrylic acid.

The method that methacrylaldehyde is prepared in the Propylene Selectivity oxidation that the present invention provides is as follows: use the reaction of fixed bed single tube Device；Entrance reactor after more than the 120 DEG C preheatings of the preheated device of reaction raw materials propylene, water, air, salt bath heating, Reaction process condition is: salt temperature 300～335 DEG C, preferably 305～325 DEG C；Air speed 800～1800h^-1, excellent Select 800～1400h^-1, feed composition: propylene 8～14 volume %, air 70～74 volume %, steam 15～20%； Fixed bed reactors are built with oxidation catalyst, and catalyst contains molybdenum, bismuth, iron, cobalt, tungsten and potassium element, main Form by formula M o_aBi_bFe_cCo_dW_eK_fSi_gA_hB_iO_x(I) represent: wherein: Mo is molybdenum, Bi is Bismuth, Fe is iron, and Co is cobalt, and W is tungsten, and K is potassium, and Si is silicon, and silicon is the carrier added in catalyst, A is at least one element in manganese, boron, lanthanum；B is at least one element in magnesium, calcium or barium； O is oxygen；A, b, c, d, e, f, g, h, i represent each Elements Atom ratio respectively, wherein a be 12 one Number, b is a number of 1.0～7, preferably 1.0～6；C is a number of 1～6, preferably 1～5；D is 1～8 A number, preferably 1～5；E is a number of 0.2～5, and f is a number of 0.1～3.2, and g is 0.2～55 A number, preferably 1～20, h is a number of 0.01～2, and i is a number of 0～2, and x is by each oxidation The numerical value that the oxygen of thing determines.Catalyst is possibly together with strontium titanates, containing molybdenum, (I) of bismuth and strontium titanates by 90～98 Finished catalyst is obtained through mediating, be molded, being dried, after roasting after % and 0.4～the mixing of 10% mass percent.

Inside reactor of the present invention is provided with thermocouple, is used for measuring each spot temperature of reactor, in order to prevent propylene In lower catalyst agent, deep oxidation affects reaction yield, and makes catalyst coking, and the present invention controls under catalyst Layer temperature, less than catalyst upper strata temperature, adjusts reaction bed temperature, salt bath temperature by controlling salt temperature Degree is preferably controlled in 305～325 DEG C, is so conducive to the long-life of catalyst to use, and propylene oxidation reaction can Long period steady running.

The preparation method of strontium titanates is not any limitation as, as adopted with the following method: by SrCl₂And TiCl₄ The ratio of 1.0～1.1 mixes in molar ratio, adds (NH₄)₂CO₃Solution and ammoniacal liquor stir, ammonia The pH value of water regulation solution is 9.5～10.5, is then spray-dried, and gained powder is at a temperature of 120～150 DEG C Drying is placed in air atmosphere 1000～1200 DEG C of roastings 4～10 hours, finally by air-flow crushing, ball milling SrTiO is obtained etc. method₃.It is also possible that preparation: by strontium carbonate, titanium dioxide according to SrTiO₃Chemistry Metering ratio mixes, and adds the suspension forming high dispersive in deionized water, is then spray-dried it, Gained powder dries at a temperature of 120～150 DEG C that to be placed on 1000～1200 DEG C of roastings 4～10 in air atmosphere little Time, obtain SrTiO finally by the method such as air-flow crushing, ball milling₃。

It is highly preferred that catalyst can also add the lanthanum cerium Zirconium oxide solid solution that weight/mass percentage composition is 0.1～4 Body, catalyst heat endurance and good hydrothermal stability, lanthanum CeO2-ZrO2 solid solution (La of the present invention_xCe_yZr_1-0.8x-yO₂ (0 < x < 1,0 < y < 1,0 < x+y < 1) prepares according to conventional coprecipitation.

It is highly preferred that containing catalyst (I) 92～97%, also strontium titanates 1.5～8% in catalyst.

The catalyst activity component that the present invention (I) represents can add active component lanthanum, lanthanum and bismuth, cobalt energy Form stable crystal phase structure, such as BiLa, BiLa₂、Co₃La₂Deng, the good dispersion of molybdenum, thus suppressing portion Point active component molybdenum loses because of distillation from catalyst surface, and active component molybdenum not easily runs off, before catalyst reaction Rear active component molybdenum content is basically unchanged, and delays activity deterioration rate, catalyst activity and good stability.Lanthanum with Molybdenum, cobalt ratio are suitable, and in formula (I), A is lanthanum, and h is a number of 0.05～1.5, and i is 0.01～1.2 A number, too much lanthanum add membership and bismuth and cobalt competition molybdenum, affect catalyst activity.Catalyst mainly comprises As shown in formula (II).

Mo_aBi_bFe_cCo_dW_eK_fSi_gLa_hB_iO_x(II)

The multi-metal-oxide catalyst (I) of the present invention uses common preparation method, as used Prepared by following step.

Will containing Mo, in Bi, Fe, the compound of Co, W, K and formula (I) AhBi relate to each Elemental constituent compound dissolves and mixes, and forms slurries, add in slurry production process after being co-precipitated One or more in silica, aluminum oxide or carborundum, dry, and shaping, roasting obtains catalyst (I).

The preparation method of catalyst of the present invention, prepares catalyst (I), strontium titanates including by coprecipitation, will urge Agent (I), strontium titanates and/or lanthanum CeO2-ZrO2 solid solution by 90～98% and 0.4～10% mass percent mix Through mediating, be molded, being dried after conjunction, obtain finished catalyst after roasting.

Catalyst of the present invention (I) and finished catalyst are required for roasting 3～10h at 400～580 DEG C, compare Not distinguishing the catalyst of roasting, repeatedly roasting can improve activity and the stability of catalyst.It can be open roasting Burning can also be enclosed roasting, and calcination atmosphere can be the inert gases such as helium, nitrogen, argon gas.

Under Oxygen Condition, catalyst molybdenum isoreactivity component under the high temperature conditions is not only easy to run off, and activity phase Being susceptible to phase in version, activity occurs phase in version to cause active selectable to be decreased obviously mutually.Such as activity phase CoMoO₄It is converted into Co₃O₄, Fe₂(MoO₄)₃It is transformed into FeMoO₄, α-Bi₂(MoO₄)₃It is changed into γ-Bi₂MoO₆Deng.

Active component molybdenums in catalyst etc. i.e. enable holding and do not run off, and before and after the reaction of molybdenum equal size, basic change is not Greatly, but easily there is phase in version through long-term operation activity compatible.The present invention is by strontium titanates and/or lanthanum cerium zirconium Oxide solid solution adds in catalyst, makes active phase more stable, is not susceptible to phase in version thus improves Catalyst activity and selectivity, makes catalyst long period steady running.

The compound of each component of catalyst of the present invention can use the nitrate of each element, ammonium salt, sulfuric acid Salt, oxide, hydroxide, chloride, acetate etc., such as lanthanum nitrate, magnesium nitrate, potassium manganate, dioxy Change manganese, ammonium borate, boric acid, titanium dioxide, barium nitrate etc., calcium nitrate, strontium nitrate etc..

After catalyst slurry of the present invention is dried, it is usually preferred to use extrusion molding, granulating and forming, compression molding etc. Forming method is processed into spherical, hollow spheres, ellipticity, cylindric, hollow circuit cylinder etc., preferably hollow circle Post or spherical.

The present invention, in order to improve the intensity of catalyst, efflorescence degree, can add glass in above-mentioned catalyst (I) In fiber, graphite, ceramic or various whisker one or more.

Evaluating catalyst performance index definition is as follows:

Detailed description of the invention

With specific embodiment, the method that Propylene Selectivity aoxidizes is described below, but the scope of the present invention is not limited to These embodiments.Following example use propylene be propylene content >=99.6%(volume fraction) high concentration Propylene.The analysis method of product composition uses method generally in the art.

Embodiment 1

The preparation of catalyst 1

Under agitation, take 197 grams of ammonium molybdates and be dissolved in 1000ml pure water (water temperature more than 65 DEG C), Obtain slurries (1), then take 73 grams of cobalt nitrates, 1.88 grams of potassium nitrate, 6.86 grams of magnesium nitrates, 112.7 grams of nitre Acid iron, 15.1 grams of lanthanum nitrates are dissolved in 500ml pure water (water temperature more than 65 DEG C), are thoroughly mixed uniformly, Obtain slurries (2).Take 45.1 grams of bismuth nitrates again, be dissolved under agitation in dust technology, obtain slurries (3). Then, slurries (1) mix with slurries (2), obtain slurries (4), then slurries (3) are added slurries (4), in, active component slurries (a) is obtained.11.7 grams of silica are added in active component slurries (a) Powder and 4 grams of graphite, 80 DEG C of strong stirrings carry out heat drying after coprecipitation reaction, with 160 DEG C of heat in nitrogen Process 3 hours, dry rear 550 DEG C of roastings 4 hours, grind to form the fine powder of below 40 μm the most again for 105 DEG C, Prepare catalyst (I), mainly comprise as Mo₁₂Bi₁Fe₃Co_2.7W₂K_0.2Si_2.1Mg_0.4La_0.5O_x。

Weigh a certain amount of cerous nitrate, lanthanum nitrate, zirconium nitrate according to stoichiometric proportion, be configured to mixed solution, In the case of being stirred continuously, to mixed solution and dripping ammonia spirit so that it is carry out coprecipitation reaction, then Through suction filtration, 120 DEG C of drying, 950 DEG C of roastings 10 hours, grind to form the fine powder of below 40 μm the most again, prepare Ce_0.6Zr_0.3La_0.22O₂, Ce_0.5Zr_0.4La_0.2O₂, Ce_0.7Zr_0.2La_0.31O₂。

By strontium carbonate, titanium dioxide according to SrTiO₃Stoichiometric proportion mix, add in deionized water Forming the suspension of high dispersive, be then spray-dried it, gained powder is at a temperature of 120～150 DEG C Drying is placed in air atmosphere 1100 DEG C of roastings 10 hours, obtains SrTiO finally by ball milling₃。

Take catalyst (I) 93 part, strontium titanates oxide 4.5 parts, lanthanum CeO2-ZrO2 solid solution Ce_0.5Zr_0.4 La_0.2O₂2.5 parts, add deionized water and mediate in kneader, the extruded hollow columnar for φ 4.5 × 5mm Grain, is dried under the conditions of 120 DEG C, and at 450 DEG C, roasting obtains catalyst 1 in 6.5 hours.

Comparative example 1

Prepare comparative catalyst 1 according to the proportioning that mainly comprises of embodiment 1, but lanthanum cerium zirconium is not with solid solution The form of oxide adds catalyst, and strontium titanates is not to add with the form of Whole Oxygen compound, but with co-precipitation Method prepares catalyst, and reaction condition is with the appreciation condition of catalyst 1.Comparative catalyst 1 mainly comprises For: Mo₁₂Bi₁Fe₃Co_2.7W₂K_0.2Si_2.1Mg_0.4Ce_0.5Zr_0.4La_0.2Ti_0.2Sr_0.2La_0.5O_x。

Comparative example 2

Prepare comparative catalyst 2 according to the proportioning that mainly comprises of comparative example 1, but strontium titanates is not with solid solution The form of oxide adds catalyst, and titanium and strontium add in co-precipitation mode, aoxidizes without lanthanum cerium zirconium in catalyst Thing solid solution, but prepare catalyst with coprecipitation method, reaction condition is with the appreciation condition of catalyst 1. Comparative catalyst 2 mainly comprise for:

Mo₁₂Bi₁Fe₃Co_2.7W₂K_0.2Si_2.1Mg_0.4Ce_0.5Zr_0.4La_0.2La_0.5O_x。

Propylene method for oxidation

Fixed bed single tube reactor internal diameter 25mm, inside sets thermocouple, fills along propylene feed orienting response device bed Enter the above-mentioned catalyst of 40ml or comparative example catalyst, salt bath heating temperature 312 DEG C.Tube inlet from the reactions above Sentence air speed 1100h^-1Import propylene 11 volume %, air 75 volume %, the mixing of steam 14 volume % Gas.Bed hot localised points temperature 364 DEG C, beds upper temp is higher than beds bottom bed Temperature 4 DEG C.Propylene conversion 99.2%, acrolein selectivity 88.4%, methacrylaldehyde yield 82.1%, propylene Aldehyde+acrylic acid yield 92.5%.Temperature Distribution is more reasonable, beneficially catalyst long period steady running.Warp Cross the reaction of 2000 hours, embodiment 1 bed hot localised points temperature 363 DEG C, beds upper temp Higher than beds bottom bed temperature.Propylene conversion 99.1%, acrolein selectivity 88.3%, propylene Aldehyde yield 82.1%, acrolein+acrylic acid yield 92.4%.Comparative example catalyst 1 was through reaction in 2000 hours After, propylene conversion is respectively 98.1%, and acrolein selectivity is respectively 84.3, and methacrylaldehyde yield is respectively 75.5%, acrolein+acrylic acid yield is respectively 87.4%.Embodiment catalyst activity component molybdenum etc. not easily runs off, Activity is not susceptible to phase in version mutually, and catalyst activity component structure is stable, improve purpose product selectivity and Yield, catalyst structure is stable, it is possible to long period steady running.Comparative example catalyst 1 and 2 oxidation reaction Sample analysis in 24 hours, bed hot localised points temperature is respectively 365 DEG C and 363 DEG C, and propylene conversion is respectively Being 98.8%, 98.3%, acrolein selectivity is respectively 85.3%, 85.4%, methacrylaldehyde yield is respectively 78.1%, 77.8%, acrolein+acrylic acid yield is respectively 88.1%, 87.7%.Comparative example catalyst choice is poor, and third Olefine aldehydr, acrylic acid yield are low.

Embodiment 2

The preparation of catalyst 2

Preparation process and primary raw material with embodiment 1 catalyst 1 are identical, through 550 DEG C of roastings 3 hours and get final product Catalyst (I), mainly comprises as Mo₁₂Bi₅Fe₅Co₆W₃K₂Ba_0.3Si_1.2B_0.5O_x.Take catalyst (I) 98 parts, strontium titanates oxide 1.5 parts, lanthanum CeO2-ZrO2 solid solution Ce_0.5Zr_0.4La_0.2O₂0.5 part, add Ionized water is mediated in kneader, and the extruded hollow columnar particle for φ 4.5 × 5mm, under the conditions of 120 DEG C Being dried, at 500 DEG C, roasting obtains catalyst 2 in 4.5 hours.

Fixed bed single tube reactor internal diameter 25mm, inside sets thermocouple, fills along propylene feed orienting response device bed Enter the above-mentioned catalyst of 45ml, salt bath heating temperature 316 DEG C.Tube inlet sentences air speed 1600h from the reactions above^-1 Import propylene 10 volume %, air 73 volume %, the mixed gas of steam 17 volume %.Oxidation reaction Sample analysis in 24 hours, bed hot localised points temperature 366 DEG C, propylene conversion 99.3%, methacrylaldehyde selects Property 88.6%, methacrylaldehyde yield 81.7%, acrolein+acrylic acid yield 92.2%.

Embodiment 3

Preparation process and primary raw material with embodiment 1 catalyst 1 are identical, through 400 DEG C of roastings 6 hours and get final product Catalyst (I).Mainly comprise as Mo₁₂Bi₇Fe₁Co₈W_0.3K_3.2Si_5.1Ca_0.3Mn_1.8O_x, take catalyst (I) 95 part, strontium titanates oxide 4 parts, lanthanum CeO2-ZrO2 solid solution Ce_0.6Zr_0.3La_0.22O₂1 part, Add deionized water to mediate in kneader, the extruded hollow columnar particle for φ 4.5 × 5mm, 120 DEG C of bars Being dried under part, at 530 DEG C, roasting obtains catalyst 3 in 5 hours.

Fixed bed single tube reactor internal diameter 25mm, inside sets thermocouple, fills along propylene feed orienting response device bed Enter the above-mentioned catalyst of 50ml, salt bath heating temperature 308 DEG C.Tube inlet sentences air speed 1000h from the reactions above^-1 Import propylene 9 volume %, air 71 volume %, the mixed gas of steam 20 volume %.Oxidation reaction Sample analysis in 24 hours, bed hot localised points temperature 358 DEG C, propylene conversion 98.7%, methacrylaldehyde selects Property 88.1%, methacrylaldehyde yield 81.2%, acrolein+acrylic acid yield 91.5%.

Embodiment 4

Preparation process and primary raw material with embodiment 1 catalyst 1 are identical, through 5 hours catalyst of 480 DEG C of roastings (I).Mainly comprise as Mo₁₂Bi_3.5Fe₄Co_4.5W₁K_0.5Si_2.4Mn_0.1Mg_0.2O_x.Take catalyst (I) 91 parts, strontium titanates oxide 5.5 parts, lanthanum CeO2-ZrO2 solid solution Ce_0.7Zr_0.2La_0.31O₂3.5 parts, add from Sub-water is mediated in kneader, the extruded hollow columnar particle for φ 4.5 × 5mm, dry under the conditions of 120 DEG C Dry, at 500 DEG C, roasting obtains catalyst 4 in 5 hours.

Fixed bed single tube reactor internal diameter 25mm, inside sets thermocouple, fills along propylene feed orienting response device bed Enter the above-mentioned catalyst of 45ml 4, salt bath heating temperature 305 DEG C.Tube inlet sentences air speed 900h from the reactions above^-1 Import propylene 9 volume %, air 72 volume %, the mixed gas of steam 19 volume %, oxidation reaction Sample analysis in 24 hours, bed hot localised points temperature 351 DEG C, propylene conversion 98.6%, methacrylaldehyde selects Property 88.4%, methacrylaldehyde yield 81.0%, acrolein+acrylic acid yield 91.0%.

Embodiment 5

Preparation process and primary raw material with embodiment 1 catalyst 1 are identical, through 560 DEG C of roastings 3 hours and get final product Catalyst (I).Mainly comprise as Mo₁₂Bi_2.2Fe_2.3Co_1.2W₅K_1.4Si_1.6La_1.2Ba_0.3O_x.Take catalyst (I) 97 part, strontium titanates oxide 3 parts, add deionized water and mediate in kneader, extruded for φ 4.5 × 5 The hollow columnar particle of mm, is dried under the conditions of 120 DEG C, and at 480 DEG C, roasting obtains catalyst 5 in 6 hours.

Fixed bed single tube reactor internal diameter 25mm, inside sets thermocouple, fills along propylene feed orienting response device bed Enter the above-mentioned catalyst of 50ml, salt bath heating temperature 310 DEG C.Tube inlet sentences air speed 1000h from the reactions above^-1 Import propylene 10 volume %, air 71 volume %, the mixed gas of steam 19 volume %.Oxidation reaction Sample analysis after 24 hours, bed hot localised points temperature 361 DEG C, propylene conversion 99.2%, methacrylaldehyde selects Property 88.3%, methacrylaldehyde yield 81.3%, acrolein+acrylic acid yield 91.7%.Oxidation reaction 2000 hours Rear sample analysis, bed hot localised points temperature 360 DEG C, propylene conversion 99.1%, acrolein selectivity 88.4%, Methacrylaldehyde yield 81.2%, acrolein+acrylic acid yield 91.8%.Catalyst activity component molybdenum etc. not easily runs off, Activity is not susceptible to phase in version mutually, and catalyst activity component structure is stable.

Embodiment 6

Preparation process and primary raw material with embodiment 1 catalyst 1 are identical, through 500 DEG C of roastings 4 hours and get final product Catalyst (I).Mainly comprise as Mo₁₂Bi₃Fe₂Co_1.7W₄K_1.0Si_1.0La_2.1Ba_0.3O_x.Take catalyst (I) 95 parts, strontium titanates oxide 5 parts, add deionized water and mediate in kneader, extruded for φ 4.5 × 5mm Hollow columnar particle, under the conditions of 120 DEG C be dried, at 520 DEG C, roasting obtains catalyst 6 in 5 hours.

Fixed bed single tube reactor internal diameter 25mm, inside sets thermocouple, fills along propylene feed orienting response device bed Enter the above-mentioned catalyst of 50ml, salt bath heating temperature 320 DEG C.Tube inlet sentences air speed 1900h from the reactions above^-1 Import propylene 11 volume %, air 71 volume %, the mixed gas of steam 18 volume %.Oxidation reaction Sample analysis after 24 hours, bed hot localised points temperature 370 DEG C, propylene conversion 99.1%, methacrylaldehyde selects Property 88.4%, methacrylaldehyde yield 81.6%, acrolein+acrylic acid yield 92.3%.Oxidation reaction 2000 hours Rear sample analysis, bed hot localised points temperature 368 DEG C, propylene conversion 99.2%, acrolein selectivity 88.5%, Methacrylaldehyde yield 81.5%, acrolein+acrylic acid yield 92.2%.

Embodiment 4 catalyst is in salt bath heating temperature 312 DEG C, air speed 1100h^-1, propylene 11 volume %, sky React 24 hours and 500 hours under conditions of gas 69 volume %, steam 20 volume %, bed localized heat Point temperature is respectively 363 DEG C, 361 DEG C, propylene conversion 99.0%, 98.8%, acrolein selectivity 88.0%, 88.2%, methacrylaldehyde yield 81.4%, 81.6%, acrolein+acrylic acid yield 91.5%, 92.4%.Temperature is divided Cloth is more reasonable, and catalyst activity component structure is stable, beneficially catalyst long period steady running.Embodiment 4 and 6 catalyst are in salt bath heating temperature 312 DEG C, air speed 1100h^-1, propylene 11 volume %, air 69 body Adjust salt temperature again after stablizing 6 hours under conditions of long-pending %, steam 20 volume % and (stop third to 350 DEG C Alkene), after 10 hours, it is down to 312 DEG C again, embodiment 4 and 6 (salt bath heating temperature under similarity condition 312 DEG C, air speed 1100h^-1, propylene 11 volume %, air 69 volume %, steam 20 volume %) anti- Answering 24 hours, bed hot localised points temperature is respectively 360 DEG C, 354 DEG C, propylene conversion 99.1%, 98.0%, Acrolein selectivity 88.0%, 85.1%, methacrylaldehyde yield 81.3%, 76.5%, acrolein+acrylic acid yield 91.4%、87.5%.In the condition processed through steam 20 volume %, 350 DEG C of hydro-thermals of salt bath heating temperature Under, relative to embodiment 6, embodiment 4 catalyst heat endurance and good hydrothermal stability, catalyst activity group Separation structure is stable, meets catalyst long period steady running.

Claims (11)

1. one kind is used for Propylene Selectivity method for oxidation, it is characterised in that；The preheated device of reaction raw materials propylene, water, air 120 DEG C with Entering reactor after upper preheating, reaction process condition is: salt temperature 300～335 DEG C, air speed 800～1800h^-1, enter Material composition: propylene 8～14 volume %, air 70～74 volume %, steam 15～20%；Fixed bed reactors are built-in There are oxidation catalyst, catalyst to contain molybdenum, bismuth, iron, cobalt, tungsten and potassium element, mainly comprise by formula Mo_aBi_bFe_cCo_dW_eK_fSi_gA_hB_iO_x(I) represent: silicon is the carrier added in catalyst, and A is selected from manganese, boron, lanthanum In at least one element；B is at least one element in magnesium, calcium or barium；O is oxygen；a、b、c、d、e、f、 G, h, i represent each Elements Atom ratio respectively, and wherein a is a number of 12, and b is a number of 1.0～7, and c is 1～6 A number, d is a number of 1～8, and e is a number of 0.2～5, and f is a number of 0.1～3.2, g be 0.2～ One number of 55, h is a number of 0.01～2, and i is a number of 0～2, and x is the number determined by the oxygen of each oxide Value；Catalyst is possibly together with strontium titanates, containing molybdenum, (I) of bismuth and strontium titanates by 90～98% and 0.4～10% percent mass Than after mixing through mediating, be molded, being dried, obtain finished catalyst after roasting.

Method the most according to claim 1, it is characterised in that be 0.1～4 possibly together with weight/mass percentage composition in used catalyst Lanthanum CeO2-ZrO2 solid solution.

Method the most according to claim 1, it is characterised in that salt temperature 305～325 DEG C.

Method the most according to claim 1, it is characterised in that air speed 800～1400h^-1。

Method the most according to claim 1, it is characterised in that beds lower floor temperature is less than beds upper strata temperature.

Method the most according to claim 1, it is characterised in that catalyst contains catalyst (I) 92～97%, also metatitanic acid Strontium 1.5～8%.

Method the most according to claim 1, it is characterised in that the preparation method of used catalyst includes preparing by coprecipitation urging Agent (I), strontium titanates oxide, catalyst (I), strontium titanates oxide are by 90～98% and 0.4～10% percent mass Than mixing, obtain finished catalyst through mediating, be molded, being dried, after roasting.

Method the most according to claim 1, it is characterised in that in used catalyst (I), A is lanthanum, h is 0.05～1.5 One number, i is a number of 0.01～1.2, and catalyst mainly comprises as shown in formula (II): Mo_aBi_bFe_cCo_dW_eK_fSi_gLa_hB_iO_x(Ⅱ)。

Method the most according to claim 1, it is characterised in that in used catalyst (I), b is a number of 1.0～6, c Being a number of 1～5, d is a number of 1～5, and g is a number of 1～20.

Method the most according to claim 1, it is characterised in that the method for preparing catalyst that used catalyst (I) represents includes Following steps: will containing Mo, in Bi, Fe, the compound of Co, W, K and formula (I) AhBi relate to each Elemental constituent compound dissolves and mixes, and forms slurries after being co-precipitated, and adds titanium dioxide in slurry production process Silicon, dries, and shaping, roasting obtains catalyst (I).

The preparation method of 11. catalyst according to claim 7, it is characterised in that catalyst (I) and finished catalyst all 400～ Roasting 3～10h at 580 DEG C, use open roasting or enclosed roasting, and calcination atmosphere is helium, nitrogen or argon gas.