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Home , Tellurium trioxide

United States Patent (19) (11) Patent Number: 4,774,352 Sasaki et al. (45) Date of Patent: Sep. 27, 1988

(54) PROCESS FOR AMMOXIDATION Attorney, Agent, or Firm-Sughrue, Mion, Zinn, 75) Inventors: Yutaka Sasaki; Yutaka Kiyomiya; Macpeak, and Seas Toshio Nakamura, all of Kanagawa, 57 ABSTRACT Japan The activity of a -free metal catalyst (73) Assignee: Nitto Chemical Industry Co., Ltd., used for ammoxidation of organic compounds at a tem Japan perature of from 300° C. to 600 C. is improved in the presence of (a) elemental tellurium or a tellurium com 21 Appl. No.: 808,684 pound which is in contact with said catalyst or in the (22) Filed: Dec. 17, 1985 presence of (a) elemental tellurium or a tellurium com pound and (b) a compound which are in Related U.S. Application Data contact with said catalyst. This activity improvement process can be applied to both the fresh catalysts and (63). Continuation of Ser. No. 426,536, Sep. 29, 1982, aban the spent catalyst having a deteriorated activity. The doned. above described component (a) is preferably composed (30) Foreign Application Priority Data of a tellurium containing solid to be used in a state of a dry physical mixture with said catalyst. The above de Oct. 7, 1981 JP Japan ...... 56-159703 scribed components (a) and (b) are preferably composed Feb. 16, 1982 JP Japan ...... 57-21993 of a tellurium containing solid and a molybdenum con 51) Int. Cl." ...... C07C 120/00; CO7C 120/14 taining solid respectively or a tellurium-molybdenum 52 U.S.C...... 558/322; 423/376; containing solid to be used in a state of a dry physical 546/286; 558/319; 558/321; 558/327; 558/328 mixture with said catalyst. 58 Field of Search ...... 558/322, 329, 319, 321, The tellurium containing solid, the molybdenum con 558/327, 328; 423/376 taining solid or the tellurium-molybdenum containing (56) References Cited solid may be at least a member selected from the follow U.S. PATENT DOCUMENTS ing group: (1) A solid wherein a tellurium component and/or a 3,164,626 l/1965 Minekawa et al...... 260/465.3 molybdenum component is supported or unsup 3,164,627 1/1965 Minekawa et al...... 260/465.3 3,164,628 1/1965 Minekawa et al...... 260/465.3 ported on an inert carrier, 3,290,354 12/1966 Eden ...... 260/465.3 (2) A solid wherein a tellurium component and/or a 3,335,169 8/1967 Eden ...... 260/465.3 molybdenum component is added to a metal oxide 3,392, 187 7/1968 Eden ...... 260/465.3 catalyst (fresh or spent) and/or said metal oxide 3,392, 188 7/1968 Eden ...... 260/465.3 catalyst is enriched with the tellurium component 3,392, 189 7/1968 Eden ...... 260/465.3 and/or the molybdenum component, and 3,396,189 8/1968 Eden ...... 260/465.3 (3) A solid composed of a compound containing at 3,412,135 11/1968 Eden ...... 260/465.3 least one element selected from the group consist 3,417,125 12/1968 Eden ...... 260/465.3 3,417,128 12/1968 Eden ...... 260/465.3 ing of an alkali metal, an alkaline earth metal, La, 3,426,059 2/1969 Eden ...... 260/465.3 Ce, V, Nb, Cr, W, Mn, Fe, Co, Ni, Cu, Zn, Cd, B, 3,426,060 2/1969 Eden ...... 260/465.3 Al, Ga, Ge, Sn, Pb, P, AS, Sb, Bi, S and Se in 3,445,500 5/1969 Eden ...... 260/465.3 addition to tellurium, molybdenum or tellurium 3,641,102 2/1972 Reullet et al...... 260/465.3 and molybdenum, or a mixture of these com 3,898,267 8/1975 Caporali et al...... 260/465.3 pounds, supported or unsupported on an inert car 3,928,409 12/1975 Pignataro et al...... 260/465.3 1. 4,316,855 2/1982 Grasselli et al...... 260/465.3 4,339,394 7/1982 Grasselli et al...... 260/465.3 The present invention is advantageously applied to 4,409,122 10/1983 Kleuskens ...... 260/465.3 ammoxidation in a fluidized bed. Primary Examiner-Joseph P. Brust 1 Claim, No Drawings 4,774,352 1. 2 a vapor of a compound of the same metal as that present PROCESS FOR AMMOXDATION in the catalyst. The process disclosed in this U.S. Patent requires a complicated operation in that the catalyst This is a continuation of application Ser. No. 426,536, component is introduced as a vapor into the reaction filed 9/29/82, now abandoned. ZO. FIELD OF THE INVENTION SUMMARY OF THE INVENTION The present invention relates to an improvement of a An object of the present invention is to prevent cata process for ammoxidation of organic compounds and, lyst deterioration during ammoxidation using a telluri more particularly, it relates to a process for ammoxida 10 um-free metal oxide catalyst. This and other objects of tion which utilizes a tellurium-free metal oxide catalyst. the invention are attained by contacting said catalyst BACKGROUND OF THE INVENTION with a tellurium component or a tellurium-molybdenum component generated as a gaseous phase from a tellu There are a number of known processes for ammoxi rium source or a tellurium-molybdenum source. dation reactions of organic compounds. The present 15 invention relates to reactions using a metal oxide cata Accordingly, in the present invention, the ammoxida lyst at a temperature of from 300° C. to 600 C. Exam tion process comprises carrying out ammoxidation of ples of organic compounds include olefinic hydrocar organic compounds at a temperature of from 300° C. to bons, alcohols, aldehydes, alkyl substituted aromatic 600 C. using a tellurium-free metal oxide catalyst. The hydrocarbons, and alkyl substituted heterocyclic con 20 ammoxidation is carried out in the presence of (a) an pounds having , and , etc., as elemental tellurium or a tellurium compound which is hetero atoms. in contact with said catalyst or in the presence of (a) It has been described in U.S. Pat. Nos. 2,904,580, elemental tellurium or a tellurium compound and (b) a 3,152,170, 3,094,565, 3,094,552, 3,197,419, 3,308,151, molybdenum compound which are in contact with said 3,911,089, 4,139,552, 3,542,843, 3,591,620, etc., that 25 catalyst. In particularly preferred embodiments of the metal oxide catalysts containing molybdenum and bis present invention, it is possible to use any of a dry physi muth, etc., and metal oxide catalysts containing anti cal mixture of said catalyst and a tellurium containing mony and , or are useful for ammoxida solid, a dry physical mixture of said catalyst, a tellurium tion of propylene, isobutene and methanol, etc. It has containing solid and a molybdenum containing solid, or been described in U.S. Pat. Nos. 2,499,055, 2,838,558, 30 a dry physical mixture of said catalyst and a tellurium 2,510,605, 3,959,297, etc., that metal oxide catalysts molybdenum containing solid. containing are useful for ammoxidation of By utilizing the present invention, it is possible to alkyl substituted aromatic hydrocarbons or alkyl substi improve the selectivity of the metal oxide catalyst for tuted heterocyclic compounds. the desired product and improve the reaction rate. Fur During the ammoxidation of these organic com 35 thermore, undesirable reduction of the reaction rate pounds, the activity of the catalyst often deteriorates with the passage of time is improved upon and there is after being used for a long period of time. The degree of restoration of the selectivity of the deteriorated catalyst deterioration varies with the kind of catalyst and the for the desired product. conditions under which the catalyst is used. The process of the present invention can be applied to The activity deterioration has various causes. Ac both a fixed-bed and a fluidized-bed. However, the cordingly, a number of different approaches have been invention can be particularly easily applied when the investigated with respect to eliminating the deteriora catalyst is used for a fluidized-bed reaction. If (a) the tion. elemental tellurium or the tellurium compound and (b) However, the specific reason for the deterioration is the molybdenum compound are solid and have suitable not always obvious which makes it difficult to deter 45 physical properties (as described hereinafter), they can mine a method of eliminating the deterioration. Some be easily added during the reaction. examples of proposed methods require change of the In the fluidized-bed reaction, a portion of the catalyst reaction condition, partial replacement of the catalyst, can be easily withdrawn or added while the reaction is exchange of all the catalysts, or regeneration of the being conducted. These operations can be carried out deteriorated catalyst taken out of the reactor. Such 50 continuously or intermittently by a simple and conven methods have not been found to be economical. tional means while the reaction is industrially carried It is very advantageous if activity of the catalyst is out. Accordingly, when using a tellurium containing maintained or recovered without adding a fresh catalyst solid, a molybdenum containing solid or a tellurium or interrupting the reaction. molybdenum containing solid as a catalyst activity in As to this, U.S. Pat. No. 3,882,159 discloses a process 55 proving agent according to the present invention, it is for regenerating catalysts which comprises contacting possible to easily add the agent while the fluidized-bed in situ a molybdenum containing fluidized-bed catalyst reaction is being conducted. The present invention does which has become deteriorated by loss of molybdenum not result in losses due to production interruptions, during an ammoxidation reaction of propylene with because the invention can be practiced during the reac fluidized-bed particles composed of an essentially inert 60 tion. This is different from many known processes for carrier and molybdenum oxide at the reaction tempera regenerating catalysts. Of course, improvement of the ture. This U.S. Patent is concerned with only regenera selectivity and/or the activity can also be carried out tion of a molybdenum containing fluidized-bed catalyst, when the catalyst and the tellurium containing solid, the wherein molybdenum oxide supported on an inert car catalyst, the tellurium containing solid and the molyb rier is simply used as the regenerating agent. 65 denum containing solid, or the catalyst and the telluri U.S. Pat. No. 3,236,782 discloses a process for regen um-molybdenum containing solid are physically mixed erating metal oxide catalysts containing at least Cr, V, in a dry state before initiation of the reaction and the Mo or W which comprises contacting the catalyst with resulting dry mixture is used for the reaction. 4,774,352 C 3 4. The mechanism by which the effects of the present C= At least one element selected from the group invention are exhibited is not clear. However, it is be consisting of Mg, Ca, Sr, Ba, La, Ti, Zr, Nb, Ta, lieved that when using a tellurium containing solid and Cr, Re, Ru, Os, Rh, Ir, Pd, Pt, Ag, Zn, Cd, B, Al, a molybdenum containing solid or a tellurium-molyb Ga, In, Tl, Ge, Pb, P, As, Bi, S and Se. denum containing solid, a tellurium component and a a = 1-10 molybdenum component (which are volatile or are b= 0-5 changed to be volatile under the reacting condition) are c=0-10 formed. The components poison active sites on the x is defined below. catalyst participating in formation of undesirable by (2) MooDEFAO (composition by atomic ratio) products such as dioxide or , 10 D= At least one element selected from the group etc., to control the formation of such by-products. Ac consisting of Fe, Ni, Co, Mn, Cr, Mg, Ca, Cu, Zn, cordingly, selectivity for desired products is improved. La, Ce, Al and Sn. The molybdenum component in a vapor phase migrates E= At least one element selected from the group at the same time and deposits on the catalyst to restore consisting of Sb, Bi, As, P and B. the active sites or to produce fresh active sites. This is 15 F= At least one element selected from the group advantageous for the formation of the desired product consisting of K, Rb and Cs. in cooperation with the tellurium component. There d=0-10 fore, the reaction rate is increased. When using a tellu e=0.1-10 rium containing solid, molybdenum containing solid or fast 0-3 a tellurium-molybdenum containing solid, the effect is 20 x is defined below. exhibited in a comparatively short time. In many cases, (3) V10GHOx (composition by atomic ratio) the effect can be clearly seen within 1 to 2 hours. Fur G=AT least one element selected from the group thermore, duration of the effect is excellent. Accord consisting of Li, Na, K, Rb, Cs, Tl, Mg, Ca,Sr and ingly, transfer of the tellurium component and the mo Ba. lybdenum component from the tellurium-molybdenum 25 H= At least one element selected from the group containing solid is carried out at a comparatively high consisting of La, Ce, Ti, Zr, Nb, Ta, Cr, Mo, W, transfer rate. It is also believed that the tellurium com Mn, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, ponent and molybdenum component deposited on the Zn, Cd, B, Al, Ga, In, Ge, Sn, Pd, P, As, Sb, Bi, S catalyst have high affinity with respect to the catalyst and Se. components. Accordingly, once attached to the cata 30 g=0-5 lyst, the tellurium component and the molybdenum h=0-20 component are not easily separated. wherein O represents oxygen, and x represents the num The mechanism suggested is based on speculation. ber of oxygen corresponding to formed by com The details of how the present invention operates are bining elements in each component (which are common not sufficiently clear at this time. The present invention 35 to the above (1) to (3)). comprises contacting the tellurium-free metal oxide The catalyst may have any form. In case of the fixed catalyst with (a) an elemental tellurium or a tellurium bed reaction, catalysts having various shapes such as compound or (a) an elemental tellurium or a tellurium pellets or balls having a size of several mm are used, compound and (b) a molybdenum compound while the preferably about 1 to 10 mm, more preferably 2 to 5 reaction is conducted. At present, the means for utiliz mm. In case of the fluidized-bed reaction, catalysts ing this invention and obtaining the desired objects having a particle size ranging from 5 to 200 microns, should be understood in view of the above described preferably 10 to 150 microns are used. mechanism. Elemental Tellurium, Tellurium Compound and Mo DETALED DESCRIPTION OF THE lybdenum Compound (activity improving agent) 45 There are a number of useful substances which can NVENTION make up (a) the elemental tellurium or tellurium com In the following, the present invention is illustrated in pound and (b) the molybdenum compound used as the detail. activity improving agent in the present invention. In Metal Oxide Catalyst preferred embodiments of the present invention, the The metal oxide catalyst used in the present invention 50 catalyst to be processed for improving the activity includes various catalysts for ammoxidation which do thereof is a catalyst for a fluidized-bed reaction and the not contain tellurium, as shown in the above described improvement of activity is carried out while conducting patent publications. The process of the present inven the fluidized-bed reaction. Accordingly, when the ac tion can be equally applied to these known tellurium tivity improving agent is solid, it is preferably com free metal oxide catalysts. 55 prised of particles capable of being fluidized under the Useful metal oxide catalysts contain at least one ele reaction conditions such that the activity improving ment selected from the group consisting of , agent is sufficiently blended with the catalyst. When molybdenum and vanadium. using a finely-divided activity improving agent, these More specifically, the catalyst used in the present finely-divided particles are preferably carefully intro invention is preferably selected from the following cata duced from a lower portion of the fluidized-bed reactor lysts. These catalysts may be used by themselves or may so that they are dispersed throughout the catalyst bed. be supported on various carriers such as silica, silica (1) Kind and Production alumina, alumina, silica-titania, titania or zirconia, etc. Examples of the tellurium containing solid used in the (1) Sb.10AaBbCOx (composition by atomic ratio) present invention include tellurium, tellurium monox A= At least one element selected from the group 65 ide, , tellurium trioxide, tellurous acid, consisting of Fe, Co, Ni, Mn, U, Ce, Sn, Cu and Ti. and organic tellurium compounds, those B= At least one element selected from the group supported on an inert carrier such as silica, alumina, consisting of V, Mo and W. silica-alumina, titania, silica-titania or zirconia, etc., and 4,774,352 5 6 tellurium containing metal oxide catalyst enriched with what inferior. When using the tellurium enriched cata tellurium, preferably tellurium oxides, hydrated tellu lyst or the tellurium-molybdenum enriched catalyst for rium oxides, and tellurium containing metal oxide cata the purpose of the present invention, the mixing ratio is lyst enriched with tellurium. not strictly limited, if the reaction rate thereof and selec Tellurium metal, tellurium dioxide, tellurium triox tivity to the desired product are not greatly different ide, tellurous acid, telluric acid and organic tellurium from those of the catalyst used. compounds, etc., may be commercially available or can Various different effects are obtained with the activ be prepared from various tellurium sources using ity improving agents when the above described various known methods. elements are used in addition to tellurium and/or mo When using the tellurium component supported on O lybdenum. The addition of these elements can be used various carriers, various means of support can be uti for increasing or decreasing the transfer rate of the lized. For example, tellurium metal, tellurium dioxide, tellurium component and/or molybdenum component tellurous acid, telluric acid, tellurium nitrate, basic tellu to the catalyst. Further, these elements can be used for rium nitrate, tellurium halide, tellurium sulfate and or controlling the physical properties of the activity im ganic tellurium compounds, etc., can be used as a tellu 15 proving agent. rium source. These compounds are mixed with a carrier material such as silica sol, alumina solor titania sol, etc., The mixing ratio in the activity improving agent followed by spray-drying. Alternatively, a carrier pre should be selected taking into consideration the above viously prepared can be impregnated with a solution described factors. prepared by dissolving the above described tellurium 20 (2) Tellurium Content and Molybdenum Content sources. Further, when using a tellurium enriched flui Since it is believed, as described above, that the tellu dized-bed catalyst for this purpose, known processes for rium component and the molybdenum component ex producing catalysts can be suitably used. Moreover, a hibit the effect directly or after conversion into volatile catalyst prepared using a known suitable process may compounds, the effect decreases, if the amounts of the be impregnated with a solution containing the tellurium 25 tellurium component and the molybdenum component component directly or after use for the reaction, fol are too small. Particularly, when using tellurium and lowed by drying and calcining. During calcination, it is molybdenum supported on an inert carrier or using a preferable to maintain a temperature of 900 C. or less catalyst enriched with these components, it may be for 0.5 to 50 hours. necessary to add them in a large amount when the tellu Examples of molybdenum compounds include mo 30 rium content and/or the molybdenum content thereof is lybdenum dioxide, , molybdic too small. acid, ammonium paramolybdate, ammonium phos However, since the tellurium and molybdenum con phomolybdate and phosphomolybdic acid, and those pounds are not themselves the catalyst for the desired supported on an inert carrier as described above, and reaction, the catalyst may be diluted by their presence. molybdenum enriched metal oxide catalysts, preferably 35 Consequently, the volume of the reactor becomes insuf molybdenum oxides, hydrated molybdenum oxides, ficient for sufficiently carrying out the reaction. ammonium paramolybdate, and molybdenum enriched In consideration of such circumstances, it is preferred metal oxide catalysts. that the tellurium content in the activity improving Preparations of the molybdenum containing solid can agents is 0.5% by weight or more, preferably 1% by be carried out using the same processes used in prepar weight or more, and the molybdenum content in the ing the above described tellurium containing solid. activity improving agents containing molybdenum is The tellurium-molybdenum containing solid differs 0.1% by weight or more, preferably 0.5% by weight or only because the tellurium component and the molyb Ote, denum component are present at the same time. It can It is preferred that the ratio of molybdenum/ tellu be prepared by known suitable processes. For example, 45 rium (atomic ratio) in the tellurium containing solid and it can be prepared by blending the above described the molybdenum containing solid or in the tellurium tellurium source and the molybdenum source and mold molybdenum containing solid to be mixed with the ing the resulting mixture, or by blending both of the catalyst is 0.05 to 10, preferably 0.05 to 5. above described sources with a carrier component and (3) Form molding the resulting mixture. It is also possible to use 50 When using (a) an elemental tellurium or a tellurium a process for producing a fluidized-bed catalyst en compound, or (a) an elemental tellurium or a tellurium riched with both tellurium and molybdenum. compound and (b) a molybdenum compound as they The tellurium containing solid, the molybdenum con are, they may be introduced into the reactor as a pow taining solid and tellurium-molybdenum containing der or they may be physically blended with the catalyst solid may contain, if desired, other elements in addition 55 in a dry condition and thereafter added to the reaction to tellurium and/or molybdenum. Namely, they may system. contain at least one element selected from the group When using the tellurium component and the molyb consisting of alkali metals, alkaline earth metals, lantha denum component as a solid, their physical properties nun, , vanadium, , , , are important. Its strength is important when used in a , iron, , , , , , 60 fixed-bed reaction. Namely, powdering and simulta , , , , tin, , phos neous volatilization of the tellurium component or the phorus, , antimony, , sulfur and . molybdenum component should be prevented because If the solid has an activity and the reaction rate is equal it increases the pressure drop of the reaction gas in the to or slightly lower than that of the catalyst when the catalyst bed. When a fluidized-bed reaction is used, the reaction is carried out using the solid alone, a positive 65 activity improving agent is preferably fluidized so that effect is observed when the amount of addition is not it can be blended well with the catalyst. Further, in excessive (for example, about 50% or more), even order for the tellurium component and the molybdenum though the selectivity to the desired product is some component to be effectively used, the activity improv 4,774,352 7 ing agent should be present in the reactor for the time necessary to be sufficiently mixed with the catalyst. Weight of molybdenum in activity Accordingly, when a fluidized-bed reaction is being improving agent added carried out, the activity improving agent preferably has Total weight of catalyst packed (g) x 100 a particle size comparatively similar to that of the cata lyst and the value of (bulk of the activity im The amount of the activity improving agent which is proving agent)/(bulk density of the catalyst) is in a preferably added depends upon properties of the activ range from 0.05 to 8, preferably a range from 0.2 to 0.6. ity improving agent. When the tellurium component Further, it is preferred for the fluidized-bed catalyst, in and the molybdenum component have a high transfer carrying out the present invention, to have a bulk den O rate, the activity improving agent is sufficient if used in sity of 0.1 to 3 (g/ml) and a particle size of 5 to 200 an amount calculated from the desired tellurium and microns. molybdenum contents. Activity Improvement Processing The activity improving agent may be physically In the ammoxidation reaction according to the pres blended with the catalyst in a dry condition prior to ent invention, the activity improvement processing of 15 initiation of the reaction or it may be added during the the metal oxide catalyst is carried out at the same time reaction, alone or as a mixture prepared by physically by contacting the metal oxide catalyst with (a) an ele blending the agent with the catalyst in a dry condition. mental tellurium or a tellurium compound or with (a) an There are no problems with the fluidized-bed reaction, elemental tellurium or a tellurium compound and (b) a 20 because the catalyst can be safely withdrawn and added molybdenum compound. Both the catalyst to be pro while conducting the reaction. cessed and the activity improving agent are preferably Addition of the active improving agent can be carried in a fluidized state. out several times while observing the conditions of the The process of the present invention can also be ap reaction. plied to a fixed-bed reaction by physically blending the 25 Although it is not necessary to contact the catalyst catalyst to be processed with the activity improving with the tellurium component together with the molyb agent in a dry condition. However, the effect of im denum component at the same time, the catalyst may be proving the activity is particularly high when carrying first contacted with the tellurium component and there out the processing while conducting the reaction in a after contacted with the molybdenum component, or 30 the reverse operation may be carried out. However, it is fluidized state using a fluidized-bed catalyst. It is be preferable, if possible, to avoid the first addition of only lieved that, since movement of the activity improving the molybdenum component, because the selectivity for agent is quick as is the movement of the catalyst, trans the desired product temporarily decreases by addition fer of the tellurium component or the tellurium compo of only the molybdenum component at the beginning. nent and the molybdenum component to the catalyst is 35 When only the elemental tellurium or the tellurium uniformly carried out to result in a good effect. compound is physically blended with the catalyst in a When the activity improving agent is solid, the total dry condition, improvement of the selectivity for the amount of the tellurium containing solid and the molyb desired product is very effectively carried out, but the denum comtaining solid or the amount of the tellurium reaction rate hardly varies or sometimes slightly de molybdenum containing solid is preferably 0.01% by CreaSeS. weight or more based on the tellurium containing metal On the other hand, when only the molybdenum com oxide catalyst. If the amount thereof is lower than pound is physically blended with the catalyst in a dry 0.01% by weight, the effect is very poor and the dura condition, the selectivity for by-products is often in tion of the effect deteriorates. With respect to the upper creased and, consequently, the selectivity for the de limit, there are various cases, which are similar to the 45 sired product decreases. cases described in the above described section "Kind As described above, though the addition of the activ and Production' for the activity improving agent. ity improving agent may be carried out using various The effect of the activity improving agent is exhibited techniques, it is necessary to add the tellurium compo by transfer of the tellurium component and the molyb nent alone or to add both the tellurium component and denum component to the catalyst. Accordingly, from 50 the molybdenum component. The latter case is particu this standpoint, the apparent increment of tellurium larly preferable. content in the catalyst resulting from physically blend Condition for Ammoxidation ing the catalyst with the activity improving agent in dry The conditions for carrying out the ammoxidation in condition is preferably 0.001 to 15% by weight, more 55 accordance with the present invention are the same as preferably 0.01 to 10% by weight, and the apparent those used for conventional ammoxidation of organic increment of molybdenum therein is preferably 0.002 to compounds such as propylene, isobutene, methanol, 10% by weight, more preferably 0.01 to 5% by weight. tert-butanol, methyl tert-butyl ether, toluene, xylene, The apparent increment of tellurium content and the picoline, etc. apparent increment of molybdenum content are defined Namely, the molar ratio of the feed gas is in a range as follows. of 1/0.3-10/0.5-5 as organic compound/oxygen/am Apparent increment of tellurium content (%)= monia (molar ratio), and the reaction temperature is in a range of 300-600 C. The reaction pressure used is in a Weight of tellurium in activity range of atmospheric pressure to 3 kg/cm2G or so. The improving agent added 65 feed gas used may be diluted with nitrogen, steam, car Total weight of catalyst packed (g) X 100 bon dioxide, carbon monoxide or helium, etc. The effects of the present invention are illustrated Apparent increment of molybdenum content (%)= below by reference to examples. 4,774,352 10 The yield of the desired product and the selectivity The yield of acrylonitrile was 74.1% at the beginning, for the desired product are defined herein as follows. but the activity of the catalyst deteriorated, because it was used for a long time, resulting in a yield of 65.2%. Weight of carbon in 5 When a tellurium containing solid containing 32% by Yield (%) --is Weight offormed carbon desired in organic product compound X 100 weight of Te was blended therewith so as to result in an fed as starting material amount of 1.5% by weight based on the catalyst to carry out the reaction, the yield of acrylonitrile after 3 Weight of carbon in 10 hours became 72.8%. Selectivity (%) -- will x 100 EXAMPLE 3 organic compound reacted An activity test was carried out under testing condi The condition for the activity test is as follows. tion (1) using a fluidized-bed catalyst having the empiri (1) Ammoxidation of Propylene 15 cal formula: Sn 10Sb25O70(SiO2)30. A fluidized-bed reactor having an inner diameter of 5 The yield of acrylonitrile was 68.9%. cm (2 inches) and a height of 2 m was packed with a When a tellurium containing solid containing 16% by catalyst in an amount suitably selected from the range of weight of Te was blended therewith so as to result in an 1,200 g to 1,800 g. Into this reactor, a gas having the 20 amount of 3.5% by weight based on the catalyst to following composition was introduced to result in an carry out the reaction, the yield of acrylonitrile after 2 apparent linear velocity of 15 cm/sec. The reaction hours became 73.5%. pressure was atmospheric pressure. O2 (introduced as air)/propylene=2.10 (molar ratio) EXAMPLE 4 NH3/propylene= 1.15 (molar ratio) 25 An activity test was carried out under testing condi The contact time is defined as follows. tion (1) using a fluidized-bed catalyst having the empiri cal formula: U10Sb30O86.7(SiO2)60. ine - Volume of catalyst packed (I) The yield of acrylonitrile was 69.5% at the beginning, Contact time = Flow rate of feed gas (l/sec) (sec) 30 but the activity of the catalyst deteriorated, because it "On the basis of apparent buik density of the catalyst was used for a long time, resulting in a yield of 64.8%. (2) Ammoxidation of Toluene When a tellurium containing solid containing 32% by The same reactor as that used for the above described weight of Te was blended therewith so as to result in an ammoxidation of propylene was used and the gas was 35 amount of 1.5% by weight based on the catalyst to introduced so as to result in an apparent linear velocity carry out the reaction, the yield of acrylonitrile after 2 of 15 cm/sec. The reaction pressure was atmospheric. hours became 70.2%. EXAMPLE 5 O2 (supplied as air)/toluene = 2.5 (molar ratio) 40 An activity test was carried out under testing condi NH3/toluene - 1.5 (molar ratio) H2O/toluene = 2.5 (molar ratio) tion (1) using a fluidized-bed catalyst having the empiri cal formula: PosKo. Fe3Ni2.5Co45BilMo12O50.3(Si O2)45. The definition of the contact time is the same as de- 45 scribed above. The yield of acrylonitrile was 75.3% at the beginning, but the activity of the catalyst deteriorated, because it EXAMPLE 1. was used for a long time, resulting in a yield of 71.8%. An activity test was carried out under testing condi When a tellurium containing solid containing 16% by tion (1) using a fluidized-bed catalyst having the empiri- 50 weight of Te was blended therewith so as to result in an cal formula: FelloSb25Vo. Po.5O65.4(SiO2)30. amount of 0.5% by weight based on the catalyst to The yield of acrylonitrile was 74.2%. carry out the reaction, the yield of acrylonitrile became When a tellurium containing solid containing 32% by 73.8% after 1.5 hours and 74.2% after 5 hours. weight of Te (the balance consisted of oxygen and sili- ss EXAMPLE 6 con) (the balance in the following examples means the same, unless otherwise stated) was blended so as to An activity test was carried out under testing condi result in an amount of 3.5% by weight based on the tion (2) using a fluidized-bed catalyst having the empiri catalyst to carry out the reaction, the yield of acryloni cal formula: P1V12O325(SiO2)50. trile after 2 hours became 77.2%. When the reaction 60 The yield of benzonitrile was 75.2%. was carried out for another 2 hours, the yield did not When a tellurium containing solid containing 16% by vary. weight of Te was blended therewith so as to result in an amount of 0.5% by weight based on the catalyst to EXAMPLE 2 65 carry out the reaction, the yield of benzonitrile after 2 An activity test was carried out under testing condi hours became 76.3%. tion (1) using a fluidized-bed catalyst having the empiri The results and conditions of Examples 1 to 6 are cal formula: Wo.5CosFelloSb25O71.5(SiO2)30. summarized in the following Table 1. 4,774,352 11 12 TABLE 1 Condition Yield Carbon Conversion of Reaction Contact of Dioxide of Composition of Catalyst Activity Temperature Time Product Gas Hydrocarbon Example (atomic ratio) Test (C.) (sec) (%) (%) (%) l Fe(Sb25V. PosO65(SiO Before blending (1) 460 7 74.2 1.3 97.2 Blending with Te (1) 460 7 77.2 9.7 96.0 containing solid 2 W 5CosFelloSb2SO5(SiO Before deterioration (1) 460 6 74.1 9.2 96.2 After deterioration (1) 460 6 65.2 12.3 92.4 Blending with Te (1) 460 6 72.8 9.5 93.1 containing solid 3 SnoSb25O10(SiO Before blending (1) 460 7 68.9 1.3 92.0 Blending with Te (1) 460 7 73.5 9.5 92.5 containing solid 4. UnSbOOR67(SiO Before deterioration (1) 470 7 69.5 9.8 95. After deterioration (1) 480 7 64.8 10.4 94.4 Blending with Te (1) 480 7 70.2 9.6 94.2 containing solid 5 Po,5K0.Fe3Ni2.5Co4.5 BitNo12O522(SiO2)45 Before deterioration (1) 430 4. 75.3 6.7 95.3 After deterioration (l) 440 4. 7.8 7.2 95.3 Blending with Te (1) 440 4. 74.2 6.5 94.5 containing solid 6 PVi2O325(SiO2)SO Before blending (2) 450 4.S 75.2 14.9 98.9 Blending with Te (2) 450 4.5 76.3 3. 96.3 containing solid

EXAMPLE 9 EXAMPLE 7 An activity test was carried out under testing condi 35 tion (1) using a fluidized-bed catalyst having the empiri An activity test was carried out under testing condi cal formula: SnoSb25O70(SiO2)30. tion (1) using a fluidized-bed catalyst having the empiri The yield of acryonitrile was 68.9%. cal formula: Fe10Sb25Vo. Po,05O65.4(SiO2)30. When the reaction was carried out by blending with The yield of acrylonitrile was 74.2%. a tellurium containing solid containing 20.0% by weight When a tellurium-molybdenum containing solid con 40 of tellurium (composed of and oxygen in addi taining 38.3% by weight of tellurium, 2.9% by weight tion to tellurium) in an amount of 1.5% by weight based of molybdenum and 47.8% by weight of on the catalyst and a molybdenum containing solid was blended therewith so as to result in an amount of containing 66.7% of molybdenum (composed of silicon 1.0% by weight based on the catalyst and the reaction and oxygen in addition to molybdenum) in an amount of was continued for 2 hours, the yield of acrylonitrile 45 0.15% by weight based on the catalyst, the yield of became 78.1%. Thereafter, the reaction was continued acrylonitrile became 74.3% after 2 hours. for 3 hours, but the yield of acrylonitrile did not vary. EXAMPLE 10 EXAMPLE 8 An activity test was carried out under the conditions An activity test was carried out under testing condi 50 of activity test (1) using a fluidized-bed catalyst having tion (1) using a fluidized-bed catalyst having the empiri the empirical formula: U10Sb30O86.7(SiO2)60. cal formula: Wo.5CosFe10Sb25O71.5(SiO2)30. The yield of acrylonitrile was 69.5% at the beginning, The yield of acrylonitrile was 74.1% at the beginning, but the activity of the catalyst deteriorated, because it but it became 70.2% when used for a long time. was used for a long time, resulting in a yield of 66.8%. A telluriumm-molybdenum containing solid contain 55 When the same tellurium-molybdenum containing ing 35.2% by weight of tellurium, 7.9% by weight of solid as that used in Example 8 was blended therewith molybdenum and 44.0% by weight of silicon dioxide so as to result in an amount of 0.85% by weight based was added thereto in an amount of 1.1% by weight on the catalyst, the yield of acrylonitrile became 72.2% based on the catalyst while conducting the reaction. after 2 hours. After blending the tellurium-molybdenum containing solid, with the catalyst, the yield of acrylonitrile became EXAMPLE 11 73.9% after 2 hours. An activity test was carried out under testing condi On the other hand, the above described tellurium tion (1) using a fluidized-bed catalyst having the empiri molybdenum containing solid was added to a fresh cal formula: Posko, Fe3Ni2.5Co45BiMo12O50.3(Si catalyst in an amount of 1.1% by weight based on the 65 O2)45. catalyst, and an activity test was carried out similarly The yield of acrylonitrile was 75.3% at the beginning, under testing condition (1). After 2 hours, the yield of but the activity of the catalyst deteriorated, because it acrylonitrile became 76.3%. was used for a long time, resulting in a yield of 72.0%. 4,774,352 13 14 When the same tellurium-molybdenum containing is recovered and the activity of the fresh catalyst is solid as that used in Example 8 was blended therewith further improved without adding a fresh catalyst or so as to result in an amount of 0.3% by weight based on interrupting the reaction. the catalyst to carry out the reaction, the yield of acry While the invention has been described in detail and lonitrile became 76.3% after 3 hours. with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes EXAMPLE 12 and modifications can be made therein without depart An activity test was carried out under testing condi ing from the spirit and scope thereof. tion (2) using a fluidized-bed catalyst having the empiri What is claimed is: cal formula: PV12O32.5(SiO2)50. 10 1. In a process for producing a nitrile by ammoxida The yield of benzonitrile was 75.2%. tion of an organic compound selected from the group When the same tellurium-molybdenum containing consisting of propylene, isobutene, methanol, tert solid as that used in Example 7 was blended therewith butanol, methyl tert-butyl ether, toluene and xylene so as to result in an amount of 0.26% by weight based using a packed metal oxide catalyst containing at least on the catalyst to carry out the reaction, the yield of 15 one element selected from the group consisting of anti benzonitrile became 77.5% after 2 hours. mony, molybdenum and vanadium at a temperature of The results and conditions of Examples 7 to 12 are 300 C. to 600 C., at atmospheric pressure to 3 summarized in the following Table 2. kg/cm2G and at a molar ratio offeed gas in the range of TABLE 2 Yield Total Condition of Conversion of Reaction Contact Desired of Organic Composition of Catalyst Activity Temperature Time Product Compound Example (atomic ratio) Test (°C) (sec) (%) (%) 7 FinSb2.5V POSO654(SiO Before processing (1) 460 7 Acrylonitrile Propylene 74.2 97.2 After activity improvement F 78.1 98.0 processing s 8 WosCosfelloSb25O71.5(SiO2)30 Before deterioration (1) 460 6 Acrylonitrile Propylene 74.1 96.2 After deterioration rt 70.2 93.2 After activity improvement A. 73.9 96.5 processing (i) After activity improvement f 76.3 98.1 processing (ii) 9 SnoSb25O10(SiO2)30 Before processing (1) 460 7 Acrylonitrile Propylene 68.9 92.0 After activity improvement 74.3 95.2 processing 10 UnSb30OR6 (SiO Before deterioration (1) 470 7 Acrylonitrile Propylene 69.5 95. After deterioration 480 FF 66.8 93.8 After activity improvement f 72.2 97.5 processing 11 PosK0. Fe3Ni2.5Co4.5 Bimol2O50.3(SiO2)45 Before deterioration (1) 430 4 Acrylonitrile Propylene 75.3 95.3 After deterioration ff 440 f 720 95.2 After activity improvement t 76.3 97.2 processing 12 PV2O325(SiO2)50 Before processing (2) 450 4.5 Benzonitrile Toluene 75.2 98.9 After activity improvement processing 77.5 99.2 From the results obtained as shown in Tables 1 and 2, it can be seen that when blending the tellurium contain ing solid, the tellurium containing solid and molybde 1/0.3-10/0.5-5 as organic compound/oxygen/am num containing solid or the tellurium-molybdenum monia (molar ratio), the improvement which comprises containing solid as a catalyst activity improving agent 60 carrying out the ammoxidation in the presence of an with a fresh catalysts or the spent catalyst having a activity improving agent which is selected from the deteriorated activity to carry out the reaction, the reac group consisting of (a) elemental tellurium which is in tion results are further improved as compared with that contact with said catalyst in the course of the ammoxi of the fresh catalyst alone or they become equal to or dation; (b) a tellurium compound which is in contact higher than that of the catalyst before the deterioration. 65 with said catalyst in the course of the ammoxidation; (c) Thus, the treatment of blending the activity improving elemental tellurium and a molybdenum compound agents described above provides an unexpected result in which are in contact with said catalyst in the course of providing the advantages that the deteriorated catalyst the ammoxidation; or (d) a tellurium compound and a 4,774,352 15 16 molybdenum compound which are in contact with said B= At least one element selected from the group catalyst in the course of the ammoxidation, all of which consisting of V, Mo, and W; are volatile or are changed to be volatile under the C = At least one element selected from the group ammoxidation conditions, said activity promoting agent consisting of Mg, Zn, boron, Al, Pb, P, and Bi; (a) to (d) being present in a catalytically effective 5 a = 1-10; amount, the activity improving agent being physically blended with the metal oxide catalyst prior to use in the ammoxidation in the form of a solid, wherein the x is defined below; amount of activity improving agent in the form of a 2. MotoDaEFAOx (composition by atomic ratio) solid is 0.01% by weight or more based on the metal 10 D= At least one element selected from the group oxide catalyst, wherein the apparent increment of tellu consisting of Fe, Ni, Co, Mn, Cr, Mg, Zn, Ce, rium content in the packed catalyst which is prepared and Sn; by physically blending the metal oxide catalyst with the E= At least one element selected from the group activity improving agent in the dry condition is 0.001 to consisting of Sb, Bi, P and B; 15% by weight, and the apparent increment of molyb 15 F= At least one element selected from the group denum content in the packed catalyst is 0.002 to 10% by consisting of K, Rb and Cs; weight, wherein the apparent increment of the tellurium d=0-10; content and the apparent increment of the molybdenum e=0.1-10; content are defined as follows: f=0-3; Apparent increment of tellurium content (%)= 2O x is defined below; and 3. V10GHiOx (composition by atomic ratio) G = At least one element selected from the group Weight of tellurium in activity improving agent added x 100 consisting of Li, Na, K, Rb, Cs, Mg, Ca,Sr and Total weight of packed catalyst (g) Ba; 25 H= At least one element selected from the group Weight at molybdenum in activity consisting of Ti, Mo, W, Mn, Fe, Co, Ni, Zn, B, improving agent added X 100 Sn, P, Sb, and Bi; Total weight of packed catalyst (g) g=0-5; and wherein said metal oxide catalyst is selected from h=0.20; the following catalysts: 30 wherein O represents oxygen, and x represents the num 1. Sb10AaBCO (composition by atomic ratio) ber of oxygen atoms corresponding to oxides formed by A= At least one element selected from the group combining elements in each component which are com consisting of Fe, Co, Ni, Mn, U, Ce, Sn, Cu and mon to the above catalysts (1) to (3). Ti; k k sk 35

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