Abstract: A catalyst comprising a promoted mixed metal oxide is useful for the vapor phase oxidation of an alkane or a mixture of an alkane and an alkene to an unsaturated carboxylic acid and for the vapor phase ammoxidation of an alkane or a mixture of an alkane and an alkene to an unsaturated nitrile.

Abstract: A catalyst comprising a promoted mixed metal oxide is useful for the vapor phase oxidation of an alkane or a mixture of an alkane and an alkene to an unsaturated carboxylic acid and for the vapor phase ammoxidation of an alkane or a mixture of an alkane and an alkene to an unsaturated nitrile.

Abstract: A catalyst comprising an In promoted mixed metal oxide is useful for the vapor phase oxidation of an alkane, or a mixture of an alkane and an alkene, to an unsaturated carboxylic acid and for the vapor phase ammoxidation of an alkane, or a mixture of an alkane and an alkene, to an unsaturated nitrile.

Abstract: A process for the manufacture of acrylic acid comprising reacting propylene and oxygen (preferably in the form of air) in a reaction zone having a catalyst characterized by the following formula: AaBbCcCadFeeBifMo12Ox where A=one or more of Li, Na, K, Rb and Cs B=one or more of Mg, Sr, Mn, Ni, Co and Zn C=one or more of Ce, Cr, Al, Sb, P, Ge, Sn, Cu, V and W and a=0.01 to 1.0; b and e =1.0-10 c=0 to 5.0, preferably 0.05 to 5.0, especially preferred being 0.05 to 4.0 d and f=0.05 to 5.0, and x is a number determined by the valence requirements of the other elements present; at an elevated temperature to produce acrylic acid and acrolein.

Abstract: The present invention provides an apparatus for producing (meth)acrylic acid and a process for producing (meth)acrylic acid with this apparatus wherein the apparatus enables to produce (meth)acrylic acid stably for a long period of time by effectively inhibiting the polymerization of (meth)acrylic acid in its production process (for example, in a reboiler). At least a part of the apparatus is made of a nickel-chromium-iron alloy with a molybdenum content of 3 to 20 mass %, but not including 3 mass %, or with a molybdenum content of 1 to 4 mass % and a copper content of 0.5 to 7 mass %.

Abstract: The invention provides process for oxidative dehydrogenation of lower alkanes, by vapor phase oxidative dehydrogenation of C2-C5 lower alkanes in the presence of a catalyst and molecular oxygen to produce the corresponding olefins, in which the catalyst has a composition expressed by a general formula (1) below: A&agr;Sb&bgr;W&ggr;D&dgr;Ox   (1) in which A is at least one metal selected from the group consisting of molybdenum and chromium; Sb is antimony; W is tungsten; O is oxygen; and D is at least one metal selected from the group consisting of V, Nb, Ta, Fe, Co, Ni, Cu, Ag, Zn, B, Tl, Sn, Pb, Te, Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, La, Ce and Sm; &agr;, &bgr;, &ggr;, &dgr; and x denote atomic numbers of A, Sb, W, D and O, respectively, where when &agr;=1, &bgr;=0.5-10, &ggr;=0.1-10 and &dgr;=0-3; and x is a numerical value determined by the state of oxidation of those elements other than oxygen.

Abstract: Process for the production of vinyl acetate in which ethylene, acid and oxygen-containing gas are combined at elevated temperature in the presence of a catalyst material to produce (i) a product mixture comprising vinyl acetate, (ii) a liquid by-product comprising acetic acid and (iii) a gaseous by-product comprising carbon dioxide. The liquid by-product is separated from the product mixture and treated to reduce the water content therein before being recycled to the reactor such that the water entering the reactor comprises less than 6 wt %, (preferably less than 4 wt %, more preferably less than 3 wt %) of the total of acetic acid and water entering the reactor.

Abstract: The present invention relates to a process for the selective preparation of acetic acid from a gaseous feed comprising ethane, ethylene or mixtures thereof plus oxygen at elevated temperature, which comprises bringing the gaseous feed into contact with a catalyst comprising the elements Mo, Pd, X and Y in gram atom ratios a:b:c:d in combination with oxygen MoaPdbXcYd  (I) where the symbols X and Y have the following meanings: X is one or more elements selected from the group consisting of: Cr, Mn, Nb, Ta, Ti, V, Te and/or W, in particular Nb, V and W; Y is one or more elements selected from the group consisting of: B, Al, Ga, In, Pt, Zn, Cd, Bi, Ce, Co, Cu, Rh, Ir, Au, Ag, Fe, Ru, Os, K, Rb, Cs, Mg, Ca, Sr, Ba, Zr, Hf, Ni, P, Pb, Sb, Si, Sn, TI and U, in particular Ca, Sb, Te and Li. The present invention further provides a catalyst for the selective preparation of acetic acid comprising the elements Mo, Pd, X and Y in the gram atom ratios a:b:c:d in combination with oxygen.

Abstract: In a process for the continuous heterogeneously catalyzed gas-phase partial oxidation of an organic compound in an oxidation reactor, whose feed gas mixture comprises, apart from the organic compound to be partially oxidized and molecular oxygen as oxidant, at least one diluent gas which is essentially inert under the conditions of the heterogeneously catalyzed gas-phase partial oxidation, where the essentially inert diluent gas consists partly of combustible gases, after passage through the oxidation reactor, the combustible constituents of the inert diluent gas present in the product gas stream leaving the oxidation reactor are not recirculated to the heterogeneously catalyzed gas-phase partial oxidation, but are put to further use for the purposes of another chemical reaction.

Abstract: The present invention is a method to produce an unsaturated carboxylic acid which includes the steps of: providing an epoxy compound; contacting the epoxy compound with carbon monoxide in the presence of a catalytically effective amount of a catalyst system comprising tin and cobalt under conditions effective for carbonylation of the epoxy; and recovering a .alpha.-.beta. unsaturated carboxylic acid product. The preferred epoxy is ethylene oxide which is reacted to acrylic acid by the method of the present invention.

Abstract: A method for producing acrylic acid from propylene at high efficiency by two-stage catalytic oxidation using a single fixed bed shell-and-tube heat exchanger type reactor is provided. The method comprises dividing the shell space of said reactor into an upper space and lower space with a partition plate, allowing a heating medium to circulate in each of the spaces substantially independently of each other, and carrying out the vapor phase oxidation under specific conditions. Said specific conditions including providing a first stage catalyst layer at lower portion of each of the reaction tubes, a second stage catalyst layer at upper portion thereof and an inert substance layer therebetween, and making void ratio of the inert substance layer 40-99.5%.

Abstract: The present invention concerns a method for producing acrolein and acrylic acid by carrying out vapor phase catalytic oxidation of propylene with molecular oxygen or a gas containing molecular oxygen using a oxidation catalysts comprising Mo, Bi and Fe as an essentially element and a fixed bed multitubular reactor, which comprisesa) using a plurality of supported catalysts having different activities, which was obtained, for example, by different calcination method in the production process of the supported catalysts,b) setting a catalyst layer in a reaction tube, which is formed by dividing it into plural portions in the tube axial direction, andc) arranging the aforementioned plural supported catalysts in such order that the activity becomes high toward the outlet from the inlet of the material gas in the reaction tube axial direction.

Abstract: A catalyst for the production of unsaturated aldehyde and unsaturated acid, obtained by loading a catalytically active component on a carrier and calcining the loaded catalyst, characterized by an average particle diameter of the catalyst of 4 to 16 mm, an average particle diameter of the carrier of 3 to 12 mm, a calcining temperature of 520 to 600.degree. C. and an amount of the catalytically active component loaded on the carrier of 5 to 80% by weight ?weight of the catalytically active component)/(weight of the catalytically active component+weight of the carrier+weight of a strength improver)!, and a process for producing unsaturated aldehyde and unsaturated acid with the catalyst.

Abstract: In a process for preparing acrolein, acrylic acid or a mixture thereof from propane, propane is partially dehydrogenated to propylene in a first stage, the product gas mixture resulting therefrom is, after separating off hydrogen and water vapor, used as feed to an oxidation reactor, the propylene formed in the dehydrogenation is partially oxidized in the oxidation reactor using molecular oxygen in the presence of non-dehydrogenated propane as inert diluent gas to give acrolein, acrylic acid or a mixture thereof and the propane present in the product gas mixture of the partial oxidation is subsequently recirculated to the dehydrogenation stage A.

Abstract: Disclosed are a process for producing an unsaturated aldehyde and an unsaturated carboxylic acid which comprises subjecting propylene, isobutylene or tertiary butanol to gas phase catalytic oxidation with molecular oxygen in the presence of (i) a catalyst comprising composite oxide of the formula Mo.sub.a Bi.sub.b Fe.sub.c A.sub.d B.sub.e C.sub.f D.sub.g O.sub.x and (ii) a molybdenum oxide which in itself is substantially inert to the gas phase catalytic oxidation; a process for reusing the catalyst deteriorated due to the gas phase catalytic oxidation after mixing it with the molybdenum oxide; and a method of regenerating the deteriorated catalyst by mixing it with the molybdenum oxide.

Abstract: A process for the gas phase catalytic oxidation of a C.sub.3-6 alkane, alkanol, alkene or alkenal using as a catalyst multimetal oxide compositions of the formula I, [X.sup.1.sub.a X.sup.2.sub.b O.sub.x ].sub.p [X.sup.3.sub.c X.sup.4.sub.d X.sup.5.sub.e X.sup.6.sub.f X.sup.7.sub.g X.sup.2.sub.h O.sub.y ].sub.q, where X.sup.1 is bismuth, tellurium, antimony, tin and/or copper, X.sup.2 is molybdenum and/or tungsten, X.sup.3 is an alkali metal, thallium and/or samarium, X.sup.4 is an alkaline earth metal, nickel, cobalt, copper, manganose, zinc, tin, cadmium and/or mercury, X.sup.6 is iron, chromium, cerium and/or vanadium, X.sup.6 is phosphorus, arsenic, boron and/or antimony, X.sup.7 is a rare-earth metal, titanium, zirconium, niobium, tantalum, rhenium, ruthenium, rhodium, silver, gold, aluminum, gallium, indium, silicon, geranium, lead, thorium and/or uranium, a is from 0.01 to 8, b is from 0.

Abstract: A novel family of chemical compounds derived from fatty compounds has two branches of two carbon atoms on the linear chain and general formula C.sub.21 H.sub.39 COOR where R represents a hydrogen atom, a lower alkyl radical or a glyceryl radical. Particular compounds for consideration have the following formulae:(C.sub.2 H.sub.5).sub.2 C.sub.17 H.sub.29 COOR (I)(C.sub.2 H.sub.5)(C.sub.2 H.sub.4)C.sub.17 H.sub.30 COOR (II)and(C.sub.2 H.sub.5)(C.sub.2 H.sub.3)C.sub.17 H.sub.31 COOR (III)also compounds with the following formulae derived from partial or total hydrogenation of the above:(C.sub.2 H.sub.5).sub.2 C.sub.17 H.sub.31 COOR (IV)(C.sub.2 h.sub.5)(C.sub.2 h.sub.4)C.sub.17 H.sub.32 COOR (V)andti (C.sub.2 H.sub.5).sub.2 C.sub.17 H.sub.33 COOR (VI)Compounds with formulae (I), (II) and (III) may be produced by addition of ethylene to compositions comprising mainly diunsaturated C.sub.

Abstract: An improved process for the production of carboxylic acids and dicarboxylic acids by the catalytic oxidation of olefins and vicinal diols by hydrogen peroxide is provided. The process employs a rhenium (VII) catalyst, and a solvent comprising a mixture of a carboxylic acid or anhydride having 2 or more carbon atoms and a high boiling cyclic or acyclic ether. Particularly suitable carboxylic acids or anhydrides include acetic acid, propionic acid and acetic anhydride. Particularly suitable high-boiling ethers include 1,4-dioxane and diglyme.

Abstract: The present invention provides a process for producing methacrolein and methacrylic acid by subjecting at least one material selected from isobutylene, t-butanol and methyl t-butyl ether to gas phase catalytic oxidation with molecular oxygen or a molecular oxygen-containing gas using a fixed bed multi-tubular reactor.

Abstract: A process for the catalytic gas-phase oxidation of acrolein to acrylic acid in a fixed-bed reactor with contacting tubes, at elevated temperature on catalytically active oxides with a conversion of acrolein for a single pass of .gtoreq.95%, wherein the reaction temperature in the flow direction along the contacting tubes in a first reaction zone before the starting reaction gases containing the reactants enter the contacting tubes is from 260.degree. to 300.degree. C. until an acrolein conversion of from 20 to 40% is reached, and the reaction temperature is subsequently reduced by a total of from 5.degree. to 40.degree. C., abruptly or successively in steps or continuously along the contacting tubes until a methacrolein conversion of .gtoreq.95% has been reached, with the proviso that the reaction temperature in this secondary reaction zone is not lower than 240.degree. C.

Abstract: A single step process for the oxidation of an olefin to its respective .alpha.-,.beta.-unsaturated carboxylic acid is described. The olefin in vapor form is reacted with oxygen in the presence of a noble metal oxidation catalyst on a hydrophobic support and an aqueous solvent.

Abstract: A process for producing an unsaturated aldehyde or an unsaturated acid comprises catalytically oxidizing propylene or at least one compound selected from isobutylene, tert.-butyl alcohol and methyl-tert.-butyl ether in a gaseous phase with molecular oxygen or a molecular oxygen-containing gas using a fixed bed multipipe reactor, wherein(a) a plurality of composite oxides, different in occupied volume, are used as catalyst,(b) a plurality of reaction zones are provided along an axial direction in each reaction pipe of the fixed bed multipipe reactor, and(c) the plurality of the catalysts different in occupied volume are filled in the plurality of the reaction zones such that the occupied volumes become lower from the starting gas inlet side to the outlet side.

Abstract: A method for oxidizing organic compounds by contacting organic compounds with molecular oxygen in the presence of a noble metal pyrochlore having the formula:A.sub.2+x B.sub.2-x O.sub.7-ywherein A is a pyrochlore structure metal cation, and B is one or more of Ru, Rh, Ir, Os, and Pt; x and y are greater than or equal to 0 and less than or equal to 1.0, at a temperature up to about 200.degree. C.

Abstract: Acrolein and acrylic acid are produced by vapor-phase catalytic oxidation of propylene in a multi-tubular, fixed-bed reaction vessel with the use of a composite oxide catalyst represented by the formula Mo.sub.a Bi.sub.b Fe.sub.c A.sub.d B.sub.e C.sub.f D.sub.g Si.sub.h O.sub.x, wherein A, B, C, and D represent components selectable from respective groups of elements, and the subscripts a through h and x are specific numbers of atoms of respective elements and groups of elements. This catalyst is adapted and packed in each reaction tube in a manner such that its activity is controlled to increase from the inlet toward the outlet of the tube.

Abstract: The present invention provides a process for the production of methacrolein and methacrylic acid by the gas phase catalytic oxidation of isobutylene or t-butanol at high temperature using molecular oxygen in the presence of catalyst consisting of molybdenum, tungsten, bismuth, iron, nickel, antimony, and an alkali metal, to which zinc or lead is added, and further phosphorus sulfur, silicon, selenium, germanium or boron, and magnesium, cobalt, manganese or tin are added.

Abstract: A process for improving the activity of tellurium containing metal oxide catalysts useful as catalysts for oxidation, ammoxidation or oxidative dehydrogenation of organic compounds by heating the catalysts together with an activity-improving agent to a temperature up to about 900.degree. C. in a gaseous atmosphere. The process can be effectively applied to deteriorated or spent catalysts, the activity of which has been deteriorated due to use for a long period of time.

Abstract: A process for producing methacrylic acid by vapor phase oxidation of methacrolein with molecular oxygen or molecular oxygen-containing gas in the presence of isobutylene and/or tertiary butanol and in the presence of a catalyst having a heteropolyacid structure represented by the following general formula:Mo.sub.a V.sub.b P.sub.c X.sub.d O.sub.ewherein Mo, V, P, and O represent molybdenum, vanadium, phosphorus, and oxygen respectively, X represents the coexistence of copper and aresenic and the a, b, c, d and e represent the atomic ratio of the elements where:a is 10,b is a number of 6 or less excluding 0,c is a number of 0.5 to 6,d is a number of 3 or less excluding 0, ande is a number determined depending on the valance and atomic ratio of the other elements.

Abstract: A 1,2-unsaturated carboxylic acid or its ester such as acrylic or methacrylic acid or its alkyl ester is purified to remove aldehyde impurities contained therein by treating the acid or its ester with a mercapto containing compound in the presence of an acid catalyst.

Abstract: A process for conducting a combination of fixed and fluid-bed catalytic reactions is achieved by employing fixed-bed catalysts on supports within the fluid bed. The fluid-bed catalysts may move in both directions through the fixed bed, thereby giving advantages of both types of beds in one reactor.

Abstract: A catalyst for production of methacrylic acid, said catalyst being molded in a ring-like shape having an outside diameter of 3.0 to 10.0 mm, an inside diameter 0.1 to 0.7 times the outside diameter and a length 0.5 to 2.0 times the outside diameter, said catalyst comprising a catalytically active material having the composition represented by the following general formulaMo.sub.a P.sub.b A.sub.c B.sub.d C.sub.e D.sub.f O.sub.

Abstract: Iron-bismuth-molybdate catalysts further containing specific promoter elements have been found to exhibit excellent redox stability even under high stress conditions in the catalytic oxidation of olefins to unsaturated aldehydes and acids.

Abstract: A catalyst for the production of unsaturated aldehydes is provided which is represented by the general formulaBi.sub.a W.sub.b Fe.sub.c Mo.sub.d A.sub.e B.sub.f C.sub.g D.sub.h O.sub.xwherein Bi represents bismuth, W represents tungsten, Fe represents iron, Mo represents molybdenum, O represents oxygen, A represents nickel and/or cobalt, B represents at least one element selected from the group consisting of alkali metals, alkaline earth metals and thallium, C represents at least one element selected from the group consisting of phosphorus, arsenic, boron, antimony, tin, cerium, lead and niobium, D presents at least one element selected from the group consisting of silicon, aluminum, zirconium and titanium, a, b, c, d, e, f, g, h and x represent the atomic ratios of the individual elements, and when d is taken as 12, a=0.1-10.0, b=0.5-10.0 (provided that a/b=0.01-6.0), c=0.1-10.0, e=2.0-20.0, f=0.001-10.0, g=0-10.0, and h=0-30, and x takes a number determined by the atomic valences of the individual elements.

Abstract: Certain multiply promoted Sn/Sb oxides are superior catalysts for the ammoxidation of olefins to the corresponding unsaturated nitriles, the selective oxidation of olefins to unsaturated aldehydes and acids, and the oxydehydrogenation of olefins to diolefins.

Abstract: Vapor phase process for the preparation of unsaturated aldehydes, carboxylic acids and mixtures thereof which comprises contacting a gaseous mixture of an open-chain olefin of from 3 to 8 carbon atoms, water and oxygen at an elevated temperature up to about 250.degree. with a solid catalyst comprising a catalytically effective amount of noble metal promoted by a solid acid consisting of mixed metal oxides.

Abstract: The present invention provides an improvement in methods for preparing and processing readily polymerizable acrylate monomers. The improvement comprises employing phenyl-para-benzoquinone, 2,5-di-phenyl-para-benzoquinone, and mixtures thereof as process inhibitors. The process inhibitors are present in a concentration of about 50 to 3000 ppm, preferably about 250 to 2000 ppm, and most preferably about 500 ppm.

Abstract: Oxide complex catalysts of iron, selenium and tellurium provide good yields of acrylonitrile in the ammoxidation of propylene with high selectivities at low temperature.

Abstract: A method for preparing attrition resistant, high percentage active component catalysts comprises using two types of silica, one of which is fumed silica, in a two stage catalyst preparation.

Abstract: A catalyst composition having a composition represented by the formula:A.sub.0.1-4 B.sub.0.02-1 Mo.sub.12 Bi.sub.0.5-10 Fe.sub.0.5-10 Na.sub.0-3 P.sub.0-2 O.sub.gwherein A is at least one element selected from the group consisting of cerium, lanthanum, neodium, praseodium, samarium, europium and gadrinium, B is at least one element selected from the group consisting of potassium, rubidium and cesium, and g is the number of oxygen atoms required to satisfy the valence requirements of the other elements present, and supported on silica.

Abstract: An improved process for the catalytic oxidation of propylene to acrylic acid the improvement comprising conducting the process in the presence of an effective amount of hydroquinone. The improved process is particularly applicable to the aqueous liquid phase reaction of propylene with molecular oxygen using a supported palladium catalyst.

Abstract: A novel catalyst comprising the elements Mo, V and Nb, and an oxidation process, is provided for oxidizing alpha-beta unsaturated aliphatic aldehydes in the vapor phase with molecular oxygen to produce the corresponding alpha-beta unsaturated carboxylic acid.

Abstract: A novel catalyst comprising the elements Mo, V and Ti, and an oxidation process, is provided for oxidizing alpha beta unsaturated aliphatic aldehydes in the vapor phase with molecular oxygen to produce the corresponding alpha-beta unsaturated carboxylic acid.

Abstract: A novel catalyst comprising the elements Mo, V and Ta, and an oxidation process, is provided for oxidizing alpha-beta unsaturated aliphatic aldehydes in the vapor phase with molecular oxygen to produce the corresponding alpha-beta unsaturated carboxylic acid.

Abstract: A stabilized heteropoly molybdate catalyst precursor in calcined form and containing anionic molybdenum in defect state is surface impregnated with certain metal cations. The stabilized precursor is one obtained by incorporating into the reaction product of a molybdate and a soluble phosphate, silicate or arsenate, an aqueous chloride ion and a compound of phosphotungstate, silicotungstate, vanadium arsenate, silico-arsenate, phosphovanadate, or silicovanadate, followed by drying and calcining. During the chloride ion stabilization step other metals may be optionally incorporated in forming the stabilized precursor.The obtained precursor is catalytically active in the conversion of the unsaturated aldehydes to the corresponding unsaturated carboxylic acids with or without incorporation of the metal cation during the chloride ion stabilization step.

Abstract: At least one olefinic hydrocarbon of 3 to 4 carbon atoms is oxidized catalytically in the gas phase in the presence of molecular oxygen at 200.degree.-450.degree. C. to produce the corresponding aldehyde and acid over a calcined catalyst of the formula Mo.sub.a Sb.sub.b Bi.sub.c Fe.sub.d Ni.sub.e Sn.sub.f X.sub.g Y.sub.h O.sub.i wherein X is at least one alkali metal selected from the group consisting of potassium, rubidium and cesium; Y is at least one metal selected from the group consisting of cobalt, uranium, germanium, tungsten and titanium; a to h are atomic ratios wherein a=12, b=0.2 to 20, c=0.2 to 12, d=0.2 to 12, e=0.2 to 12, f=0 to 20, g=0.01 to 4 and h=0 to 6; and i is determined according to the oxidation states of the metal atoms in the catalyst.

Abstract: In the production of acrylic acid by a two-stage, vapor-phase catalytic oxidation of propylene, a composite oxide catalyst expressed by the formula Mo.sub.a Bi.sub.b Ni.sub.c Co.sub.d Fe.sub.e Na.sub.f Mn.sub.g B.sub.h K.sub.i Si.sub.j O.sub.x is used in the first-stage reaction, which is carried out under specific reaction and operational conditions, and the second-stage reaction is carried under specific reaction and operational conditions while oxygen is supplied by a specific mode.

Abstract: A process for preparing 2-butenolide, a useful product for the manufacture of gamma-butyrolactone, is disclosed which comprises reacting furan with oxygen in the presence of a catalytically effective amount of a catalyst comprising a mixed metal oxide containing titanium, boron and molybdenum.

Abstract: Certain multiply promoted Sn-Sb oxides are superior catalysts for the ammoxidation of olefins to the corresponding unsaturated nitriles, the selective oxidation of olefins to unsaturated aldehydes and acids, and the oxydehydrogenation of olefins to diolefins.

Abstract: In the recovery of acrylonitrile from the gross reaction product produced during the commercial ammoxidation of propylene to produce acrylonitrile, an ammoxidation waste gas containing at least 65% nitrogen, carbon dioxide, carbon monoxide and a small amount of unreacted propylene is produced. In accordance with the invention, this ammoxidation waste gas is passed through a catalytic converter containing an oxidation or ammoxidation catalyst to convert the unreacted propylene into valuable product.

Abstract: The catalytic vapor phase oxidation of an olefin of 3 to 5 carbon atoms to .alpha.,.beta.-unsaturated aldehydes with the formation of substantially no .alpha.,.beta.-unsaturated acids is achieved by contacting the olefin, oxygen, an inert gas or moderator and optionally water with a catalyst at a temperature of from 300.degree. C. to 500.degree. C. for a period of time sufficient to achieve from 25 to 80% conversion of said olefin to said aldehyde, separating unreacted olefin and byproduct inert gas from the product stream and recycling the unreacted olefin and byproduct inert gas together with additional olefin and oxygen if required to react with said catalyst.

Abstract: A vapor phase catalytic oxydehydrogenation process for the conversion of a steam of mixed isomeric isoamylenes, methyl butanols or mixtures thereof to isoprene with relatively short contact times at a reactor temperature in the range of 500.degree. F. to 1100.degree. F. at from 0.5 to about 10 atmospheres pressure. The catalysts comprise an alkali metal as an essential catalytic ingredient.