Abstract: ?,?-ethylenically unsaturated aldehydes and/or carboxylic acids are prepared by means of a two-stage catalytic gas-phase oxidation in which a gas mixture comprising at least an alkane or alkene having from three to six carbon atoms and oxygen is subjected to a catalytic oxidation reaction, in the first stage (1). oxygen is added to the gases produced in the first stage (1) and the resulting mixture is introduced into the second stage (2) in which it is subjected to a further catalytic oxidation reaction. In the process of the present invention, a signal which correlates with the oxygen content of the reaction gases before and/or after the addition of oxygen between the first and second stages (1, 2) is generated and the oxygen addition is regulated as a function of the signal.

Abstract: A multimetal oxide material contains the elements Mo, V and Te and/or Sb and at least one of the elements Nb, Ti, W, Ta and Ce and promoters and has a specific X-ray diffraction pattern. Moreover, such a multimetal oxide material is used as a catalyst for heterogeneously catalyzed gas-phase partial oxidations of hydrocarbons.

Abstract: Process for the preparation of acrolein and/or acrylic acid by catalytic gas-phase selective oxidation reaction of propane, the process comprising contacting a reaction gas containing propane and an oxygen-containing gas over a mixed metal oxide solid catalyst supported on a TiO2—MoO3 porous support.

Abstract: A reactor system for oxidative conversion of hydrocarbons comprising at least one reactor tube being provided with a plurality of perforations along a wall of the tube and a reaction zone with an active catalyst arranged on tube side and/or shell side of the reactor tube; and a bed of particulates material surrounding the at least one reactor tube, the bed of particulate material being adapted to be fluidised by an oxygen containing atmosphere and to transport heat from the reactor tube.

Abstract: A process for the oxidation of a C2 to C4 alkane to produce the corresponding alkene and carboxylic acid which process comprises contacting in an oxidation reaction zone, said alkane, molecular oxygen-containing gas, and the corresponding alkene and optionally, water, in the presence of at least one catalyst active for the oxidation of the alkane to the corresponding alkene and carboxylic acid, to produce a product stream comprising alkene, carboxylic acid and water, wherein in said process the molar ratio of alkene to carboxylic acid produced in said oxidation reaction zone is adjusted or maintained at a pre-determined value by controlling the concentrations of the alkene and optional water in said oxidation reaction zone and optionally by also controlling one or more of the pressure, temperature and residence time of the oxidation reaction zone. Such an oxidation process may be used in an integrated process, such as for the manufacture of vinyl acetate or ethyl acetate.

Abstract: A continuously operated heterogeneously catalyzed gas-phase partial oxidation of at least one organic compound in an oxidation reactor is operated safely by a process in which an explosion diagram for the feed gas mixture is deposited as the basis of a cut-out mechanism in a computer.

Abstract: Hydrothermally synthesized catalysts comprising a mixed metal oxide are utilized to produce unsaturated carboxylic acids by the vapor phase oxidation of an alkane, or a mixture of an alkane and an alkene, in the presence thereof; or to produce unsaturated nitriles by the vapor phase oxidation of an alkane, or a mixture of an alkane and an alkene, and ammonia in the presence thereof.

Abstract: A method for producing an unsaturated carboxylic acid comprises: (a) contacting, in a reaction zone, an alkane with a catalyst containing a mixed metal oxide, under conditions which produce a product gas comprising the unsaturated carboxylic acid, unreacted alkane and a product alkene; (b) recovering unreacted alkane and product alkene from the product gas; and (c) recycling the recovered unreacted alkane and product alkene to the reaction zone; wherein the mixed metal oxide consists of a material having the formula AaMmNnXxOo wherein A is at least one element selected from the group consisting of molybdenum and tungsten, wherein M is at least one element selected from the group consisting of vanadium, cerium and chromium, wherein N is at least one element selected from the group consisting of tellurium, bismuth and selenium, wherein X is at least one element selected from the group consisting of niobium, tantalum, titanium, aluminum, zirconium, chromium, manganese, iron, ruthenium, cobalt, rhodium, nickel,

Abstract: A method for producing polyacrylic acid includes a combined process of an acrylic acid production process and a polyacrylic acid production process. The acrylic acid production process includes the steps of catalytically oxidizing propylene and/or propane in a gaseous phase to generate reaction product, absorbing the reaction product in a solvent, and purifying acrylic acid from an acrylic acid aqueous solution containing the solvent by purification. The polyacrylic acid production process includes the step of utilizing heat medium recovered in the acrylic acid production process to purify polyacrylic acid from the acrylic acid aqueous solution or from acrylic acid.

Abstract: A process for preparing a multimetal oxide material which contains the elements Mo, V and Te and/or Sb and at least one of the elements Nb, Ti, W, Ta and Ce and if desired promoters and has a specific X-ray diffraction pattern, in which process the last process step comprises washing with acidic liquids. In addition, a multimetal oxide material obtainable in such a way is used as a catalyst for heterogeneously catalyzed gas-phase partial oxidations and/or ammoxidation of hydrocarbons.

Abstract: Unsaturated carboxylic acids (and esters thereof) are prepared directly from alkanes (and alcohols) utilizing vapor phase oxidative esterification.

Abstract: A process for preparing (meth)acrylic acid by conducting a saturated hydrocarbon precursor compound through a catalyst bed I whose catalysts I have, as the active composition, a multimetal oxide I which has a specific X-ray diffractogram and contains the elements Mo and V, at least one of the elements Te and Sb, and also at least one of the elements from the group consisting of Nb, Ta, W, Ce and Ti, wherein the catalyst bed I is interrupted by at least one catalyst bed II whose catalysts II have, as the active composition, a multimetal oxide II which contains the elements Mo, Bi and Fe.

Abstract: A carboxylic acid is produced by oxidative cleavage of a cycloalkane with oxygen and performs a reaction in the presence of a catalyst including an imide compound and a metallic compound, the imide compound having a cyclic imide skeleton represented by the following Formula (I): wherein X is an oxygen atom or an —OR group, and wherein R is a hydrogen atom or a hydroxyl-protecting group, under conditions of a reaction temperature of 80° C. or higher and a concentration of the cycloalkane of 21% by weight or more.

Abstract: The invention disclosed is a process for the selective conversion of an alkane to an unsaturated carboxylic acid in a one-step process with a mixed metal oxide catalyst composition having the general formula: MoVaNbbTecSbdMeOx wherein M is optional and may be one or more selected from silver, silicon, sulfur, zirconium, titanium, aluminum, copper, lithium, sodium, potassium, rubidium, cesium, gallium, phosphorus, iron, rhenium, cobalt, chromium, manganese, arsenic, indium, thallium, bismuth, germanium, tin, cerium or lanthanum. This catalyst may be prepared by co-precipitation of metal compounds which are calcined to form a mixed metal oxide catalyst.

Abstract: A catalyst comprising a 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. The catalyst is treated with a source of hydrogen, an alcohol, a source of NOx or a mixture thereof.

Abstract: The present invention provides a process in which, when an unsaturated aldehyde and/or an unsaturated carboxylic acid are produced by carrying out a catalytic gas phase oxidation reaction by using a fixed-bed multitubular reactor which is packed with a molybdenum-containing catalyst, the deterioration of the catalyst as located at a hot spot portion can be suppressed; so that the reaction can be continued for a long time while a high yield is maintained, regardless of where the hot spot portion occurs and also even if the concentration of a raw gas is high.

Abstract: A process prepares methacrylic acid from isobutane by subjecting isobutane to a partial catalytic dehydrogenation in the gas phase and charging an oxidation zone with the isobutenic product gas mixture after the components other than isobutane and isobutene have been substantially removed from the product gas mixture. The oxygen required to charge the oxidation zone is introduced accompanied by nitrogen.

Abstract: Improved processes for the preparation of olefins, unsaturated carboxylic acids and unsaturated nitriles involve the use of dehydrogenation catalysts suitable for the conversion of alkanes to alkenes and catalysts suitable for the conversion of alkanes and/or alkenes to unsaturated carboxylic acids or unsaturated nitriles.

Abstract: The invention relates to a method for producing acrylic acid by the heterogeneously catalysed gas-phase oxidation of propane on a multi-metal oxide mass, said mass containing the elements Mo, V, Te and/or Sb and having a specific X-ray diffractogram.

Abstract: The invention relates to a process for manufacturing acrylic acid from propane. According to this process, a gas mixture, which is free from molecular oxygen and comprises propane, steam as well as, optionally, an inert gas, is passed over a solid composition of formula (I) Mo1VaTebNbcSidOx  (I) in which: a is between 0.006 and 1, including the end points; b is between 0.006 and 1, including the end points; c is between 0.006 and 1, including the end points; d is between 0 and 3.5, including the end points; and x is the quantity of oxygen bound to the other elements, and depends on their oxidation states, in order to oxidize the propane according to the following redox reaction (1): SOLIDoxidized+PROPANE→SOLIDreduced+ACRYLIC ACID  (1).

Abstract: A catalyst composition and its use for the selective oxidation of ethane to acetic acid and/or for the selective oxidation of ethylene to acetic acid which composition comprises in combination with oxygen the elements molybdenum, vanadium, niobium, gold in the absence of palladium according to the empirical formula: MoaWbAucVdNbeZf wherein Z is one or more elements selected from the group consisting of B, Al, Ga, In, Ge, Sn, Pb, Sb, Cu, Pt, Ag, Fe and Re; a, b, c, d, e and f represent the gram atom ratios of the elements such that: 0<a≦1; 0≦b<1 and a+b=1; 10−5&phgr;c≦0.02; 0<d≦2; 0<e≦1; and 0.0001≦f≦0.05.

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 useful for the gas phase oxidation of alkanes to unsaturated aldehydes or carboxylic acids is disclosed. Processes for preparing the catalyst and using the catalyst to convert alkanes to unsaturated aldehydes or carboxylic acids are also disclosed.

Abstract: A mixed metal oxide, which may be an orthorhombic phase material, is improved as a catalyst for the production of unsaturated carboxylic acids, or unsaturated nitrites, from alkanes, or mixtures of alkanes and alkenes, by contact with a liquid contacting member selected from the group consisting of organic acids, alcohols, inorganic acids and hydrogen peroxide.

Abstract: A catalyst comprising a 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: The invention relates to a method for producing acetic acid by oxidizing ethane in fluid bed reactors with high selectivity and high yields.

Abstract: A method for preparing methacrylic acid at high selectivities and high yields by catalytically vapor phase oxidizing isobutane is provided. In the method, a catalyst comprising (i) a sparingly water-soluble salt of a hetero poly acid and (ii) a composite oxide containing phosphorus, molybdenum and vanadium is used. Component (i) preferably has the element composition (but excluding oxygen) represented by the general formula AaBbMocWdVe (wherein A is a counter cation, for example cesium, B is the hetero atom of the hetero poly acid, for example silicon, and a, b, c, d and e represent an atomic ratio of the respective elements.), and component (ii) preferably has the element composition represented by the general formula PpMoqVrXsOt (wherein X is for example cesium, and p, q, r, s and t represent an atomic ratio of the respective elements.).

Abstract: Unsaturated carboxylic acids are produced by the vapor phase catalytic oxidation of mixtures of alkenes and alkanes in the presence of a catalyst containing a mixed metal oxide. Similarly, unsaturated nitrites are produced by the vapor phase catalytic oxidation of alkenes or mixtures of alkenes and alkanes and ammonia in the presence of a catalyst containing a mixed metal oxide.

Abstract: A process for preparing saturated carboxylic acids having from 1 to 4 carbon atoms at a reaction temperature of from 100° C. to 400° C. and pressures of from 1.2×105 Pa to 51×105 Pa by gas phase oxidation of saturated and/or unsaturated C4-hydrocarbons, with an oxygen-containing gas and water vapor in the presence of at least one catalyst. The gas leaving the reactor is partly recirculated in a reaction gas circuit. This reaction gas circuit is configured such that part of the organic acids formed in the gas-phase oxidation is taken from the gas leaving the reactor so that the acid content of the recirculated part of the gas leaving the reactor is from 0.01% to 6.0% by volume.

Abstract: The invention relates to a method for producing acetic acid from ethane and oxygen on a fixed bed catalyst, characterized in that a reactor cascade with an oxygen feed between the reactor levels is used. This particularly advantageous method provides high conversion rates, highly pure acetic acid and low ethylene and carbon monoxide formation.

Abstract: A catalyst comprising a 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 mixed metal oxide Mo—V—Ga—Pd—Nb—X catalytic system, where X is selected from La, Te, and Zn, provides the oxidation of C2-C8 hydrocarbons to corresponding acids with a molecular oxygen-containing gas.

Abstract: In the presence of (1) an oxidizing catalyst comprising an imide compound such as N-hydroxyphthalimide, or (2) an oxidizing catalyst comprising such imide compound and a transition metal element-containing compound as a co-oxidizing agent (e. g., oxides, halides, complexes, hetero polyacid salts) a hydrocaron, an alcohol, an aldehyde, or a ketone as a substrate is brought into contact with molecular oxygen for oxidation. In the above-described oxidation process, the water content of the oxidizing reaction system is 200 mol or lower relative to 1 mol of the imide compound. According to the present invention, a substrate is efficiently oxidized with molecular oxygen under mild conditions, and there can be obtained the object compound(s) of high quality.

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 novel method for preparing a heteropolyacid catalyst containing a heteropolyacid composed of molybdophosphoric acid and/or molybdovanadophosphoric acid, or a salt of the heteropolyacid, is provided. The method comprises preparing an aqueous solution or aqueous dispersion which (1) contains the nitrogen-containing heterocyclic compound, nitrate anions and ammonium ions, (2) the ammonium ion content not exceeding 1.7 mols per mol of the nitrate anion content, and (3) the ammonium ion content not exceeding 10 mols per 12 mols of the molybdenum atom content by mixing raw materials containing the catalyst-constituting elements with the nitrogen-containing heterocyclic compound in the presence of water, drying and calcining the same. This heteropolyacid catalyst excels over conventional catalysts in performance, life and strength.

Abstract: Methods for the catalytic production of vinyl acetate monomer from ethane, ethylene or an ethanelethylene mixture using a first catalyst containing MoVNbPd, MoVLaPdbX (where X is Al, Ga, Ge or Si) or MoVNbX (where X is P, B, Hf, Te, As or mixtures thereof) in the first step of oxidation and using a conventional VAM catalyst for the second step. The method produces high yields to acetic acid and vinyl acetate without the coproduction of carbon monoxide. Furthermore, the ethylene and acetic acid produced in the first step may be utilized in the second step for VAM production.

Abstract: Apparatus and process for heat exchange with fluid beds comprises heat-exchange tubes located longitudinally with respect to the axis of a fluidization zone with a rectangular pitch, one side of which having a length at least one and a half times the length of the other side and/or with a triangular pitch, having two sides each at least one and a half times the length of the shortest side reduces the impact of the heat-exchange tubes on the fluidization characteristics of the fluid bed. The invention is particularly suitable for oxidation reactions using molecular oxygen-containing gas in the presence of a fluid bed of fluidizable catalyst, such as (a) the acetoxylation of olefins, (b) the oxidation of ethylene to acetic acid and/or the oxidation of ethane to ethylene and/or acetic acid, (c) the ammoxidation of propylene and/or propane to acrylonitrile and (d) the oxidation of C4's to maleic anhydride.

Abstract: An active and selective hydrocarbon partial oxidation catalyst comprises an activated partially-reduced polyoxometallate, preferably niobium polyoxomolybdate, that is prepared from a suitable polyoxoanion, which has been exchanged with a suitable cation and activated by heating to an activation effective temperature in the presence of a suitable reducing agent such as pyridinium. C3 and C4 hydrocarbons may be partially oxidized selectively to acrylic acid and maleic acid.

Abstract: For use in a process for the production of (meth)acrylic acid comprising at least a step for the reaction of (meth)acrylic acid by catalytic gas phase oxidation and a step for the absorption thereof, a method for preventing an effluent gas pipe from blocking is disclosed, which method is characterized by causing part or the whole of the gas discharged from the step for absorption, while being circulated via the effluent gas pipe to the step for the reaction or being discarded, to be subjected to temperature elevation and application of pressure and/or mist separation. Particularly by setting the temperature of the waste gas from the absorption column at a level in the range of 30-70° C.

Abstract: A method for separating an oxidation catalyst, an oxidation reaction product and a reaction solvent from a reaction mixture obtained by oxidizing a substrate in the presence of an oxidation catalyst containing an aromatic N-hydroxyimide compound and a transition metal, the method including (i) distilling the reaction solvent from the reaction mixture in the presence of an organic solvent which is immiscible with the reaction solvent to obtain the reaction mixture containing the reaction solvent in an amount of 5 parts by weight or less per one part by weight of the N-hydroxyimide compound, and the oxidation catalyst precipitated, and (ii) separating the reaction mixture obtained in the step (i) by a solid-liquid separation method into the oxidation product and the oxidation catalyst.

Abstract: In the production of acrolein and acrylic acid by the catalytic gas phase oxidation of propylene with a molecular oxygen-containing gas, a method is provided which enables acrolein and acrylic acid to be stably produced with a high yield for a long time from propylene by effectively repressing such secondary reactions as are responsible for the formation of organic acids, high boiling compounds, and tarry compounds, the deposition of carbonized materials, and the deterioration of the quality of products. The content of unsaturated hydrocarbons (excluding propylene) of 2-5 carbon atoms in the raw material for propylene is kept below 500 ppm (by weight). Particularly, it is proper to use a raw material for propylene which has a content of unsaturated hydrocarbons (excluding propylene) of 2-5 carbon atoms of not more than 200 ppm (by weight) and a total content of diene and acetylenic compounds of 2-5 carbon atoms of not more than 200 ppm (by weight).

Abstract: In a process for heterogeneously catalyzed gas-phase oxidation, a reaction gas starting mixture comprising propane, molecular oxygen and, if desired, inert gas is passed at from 300 to 500° C. over a fixed-bed catalyst.

Abstract: A process for producing olefins and carboxylic acids from lower alkanes using a mixed metal oxide catalytic system comprising a catalyst having the formula MoaVbAlcXdYeOz wherein: X is at least one element selected from the group consisting of W and Mn; Y is at least one element selected from the group consisting of Pd, Sb, Ca, P, Ga, Ge, Si, Mg, Nb, and K; a is 1; b is 0.01 to 0.9; c is >0 to 0.2; d is >0 to 0.5; e is >0 to 0.5; and z is an integer representing the number of oxygen atoms required to satisfy the valency of Mo, V, Al, X, and Y.

Abstract: Process for the oxidation of a hydrocarbon substrate to a corresponding oxidised hydrocarbon compound by contacting the hydrocarbon substrate with an oxygen containing atmosphere in presence of a catalyst being active in the oxidation of the hydrocarbon substrate, which process comprises the steps of: passing a process gas containing the hydrocarbon substrate through a reaction zone with the catalyst; introducing the oxygen containing atmosphere divided into a plurality of substreams successively into the reaction zone; within the reaction zone reacting the process gas continuously with the oxygen containing atmosphere; and withdrawing from the reaction zone a product gas containing oxidised hydrocarbon compound and carbon monoxide.

Abstract: A process for preparing a metal oxide catalyst for acrylic acid production which comprises calcining a metal compound mixture at 400° C. or higher to prepare a metal oxide powder comprising Mo, V, Sb, and at least one element selected from the group consisting of Nb and Ta, and supporting a compound comprising at least one element selected from the group consisting of Sb, Tl, Se, As, Pb, Sn, Ag, Cu, Ru, and Rh on the metal oxide powder, and a process for producing acrylic acid by gas phase oxidation of propane using the catalyst.

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 process for preparing saturated carboxylic acids having from 1 to 4 carbon atoms at a reaction temperature of from 100° C. to 400° C. and pressures of from 1.2×105 Pa to 51×105 Pa by gas phase oxidation of saturated and/or unsaturated C4-hydrocarbons, with an oxygen-containing gas and water vapor in the presence of at least one catalyst. The gas leaving the reactor is partly recirculated in a reaction gas circuit. This reaction gas circuit is configured such that part of the organic acids formed in the gas-phase oxidation is taken from the gas leaving the reactor so that the acid content of the recirculated part of the gas leaving the reactor is from 0.01% to 6.0% by volume.

Abstract: A promoted multi-metal oxide catalyst 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 preparing saturated carboxylic acids having from 1 to 4 carbon atoms at a reaction temperature of from 100° C. to 400° C. and pressures of from 1.2×105 Pa to 51×105 Pa by gas phase oxidation of saturated and/or unsaturated C4-hydrocarbons, with an oxygen-containing gas and water vapor in the presence of at least one catalyst. The gas leaving the reactor is partly recirculated in a reaction gas circuit. This reaction gas circuit is configured such that part of the organic acids formed in the gas-phase oxidation is taken from the gas leaving the reactor so that the acid content of the recirculated part of the gas leaving the reactor is from 0.01% to 6.0% by volume.

Abstract: A process for the oxidation of a C2 to C4 alkane to produce the corresponding alkene and carboxylic acid which process comprises contacting in an oxidation reaction zone, said alkane, molecular oxygen-containing gas, and optionally, at least one of the corresponding alkene and water, in the presence of at least two catalysts each active, with different selectivities, for the oxidation of the alkane to the corresponding alkene and carboxylic acid, to produce a product stream comprising said alkene, carboxylic acid and water, and in which process the molar ratio of alkene to carboxylic acid produced in said oxidation reaction zone is adjusted or maintained at a pre-determined value by controlling the relative proportions of the at least two catalysts in said oxidation reaction zone. Such an oxidation process may be used in an integrated process, such as for the manufacture of ethyl acetate or vinyl acetate.