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: C2–C30-alkanes are dehydrogenated in a process in which (i) ethylbenzene is dehydrogenated to styrene in a first part process to give a hydrogen-containing offgas stream, and (ii) one or more C2–C30-alkanes are dehydrogenated in the presence of a heterogeneous catalyst in one or more reaction zones in a second part process to give the corresponding olefins, with a hydrogen-containing gas stream being mixed into the reaction gas mixture of the dehydrogenation in at least one reaction zone, wherein at least part of the hydrogen-containing offgas stream obtained in the dehydrogenation of ethylbenzene is mixed into the reaction gas mixture of the alkane dehydrogenation.

Abstract: Novel processes for the production of polyolefins, other polymers, and oxygenated compounds, such as polypropylene, polyethylene, polybutene-1, poly(isobutylene), polystyrene, poly(1,3-butadiene), ethylene oxide, propylene oxide, acrylonitrile, acrolein and others, within gas phase and slurry phase type reactors, from olefins produced via the catalytic dehydrogenation of corresponding paraffins and other monomers inside permeable catalytic membrane reactors or non-permeable conventional reactors. The developed processes can produce both homopolymers and copolymers depending on the operating conditions of the preceding dehydrogenation permreactor. The invented processes utilize integrated separation, recycling and re-reaction operations of the unconverted olefins, paraffins and other utilized monomers and hydrocarbon molecules.

Abstract: A process is provided for use in the conversion of alkanes into alkylene oxides, having particular utility in the conversion of propane to form propylene oxide, using a lanthanide-promoted, supported, silver catalyst prepared via precipitation. A preferred embodiment uses silver nitrate and lanthanum nitrate to form the catalyst on a BaCO3 support.

Abstract: Catalytic system for partial oxidation reactions of hydrocarbons characterized in that it contains:

Abstract: This invention provides an article, compositions, methods of making and uses of vapor-deposited metal compounds immobilized on porous substrates. The substrate is a porous substrate having an average pore size of at least about 8 Å and a surface area of at least about 10 m2/g. The methods describe the vapor-deposition of an inorganic compound onto the substrate where the deposition is accomplished with a relatively small amount of ligand loss. The substrate can be pre-treated to achieve a uniformly dispersed metal compound deposited on the substrate. The inorganic compound can decompose into a metal compound. The article can also function as a catalyst for carbon-heteroatom coupling reactions such as carbon-carbon coupling reactions, most notably, the Heck reaction.

Abstract: Catalysts comprising iron and potassium and, if desired, further elements, which catalysts are suitable for dehydrogenating hydrocarbons to give the corresponding olefinically unsaturated hydrocarbons, are prepared by calcining a finely divided dry or aqueous mixture of an iron compound with a potassium compound and, if desired, compounds of further elements in a first step that agglomerates having a diameter of from 5 to 50 .mu.m and formed from smaller individual particles are obtained and, in a second step, preferably after shaping, calcining it at from 300 to 1000.degree. C., with the maximum calcination temperature in the second step preferably being at least 30.degree. below the calcination temperature in the first step. The catalysts thus prepared are useful, in particular, for dehydrogenating ethylbenzene to give styrene.

Abstract: A method for dehydrogenation of a hydrocarbon, which comprises selectively oxidizing hydrogen in a gas mixture which is obtained by subjecting a feed hydrocarbon to a dehydrogenation reaction in the presence of a dehydrogenation catalyst and which comprises a dehydrogenated hydrocarbon, an unreacted feed hydrocarbon and hydrogen, by contacting the gas mixture with an oxygen-containing gas in the presence of an oxidation catalyst, and further subjecting a hydrocarbon-containing gas obtained by the oxidation reaction to a dehydrogenation reaction, wherein a catalyst comprising a component having platinum and/or palladium supported on a carrier obtained by calcining at least one member selected from the group consisting of tin oxide, titanium oxide, tantalum oxide and niobium oxide, at a temperature of from 800.degree. C. to 1,500.degree. C., is used as the oxidation catalyst.

Abstract: A process for carrying out a chemical equilibrium reaction is disclosed in which, in a first stage, one or more reactants are contacted with a fixed arrangement of a catalyst under conditions such that the reactants and the products of the reaction are gaseous, the unconverted reactants and products of the first stage being passed to a second stage, in which they are contacted with a fixed arrangement of a catalyst and the reaction allowed to proceed in the presence of an absorbent capable of absorbing a product of the reaction.

Abstract: An improved process for the catalytic dehydrogenation of paraffinic hydrocarbons is disclosed. Feed paraffinic hydrocarbons are dehydrogenated by means of contacting the dehydrogenatable hydrocarbon with a dehydrogenation catalyst in a first dehydrogenation zone wherein the endothermic dehydrogenation reaction reduces the temperature of the resulting hydrocarbon stream containing dehydrogenated hydrocarbon compounds. The resulting effluent from the preceding dehydrogenation zone is then contacted with a hot hydrogen-rich gaseous stream having a temperature greater than the hydrocarbon stream to increase the temperature of the hydrocarbon stream and then the resulting heated stream is introduced into a subsequent dehydrogenation zone to produce additional dehydrogenated hydrocarbon compounds.

Abstract: A process for the oxidative dehydrogenation of hydrocarbons is disclosed in which C.sub.2 -C.sub.6 alkanes are contacted with an oxygen containing gas in a fluidized catalyst bed of platinum, rhodium, nickel or platinum-gold supported on .alpha.-alumina or zirconia. Ethane is dehydrogenated to ethylene and higher alkanes are dehydrogenated to ethylene, propylene and iso-butylene.

Abstract: There is provided a process for the net catalytic oxidative dehydrogenation of alkanes to produce alkenes. The process involves simultaneous equilibrium dehydrogenation of alkanes to alkenes and combustion of the hydrogen formed to drive the equilibrium dehydrogenation reaction further to the product alkenes. In the present reaction, the alkane feed is passed into a reactor containing both an equilibrium dehydrogenation catalyst and a reducible metal oxide, whereby the alkane is dehydrogenated and the hydrogen produced is simultaneously and selectively combusted in oxidation/ reduction (REDOX) reaction with the reducible metal oxide. This particular mode of operation is termed a same reactor, REDOX mode. The equilibrium dehydrogenation catalyst may comprise platinum and the reducible metal oxide may contain bismuth, antimony, indium, or molybdenum, or a mixture thereof.

Abstract: There is provided a process for the net catalytic oxidative dehydrogenation of alkanes to produce alkenes. The process involves simultaneous equilibrium dehydrogenation of alkanes to alkenes and combustion of the hydrogen formed to drive the equilibrium dehydrogenation reaction further to the product alkenes. In the present reaction, the alkane feed is dehydrogenated over an equilbrium dehydrogenation catalyst in a first reactor, and the effluent from the first reactor, along with oxygen, is then passed into a second reactor containing a metal oxide catalyst which serves to selectively catalyze the combustion of hydrogen. This particular mode of operation is termed a separate reactor, cofed oxygen mode. The equilibrium dehydrogenation catalyst may comprise platinum and the selective metal oxide combustion catalyst may contain bismuth, antimony, indium, molybdenum, or a mixture thereof.

Abstract: A process is provided for catalyst dehydrogenation of light paraffinic hydrocarbons using a catalyst comprising a noble metal and an intermediate pore size zeolite having a specified alkali content. The catalyst is sulfur tolerant, so that the dehydrogenation process can be carried out in the presence of sulfur or with periodic exposure to sulfur.

Abstract: An improved process for the catalytic dehydrogenation of paraffinic hydrocarbons is disclosed. Feed paraffinic hydrocarbons are dehydrogenated by means of contacting the dehydrogenatable hydrocarbon with a dehydrogenation catalyst in a first dehydrogenation zone wherein the endothermic dehydrogenation reaction reduces the temperature of the resulting hydrocarbon stream containing dehydrogenated hydrocarbon compounds. The resulting effluent from the first dehydrogenation zone is then contacted with a hot hydrogen-rich gaseous stream having a temperature greater than the hydrocarbon stream to increase the temperature of the hydrocarbon stream and then introducing the resulting heated stream into a second dehydrogenation zone to produce additional dehydrogenated hydrocarbon compounds.

Abstract: Aliphatic feeds are converted to olefins and/or aromatics in a multi pressure reactor system. A high pressure first stage reactor generates much or all of the hydrogen needed to reduce catalyst coking in lower pressure downstream reactors. High pressure operation protects catalyst stability in the first reactor, while produced hydrogen helps protect downstream catalyst. Low pressure downstream operation improves yields.

Abstract: Disclosed is an integrated process for producing olefins by starting from methane containing gas mixture, which process essentially comprises the following steps:converting methane into higher hydrocarbons by oxidative coupling carried out in the presence of air and/or oxygen;dehydrogenating, with the aid of a catalyst, said higher hydrocarbons, with an olefin-rich mixture being obtained;removing H.sub.2 O, CO.sub.2, CO and H.sub.2 from the resulting olefinic mixture;removing from said olefinic mixture any not converted methane, and recycling it upstream from the oxidating coupling;separating ethylene from the olefinic mixture;separating any not dehydrogenated ethane from the olefinic mixture.

Abstract: An improved process for the catalytic dehydrogenation of paraffinic hydrocarbons is disclosed. Feed paraffinic hydrocarbons are dehydrogenated by means of contacting the dehydrogenatable hydrocarbon with a dehydrogenation catalyst in a first dehydrogenation zone wherein the endothermic dehydrogenation reaction reduces the temperature of the resulting hydrocarbon stream containing dehydrogenated hydrocarbon compounds. The resulting effluent from the first dehydrogenation zone is then contacted with a stream of gas comprising normally gaseous hydrocarbon compounds having a temperature greater than the hydrocarbon stream to increase the temperature of the hydrocarbon stream and then introducing the resulting heated stream into a second dehydrogenation zone to produce additional dehydrogenated hydrocarbon compounds.

Abstract: An alkane-containing feedstream is passed through one or more tubes, which may contain alkane-dehydrogenation catalyst, immersed in a bed of fluidized particles. The bed is at an elevated temperature which maintains the temperature within the tube(s) at an alkane-dehydrogenation temperature. The particles may be inert, chemically active and/or catalytically active. In one embodiment, cracking catalyst particles are circulated between a reaction zone wherein they contact a cracker feedstock which is converted to cracked hydrocarbon products and a regenerator (22) wherein carbonaceous deposits on the catalyst particles are exothermically removed by contact with an oxygen-containing gas (24). Hot regenerated particles from the regenerator (22) are recirculated (27) to the reaction zone for re-use therein.

Abstract: A continuous process for the dehydrogenation of paraffinic and olefinic hydrocarbons in the presence of a catalyst comprises circulating a charge containing said paraffinic hydrocarbons through at least two reactions zones of the moving bed type which are arranged in series, the catalyst flowing successively in each reaction zone. The catalyst which is drawn off from the last reaction zone is sent to a regeneration zone at the exit from which it is reintroduced close to the first reaction zone. The process comprises the injection of sulphur and/or at least one sulphur compound before or simultaneously to the introduction of the charge into the first reaction zone. In accordance with the process, the catalyst which is drawn off from the last reaction zone is sent into a stripping zone wherein the sulphur which it contains is removed before the catalyst is sent to the regeneration zone.

Abstract: The activity, selectivity and yield of a dehydrogenation process used to produce olefins from normal paraffin hydrocarbons having 2 to 5 carbon atoms per molecule is improved by the introduction of an essentially constant level of water into the inlet of two or more beds of dehydrogenation catalyst.

Abstract: In a dehydrogenation process wherein catalyst is regenerated off-stream by use of heated air, at least two reactors are in the regeneration cycle, with regeneration air being heated to regeneration catalyst temperature for introduction into the first reactor, and thereafter being reheated to catalyst regeneration temperature and introduced into the second reactor. Such air may also be employed for preheating feed to the dehydrogenation reactor and/or for steam generation by heating such air to the temperature required for such procedure.

Abstract: The present invention relates to a process for the production of olefins from light paraffins. Specifically, the present invention relates to a process for the production of olefins from ethane, propane, butane, isobutane, pentane and isopentane, preferably utilizing moderate or high activity dehydrogenation catalysts at kinetic residence times of from about 0.1 to about 2.0 seconds, and at temperatures of from about 900.degree. F. to about 1600.degree. F. The present invention further relates to the production of an olefin from its corresponding paraffin, and a process for the production of a mixture of olefins.

Abstract: Disclosed is a method for cracking a hydrocarbon material. The method includes introducing a stream including a hydrocarbon fluid and a carrier fluid into a reaction zone. A microwave discharge plasma is continuously maintained within the reaction zone, and in the presence of the hydrocarbon fluid and the carrier fluid. Reaction products of the microwave discharge are collected downstream of the reaction zone.

Abstract: There is provided a catalyst and a process for the direct partial oxidation of methane with oxygen, whereby hydrocarbons having at least two carbon atoms are produced. The catalyst used in this reaction is a spinel oxide, such as MgMn.sub.2 O.sub.4 or CaMn.sub.2 O.sub.4, modified with an alkali metal, such as Li or Na.

Abstract: A process and apparatus are disclosed for the catalytic conversion of hydrocarbons in a transport or sub-transport fluidized bed reaction zone. Inert particles are used to transfer heat to the reaction zone. The particles may be heated separately from the catalyst in a combustion zone or together with the catalyst in a regenerator. Fuel is fired to heat the inert particles or a mixture of catalyst and inert particles. Hydrogen deficient fuels such as charcoal or coke are preferred.

Abstract: There is provided a process for the direct partial oxidation of methane with oxygen, whereby hydrocarbons having at least two carbon atoms are produced. The catalyst used in this reaction is a spinel oxide such as ZnMn.sub.2 O.sub.4.

Abstract: An improved process is provided for the production of oxides from alkanes by reaction with oxygen, air or a gas enriched in oxygen relative to an air in the presence of an oxidation catalyst. An alkane, e.g. propane, is converted to an alkene in a multistage dehydrogenator. The product stream is withdrawn from an intermediate reactor in the dehydrogenator, other than the first and the last reactor, and introduced into an oxidation reactor. The product formed in the oxidation reactor is recovered in a conventional quench tower. The gaseous effluent from the quench tower is treated in a pressure swing adsorption (PSA) unit to form a gaseous stream containing the unreacted alkane and alkene as well as a minor amount, i.e. less than about 2 percent by volume, of oxygen and nitrogen, if present in the feed to the oxidation reactor.

Abstract: This invention relates to a process for (a) catalytically dehydrogenating a saturated hydrocarbon to the corresponding unsaturated hydrocarbon and hydrogen, (b) removing hydrogen from the products of step (a) over a catalyst supported on tin oxide and (c) dehydrogenating the products from step (b) under conditions of step (a). The process is effective for the production of e.g. styrene from ethylbenzene.

Abstract: An improved process is provided for the production of oxides from hydrocarbons by reaction with oxygen, air or a gas enriched in oxygen relative to air, preferably the latter, in the presence of an oxidation catalyst. An alkane, e.g. propane, is converted to an alkene in a dehydrogenator. The product stream is introduced into an oxidation reactor. The product formed therein is recovered in a quench tower. The gas phase from the quench tower is treated in a PSA unit to form a gaseous stream containing the unreacted alkane, alkene, a minor amount of oxygen, i.e. less than about 2 percent by volume, and nitrogen if present in the feed to the oxidation reactor. The gaseous stream, which may or may not contain hydrogen depending on the adsorbent on the PSA unit, is introduced into a selective oxidation unit to remove the remaining oxygen and then recycled to the dehydrogenator.

Abstract: A process for the oxydehydrogenation of ethane to ethylene in a reaction system of open series connected stages, includes changing the total water and acetic acid content in the output gaseous stream after at least one stage other than the last stage of the series.

Abstract: The rate at which an oxygen-containing gas stream is admixed with hydrocarbons and hydrogen upstream of a catalytic hydrogen oxidation zone is controlled on the basis of temperature differentials across the oxidation zone and an upstream catalytic dehydrogenation zone. This control overrides the normal control mode based upon the outlet temperature of the oxidation zone effluent stream, which is the inlet temperature to a subsequent bed of hydrocarbon conversion catalyst. The control method can be used to apply oxidative reheat technology to a variety of processes.

Abstract: Methods for inhibiting coke formation in pyrolytic reactors and furnaces are disclosed wherein effective alkaline earth metal salt coke retardant treatments are used. Exemplary coke retardant treatments include magnesium and calcium salts such as the acetate, chloride, and nitrate, and magnesium sulfate salt.

Abstract: Lower alkanes are converted to olefins in a `third bed` external catalyst cooler (ECC) in which hot catalyst, from a first regenerator (`second bed`) operating in conjunction with a fluid catalytic cracker (`first bed`), thermally cracks and dehydrogenates the alkanes. Because this is an endothermic reaction, the catalyst is autogeneously cooled before it is recirculated to the FCC regenerator. The cracking catalyst is the catalyst of choice in the FCC reactor. Maximum conversion of alkanes to olefins is sought, and can be maintained because the FCC regenerator burns the coke made during alkane dehydrogenation. The olefins produced are then oligomerized in an oligomerization reactor ("fourth" bed) operating in conjunction with a second regenerator ("fifth" bed) to produce a gasoline range stream.

Abstract: A process is provided for the conversion of methane to higher hydrocarbons; methane is first oxidatively coupled to form a product mixture comprised of ethylene, hydrogen, and carbon monoxide, and this product mixture is reacted over a dual catalyst comprised of a metal oxide effective for the reaction of carbon monoxide and hydrogen and a zeolite component effective for the oligomerization of ethylene.

Abstract: Isobutane is dehydrogenated to isobutylene with minimal, preferably no more than 15%, loss of the fresh feed isobutane by structural isomerization or cracking, even when the dehydrogenation feed contains substantial amounts of isobutylene. The catalysts employed comprise platinum and promoting amounts of at least one of indium, neodymium, and tin on a nonacidic support, such as zinc aluminate. The reaction is carried out at a pressure of 0.14 to 2 bar, and an outlet temperature, .sup.o K, minimum residence time, sec., defined by the equationR=1.76.times.10.sup.-4 e.sup.7890/T.

Abstract: Ethane is catalytically dehydrogenated in a reaction zone comprising at least two separate beds of dehydrogenation catalyst. The reactants are reheated and hydrogen is consumed through use of an intermediate bed of hydrogen selective oxidation catalyst. The amount of hydrogen consumed in the combustion step is increased by cooling the effluent of the first dehydrogenation catalyst bed by direct or indirect heat exchange.

Abstract: Dehydrogenatable hydrocarbons may be subjected to a dehydrogenation reaction in which the hydrocarbons are treated with a dehydrogenation catalyst comprising a modified iron catalyst in the presence of steam in a multicatalyst bed system. The reaction mixture containing unconverted hydrocarbons, dehydrogenated hydrocarbons, hydrogen and steam is then contacted with an oxidation catalyst whereby hydrogen is selectively oxidized. The selective oxidation catalyst which is used will comprise a noble metal of Group VIII of the Periodic Table, a metal of Group IVA and, if so desired, a metal of Group IA or IIA composited on a porous inorganic support. The inorganic support will comprise an alumina precursor which possesses and ABD less than about 0.6 g/cc, a pore volume greater than about 0.5 cc/g, and a pore distribution such that between 10% and 70% of the pore volume is present as pores whose diameters are greater than about 300 Angstroms. After peptizing and calcination at a temperature of about 900.degree.

Abstract: Unsaturated hydrocarbons may be prepared by subjecting dehydrogenatable hydrocarbon to dehydrogenation in the presence of a dehydrogenation catalyst. The effluent stream from this step, comprising unconverted hydrocarbons, dehydrogenated hydrocarbons, hydrogen and steam, may then be passed to a selective oxidation step in which the hydrogen is selectively oxidized in the presence of an oxygen-containing gas to the substantial exclusion of the oxidation of the hydrocarbons. The oxidation catalyst which is employed will comprise a Group VIII noble metal, a Group IVA metal and a Group IA or IIA metal composited on a metal oxide support. The metal oxide support such as alumina will possess a particular configuration such as a polylobular particle containing from 3 to about 8 lobes and having a ratio of exterior surface to catalyst volume greater than [4D+2L] in which D is the largest representative diameter and L is the length of the particle.

Abstract: An improved method for dehydrogenating dehydrogenatable hydrocarbons by contacting a gas comprising said hydrocarbons and an oxidative dehydrogenation agent at dehydrogenation conditions, the improvement which comprises contacting the hydrocarbon with an oxidative dehydrogenation agent containing a promoting amount of alkali metal and/or compounds thereof and associated with a support selected from the group consisting of alkaline earth metals and compounds thereof.

Abstract: A system is disclosed for circulating an ancillary hydrogen-rich gas stream through a part of a moving bed hydrocarbon conversion process. The gas stream may be employed in lockhopper systems, catalyst transfer equipment and catalyst treating zones as for reducing the catalyst. The used ancillary gas is discharged into a partitioned vapor-liquid separation vessel. The partially condensed reaction zone effluent stream is discharged into a different chamber of the same vessel. The net off gas stream is withdrawn from the chamber receiving the used ancillary gas to prevent contamination of a recycle gas stream, which is drawn off the other chamber.

Abstract: Hydrocarbons are catalytically dehydrogenated in a reaction zone comprising at least two separate beds of dehydrogenation catalyst. The reactants are reheated and hydrogen is consumed through use of an intermediate bed of hydrogen selective oxidation catalyst. The amount of hydrogen consumed in the combustion step is increased by cooling the effluent of the first dehydrogenation catalyst bed by direct or indirect heat exchange.

Abstract: A process and apparatus for dehydrogenating alkanes such as iso-butane comprises contacting the alkane in admixture with steam under dehydrogenation conditions with a dehydrogenation catalyst. The catalyst is substantially free of Group VIII metals of Atomic Number 27 and higher. The catalyst is provided in a heated tubular reactor which preferably contains groups of tubes mounted in a furnace each group of tubes having a common header, to enable continuous dehydrogenation, while permitting catalyst reactivation.

Abstract: This invention relates to a new process for dehydrogenating hydrocarbons utilizing a catalyst comprising a platinum group component, an alkali or alkaline earth component and a porous support material. After the catalyst is used to dehydrogenate hydrocarbons it is contacted in a catalyst regeneration zone with a halogen component to produce a regenerated catalyst containing added halogen component, which regenerated catalyst can then be reused to dehydrogenate hydrocarbons. The added halogen component increases the catalyst's activity and stability in the dehydrogenation process.

Abstract: Dehydrogenatable hydrocarbons may be subjected to a dehydrogenation reaction in which the hydrocarbons are treated with a dehydrogenation catalyst such as a modified iron compound in the presence of steam in a multi-catalyst bed system. The reaction mixture containing unconverted hydrocarbon, dehydrogenated hydrocarbon, hydrogen and steam is then contacted with a selective oxidation catalyst such as a noble metal of Group VIII of the Periodic Table, a metal of Group IVA of the Periodic Table and, if so desired, a metal of Group IA or IIA of the Periodic Table composited on a highly porous inorganic support. The oxidation catalyst will selectively oxidize the hydrogen to improve the combustion thereof and supply the necessary heat required for a subsequent dehydrogenation treatment.

Abstract: A multiple reaction zone process for dehydrogenating light hydrocarbons, preferably propane, is disclosed. The feed stream and intermediate streams are first heated by indirect heat exchange to temperatures slightly below the desired inlet temperature of the dehydrogenation catalyst beds. These streams are then transported to a location which is in close proximity of the dehydrogenation catalyst bed and further heated by the selective combustion of hydrogen present in these streams through the use of beds of oxidation catalyst. This eliminates lengthy high temperature reactant residence times in transfer lines extending between fired heaters and the dehydrogenation catalyst beds, thereby reducing thermal cracking of the feed and increasing the selectivity of the process. The process has special utility with stacked moving bed reactors, which have larger volume reactant transfer lines.

Abstract: The present invention is a reactor that consists of a single shell that contains a reaction zone and a regeneration zone. The reaction zone and regeneration zone are arranged in such a manner that (a) a particulate solid may be transferred by flow of gases from the regeneration zone to the reaction zone by a first route and then back to the regeneration zone by a second route; and (b) the gases passing through the regeneration zone are not transferred to the reaction zone and the gases passing through the reaction zone are not transferred to the regeneration zone.

Abstract: Oxide complex catalysts comprising Fe-Sb-Bi-O.sub.x promoted with a wide variety of different elements have been found to be especially useful in the ammoxidation of olefins to nitriles such as acrylonitrile and methacrylonitrile. Not only are the desired nitriles obtained with high yields when these catalysts are used, but also the production of unwanted liquid byproducts such as acrolein, acrylic acid and acetonitrile is significantly reduced.