Abstract: This invention relates to a supported silver catalyst for the manufacture of ethylene oxide which contains a combination of (a) cesium and (b) at least one other alkali metal selected from the group consisting of lithium, sodium, potassium and rubidium, which combination comprises (a) and (b) in amounts in relation to the amount of silver therein sufficient to increase the efficiency of ethylene oxide manufacture to a value greater than the efficiencies obtainable under common conditions from respective catalysts which are the same as said catalyst except that instead of containing both (a) and (b), one contains the respective amount of (a), and the other contains the respective amount of (b). There is also described herein a process of making such catalyst and a process for producing ethylene oxide with such catalyst.

Abstract: The invention relates to an improved process for production of ethylene oxide which minimizes unreacted ethylene losses through the use of semi-permeable membrane units, thereby allowing an effective, selective removal of argon from the process cycle gas, without significant ethylene losses.

Abstract: An improved silver catalyst for the oxidation of ethylene with molecular oxygen is made by impregnating a support with a silver salt prepared by reacting a silver compound with a neo-acid, in a hydrocarbon solvent with the reaction completed under reflux conditions; drying and activating the resultant precatalyst by heating in air; thereafter impregnating the activated catalyst with an amount, 800 to 5000 wppm of alkali metal, preferably Cs, to deactivate the catalyst to form a catalyst precursor and heating the catalyst precursor at 450.degree.-700.degree. C. for 0.1 to 4.5 hours at a steady state in a substantially inert atmosphere to reactivate it.

Abstract: Process is disclosed for the selective mono epoxidation of olefins having no allylic hydrogens. Such olefins are contacted with an oxygen-containing gas in the presence of a silver catalyst under defined reaction conditions, thereby selectively producing monoepoxides in good yield.

Abstract: Disclosed is a process for making styrene oxide which comprises contacting styrene in the vapor phase with a molecular oxygen-containing gas over a silver metal catalyst containing a promoting amount of at least one alkali metal hydroxide selected from sodium, potassium and lithium hydroxides, on an inert solid inorganic support at contact times of from 0.6 to 10 seconds and temperatures from 200.degree. to 350.degree. C.

Abstract: In an exothermic reaction the reactants are passed through a fixed catalyst bed through which heat exchange tubes pass, reactants are flowed transversely to the tubes, heated by a first group of tubes and cooled by a second group of tubes, heat exchange fluid being passed from the first group of tubes to the second. This reduces the need to preheat incoming reactants.

Abstract: An improved process is disclosed for producing ethylene oxide; the process utilizing suitable semipermeable membrane units to selectively remove desired amounts of both carbon dioxide and argon diluents from the reaction recycle gas. The utilization of such a process makes possible to utilize a much cheaper low purity oxygen source without concern for feed purge losses.

Abstract: A supported silver catalyst for the oxidation of ethylene to ethylene oxide with molecular oxygen is made by impregnating a support with a hydrocarbon solution of a silver salt of a neo-acid having 7 or more carbon atoms, substantially free of water and said neo-acid. Preferably, the hydrocarbon solvent is toluene, xylene, ethyl benzene, cyclohexane, or cumene. The impregnated support is dried and the silver is activated under conditions chosen to provide the optimum selectivity to ethylene oxide. Thereafter, the activated silver catalyst maybe impregnated with an alkali metal solution sufficient to increase selectivity of the silver catalyst above its alkali-free state. The amount of alkali metal on the finished catalyst is the optimum for the particular support selected and preferably will be about 1-6.times.10.sup.-3 gew/kg of catalyst. The catalyst may also include additional promoters, such as the alkaline earth metals, preferbly barium.

Abstract: In a process of producing ethylene oxide by contacting ethylene and oxygen with a main body of a solid catalyst in a reaction zone and passing product from that zone through a substantial volume to a cooler, acetaldehyde is produced by isomerization of ethylene oxide in the volume. The acetaldehyde content of the gases entering the cooler is reduced in this invention by passing them through a second, smaller bed of catalyst before the gases are passed to the cooler.

Abstract: A supported silver catalyst for the oxidation of ethylene with molecular oxygen to ethylene oxide is made by depositing silver on a support capable of selectively adsorbing alkali metals, activating the silver under conditions chosen to provide the optimum selectivity of ethylene oxide and thereafter depositing an amount of an alkali metal sufficient to increase selectivity of the silver catalyst above its alkali-free state. The catalyst most preferably employs a ceramic support having a surface area of 0.3-0.8 m.sup.2 /gm. The amount of alkali metal on the finished catalyst is most preferably 50-300 ppm by weight. The catalyst may also include additional promoters, such as the alkaline earth metals, preferably barium.

Abstract: The performance of a catalyst for the oxidation of alkenes to alkylene oxides which comprises silver on alpha alumina is improved by introducing an alkali metal selected from lithium, sodium, rubidium and/or potassium to the catalyst in a ratio of one part chemically absorbed to at most three parts physically absorbed by impregnation with a solution of an alkali metal compound in a solvent which has dielectric constant of at most 8.

Abstract: A supported silver catalyst selective to the formation of ethylene oxide in the reaction of ethylene with molecular oxygen is made by depositing an amount of an alkali metal sufficient to depress the activity and selectivity of the silver catalyst below that of its alkali-free state and thereafter heating the alkali metal-containing catalyst in a substantially oxygen-free atmosphere to reactivate it. In one embodiment, a large amount of alkali metal is deposited which removes substantially all activity from the silver catalyst and then activity and selectivity for oxidation of ethylene to ethylene oxide is recovered and enhanced by heating the catalyst in a nitrogen atmosphere to a temperature above 400.degree. C. for a sufficient period of time.

Abstract: Ethylene is oxidized into ethylene oxide by bringing a feed gas mixture, which contains the ethylene, oxygen and at least 1 vol. % of carbon dioxide as well as at least 0.5 vol. ppm of a chlorine-containing burning reaction decelerator and at least 1 vol. ppm as calculated in terms of nitrogen monoxide of a nitrogen oxide and/or a precursor thereof, into contact with a catalyst which carries silver and as a practically sole alkali metal, rubidium at an Rb/Ag atomic ratio of 2/1000-7/1000 on a fire-resistant carrier having a specific surface area of 1 m.sup.2 /g or smaller.

Abstract: A silver catalyst containing lithium and cesium as promoters for the direct oxidation of ethylene with oxygen to give ethylene oxide is applied to a porous carrier and essentially consists of .alpha.-alumina and contains certain amounts of soluble calcium, aluminum, potassium and sodium salts. The carrier has a BET surface area of from 0.4 to 0.8 m.sup.2 /g, a pore volume of not less than 0.45 ml/g, the pores being equally accessible to cold and warm water, a bulk density of less than 700 kg/m.sup.3 and a shape which, in the reactor, provides a geometrical surface area of not less than 600 m.sup.2 /m.sup.3, on which more than 13% by weight of silver are applied as active component and more than 115 kg of silver are available per m.sup.3 of reactor, and from 100 to 300 ppm by weight of lithium and from 200 to 600 ppm by weight of cesium are present as promoters. A process for the preparation of the silver catalyst and its use for the oxidation of ethylene are described.

Abstract: The invention relates to a novel mixed ion and electron conducting catalytic ceramic membrane and to its use in hydrocarbon oxidation and or hydrogenation processes, the membrane consists of two layers, layer 1 which is an impervious mixed ion and electron conducting ceramic layer and layer 2 which is a porous catalyst-containing ion conducting ceramic layer.

Abstract: Ethylene oxide is produced by contacting ethylene and oxygen in the presence of a chlorine containing reaction modifier with a silver containing catalyst, nitropropane being also present. The nitropropane raises the selectivity of the process.

Abstract: Silver containing catalysts for the oxidation of alkenes to alkylene oxides are produced by impregnating a support with a solution of a silver compound and an organic compound and decomposing the silver compound to silver in the presence of an alkali metal compound. Organic residues are then removed by washing and fresh alkali metal introduced.

Abstract: A supported silver catalyst having improved thermostability is prepared by depositing silver particles on a carrier or support having a stepped structure.

Abstract: A silver catalyst having fine silver particles dispersed and deposited fast on the outer surface of a porous inorganic refractory carrier and on the inner wall surface of pores in said carrier and used in the production of ethylene oxide by the catalytic gas-phase oxidation of ethylene with molecular oxygen, which silver catalyst is characterized by containing a compound of at least one metal ion selected from the group consisting of cesium, rubidium, potassium, and thallium (monovalent) as dispersed and deposited fast in an amount in the range of 1.times.10.sup.-6 to 5.times.10.sup.-6 gram equivalent per the unit surface area, m.sup.2, of said silver on the surface of said silver.

Abstract: A supported silver catalyst for the oxidation of ethylene with molecular oxygen to ethylene oxide is made by depositing silver on a support capable of selectively adsorbing alkali metals, activating the silver under conditions chosen to provide the optimum selectivity to ethylene oxide and thereafter depositing an amount of an alkali metal sufficient to increase selectivity of the silver catalyst above its alkali-free state. The catalyst most preferably employs a ceramic support having a surface area of 0.3-0.8 m.sup.2 /gm. The amount of alkali metal on the finished catalyst is most preferably 50-300 ppm by weight. The catalyst may also include additional promoters, such as the alkaline earth metals, preferably barium.

Abstract: The invention relates to an improved silver catalyst, suitable for use in the oxidation of ethylene to ethylene oxide, characterized by(a) a calcined, alkali metal-enriched alumina carrier and(b) from 1 to 25 percent by weight of metallic silver, based on the weight of the total catalyst,(c) an alkali metal of the group consisting of potassium, rubidium, cesium and mixtures, in the form of an oxide or hydroxide as a promoter and(d) a fluoride-anion,the latter two under (c) and (d) each being in an amount between 10 and 1000 parts by weight per million parts by weight of the total catalyst.

Abstract: A silver catalyst for the direct oxidation of ethylene with oxygen to give ethylene oxide is applied on a porous carrier and essentially consists of .alpha.-alumina and contains certain amounts of soluble calcium, aluminum, potassium and sodium salts. The carrier has a BET surface area of from 0.2 to 0.8 m.sup.2 /g, a pore volume of not less than 0.5 ml/g, the pores being equally accessible to cold and warm water, and a bulk density of less than 650 kg/m.sup.3, and has a shape which, in the reactor, provides a geometric surface area of not less than 600 m.sup.2 /m.sup.3, on which more than 13% by weight of silver are applied as the active component, more than 110 kg of silver being available per m.sup.3 of reactor.

Abstract: The invention relates to a process for the preparation of a silver catalyst suitable for the oxidation of ethylene to ethylene oxide, characterized in that a silver compound and, if desired, a promoter are applied to a carrier, after which the silver compound is reduced to metallic silver, and in which process the carrier has been prepared by mixing an aluminum compound with an alkali metal hydroxide and with an organic fluorine compound and by calcining the obtained mixture, to the silver catalysts prepared by means of this process and to the use of the silver catalysts in the preparation of ethylene oxide.

Abstract: A process for manufacturing silver catalysts deposited on a porous refractory support, comprising impregnating a refractory support with a portion of the silver required for the catalyst by immersing the support in a practically anhydrous solution of an organic carboxylic acid salt of silver in an organic liquid which complexes the silver ions, removing excess organic liquid from the support without causing the deposition of metallic silver thereon; depositing the remainder of the silver and at least one promoter selected from cesium, rubidium, or potassium on the support modified by the first silver deposit by immersing said modified support in a practically anhydrous solution of an organic carboxylic acid salt of silver in an organic liquid which complexes the silver ions, said organic liquid containing in the solubilized state, a salt of at least one of the promoters, before transformation of the silver deposited into metallic silver.

Abstract: A silver salt solution suitable for depositing silver on a support in the preparation of silver catalysts is made by reacting a silver compound with a neo-acid, in a hydrocarbon solvent. The reaction is completed under reflux conditions, thereby removing water formed by the reaction and reacting at least 90% of the unreacted acid. Therefore, the solution may be used without further processing to impregnate a porous support, thereby providing a catalyst useful for oxidation of ethylene oxide.

Abstract: A packing material for a reactor for producing ethylene oxide by the catalytic oxidation of ethylene in the presence of molecular oxygen, wherein the packing material is used at the inlet side of a catalyst layer of the reactor, is silica-alumina containing 10 to 8 wt. % of silica, and is produced by sintering the silica-alumina at 1200.degree. to 1500.degree. C.

Abstract: A supported silver catalyst for the oxidation of ethylene to ethylene oxide with molecular oxygen is made by impregnating a support with a hydrocarbon solution of a silver salt of a neo-acid having 7 or more carbon atoms, substantially free of water and said neo-acid. Preferably, the hydrocarbon solvent is toluene, xylene, ethyl benzene, cyclohexane, or cumene. The impregnated support is dried and the silver is activated under conditions chosen to provide the optimum selectivity to ethylene oxide. Thereafter, the activated silver catalyst may be impregnated with an alkali metal solution sufficient to increase selectivity of the silver catalyst above its alkali-free state. The amount of alkali metal on the finished catalyst is the optimum for the particular support selected and preferably will be about 1-6.times.10.sup.-3 gew/kg of catalyst. The catalyst may also include additional promoters, such as the alkaline earth metals, preferably barium.

Abstract: The subject invention relates to a process for regenerating silver-containing carrier catalysts used in the preparation of ethylene oxide which comprises treating a deactivated catalyst with a solution comprising a potassium, rubidium, or cesium compound and a reducing agent. The subject process provides improved catalyst regeneration.

Abstract: A method for improving the activity of a used supported silver catalyst, used for the manufacture of ethylene oxide by reaction of ethylene with oxygen or air, which method consists essentially of:(a) impregnating said used catalyst at a temperature from 80.degree. C. to 150.degree. C. and for 0.75 hour to 10 hours with an impregnating solution containing water, a water-miscible organic solvent selected from the group consisting of methanol, ethanol, propanol, and isopropanol, at least one compound of cesium, rubidium, or of cesium and rubidium in an amount providing from 50 mg to 1000 mg per kilogram of solution, said solution containing from 5 to 50 percent by weight of water;(b) separating the impregnated catalyst from excess impregnating solution; and(c) drying the impregnated catalyst.

Abstract: A method for making a silver catalyst by applying a promoter and a complex formed between a silver salt and a mixture of a tert.-alkyl amine and a sec.-alkyl amine to a heat resistant porous support and then thermally decomposing said complex to metallic silver.

Abstract: This invention relates to a supported silver catalyst for the manufacture of ethylene oxide prepared by a process comprising impregnating a porous catalyst support with a solvent containing a silver salt and treating the impregnated support to effect deposition of silver on the support surface. Following silver deposition, the support is impregnated with a liquid containing more than 30%, by volume, of an organic solvent capable of forming a complex with silver ion, and a compound of at least one metal promoter in an amount sufficient to deposit the desired amount of metal cation on said support. The impregnated support is then treated to effect deposition of the promoter. There is also described herein a process of making such catalyst and a process for producing ethylene oxide.

Abstract: The performance of silver-based catalyst used for the direct oxidation of ethylene to ethylene oxide is improved by regeneration in which from 1 to 1,000 parts per million of a regenerate is added to the catalyst in solution and the solvent is removed by drying the catalyst with a upflow of inert gas through the catalyst at ambient temperature and pressure.

Abstract: This invention relates to a supported silver catalyst for the manufacture of ethylene oxide prepared by a process comprising impregnating a porous catalyst support with a solvent containing a silver salt and treating the impregnated support to effect deposition of silver on the support surface. Following silver deposition, the support is impregnated with a liquid containing a compound of at least one metal promoter dissolved in an organic solvent in which water is soluble at ambient temperature in an amount no greater than about 50 wt. % based on the weight of the water-solvent solution. The impregnated support is then treated to effect deposition of the promoter. There is also described herein a process of making such catalyst and a process for producing ethylene oxide.

Abstract: The activity and the service life of supported silver catalysts used in the preparation of ethylene oxide by the catalytic vapor phase oxidation of ethylene with molecular oxygen are extended by using mixtures of:(a) supported silver catalysts and promoter metal compounds;(b) supported silver catalysts and supported promoter metal compounds;(c) promoter metal compound treated supported silver catalysts and promoter metal compounds; or(d) promoter metal compound treated supported silver catalysts and supported promoter metal compounds.Promoter metal compounds containing about 0.001-0.05% by weight rubidium, about 0.01-0.20% by weight potassium, about 0.001-0.5% by weight cesium or about 0.01-0.25% by weight barium, based on the total weight of catalyst, are suitable.

Abstract: An improved method is disclosed for improving the selectivity of supported silver catalysts by incorporating a promoter therein. The improvement comprises forming a solution of a compound of the promoter and an anion selected from the group consisting of unsaturated carboxylic acids, aminoorganic acids, and hydroxybenzoic acids in a solvent and contacting the catalyst with the solution.

Abstract: A composition and method for removing alkali metal-containing impurities from supported silver catalysts wherein the composition is comprised of an inert organic liquid and a solubilizing agent. The method is used prior to regeneration of the catalyst with cesium, rubidium, or mixtures thereof to improve the selectivity of the regenerated catalyst.

Abstract: A process for the production of ethylene oxide by the vapor-phase catalytic oxidation of ethylene with molecular oxygen, which process comprises passing a mixed gas containing ethylene and molecular oxygen through a catalyst bed filled with a silver catalyst and subsequently passing the resultant reaction product gas through a cooling zone filled with a particulate material containing a substance capable of inhibiting the isomerization of ethylene oxide to acetaldehyde carrying at least one metal selected from the group consisting of sodium, potassium, rubidium, cesium, calcium, strontium, barium and thallium or a compound of said metal to be carried on an inert refractory particulate material.

Abstract: An improved method is disclosed for the vapor phase epoxidation of ethylene to ethylene oxide which includes intimately contacting an ethylene-containing feed stream with an epoxidizing amount of molecular oxygen epoxidizing agent in the presence of a catalytically effective amount of an improved catalyst comprising an inorganic porous support containing metallic silver and an effective amount of a cesium promoter which have been deposited coincidentally on the support, and, optionally, an effective amount of at least one inhibitor which retards combustion of ethylene to carbon dioxide at temperatures of from about 200.degree. C. to about 300.degree. C.The novel silver catalyst is best described in terms of its method of preparation. The catalyst is prepared by impregnating certain inorganic porous substrates with a specific silver carboxylate/amine complex, such as silver oxalate/diethylenetriamine complex, impregnating solution containing an effective amount of a cesium salt.

Abstract: A silver catalyst for the production of ethylene oxide, comprising a granular .alpha.-alumina carrier having a sodium content of not more than 0.07% by weight and a specific surface area within the range of from 0.5 to 5 m.sup.2 /g, a finely divided metallic silver deposited on said carrier in an amount within the range of from 5 to 25% by weight based on the total catalyst, and at least one member selected from the group consisting of alkali metals of Atomic Numbers 19 to 55 and alkali metal compounds said at least one member being in an amount within the range of from 0.001 to 0.05 gram equivalent weight per kilogram of the complete catalyst.

Abstract: When supported silver materials are being prepared, deposits of from about 4.0.times.10.sup.-5 to about 8.0.times.10.sup.-3 gram equivalent weights per kilogram of finished product of ionic, higher alkali metals, i.e., ionic potassium, rubidium or cesium simultaneously with the deposit of silver improves the selectivity of these materials as catalysts for ethylene oxide production. Particularly good results are obtained with potassium.

Abstract: Silver coated particles having high concentrations of metallic silver are produced which are useful in forming alloys with metals such as mercury. The process comprises admixing carrier particles with an aqueous solution of a silver salt to form a slurry. A hydrazine compound is added to the slurry to precipitate metallic silver on the carrier particles in a medium which becomes increasingly acidic. Silver coated particles having a metallic silver content up to 90 percent by weight of the coated particle can be produced in a single impregnation under conditions which prevent the formation of explosive by-products such as silver nitride. The silver coated particles are particularly suitable for the recovery of metals such as mercury from fluids.

Abstract: A supported silver catalyst for oxidation of ethylene to ethylene oxide is prepared by impregnation of the support, activation, and solvent washing, with each step being carried out at a relatively low temperature. Silver so deposited has an average particle diameter of about 0.5-0.7 microns and is capable of being promoted by post-deposition of alkali metals such as cesium, rubidium, and potassium.

Abstract: Supported silver catalysts, which should have as high an activity as possible, are employed for the manufacture of ethylene oxide by oxidizing ethylene by means of oxygen or air. A process is described for improving the activity of supported silver catalysts which have already been used, in which the used catalyst is first washed with an inert liquid containing ammonia and/or aliphatic amines and 1 to 1,000 parts, per 1 million parts of catalyst, of cesium, rubidium or a mixture thereof is then deposited on the washed catalyst. The deposition is generally effected with the aid of an impregnating solution containing the cesium and/or rubidium compounds in a suitable quantity. This process makes it possible to improve considerably the activity of supported silver catalysts which have already been in use for the oxidation of ethylene by means of oxygen or air.