Patent classifications
B01J23/68
Catalyst for producing ethylene oxide by gas-phase oxidation
A shaped catalyst body for producing ethylene oxide by gas-phase oxidation of ethylene, comprising silver deposited on a porous refractory support, the shaped catalyst body having a first face side surface, a second face side surface and a circumferential surface, characterized by a content of at least 20 wt.-% of silver, relative to the total weight of the shaped catalyst body; a multilobe structure; a plurality of passageways extending from the first face side surface to the second face side surface, outer passageways being arranged around a central passageway with one outer passageway being assigned to each lobe, wherein neighboring outer passageways are arranged essentially equidistantly to each other and the outer passageways are arranged essentially equidistantly to the central passageway; a minimum wall thickness A between two neighboring passageways in the range of 0.6 to 1.3 mm; a minimum wall thickness B between each outer passageway and the circumferential surface in the range of 1.1 to 1.8 mm; and a BET surface area in the range of 1.6 to 3.0 m.sup.2/g. The shaped catalyst bodies allow for a favorable balance between mechanical stability, pressure drop and selectivity. The invention also relates to a process for producing ethylene oxide by gas-phase oxidation of ethylene, comprising reacting ethylene and oxygen in the presence of a shaped catalyst body as defined above. The invention further relates to a process for preparing a shaped catalyst body as above, comprising i) impregnating a refractory support having a BET surface area in the range of 1.4 to 2.5 m.sup.2/g with a silver impregnation solution; and ii) subjecting the impregnated refractory support to a calcination process; wherein steps i) and ii) are optionally repeated.
ETHYLENE EPOXIDATION CATALYSTS, ASSOCIATED METHODS OF MANUFACTURE, AND ASSOCIATED METHODS FOR THE PRODUCTION OF ETHYLENE OXIDE
An ethylene epoxidation catalyst is disclosed that comprises a fluoride-mineralized carrier having silver and a rhenium promoter deposited thereon, wherein the fluoride-mineralized carrier has: a total fluorine (TF) content less than 5000 ppm as measured by XRF, a water extractable fluorine (WEF) content greater than 45 ppm as measured by microwave extraction and ion specific electrode, and wherein the ratio of TF:WEF is between 10 and 110. Associated methods of manufacturing such catalysts and epoxidation methods using such catalysts are similarly provided.
Organo-catalytic biomass deconstruction
The present invention provides processes for catalytic deconstruction of biomass using a solvent produced in a bioreforming reaction.
Photocatalyst for water splitting comprising gallium selenide and photoelectrode for water splitting comprising the same
Provided are a photocatalyst having higher activity for hydrogen production through water splitting and a photoelectrode comprising the photocatalyst. The photocatalyst for water splitting of the present invention comprises a Ga selenide, an AgGa selenide, or both thereof.
Multi-lobed porous ceramic body and process for making the same
A carrier having at least three lobes, a first end, a second end, a wall between the ends and a non-uniform radius of transition at the intersection of an end and the wall is disclosed. A catalyst comprising the carrier, silver and promoters deposited on the carrier and useful for the epoxidation of olefins is also disclosed. A method for making the carrier, a method for making the catalyst and a process for epoxidation of an olefin with the catalyst are also disclosed.
Method of formulating alkylene oxide catalyst in relation to catalyst reference properties
Methods of preparing a second high-efficiency, rhenium-promoted silver catalyst for producing alkylene oxide from an alkylene based on a first catalyst are disclosed and described. In accordance with the disclosed methods, the first and second catalysts include at least one promoter that includes a rhenium promoter. The target catalyst concentrations of one or more promoters of the at least one promoter on the second catalyst are determined based on the values of a catalyst reference property for the two catalysts and the concentration of the one or more promoters of the at least one promoter on the first catalyst. Suitable catalyst reference properties include carrier specific surface area and silver specific surface area. Reaction systems utilizing the first and second catalysts are also described.
DIENE PRODUCTION METHOD
A method for producing diene comprises a step 1 of obtaining a straight chain internal olefin by removing a branched olefin from a raw material including at least the branched olefin and a straight chain olefin; and a step 2 of producing diene from the internal olefin by oxidative dehydrogenation using a first catalyst and a second catalyst, and the first catalyst has a complex oxide including bismuth, molybdenum and oxygen, and the second catalyst includes at least one selected from the group consisting of silica and alumina.
EPOXIDATION CATALYST
An epoxidation catalyst comprising silver, cesium, rhenium and tungsten deposited on an alumina support, wherein the catalyst comprises 20 to 50 wt.-% of silver, relative to the weight of the catalyst, an amount of cesium C.sub.cs of at least 7.5 mmol per kg of catalyst, and an amount of rhenium CR6 and an amount of tungsten Cw so as to meet the following requirements: C.sub.Re6.7 mmol per kg of catalyst; and C.sub.Re+(2c.sub.w)13.2 mmol per kg of catalyst. The epoxidation catalyst allows for a more efficient conversion of ethylene oxide by gas-phase oxidation of ethylene, particularly displaying high selectivity and high activity. The invention also relates to a process for preparing an epoxidation catalyst as defined in above, comprising i) impregnating an alumina support with a silver impregnation solution; and ii) subjecting the impregnated refractory support to a calcination process; wherein steps i) and ii) are optionally repeated, and at least one silver impregnation solution comprises rhenium, tungsten and cesium. The invention moreover relates to a process for producing ethylene oxide by gas-phase oxidation of ethylene, comprising reacting ethylene and oxygen in the presence of an epoxidation catalyst according to any one of the preceding claims.
Process for producing ethylene oxide by gas-phase oxidation of ethylene
A process for producing ethylene oxide by gas-phase oxidation of ethylene, comprising: directing a feed comprising gaseous ethylene and gaseous oxygen through a packing of individual shaped catalyst bodies, under conditions conducive to obtain a reaction mixture containing at least 2.7 vol.-% of ethylene oxide, wherein each shaped catalyst body comprises silver deposited on a refractory support and is characterized by a content of at least 20 wt.-% of silver, relative to the total weight of the shaped catalyst body; a BET surface area in the range of 1.6 to 3.0 m.sup.2/g; a first face side surface, a second face side surface and a circumferential surface with a plurality of passageways extending from the first face side surface to the second face side surface; and a uniform multilobed cross-section; and a longest direct diffusion pathway d, with 2d being in the range of 0.7 to 2.4 mm, wherein the longest diffusion pathway d is defined as the shortest distance from the geometric surface of the shaped catalyst body to a point inside the structure of the shaped catalyst body for which point the shortest distance is the largest among all points. The process allows for increased activity and/or stability of the catalyst while maintaining or increasing selectivity at high productivity.
ORGANO-CATALYTIC BIOMASS DECONSTRUCTION
The present invention provides processes for catalytic deconstruction of biomass using a solvent produced in a bioreforming reaction.