Abstract: A method for selectively hydrogenating acetylene in a cracked gas from a steam cracking unit for producing olefins may include separating a hydrogenation feed from the cracked gas. The hydrogenation feed may include acetylene, hydrogen, carbon monoxide, and at least one product. The method may further include contacting the hydrogenation feed with an acetylene hydrogenation catalyst, the contacting causing hydrogenation of at least a portion of the acetylene of the hydrogenation feed to produce a hydrogenation effluent. In response to a change in a composition of a feedstock to the steam cracking unit that results in a change in a hydrogen concentration in the hydrogenation feed, the method may further include determining the hydrogen concentration in the hydrogenation feed and increasing or decreasing a temperature of the hydrogenation feed based on the determined hydrogen concentration of the hydrogenation feed.

Abstract: A method for selectively hydrogenating acetylene in a cracked gas from a steam cracking unit for producing olefins may include separating a hydrogenation feed from the cracked gas. The hydrogenation feed may include acetylene, hydrogen, carbon monoxide, and at least one product. The method may further include contacting the hydrogenation feed with an acetylene hydrogenation catalyst, the contacting causing hydrogenation of at least a portion of the acetylene of the hydrogenation feed to produce a hydrogenation effluent. In response to a change in a composition of a feedstock to the steam cracking unit that results in a change in a hydrogen concentration in the hydrogenation feed, the method may further include determining the hydrogen concentration in the hydrogenation feed and increasing or decreasing a temperature of the hydrogenation feed based on the determined hydrogen concentration of the hydrogenation feed.

Abstract: 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.

Abstract: A method for the production of ethylene oxide wherein the partial pressure of water vapor at the inlet of the reactor is at least about 8 kPa using a high purity carrier comprising alpha-alumina, a promoting amount of at least one Group IA metal, and a promoting amount of rhenium.

Abstract: 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.

Abstract: A method for the production of ethylene oxide wherein the partial pressure of water vapor at the inlet of the reactor is at least about 8 kPa using a high purity carrier comprising alpha-alumina, a promoting amount of at least one Group IA metal, and a promoting amount of rhenium.

Abstract: 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.

Abstract: A method for the production of ethylene oxide wherein the partial pressure of water vapor at the inlet of the reactor is at least about 8 kPa using a high purity carrier comprising alpha-alumina, a promoting amount of at least one Group IA metal, and a promoting amount of rhenium.

Abstract: A method for the production of ethylene oxide wherein the partial pressure of water vapor at the inlet of the reactor is at least about 8 kPa using a high purity carrier comprising alpha-alumina, a promoting amount of at least one Group IA metal, and a promoting amount of rhenium.

Abstract: 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.

Abstract: A method of isomerizing an isoimide to an n-imide is described wherein an electron is supplied to the isoimide which induces the isomerization and wherein the isomerization is catalytic to the electron which remains available to initiate further isomerization. A polyimide is deposited onto a conductive substrate by providing a composition containing a polyisoimide and an electrolyte providing the substrate and a counter electrode in the composition, and providing a bias between the substrate and counter electrode to thereby supply an electron to the polyisoimide which isomerizes to deposit the insoluble polyimide on the substrate.

Abstract: The invention relates to the formation of isoimides from amic acids, especially polyisoimides by a novel process in which polyimides are first converted to polyamic acids and then contacted with an isoimidizing agent. An acyl halide of a heterocyclic nitrogen compound or an acyl halide of a heterocyclic sulphur compound can be used as the isoimidizing agent. The isoimidization may also be carried out in the presence of a compound containing a heterocyclic nitrogen especially a solvent containing a heterocyclic nitrogen.The invention is especially applicable to conducting nucleophilic addition reactions on the surface of polyimides where the surface has been converted to a polyamic acid or on the surface of polyamic acid materials followed by isoimidization and reaction of the isoimide with a nucleophile such as an amine or organic hydroxy compound.Photosensitive metal compounds or electroless metal coating catalysts can be coordinated with the compositions obtained.