Colloidal silver catalysts for oxidation of ethylene

Kinetic hydrogen isotope effects in ethylene oxidation on silver catalysts

High surface area α-aluminas III. Oxidation of ethylene, ethylene oxide, and acetaldehyde over silver dispersed on high surface area α-alumina

This article is devoted to the consideration of methods for the industrial production of ethylene oxide. Ethylene oxide is produced in large quantities and is primarily used as an intermediate in the production of a number of industrial chemicals, the best known of which is ethylene glycol. The process of producing ethylene oxide is carried out by a direct vapor-phase oxidation process, in which ethylene is oxidized to ethylene oxide by air or oxygen and a silver catalyst at 10-30 atm (1–3 MPa) and 200-300 °C. Ethylene oxidation can be carried out in several ways: air, oxygen under nitrogen ballast, oxygen under methane ballast. The production of ethylene oxide is one of the most dynamically developing. In Russia, the leading place in the production of ethylene oxide is occupied by the enterprise PJSC Nizhnekamskniftekhim. In 2012, the installation for producing ethylene oxide was reconstructed. The reconstruction consisted of transferring the ethylene oxide synthesis stage to methane ballast conditions. A patent analysis was carried out to determine the relevance of this process.

Supported silver catalysts for the oxidation of ethylene: The effects of thermal treatment of alumina as catalyst support

Support participation in chemistry of ethylene oxidation on silver catalysts

Epoxide, cyclic ether with a three-membered ring. the essential structure of an epoxide contains an oxygen atom attached to two adjacent carbon atoms of a hydrocarbon. The strain of the three-membered ring makes an epoxide far more reactive than a typical acyclic ether. Ethylene oxide is economically the foremost important epoxide and is formed from oxidation of ethylene over a silver catalyst. it's used as a fumigant and to form antifreeze, glycol , and other useful compounds.

Epoxidation of ethylene by anion radicals of α-oxygen on the surface of FeZSM-5 zeolite

Catalytic oxygen transfer between ethylene and ethylene oxide

Additive effect of alkali metal ions on preferential CO oxidation over Pt/Al 2O 3

Novel mono-Schiff base MnIII complexes with pendant aza-crown or morpholino groups have been synthesized and studied as catalysts in aerobic oxidation of p-xylene to p-toluic acid. The oxidation of p-xylene to p-toluic acid with air at 120 °C under normal atmospheric pressure occured efficiently in the presence of aza-crown ether substituted mono-Schiff base MnIII complexes. Significant selectivity (up to ~90%) and conversion levels (up to ~38%) were obtained. The effect of the aza-crown ether pendant in MnIII Schiff base complexes on the oxidation of p-xylene was also investigated by comparison with the morpholino pendant analogues. The addition of alkali metal ions accelerated the rate of conversion of p-xylene to p-toluic acid.

Self-assembly, conductivity and chemosensor behavior of biphenylsulfone based Janus polycatenar

This research has been performed in the Ethylene Oxide production process. It is a flammable and colorless gas at temperatures above 11 °C. It is an important commodity chemical for the production of solvents, antifreeze, textiles, detergents, adhesives, polyurethane foam, and pharmaceuticals. Small amounts of Ethylene Oxide [EO] are used in manufacturing fumigants and sterilants for spices and cosmetics, as well as hospital sterilization for surgical equipment. Modern Ethylene oxide [EO] productions employ either air or oxygen (O2)to oxidize ethylene (C2H4) with a silver catalyst on an alumina oxide carrier[Ag/Al2O3]catalyst packed in a fixed-bed reactor (plug-flow reactor)but the oxygen-base reaction process is more desirable here we used oxygen. Mainly two reactions occur, partial oxidation of ethylene to ethylene oxide and total oxidation of ethylene to carbon dioxide and water. The design models of the process in this research based on a three-part system. They are: the reaction system, absorption system and Ethylene Oxide [EO] purification system. The largest cost in production of ethylene oxide is ethylene therefore, it’s important to optimize the selectivity towards ethylene oxide and thus reduce the consumption of Ethylene. The aim of this work is to create a simulation model of the Ethylene Oxide production process from Ethylene using Aspen Hysys V9. Also to knowing the optimum operational conditions (temperature –pressure –flow rate) for the oxidation reactions of Ethylene. The simulation was running three times with various operational conditions to make a good result. The conclusion was that during operational time the activation energy increased for both reactions which have to be compensated with increasing reactor temperature. At the same time the selectivity for producing Ethylene Oxide decreases, i.e. more carbon dioxide and water are formed. The simulation models yield Ethylene Oxide with purity of 99.2%.

Experimental determination of reactor activity factors for structure-sensitive catalyst deactivation

High surface area (HAS) silver supported on alumina (Ag/Al2O3) catalyst were prepared by sol-gel method, and the activity and selectivity to ethylene oxide (EO) during ethylene oxidation over these catalysts were determined in the absence and presence of H2. The effect of calcination and oxidation-reduction method on the catalytic activity was also studied. Over all the (HAS) Ag/Al2O3 catalysts showed no selectivity to EO in ethylene oxidation and only CO2 and H2O were obtained as final products. Low surface area (LSA) Ag/a-Al2O3 catalysts were also prepared by incipient wetness impregnation method and the effect of silver loading, molar ratio of C2H4 to O2 and the effect of calcination and oxidation reduction method on the catalytic performance for selective oxidation of ethylene at different reaction temperatures were studied. Maximum selectivity to EO was obtained over (LSA) Ag/a-Al2O3 catalyst with 15 wt% Ag at a temperature of 210℃. The 0.5 molar ratio of C2H4 to O2 exhibited the best ratio for the maximum EO selectivity. The reduction with hydrogen of previously oxidized 15 wt% Ag/a-Al2O3 catalyst caused an increase in the activity for selective oxidation of ethylene.

The oxidation of ethylene over evaporated palladium-silver alloy films: II. Variation of activity with catalyst composition