From ethylene oxide

In the early versions, ethylene cyanohydrin was obtained from ethylene chlorohydrin and sodium cyanide. In later versions, ethylene oxide (from the dkect catalytic oxidation of ethylene) reacted with hydrogen cyanide in the presence of a base catalyst to give ethylene cyanohydrin. This was hydrolyzed and converted to acryhc acid and by-product ammonium acid sulfate by treatment with about 85% sulfuric acid. 

The ethylene oxide recovered in the desorber contains some carbon dioxide, nitrogen, aldehydes, and traces of ethylene and ethane. In the stripper the light gases are separated overhead and vented, and the partially purified ethylene oxide is sent from the bottom of the stripper to the mid-section of a final refining column. The ethylene oxide from the refining section should have a purity of >99.5 mol %. The final product is usually stored as a Hquid under an inert atmosphere. 

Biological. Several recent patents have claimed the production of ethylene oxide from a wide variety of raw materials using enzymatic catalysts (221—224). However, no commercial production routes based on biological mechanisms have been proposed. 

Dioxane forms by the chemical cleavage of two molecules of ethylene oxide from the parent ethoxylated alcohol. Dioxane is the undesirable byproduct. The amount of dioxane ranges from traces to hundreds, even thousands, of ppm (mg/kg) depending on raw material quality and sulfonation/neutralization process conditions. 

DMC and EG were main products of the transesterification reaction. No by-product such as dimethyl ether and glycol monoethyl ether was observed in the resulting products. Only small peaks of ethylene oxide from the decomposition of EC could be detected at longer reaction time and at high temperature. 

For sterile drug substances, an understanding of the drug substance and the sterilization process will help in avoiding potential impurities, for example, compounds formed by the appropriate functional groups of the drug substance reacting with residual ethylene oxide from the sterilization process. 

There are two important methods for the manufacture of propylene oxide, each accounting for one half the total amount produced. The older method involves chlorohydrin formation from the reaction of propylene with chlorine water. Before 1969 this was the exclusive method. Unlike the analogous procedure for making ethylene oxide from ethylene, which now is obsolete, this method for propylene oxide is still economically competitive. Many old ethylene oxide plants have been converted to propylene oxide synthesis. 

Since approximately 2.2 lb of /-butyl alcohol would be produced per 1 lb of propylene oxide, an alternative reactant in this method is ethylbenzene hydroperoxide. This eventually forms phenylmethylcarbinol along with the propylene oxide. The alcohol is dehydrated to styrene. This chemistry was covered in Chapter 9, Section 6 as one of the syntheses of styrene. Thus the side product can be varied depending on the demand for substances such as /-butyl alcohol or styrene. Research is being done on a direct oxidation of propylene with oxygen, analogous to that used in the manufacture of ethylene oxide from ethylene and oxygen (Chapter 9, Section 7). But the proper catalyst and conditions have not yet been found. The methyl group is very sensitive to oxidation conditions. 

Silver is used in the form of porous pellets or, more often, supported on an inert carrier with wide pores (e.g., corundum). Commercially, the reaction is performed with ethylene-oxygen and ethylene-air mixtures at about 250°C, 10-25 atm and time of contact of the order of 1 sec. Higher pressures facilitate the subsequent separation of ethylene oxide from the exit gas mixture. Small amounts of some elements are added to silver this increases the selectivity [i.e., the fraction of ethylene converted according to (218) in the total amount of ethylene converted]. 

Heterogeneous oxidative processes operate at high temperatures (250-450 6C) and are useful for the synthesis of acrolein and acrylic acid from propylene over bismuth molybdate catalysts, the synthesis of maleic and phthalic anhydrides from the oxidation of benzene (or C4 compounds) and naphthalene (or o-xylene) respectively over vanadium oxide,101 arid the synthesis of ethylene oxide from ethylene over silver catalysts.102... 

It is very interesting the adsorption behavior of poly (ethylene oxide) from water solution to the air - water interface. This adsorption was considerably enhanced by a hydrophobic group placed at ends of the molecules. 

Ethoxylation of the alcohols to biodegradable detergent species using ethylene oxide from direct ethylene oxidation. This process is also in wide use. 

Ethylene oxide, glycol Reactor effluent Ethylene oxide Water Ethylene oxide recovery Stripping is practiced to recover ethylene oxide from the solution... 

The lower part of tower 1 is simultaneously filled with ethyl mercaptan and ethylene oxide from batch boxes 2 and 3 accordingly in the (1.55-5-1.85) 1 ratio. The ratio of ethyl mercaptan and ethylene oxide is established depending on the percentage of ethyl mercaptan in raw stock. 

The dark brown blobs In this STM picture recorded at a temperature of 4 K are individual oxygen atoms adsorbed on a silver surface. The light blobs are individual ethylene (ethene) molecules. Ethylene will only adsorb on silver if adjacentto an oxygen atom, This is an atomic scale view of a very important industrial process—the production of ethylene oxide from ethylene and oxygen using a silver catalyst. 

Fig. 39. Contour plot of chemical shift vs. retention time and chemigram of the on-line HPLC-NMR analysis of a technical poly(ethylene oxide) (from [210] with permission)...

In the glycol reactor (2), sufficient residence time is provided to react (noncatalytically) all of the ethylene oxide. Operating pressure of the reaction is controlled at a level that limits or avoids vaporization of ethylene oxide from the aqueous solution. 

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