Ethyl alcohol dehydration

It seems that kinetic studies of ethyl alcohol dehydration cannot bring us nearer to the solution of the general problem of dehydration of primary alcohols which, as we shall see, is very challenging and interesting and mostly unsolved up to now. 

Absolute. Pure and free from admixture with other substances. (Absolute alcohol is ethyl alcohol dehydrated to 99% pure.)... 

Kew Words Selective ethyl alcohol dehydration 1. INTRODUCTION... 

Ethylene was first produced from ethyl alcohol over heated alumina or silica [1]. Later, activated alumina and phosphoric acid on a support were commercially used [2], The fixed bed ethyl alcohol dehydration process was developed during world war I. In 1978, small plants were operative in India, Pakistan, Brazil and Peru. The viability of this process increased after the world wide oil crisis in 1973. A fluid-bed process was developed, which significantly reduced the plant installation and operative costs [3,4]. Further, an adiabatic reactor was designed by Barocas et al [5]. 

Si Sjau-Fan and Wu Yue (463) have applied the method of volcanoshaped curves to ethyl alcohol dehydration on AI2O3 prepared by eight... 

C,flH2o02- White crystals, m.p. 168-171 °C. Prepared from deoxyanisoin by ethylation, conversion to the alcohol, dehydration and demethylation. It is an oestrogenic substance which is highly active when administered orally. It is used for treating menopausal symptoms, for the suppression of lactation and for treatment of cancer of the prostate. 

Absolute ethyl alcohol. Ethyl alcohol of a high degree of purity is frequently required in preparative organic chemistry. For some purposes alcohol of ca. 99 -5 per cent, purity is satisfactory this grade may be purchased (the absolute alcohol of commerce), or it may be conveniently prepared by the dehydration of rectified spirit with quicklime. Rectified spirit is the constant boiling point mixture which ethyl alcohol forms with water, and usually contains 95 6 per cent, of alcohol by weight. Wherever the term rectified spirit is used in this book, approximately 95 per cent, ethyl alcohol is to be understood. 

Extremely dry (or super-dry ) ethyl alcohol. The yields in several organic preparations e.g., malonic ester syntheses, reduction with sodium and ethyl alcohol, veronal synthesis) are considerably improved by the use of alcohol of 99-8 per cent, purity or higher. This very high grade ethyl alcohol may be prepared in several ways from commercial absolute alcohol or from the product of dehydration of rectified spirit with quicklime (see under 4). 

Anhydrous stannous chloride, a water-soluble white soHd, is the most economical source of stannous tin and is especially important in redox and plating reactions. Preparation of the anhydrous salt may be by direct reaction of chlorine and molten tin, heating tin in hydrogen chloride gas, or reducing stannic chloride solution with tin metal, followed by dehydration. It is soluble in a number of organic solvents (g/100 g solvent at 23°C) acetone 42.7, ethyl alcohol 54.4, methyl isobutyl carbinol 10.45, isopropyl alcohol 9.61, methyl ethyl ketone 9.43 isoamyl acetate 3.76, diethyl ether 0.49, and mineral spirits 0.03 it is insoluble in petroleum naphtha and xylene (2). 

The chemistry of ethyl alcohol is largely that of the hydroxyl group, namely, reactions of dehydration, dehydrogenation, oxidation, and esterification. The hydrogen atom of the hydroxyl group can be replaced by an active metal, such as sodium, potassium, and calcium, to form a metal ethoxide (ethylate) with the evolution of hydrogen gas (see Alkoxides, metal). 

An ethyl acetate yield of 24% is obtained using a copper oxide catalyst with 0.1—0.2% thoria at 350°C. Dehydration. Ethyl alcohol can be dehydrated to form ethylene or ethyl ether. 

Suppose the following rate data are obtained at the same T from a 400-cm3 CSTR in a kinetics investigation of the vapor-phase dehydration of ethyl alcohol to form ethyl ether ... 

Before discussing the mechanism of dehydration of primary alcohols, it might be worthwhile to consider some of the published results on the dehydration of ethyl alcohol. Chiefly, two products result ethyl ether and ethylene. Most of the discussions over the years have centered around the problem whether ether is formed simultaneously, in-... 

The kinetic studies carried out in recent years on the dehydration of ethyl alcohol did not lead to identical conclusions. Much of the divergence is probably due to the fact that the various investigators paid no attention to the intrinsic acidities of the aluminas used in their studies. 

Uses Denaturant for ethyl alcohol manufacturing flavors, perfumes (artificial musk), flotation agents solvent paint removers octane booster for unleaded gasoline dehydrating agent chemical intermediate. 

Styphnic acid. Ammonia, Barium chlorate dehydrate. Acetone Benzyl chloride. Sodium cyanide. Ethyl alcohol. Liquid hromine, Carhon tetrachloride. Sodium hydroxide. Sodium sulfate. Chloroform... 

Azeotropic Distillation. The concept of azeotropic distillation is not new. The use of benzene to dehydrate ethyl alcohol and butyl acetate to dehydrate acetic acid has been in commercial operation for many years. However, it was only during World War II that entrainers other than steam were used by the petroleum industry. Two azeotropic processes for the segregation of toluene from refinery streams were developed and placed in operation. One used methyl ethyl ketone and water as the azeo-troping agent (81) the other employed methanol (1). 

In the mid-l O s, it was found that acetic acid itself could be catalytically dehydrated to ketene, which when absorbed in fresh acid gave the anhydride. Soon after this process became commercially established, the older processes of making the anhydride were discontinued. By this time synthetic acetic acid was being made from acetylene via acetaldehyde oxidation, from synthetic ethyl alcohol also via acetaldehyde, and by the direct oxidation of fermentation ethyl alcohol. The ketene route to acetic anhydride, in addition to starting from acetic acid, later employed acetone as raw material. 

In the 1940 s, in addition to these operations, two other processes became important. Acetic acid was made by reacting methanol with carbon monoxide, and acetic anhydride was being made by the ethylidene diacetate process, which in effect is the dehydration of acetic acid to the anhydride by the use of acetylene. Fermentation ethyl alcohol was converted to acetic acid via acetaldehyde as well as by the direct oxidation of ethyl alcohol. A new operation on the Gulf Coast was also based on acetaldehyde. However, the acetaldehyde is made by the direct oxidation of liquefied petroleum gas. A further process for the production of these materials, in which acetaldehyde is oxidized in one step to a mixture of anhydride and acid, was also begun. 

The petroleum ether purification step may be eliminated with equally satisfactory results. After dehydration with ethyl alcohol, the residue is dried under reduced pressure to constant weight and used directly for the next step. 

In modern industrial ethyl alcohol plants, the compound is produced in two principal ways (I) by direct hydration of ethylene, or (2) by indirect hydration of ethylene. In the direct hydratiun process. H 0 is added to ethylene in the vapor phase in Lhe presence of a catalyst CH CH 4- H 0 CHiCHiOH. A supported acid catalyst usually is Used. Important factors affecting the conversion include temperature, pressure, the H 0/CH CH ratio, and the purity of (he ethylene, Further, some byproducts are formed by other reactions taking place, a primary side reaction being the dehydration of ethyl alcohol into diethyl ether 2C HjOH (C Hs)jO + HiO. To overcome these problems, a large... 

At one time, ethylene was produced by the dehydration of ethyl alcohol over alumina. 

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