Ethyl process, alcohols

The Ziegler process produces linear alcohols with an even number of carbon atoms and is based on the polymerization of ethylene under catalytic conditions, generally with triethylaluminum as in the Alfol and the Ethyl processes. The distribution of alkyl chains depends on the version of the process employed but the alcohols obtained after fractionation can be equivalent to those obtained from fats and oils or have purpose-made distributions depending on the fractionation conditions. 

Ethyl hexanol, sometimes called 2-ethyl hexyl alcohol, 2-ethyl hex, or more simply 2-EH, is one of the oldest high molecular weight aliphatic alcohols. What does it have in common with NBA Both are made from propylene via the Oxo process, and both have the same aldehyde intermediate— normal butyraldehyde. 

In the mid 1950 s, Dr. Karl Ziegler (4) and his associates at the Max Planck Institute carried out fundamental research which provided the basis for schemes to synthesize even carbon-numbered, linear alcohols similar to natural alcohols. Commercial plants were built by Conoco in 1962, Condea in 1964, and Ethyl in 1965. The Conoco and Condea processes are virtually identical and different from the Ethyl process. 

The aluminum trialkoxides are then hydrolyzed with dilute sulfuric acid in the Ethyl process (23)- This forms free alcohol and an aqueous aluminum sulfate solution which are separated by phase split. The aqueous aluminum sulfate is sold. Product alcohols are washed with caustic to remove traces of acid, dried, and fed to conventional distillation train. The product alcohols are sold by Ethyl under the trade name of EPAL alcohols. 

The adsorption of liquid ethyl alcohol on AljOj occurs by H bonding (1108), and without doubt other proton donors are similarly affected. Some part of adsorption from binary solutions (e.g. ethyl alcohol and benzene) is explained by the three-step process alcohol H bonds to the surface, chemisorbs, and then the second component (and more alcohol) physically adsorb on this layer. (See Section 11.2.1 for a discussion of the similar action of water on silicic acid.) Such hydroxyl-covered surfaces are industrially important in cracking and other catalytic processes (2172, 956), and in drying. Plank and Drake (1646) discuss the influence of H bonds in the formation of such materials. 

Two processes have been commerdalized on the basis of the oligomerization of ethylene, one by Conoco Chemical and the second by Ethyl Corporation. They differ in the distribution curve of the different alcohols formed. Whereas Conoco s Alfol alcohols range from C2 to C22 with about 55 per cent C12 or above (Fig. 9.S), the alcohol distribution of the Ethyl process is narrower and comprises 85 par cent C 2 - Tins change in the distribution curve results from the insertion of an additional stage of transalkylation by triisobutyUluminum. 

Although there are many examples of yeast-mediated hydrogenations of alkenes to yield alkanes, examples for the reverse process are scarcely found. Thus, methyl-5-thiastearate (323) (Fig. 80) upon BY treatment gave methyl 5-thiaoleate (324) in 66% yield [495]. In addition, several a-allenic alcohols 325 have been reduced to the corresponding p-ethyl-enic alcohols 326, whereas the p-allenic alcohol 327 gave 35% of y-acetylenic alcohol 328 [442]. 

This preparation was discovered independently by Geuther (1863) and by Frankland and Duppa (1865). The reaction was subsequently investigated in detail and so w idely extended by Claisen that it has become solely a specific example of the more general process known as the Claisen Condensation. Claisen showed that an ester under the influence of sodium ethoxide would not only condense with itself (as in the preparation of ethyl acetoacetate), but also with (i) another ester, (ii) a ketone, if of formula RCHgCOR, (iii) a nitrile, if of formula RCH CN, in each case with the elimination of alcohol. Examples of these modifications are ... 

Diethyl ether may be prepared from ethyl alcohol by the sulphuric acid process. A mixture of alcohol and sulphuric acid in equimolecular proportions is heated to about 140° and alcohol is run in at the rate at which the ether produced distils from the reaction mixture. Ethyl hydrogen sulphate (or ethyl sulphuric acid) is first formed and this yields ether either by reacting directly with a molecule of alcohol or by the formation and alcoholysis of diethyl sulphate (I) ... 

Ethyl acetate. Use 58 g. (73-5 ml.) of absolute ethyl alcohol, 225 g. of glacial acetic acid and 3 g. of concentrated sulphuric acid. Reflux for 6-12 hours. Work up as for n-propyl acetate. B.p. 76- 77°. Yield 32 g. Much ethyl acetate is lost in the washing process. A better yield may be obtained, and most of the excess of acetic acid may be recovered, by distilhng the reaction mixture through an efficient fractionating column and proceeding as for methyl acetate. 

Ethyl a-naphthylacetate is prepared as follows. To a solution of 10 g. of the diazo ketone in 150 ml. of ethanol at 55-60°, add a small amount of aslurry of silver oxide, prepared from 10 ml. of 10 per cent, aqueous silver nitrate and stirred with 25 ml. of ethanol. As soon as the evolution of nitrogen subsides, introduce more of the silver oxide and continue the process until all the slurry has been added. Reflux the mixture for 15 minutes, add 2-3 g. of decolourising carbon, filter and evaporate the alcohol on a water bath. Distil the residue and collect the ethyl a-naph-thylacetate at 176-178°/ 1 mm. the yield is 9 g. 

Purchasing research Pure alcohols Pure ethyl silicate Pure Natural Pure silicon PUREX Purex process PUR foams Purgatives Purging Purification Purified Pork Insulin... 

Since 1960, the Hquid-phase oxidation of ethylene has been the process of choice for the manufacture of acetaldehyde. There is, however, stiU some commercial production by the partial oxidation of ethyl alcohol and hydration of acetylene. The economics of the various processes are strongly dependent on the prices of the feedstocks. Acetaldehyde is also formed as a coproduct in the high temperature oxidation of butane. A more recently developed rhodium catalyzed process produces acetaldehyde from synthesis gas as a coproduct with ethyl alcohol and acetic acid (83—94). 

Chloroacetate esters are usually made by removing water from a mixture of chloroacetic acid and the corresponding alcohol. Reaction of alcohol with chloroacetyl chloride is an anhydrous process which Hberates HCl. Chloroacetic acid will react with olefins in the presence of a catalyst to yield chloroacetate esters. Dichloroacetic and trichloroacetic acid esters are also known. These esters are usehil in synthesis. They are more reactive than the parent acids. Ethyl chloroacetate can be converted to sodium fluoroacetate by reaction with potassium fluoride (see Fluorine compounds, organic). Both methyl and ethyl chloroacetate are used as agricultural and pharmaceutical intermediates, specialty solvents, flavors, and fragrances. Methyl chloroacetate and P ionone undergo a Dar2ens reaction to form an intermediate in the synthesis of Vitamin A. Reaction of methyl chloroacetate with ammonia produces chloroacetamide [79-07-2] C2H ClNO (53). 

Esterifica.tlon. The process flow sheet (Fig. 4) outlines the process and equipment of the esterification step in the manufacture of the lower acryflc esters (methyl, ethyl, or butyl). For typical art, see References 69—74. The part of the flow sheet containing the dotted lines is appropriate only for butyl acrylate, since the lower alcohols, methanol and ethanol, are removed in the wash column. Since the butanol is not removed by a water or dilute caustic wash, it is removed in the a2eotrope column as the butyl acrylate a2eotrope this material is recycled to the reactor. 

Acetylene-Based Routes. Walter Reppe, the father of modem acetylene chemistry, discovered the reaction of nickel carbonyl with acetylene and water or alcohols to give acryUc acid or esters (75,76). This discovery led to several processes which have been in commercial use. The original Reppe reaction requires a stoichiometric ratio of nickel carbonyl to acetylene. The Rohm and Haas modified or semicatalytic process provides 60—80% of the carbon monoxide from a separate carbon monoxide feed and the remainder from nickel carbonyl (77—78). The reactions for the synthesis of ethyl acrylate are... 

The stoichiometric and the catalytic reactions occur simultaneously, but the catalytic reaction predominates. The process is started with stoichiometric amounts, but afterward, carbon monoxide, acetylene, and excess alcohol give most of the acrylate ester by the catalytic reaction. The nickel chloride is recovered and recycled to the nickel carbonyl synthesis step. The main by-product is ethyl propionate, which is difficult to separate from ethyl acrylate. However, by proper control of the feeds and reaction conditions, it is possible to keep the ethyl propionate content below 1%. Even so, this is significantly higher than the propionate content of the esters from the propylene oxidation route. 

The Ziegler process, based on reactions discovered in the 1950s, produces predorninandy linear, primary alcohols having an even number of carbon atoms. The process was commercialized by Continental Oil Company in the United States in 1962, by Condea Petrochemie in West Germany (a joint venture of Continental Oil Company and Deutsche Erdid, A.G.) in 1964, by Ethyl Corporation in the United States in 1965, and by the USSR in 1983. 

Fig. 5. Flow diagram for oxo alcohol manufactured by the two-stage process. Courtesy of the Ethyl Corporation.

A.luminum Jilkyl Chain Growth. Ethyl, Chevron, and Mitsubishi Chemical manufacture higher, linear alpha olefins from ethylene via chain growth on triethyl aluminum (15). The linear products are then used as oxo feedstock for both plasticizer and detergent range alcohols and because the feedstocks are linear, the linearity of the alcohol product, which has an entirely odd number of carbons, is a function of the oxo process employed. Alcohols are manufactured from this type of olefin by Sterling, Exxon, ICI, BASE, Oxochemie, and Mitsubishi Chemical. 

Direct oxidation yields biacetyl (2,3-butanedione), a flavorant, or methyl ethyl ketone peroxide, an initiator used in polyester production. Ma.nufa.cture. MEK is predominandy produced by the dehydrogenation of 2-butanol. The reaction mechanism (11—13) and reaction equihbtium (14) have been reported, and the process is in many ways analogous to the production of acetone (qv) from isopropyl alcohol. 

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