THE paper forms a general survey of the literature, patent and otherwise, dealing with the separation and conversion into alcohols, and the corresponding ketones, of olefines obtained either as by-products in cracking. operations or by the cracking of the lower paraffins.
There.are two main sections; the first deals with the production, concentration, separation and purification of the lower olefines, while the second describes their conversion into alcohols chiefly through the agency of sulphuric acid, the effect of catalysts, the properties of the alcohols and finally of the acetates and ketones derived therefrom.
After an extensive review of the literature dealing with the concentration of ethylene by such methods as activated charcoal, cooling and compression, absorption in oil, etc., the conclusion is reached that for the production of ethyl alcohol it is doubtful whether any useful purpose is really served, as the gas is readily removed by 95% sulphuric acid at 60–80 C. even in concentrations as low as 2-5%.
Actual separation of the individual olefines from the gases contag them is undoubtedly accomplished most successfully by the use of sulphuric acid, although different writers show considerable variation in the pressures, temperatures and strengths of acid used. Catalysts increase the rate of absorption but tend to increase polymer formation. Gas oil mixed with the acid definitely increases the efficiency of the scrubbing operation.
The necessity for the removal of sulphur compounds from the olefines is emphasised, although the resulting unpleasant odour of the alcohols when this is not done is an advantage if it is proposed to use them as denaturants. Alcohols containing sulphur compounds may.be may. be purified by oxidation.
The preparation of ethyl, isopropyl, butyl, amyl and hexyl alcohols from the appropriate olefines and sulphuric acid is discussed together with the properties and products of the corresponding acetates. The conversion of secondary alcohols into the corresponding ketones by means of a brass catalyst at 500800 C. is mentioned and the properties of the ketones obtainable given.
In recent years the synthetic products made from petroleum, or oil gas, have been manufactured in a high degree of purity. This has been due to the large amount of research done and also to the perfection of physical methods of separating pure raw materials. The alcohol esters and particularly the ketones have established themselves in the nitro-cellulose lacquer industry and the manufacture of synthetic ethyl alcohol, of high purity, has been established on a large scale during a period of unprecedented low molasses prices. Ethylene glycol, ethanolamines and ethylene oxide, all chemical curiosities prior to 1921, have found important commercial uses. Acetone, heretofore obtained by fermentation and wood distillation, is cheaply m
