Patent GB-248375-A (GB)
Title: Improvements in the preparation and treatment of olefines
Filed: 1926-02-24
Abstract: 248,375. Petroleum Chemical Corporation, (Assignees of Davis, H. S., and Murray, W. J.). Feb. 24, 1925, [Convention date]. Olefines; sulphates, ethereal; monohydric alcohols; amyl chlorides.-A mixture of olefines obtained, for example, by cracking petroleum vapours and containing ethylene is fractionated and each fraction is separately treated with an acid reagent, preferably in a selective manner, for the production of derivatives. To obtain the olefine mixtures, gas oil from a tank 1 is cracked, after preliminary vaporization, in a tube 7 at a temperature of 600-659‹ C., and the products, after treatment in a separator 8, traverse towers 11, 12, a condenser 13, and a cooler 18. The tower 12 is fed with the condensate from the condenser 13 and the tower 11 with the bulk of the condensate from the tower 12 part of which is, however, stripped of its lighter hydrocarbons in a tower 12<a>. The uncondensed effluent from the cooler 18 constitutes the olefme mixture, which is scrubbed in towers 20, 21 by cool oil delivered from a tank 23; the unabsorbed residue, consisting mainly of ethylene and propylene, is collected in a holder 22. The saturated oil leaving the tank 20 passes through a still 29 and vaporizer 30 to a tower 31 in which the dissolved olefines are separated. These may be separated together or may be treated in a condenser 34, separator 35, compressor 36 and storage tank 37 to yield a condensate, comprising mainly amylenes, which is collected in a tank 17, and an uncondensed residue, consisting mainly of butylenes, which is collected in a holder 40. Alternatively, the olefine mixture from the cooler 18 may be fractionated by compression followed by distillation. The ethylene-propylene fraction collected in the holder 22 may be subjected to successive treatments with sulphuric acid. In the first treatment, with acid of 80-84 per cent strength, any olefines higher than propylene in. cidentally present are removed, while in the second treatment, with more concentrated acid, propylene is absorbed; the ethylene remains substantially unaffected and may be in turn absorbed in hot sulphuric acid. The products may be hydrolyzed to yield, particularly, ethyl and isopropyl alcohols. The butylene fraction collected in the holder 40 may be similarly treated. In the first treatment, with acid of about 60 per cent strength, isobutylene is removed and any diolefines incidentally present are polymerized, while in the second treatment, with acid of about 80 per cent strength, the remaining butylenes are absorbed. The products on hydrolysis yield tertiary and secondary butyl alcohols which may be distilled off preferably, in the case of the tertiary compound, after neutralization of the liquor. The amylene fraction collected in the tank 17 may similarly be treated with sulphuric acid in stages. The first treatment absorbs the amylenes convertible into tertiary derivatives, together with any isobutylene. diolefines, and acetylenic hydrocarbons incidentally present. In the second treatment, with stronger acid, the remaining amylenes, together with secondary hexylenes &c. are absorbed. The corresponding alcohols may be obtained by dilution and distillation, preferably, in the case of the tertiary alcohols, after neutralization. Alternatively, the amylene fraction may be distilled, into fractions comprising (a) isopropylethylene, (b) the remaining amylenes, and (c) hexylenes and higher olefines. which fractions may be separately treated. Fraction (b) may be treated with concentrated hydrochloric acid, whereon the amylenes which are convertible into tertiary derivatives, together with diolefines &c., are converted into easily separable chlorides which may be hydrolyzed, preferably with the addition of alkali, to yield tertiary alcohols.