GB563142A - Production of hydrocarbon alkylation products - Google Patents

Abstract

Hydrocarbons for use in motor fuels are prepared by alkylating lower boiling hydrocarbons in the presence of sulphuric acid of alkylating strength and contacting the product in the liquid phase under superatmospheric pressure with an aqueous basic solution at above 100 DEG C. to remove sulphur compounds. 2-10 per cent aqueous solutions of alkali or alkaline earth hydroxides, preferably sodium, calcium or ammonium hydroxide, or other strong bases such as quaternary ammonium bases, may be used. Cyclic hydrocarbons, such as benzene, toluene, xylene or naphthalene or hydrogenation products thereof, or isoparaffins such as isobutane or isopentane or mixtures thereof or containing them may be alkylated with propylene, butylenes, amylenes, olefinic polymers such as di- and tri-isobutylenes, alcohols such as propyl, isopropyl, primary, secondary and tertiary butyl alcohols, ethers such as di-isopropyl and methyl tertiary butyl ethers, inorganic and organic esters of such alcohols, e.g. the mono- or di-sulphates or phosphates, alkyl halides or mixtures of or containing any of these. Cumene may be produced, for example, by alkylating benzene, preferably purified from sulphur by agitating with an equal volume of 98 per cent sulphuric acid at 40-50 DEG C. for 20-30 mins. and then washing with aqueous caustic soda. Alkylation is effected with propylene using at least 3 mols. of benzene, preferably 5-10 mols. per mol. of olefine, and 80-95 per cent sulphuric acid, for example, 86 per cent acid at 50 DEG C. or 88 per cent at 40 DEG C. with contact times of 10-40, preferably 20-30 mins. An emulsion of hydrocarbon and acid may be circulated while fresh reactants are continuously fed and products removed to a separator. Acid is returned and the crude hydrocarbon phase treated with about 10-50 per cent by volume of 2-10 per cent caustic soda solution at about 100-180 DEG C., preferably 140-160 DEG C. for at least 5, preferably 10-30 mins. Hydrocarbons lower boiling than benzene and, if desired, benzene also, may be separated from the alkylation product during or before the alkali treatment. The treated product may be further fractionated or otherwise treated. Sulphur figures for treated cumene are compared with those for the untreated and ordinary alkali-washed product, and the results of engine tests on blends of 20 per cent cumene and 80 per cent 100 octane aviation gasoline containing 4 c.c. T.E.L. per U.S.A. gallon are given.