GB661916A - Process for the separation of hydrocarbons from oxygenated derivatives - Google Patents

Abstract

A mixture of hydrocarbons and substantially water-insoluble oxygenated derivatives, especially the water-insoluble portion of the reaction products from carbon monoxide and hydrogen comprising hydrocarbons, alcohols, aldehydes, ketones, and carboxylic acids, is separated by extraction with two solvents flowing in counter-current to each other, one solvent consisting substantially of liquid sulphur dioxide and the other of one or more paraffins of a boiling range outside that of the initial mixture. Suitable paraffins are n-heptane or mixtures such as gasoline or aromatic-free mineral oil fractions of higher boiling range such as medicinal paraffin. Temperature is preferably below -10 DEG , e.g. about -25 DEG C., when ordinary pressure may be used. The high partition coefficients of various ketones and alcohols with respect to a mixture of equal volumes of sulphur dioxide and medicinal paraffin are illustrated. By modifying the catalyst, a product containing 10 per cent or more water-insoluble oxygenated compounds may be obtained by a Fischer Tropsch synthesis, said compounds being extracted as described. In examples, a mixture of methyl isobutyl ketone, n-butanol, and 8-10 C atom paraffins is extracted in a multi-stage extraction system with SO2 and medicinal paraffin or n-heptane.