GB643862A - Improvements in or relating to methods of oxidation of hydrocarbons and the productsresulting therefrom - Google Patents

Abstract

Products mainly comprising aldehydes are obtained from saturated aliphatic hydrocarbon gases by mixing with sulphur trioxide in vapour form in the absence of free oxygen and contacting with an adsorptive material while maintaining a temperature in the range from substantially 175 DEG C. to substantially 450 DEG C. Adsorptive materials specified are charcoal, silica gel, alumina, fuller's earth, bauxite, kieselguhr, aluminium silicates, hydrated aluminium or magnesium silicates, which may be impregnated with salts or oxides of metals, of which a list is given, as catalysts. The adsorptive material may be subjected to a preliminary heat treatment. The sulphur trioxide may be supplied either as the gas itself or in the form of sulphuric acid vapour. Preferably 0.2-15 per cent by volume of sulphur trioxide is present in the gas entering the reaction chamber, a recycling system being employed in which only a small proportion of hydrocarbon is oxidized per pass. Hydrocarbons specified are methane, ethane, propane, butane, and cyclic non-aromatic hydrocarbons. In examples, formaldehyde, acetaldehyde and isobutyraldehyde are obtained by mixing gases consisting predominantly of methane, ethane, or isobutane with sulphur trioxide vapour and passing the mixture over heated, activated, charcoal, alumina, or silica gel, which may be impregnated with cobalt sulphate, silver nitrate, ceric sulphate, or copper sulphate. Specifications 606,554 and 606,967 are referred to.