GB397161A - Improvements in or relating to the oxidation of olefines - Google Patents

Abstract

Oxygen-containing organic compounds other than glycols or alcohols, such as olefine oxides, aldehydes, ketones and acids are produced by the oxidation under increased pressure of olefines containing not more than five carbon atoms with oxygen or air in presence of water or steam at least sufficient to saturate the gases at room temperature and pressure but insufficient to produce substantial quantities of alcoholic products such as glycols, the production of which is covered by Specification 387,372. The gases may be passed through hot liquids containing oxygen carriers, preferably liquids of an acid nature or containing oxygen carriers of an acid nature such as chromic acid, manganese acetate, or chromium acetate which may be dissolved in water or acetic acid. Unless the solution comprises water, steam is added to the gases. Preferably the gas mixture is treated at high temperatures such as 200-600 DEG C. in presence or absence of catalysts such as heavy metals or their compounds, for instance, silver or copper, or silver, copper, chromium, cobalt, or iron oxides or vanadium pentoxide, which may be associated with promoters such as alkali or alkaline earth compounds, and carriers such as pumice, kieselguhr, carborundum or silica gel may be employed. The pressure may be up to 10 atmospheres, preferably 2-5 atmospheres. Diluent gases such as nitrogen and carbon dioxide may be used. When ethylene oxide is desired, its further change may be minimized by using moderate temperatures, a considerable quantity of diluent, high speed of the gas, and avoidance of acid catalysts in the reaction zone, ammonia or other volatile base being added to the gases if desired; inert packing may be used instead of catalysts, or neither filling materials nor catalysts may be employed. To produce acetaldehyde hydration catalysts such as phosphoric acids and zinc chloride may be used, or the products of reaction may be passed over these catalysts at 300-400 DEG C. The formation of acetic acid is favoured by the use of an excess of oxygen, relatively high temperatures and oxidation catalysts such as silver, copper, or their oxides. Propylene may be oxidized to acetone, and butylenes and amylenes to the corresponding ketones.