GB398527A - Manufacture of esters - Google Patents

Abstract

Esters are produced by reacting a fatty acid having five or less carbon atoms with an olefine having seven or less carbon atoms in presence of a catalyst at above the boiling-point of the ester under the reaction conditions and continuously withdrawing the ester from the reaction space in the vapour form. When the ester has a higher boiling-point than the acid, the acid must be employed in the form of vapour, but otherwise the acid may be in the liquid form. Suitable catalysts are chlorides, bromides, phosphates and sulphates of zinc, aluminium, mercury, copper, cadmium, bismuth and antimony, relatively non-volatile inorganic acids such as sulphuric and phosphoric acids, and the metal acid salts and alkyl and aryl derivatives of these acids, such as sodium bisulphate, ethyl sulphuric acid, and benzene sulphonic acid. A porous or adsorbent carrier may be used for the catalyst. Reduced, normal, or increased pressure may be employed. Preferably the temperature is as little above the boiling-point of the ester as will ensure the quick removal of the vapour from the reaction space. The excess reagents may be passed through a number of reaction vessels until substantially the whole have combined. In examples, (1) 500 parts adsorbent carbon are treated with 50 parts of 75 per cent phosphoric acid and heated to 150-250 DEG C. for two hours in a current of air, and a mixture of acetic acid vapour and propylene is passed over this catalyst at 110 DEG C.; (2) adsorbent carbon is treated with 10 per cent of a 50 per cent solution of zinc chloride and heated as before, the production of ester being effected in a similar manner. Specification 362,215 is referred to.ALSO:Catalysts for the production of esters from fatty acids and olefines are chlorides, bromides, phosphates and sulphates of zinc, aluminium, mercury, copper, cadmium, bismuth and antimony, relatively non-volatile inorganic acids such as phosphoric and sulphuric acids, and the metal acid salts and alkyl and aryl derivatives of these acids, such as sodium bisulphate, ethyl hydrogen sulphate, and benzene sulphonic acid. A porous or adsorbent carrier may be used for the catalyst. In the examples, catalysts are prepared by treating 500 parts of adsorbent carbon with 50 parts of 75 per cent phosphoric acid or 10 per cent of 50 per cent solution of zinc chloride, the mass being heated for two hours at 150-250 DEG C. in a current of air. Specification 362,215, [Group IV], is referred to.