GB727805A - Process for the synthesis of oxygen-containing organic compounds - Google Patents

Abstract

Oxygen-containing organic compounds with a high ester content are obtained by the hydrogenation of carbon monoxide in the presence of a precipitated, copper-containing iron catalyst at a synthesis pressure greater than 5 atmospheres, the catalyst containing more than 15, preferably 15-50, per cent of copper and 4-15, preferably 6-12, per cent of free alkali calculated as K2O and based on the total iron content of the catalyst. The term "free alkali" is defined as the hydroxides, carbonates and bicarbonates of alkali-metals. Small quantities of catalyst promoters, e.g. aluminium oxide, zinc oxide and other difficulty reducible metal oxides, may be present. Advantageously the catalysts have more than 50, preferably more than 60, per cent of their iron content as free iron. The catalysts are preferably made by precipitation from a boiling solution of the two metallic nitrates using a boiling solution of an alkali such as ammonia, sodium or potassium carbonate or the corresponding hydroxides at a final pH of 7-9, the desired content of alkali being left in the product or added prior to moulding and reduction which is preferably effected at 250-300 DEG C. with carbon monoxide, hydrogen or hydrogen-nitrogen mixtures. The synthesis pressure is preferably above 10 atmospheres, e.g. 30-50 atmospheres, and the temperature preferably above 170 DEG C. 0.5-2 parts of H2 per part of CO may be used. Some methane is also obtained. In examples the precipitated catalyst contains potassium carbonate and the quantities of esters in the oxygen-containing organic compounds range from 22 to 40 per cent. Alcohols and a small quantity of aldehydes and ketones are also formed.ALSO:A catalyst used in the hydrogenation of carbon monoxide to provide a high yield of esters comprises a precipitated, copper-containing iron catalyst which contains more than 15, preferably 15-50, per cent. of copper and 4-15, preferably 6-12, per cent. of free alkali calculated as K2O and based on the total iron content of the catalyst. The term "free alkali" is defined as the hydroxides, carbonates and bicarbonates of alkali-metals. Small quantities of catalyst promoters, e.g. aluminium oxide, zinc oxide and other difficulty reducible metal oxides, may be present. Advantageously, the catalysts have more than 50, preferably more than 60, per cent. of their iron content or free iron. The catalysts are preferably made by precipitation from a boiling solution of the two metallic nitrates using a boiling solution of an alkali such as ammonia, sodium or potassium carbonate or the corresponding hydroxides at a final pH of 7-12, especially 7-9, the desired content of alkali being left in the product or added prior to moulding and reduction, which is preferably effected at 250-300 DEG C. with carbon monoxide, hydrogen or hydrogen-nitrogen mixtures. Advantageously 55-70 per cent. of water is present in the catalyst mass before moulding and the catalyst is moulded into a cylindrical form. Examples are provided of the detailed preparation of catalysts by the methods given above.