GB690432A - Process for the hydrogenation of carbon monoxide in the presence of an iron catalyst - Google Patents

Abstract

Hydrocarbons and oxygen-containing organic compounds are made by hydrogenating carbon monoxide at atmospheric pressure in the presence of an iron catalyst which is brought into operation at a temperature within the range 170-200 DEG C., and in such manner that during the first 500 hours of operation it is extracted from four to seven times to remove high boiling synthesis products therefrom, the synthesis thereafter being continued at 170-200 DEG C., preferably 190-200 DEG C. In the subsequent synthesis the conversion remains high (approx. 72 per cent) for about 2000-4000 hours and further reduction in catalyst activity may be restored by increasing the synthesis temperature. The permissible end temperature is approx. 230-235 DEG C. Advantageously an iron catalyst is used impregnated with an alkali-metal salt of a non-volatile acid, e.g. potassium silicate or phosphate. The reduction of the catalyst is effected at a high rate of flow of hydrogen at 200-350 DEG C., preferably 200-250 DEG C. Methane production is lower and the content of hydrocarbons boiling above 300 DEG C. higher than in conventional processes. In an example an iron catalyst containing copper and calcium oxide is precipitated with sodium carbonate from a solution of the nitrates at pH7, washed, dried, impregnated with potassium silicate and reduced with hydrogen at 225 DEG C., and then put on stream with water gas at 160 DEG C., the temperature being raised to 195 DEG C. after 48 hours. After a further 48 hours the catalyst is extracted with Diesel oil (B.R. 220-300 DEG C.) and again used in the synthesis and subsequent extractions of the catalyst are made after 216, 316, 416 and 516 hours on stream, the conversion after the fifth extraction being about 72 per cent at a synthesis temperature of 198 DEG C., it then being necessary to extract the catalyst every seven days at first and later on every 10-14 days.ALSO:In a process for the production of hydrocarbons and oxygen-containing organic compounds by hydrogenating carbon monoxide at atmospheric pressure an iron catalyst is brought into operation at 170 DEG -200 DEG C and extracted from four to seven times to remove high boiling synthesis products therefrom during the first 500 hours of operation, the synthesis then being continued at 170 DEG -200 DEG C, preferably 190 DEG -200 DEG C. Advantageously an iron catalyst is used impregnated with an alkali-metal salt of a non-volatile acid, e.g. potassium silicate or phosphate. Reduction of the catalyst is effected at a high rate of flow of hydrogen at 200 DEG -350 DEG C, preferably 200 DEG -250 DEG C. In an example an iron catalyst containing copper and calcium oxide is precipitated with sodium carbonate from a solution of the nitrates at pH 7, washed, dried, impregnated with potassium silicate and reduced with hydrogen at 225 DEG C, and then put on stream with water gas at 160 DEG C, the temperature being raised to 195 DEG C after 48 hours. After a further 48 hours the catalyst is extracted with diesel oil (B.R. 220 DEG -300 DEG C) and again used in the synthesis and similar extractions are made after 216, 316, 416 and 516 hours on stream, the conversion after the fifth extraction being about 72 per cent at a synthesis temperature of 198 DEG C, it then being necessary to extract the catalyst every seven days at first and later on every 10-14 days.