GB631682A - An improved process for the synthesis of hydrocarbons - Google Patents

Abstract

<PICT:0631682/III/1> Hydrocarbons and oxygenated products are prepared by feeding carbon monoxide and hydrogen to a reaction zone containing fluidized powdered iron or cobalt catalyst, cooling the product to give a condensate and a gaseous fraction, charging a feed mixture p comprising said gaseous fraction, and containing a ratio of hydrogen to carbon monoxide higher than that in the feed to the first zone, to a second zone containing fluidized iron or cobalt catalyst at a higher temperature than that of the first zone, and cooling the products to recover those normally liquid. Suitable catalysts are prepared by reacting spent pyrites and reducing in hydrogen or by fusing iron oxide with potassium salts and alumina, cooling, grinding and reducing. They are ground to a particle size of 20-80m with about 25 per cent within 0-20m . Gases containing hydrogen and carbon monoxide in molar ratio of from 1-2, preferably 1.5 : 1 and a little carbon dioxide are forced into reactor 1 through line 5 with a velocity of, say 1/2 -1\ba1/2 ft./sec. to maintain the catalyst in fluidized form. Instead of a hindered settling reactor as shown, gases at speeds up to 10 ft./sec. may be used to give a single phase suspension. A heat exchanger 16 serves for cooling. After separation of fines in separators 10, the products are cooled in 20 to, say, 100-150 DEG F., condensate being withdrawn at 25 for recovery of liquid hydrocarbons, alcohols, ketones and the like. Gases pass, optionally via an oil scrubber 32, to line 37 and second reactor 2 while part is rejected through line 36. Using reactor 1 at 550-750 DEG F. and 125-750 p.s.i. with a feed rate of 20-200 cu. ft. per lb. of iron present per hour, the amount of catalyst is adjusted to give 80-99 per cent conversion of the CO in the feed. The feed to reactor 2 contains 2-20 mols. of hydrogen per mol. of carbon monoxide, and a ratio of the dioxide to monoxide of about 5-10 : 1. The volumetric ratio of gas in line 37 to fresh feed in line 5 is from 0.2-4. Water may be added through 39. Temperature in reactor 2 is 100-150 DEG F. above that of reactor 1 and feed rate from 1/2 -\ba1/10 that of 1. Products leaving at 43 are mixed with those from reactor 1 or withdrawn at 21. Catalyst flows from reactors 1 to 2 by pipe 50, and from 2 to 1 by pipes 52, 55 being carried by feed gas from line 5 and/or recycle gas from line 37. More than two single-pass reactors may be used or recycling may be used in the first or second reactor only, successively lower pressures may be used in the reactors, and different catalysts may be used without circulation.ALSO:<PICT:0631682/IV (b)/1> Hydrocarbons and oxygenated products are prepared by feeding carbon monoxide and hydrogen to a reaction zone containing fluidized powdered iron or cobalt catalyst, cooling the product to give a condensate and a gaseous fraction, charging a feed mixture comprising said gaseous fraction, and containing a ratio of hydrogen to carbon monoxide higher than that in the feed to the first zone, to a second zone containing fluidized iron or cobalt catalyst at a higher temperature than that of the first zone, and cooling the products to recover those normally liquid. Suitable catalysts are prepared by roasting spent pyrites and reducing in hydrogen or by fusing iron oxide with potassium salts and alumina, cooling, grinding, and reducing. They are ground to a particle size of 20-80 m with about 25 per cent within 0-20 m . Gases containing hydrogen and carbon monoxide in molar ratio of from 1-2, preferably 1.5-1 and a little carbon dioxide are forced into reactor 1 through line 5 with a velocity of, say, 1/4 -1\ba1/2 ft./sec. to maintain the catalyst in fluidized form. Instead of a hindered settling reactor as shown, gases at speeds up to 10 ft./sec. may be used to give a single phase suspension. A heat exchanger 16 serves for cooling. After separation of fines in separators 10, the products are cooled in 20 to, say, 100-150 DEG F., condensate being withdrawn at 25 for recovery of liquid hydrocarbons, alcohols, ketones and the like. Gases pass, optionally via an oil scrubber 32, to line 37 and second reactor 2 while part is rejected through line 36. Using reactor 1 at 550-750 DEG F. and 125-750 p.s.i., with a feed rate of 20-200 cubic feet per lb. of iron present per hour, the amount of catalyst is adjusted to give 80-99 per cent conversion of the CO in the feed. The feed to reactor 2 contains 2-20 mols. of hydrogen per mol. of carbon monoxide, and a ratio of the dioxide to monoxide of about 5-10 : 1. The volumetric ratio of gas in line 37 to fresh feed in line 5 is from 0.2-4. Water may be added through 39. Temperature in reactor 2 is 100-150 DEG F. above that of reactor 1 and feed rate from 1/2 -\ba1/10 that of 1. Products leaving at 43 are mixed with those from reactor 1 or withdrawn at 21. Catalyst flows from reactors 1 to 2 by pipe 50, and from 2 to 1 by pipes 52, 55 being carried by feed gas from line 5 and/or recycle gas from line 37. More than two single-pass reactors may be used or recycling may be used in the first or second reactor only, successively lower pressures may be used in the reactors, and different catalysts may be used without circulation.