| 摘要 |
A mixture of hydrogen and oxygen, suitable for use as ammonia-synthesis feed-gas, is made by separately reaching a light hydrocarbon, i.e. C1 to C4, e.g. methane, ethane, propane, butane or mixture thereof, with steam, yielding carbon monoxide and hydrogen, and a hydrocarbon of higher molecular weight, i.e. C5 upwards, e.g. hexane, naphtha or crude oil, and air with or without steam, yielding carbon monoxide and hydrogen, mixing the two effluent streams, and purifying the mixed gas. The light hydrocarbon and steam react, in the presence of a reforming catalyst, e.g. iron oxide, aluminium oxide or nickel oxide, at a temperature of 1200-2000 DEG F., the space velocity being 1000 to 2000 v/v/hr. The hydrocarbon of high molecular weight and air with or without steam are preheated to 600-1500 DEG F., and are reacted in a partial oxidation reactor, at a temperature above 2000 DEG F., at a pressure of 50-350 p.s.i.g. The two effluent streams are mixed in the proportion of 1.5 to 3 volumes steam-reformer effluent per volume of the partial-oxidation effluent. The mixed gases are then reacted with steam in a water-gas shift reactor, containing a catalyst, e.g. iron oxide promoted with oxides of chromium, potassium, manganese and aliminium, operating at a temperature of 700 DEG to 800 DEG F., and with space velocity between 100 and 500 v/v/hr. The gases are then scrubbed with water or basic aqueous solutions, for example monoethanolamine solution or cuprous ammonium acetate solution or both, and sodium hydroxide solution. The water-gas shift reaction and scrubbing, which remove most of the water, carbon dioxide and carbon monoxide, may be repeated. The gases may now be passed through a methanizer, containing a catalyst, for example copper oxide or nickel or alumina, operating at 550-750 DEG F. and 150-500 p.s.i.g. with space velocity of 1000 to 4000 v/v/hr; this process removes residual carbon monoxide. |
