| 摘要 |
1349449 Making combustible gas IMPERIAL CHEMICAL INDUSTRIES Ltd 2 Aug 1971 [26 Aug 1970] 41040/70 Heading C5E In a continuous process for catalytically steam reforming hydrocarbons, e.g. methane, optionally in the presence of hydrogen, the catalyst bed contains less than 0À5% alkali (calculated as equivalent K 2 O), and the following conditions are observed: the temperature of the reactants entering the bed is in the range 250‹ to 650‹ C., the temperature of the reactants leaving the bed is 750‹ to 1000‹ C., the pressure is at least 200 p.s.i.g., and the space velocity (steam plus hydrocarbons) is at least 3 kg. per litre of catalyst per hour. The rate of reaction of hydrocarbon and steam is such that at the region of the bed which is at 700‹ C. the reaction mixture satisfies the condition that F exceeds 6, where and P= pressure in atmospheres absolute. The value of F is kept above 6 by ensuring adequate catalyst activity, e.g. by desulphurizing the feed to below 0À5 p.p.m. of sulphur by weight, or by supplying hydrogen to the inlet or to an intermediate part of the bed. The process mitigates overheating of catalyst-containing tubes in certain bands. Recycling of H 2 -containing gas before or after shift-conversion and CO 2 removal, to the reforming process and to a catalytic desulphurization stage preceding it, is described. Reforming catalysts may be supported nickel and may include a promoter comprising an oxide of an alkaline earth metal, or of U, or of Zr. |
