| 摘要 |
1,152,009. Making combustible gas. GAS COUNCIL. 21 Feb., 1967 [24 Feb., 1966], No. 8257/66. Heading C5E. A gas containing a high proportion of CH 4 is made by passing a gas mixture containing H 2 , CO, CO 2 , steam and at least 25 vol. per cent CH 4 over two methanation catalysts in series, part at least of the steam being removed from the gases between the two catalyst stages. The first catalyst is at 200‹ to 450‹ C., and the second is in a temperature range which is lower than the exit temperature of the gases leaving the first stage. The original gas mixture may be one made by the catalytic steam reforming of light hydrocarbons, e.g. as described in Specification 820,257. The gases are cooled between the stages and condensate is removed, only enough steam being left in to prevent carbon deposition on the second catalyst. Further cooling and methanation stages may succeed the second stage. A suitable catalyst is active nickel-alumina, e.g. as described in Specification 969,637, and the process may be operated at up to 100 atmospheres pressure. The catalysts may be fluidized beds, and one or both may be cooled, e.g. as described in Specification 1,152,008.
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