| 摘要 |
H2 is obtained from a gas mixture containing H2, CO, and hydrocarbons, including acetylenes, by catalytic hydrogenation followed by steam conversion of CO to CO2 and removal of the CO2, and separation of H2 from the hydrocarbon and any residual CO. The gas mixture may contain at least 60% H2 + CO, and at most 30% hydrocarbons and may be the residual gas from the synthesis of C2H2 from hydrocarbons, e.g. CH4. Hydrogenation is effected at 100-300 DEG C. over a Pd on Al2O3 catalyst; acetylenic and conjugated hydrocarbons are then absent. CO conversion is effected by saturating the gas with H2O at 150 DEG C. and passing it over an Fe and Cr oxide catalyst at 410 DEG C., then over a Zn and Cu oxide catalyst at 200 DEG C. CO2 is washed out e.g. with H2O, monoethanolamine or K2CO3, and the H2 is separated by low temperature fractionation and washing with liquid N2. The whole process may be operated under the same pressure, e.g. 8-80 atm. N2 may be finally added to give an NH3 synthesis gas. |
