| 摘要 |
In the prepn. of gas mixts. contg. H2 by reacting hydrocarbons with steam, part of the steam needed is generated by saturating the hydrocarbon charge with water heated by >=1 heat source to 420 degrees C. This heat source is available within the process and is (a) combustion gases or (b) H2-contg. mixts. The hydrocarbon and/or an air feed (when used), are pref. satd. with water in a multi-stage column. Pref. the heat source is H2-contg. gas moved from the prodn. unit to the purification unit; or gases from the primary reformer. Esp. used for making NH3 synthesis gas. Better utilisation of heat and improved thermodynamic efficiency are obtd. Water used for steam raising need not be so pure as normal, at least some can be provided by aq. condensates from with the system. |
