VENT LINE FOR USE IN AMMONIA AND HYDROGEN PLANTS

摘要

In an ammonia or hydrogen plant comprising a desulfurisation section, a reforming section and a shift section, where the shift section comprises a low temperature shift converter and a medium temperature shift converter, a vent line is arranged downstream from the low temperature shift converter and the medium temperature shift converter in order to allow the shift converters to be re-heated with process gas at a low pressure (typically 3-7 bar). This way condensation of water vapour in the process gas is avoided. By applying this vent line it becomes possible to save significant time, more specifically 8-24 hours, for restarting the production after temporary shut-down thereof, because a heat-up of the LTS/MTS converter in circulating nitrogen is avoided.

主权项

1. An ammonia or hydrogen plant, wherein the synthesis gas generation part comprises a reforming section, a shift section, a carbon dioxide removal unit and a methanator, said shift section comprising a low temperature shift (LTS) converter and/or a medium temperature shift (MTS) converter, characterised by a vent line being arranged downstream from the shift section comprising the LTS converter and/or the MTS converter, said vent line allowing the shift converter (s) to be re-heated with process gas at a pressure of 3 to 7 bar, and by an inlet pressure reducing valve placed at the inlet of the shift section and a vent valve placed in the vent line downstream from the shift section, said valves facilitating the pressure control.