Process and apparatus for the production of carbon monoxide and hydrogen

摘要

Carbon monoxide is separated from a gas mixture (50) by partial condensation in a heat exchanger (31) and separation in a separator pot (320), draining column (330) and distillation column (340). The hydrogen produced at the top of the separator is scrubbed (350) and mixed with nitrogen (372) to produce an ammonia synthesis gas (385). All columns and exchangers are in a single cold box The gas is submitted at high pressure to a partial condensation by passing it through a heat exchanger (310) and separating it in a separator pot (320) to produce a flow of impure hydrogen (H2) at the top (321) and a condensed fraction rich in carbon monoxide (CO) at the bottom (322). The CO is purified by separation under medium pressure in a first draining column (330), eliminating dissolved H2 at the top and then distillation at low pressure in a distillation column (340) to separate the methane from the bottom mixture. The H2 from the top of the draining column is sent to a scrubbing column without reheating it to ambient temperature. The impure H2 from the separator is purified by washing it with a nitrogen flow in a scrubbing column (350) to extract a liquid fraction rich in carbon monoxide. An ammonia synthesis mixture is produced (385) by adding nitrogen (372) extracted from a high pressure nitrogen flow (370) to the H2 flow (353) from the top of the scrubbing column (350). The partial condensation stage and washing in nitrogen are carried out in the same installation (300). A second liquid fraction (352) is extracted from an intermediate point on the scrubbing column (350). The fraction rich in CO from the scrubbing column (350) is purified in a second draining column (360) at low pressure, separating the dissolved hydrogen at the top. The nitrogen is cooled in the heat exchanger before feeding it to the reboiler in the low pressure draining column. The separator pot contains plates or trays and the mixture is washed in CO to produce H2 at the top which is clear of methane. Installation for carrying out the above process.