PRODUCTION OF AMMONIA MAKE-UP SYNGAS WITH CRYOGENIC PURIFICATION

摘要

A process and a related equipment for making ammonia make-up synthesis gas are disclosed, where: a hydrocarbon feedstock is reformed obtaining a raw ammonia make-up syngas stream; said raw syngas is purified in a cryogenic purification section refrigerated by a nitrogen-rich stream produced in an air separation unit; the nitrogen-rich stream at output of said cryogenic section is further used for adjusting the hydrogen/nitrogen ratio of the purified make-up syngas; an oxygen-rich stream is also produced in said air separation unit and is fed to the reforming section.

主权项

1. A process for making ammonia make-up synthesis gas, comprising the steps of:
reforming a hydrocarbon feedstock, followed by steps of shift, CO2 removal and methanation, to obtain a raw ammonia make-up syngas stream comprising hydrogen and nitrogen;
treating said raw syngas in a cryogenic purification section obtaining a purified syngas stream;feeding a liquid nitrogen-rich stream at a cryogenic temperature to said cryogenic purification section;providing an indirect heat exchange between the syngas and said liquid nitrogen-rich stream in the cryogenic section, said liquid nitrogen-rich stream being at least partly evaporated to provide refrigeration of said cryogenic section; andtreating an air stream in an air separation unit, obtaining said liquid nitrogen-rich stream and an oxygen-rich stream.