A process for the purification of a synthesis gas containing Hydrogen and Impurities.

摘要

A process for purification of a current of hydrogen synthesis gas (100), particularly in the front-end of an ammonia plant, wherein said gas contains hydrogen and minor amounts of carbon monoxide, carbon dioxide, water and impurities, said process including steps of methanation (13) of said current (100), converting residual amounts of carbon monoxide and carbon dioxide to methane and water, dehydration (14) of the gas to remove water, and then a cryogenic purification such as liquid nitrogen wash (15), to remove methane and Argon; a corresponding plant and method for revamping an ammonia plant are also disclosed.