METHOD AND APPARATUS FOR CLEANING AT CRYOGENIC TEMPERATURE FOR THE PRODUCTION OF A MIXTURE OF HYDROGEN AND NITROGEN

摘要

In a cryogenic temperature washing process for producing a mixture of hydrogen and nitrogen, a gaseous mixture (3, 11) containing at least hydrogen, methane and carbon monoxide is cooled in a heat exchanger (9A, 9) to a cryogenic temperature and fed to a washing column (13), a nitrogen-rich liquid (31) is sent to the top of the washing column, a gas containing hydrogen and carbon dioxide. nitrogen (35) is withdrawn from the head of the washing column and heated to form the mixture of hydrogen and nitrogen, a nitrogen gas flow (25) is cooled in the heat exchanger and divided into two parts, a first portion of the nitrogen is liquefied to form the nitrogen-rich liquid and a second portion (27) of the nitrogen is expanded in a turbine (41), the expanded nitrogen is heated in the heat exchanger to form an auxiliary flow of nitrogen (43).