Abstract: In the liquefaction of a hydrocarbon by indirect heat exchange with the refrigerant mixture of a refrigerant mixture cycle, the refrigerant mixture being compressed in multiple stages, the compressed refrigerant mixture (23) is at least partially condensed (E4) downstream of the penultimate compressor stage and is fractionated (D4) into a higher-boiling liquid fraction (26) and a lower-boiling gas fraction (24). The lower-boiling gas fraction (24) is compressed to the final pressure, partially condensed (E5) and fractionated (D5) into a lower-boiling gas fraction (10) and a higher-boiling liquid fraction (27). The higher-boiling liquid fraction (27) is added to the partially condensed refrigerant mixture stream (23), and the gas fraction (10) forms the lower-boiling refrigerant mixture fraction and the liquid fraction (26) forms the higher boiling refrigerant mixture fraction of the refrigerant mixture cycle.

Abstract: A mixture of gases containing hydrogen and at least one further component, for example nitrogen and argon, is enriched in hydrogen in a separation stage by adsorption, or cooling and partial condensation and/or rectification and/or scrubbing. Upstream of this separation stage, at least part of the hydrogen is separated by membrane diffusion, thereby resulting in a highly improved process as compared to using either the separation stage or membrane diffusion alone, especially in connection with gaseous mixtures having components which are to be used at high pressures, e.g., a purge gas from an ammonia synthesis gas process.