Separation of hydrogen-hydrocarbon gas mixtures using closed-loop gas expander refrigeration

A method for the recovery of hydrogen and one or more hydrocarbons having one or more carbon atoms from a feed gas containing hydrogen and the one or more hydrocarbons, which process comprises:

• (a) cooling and partially condensing the feed gas to provide a partially condensed feed;
• (b) separating the partially condensed feed to provide a first liquid stream enriched in the one or more hydrocarbons and a first vapor stream enriched in hydrogen;
• (c) further cooling and partially condensing the first vapor stream to provide an intermediate two-phase stream;
• and
• (d) separating the intermediate two-phase stream to yield a further-enriched hydrogen stream and a hydrogen-depleted residual hydrocarbon stream;
• wherein some or all of the cooling in (a), or in (c), or in (a) and (c) is provided by indirect heat exchange with cold gas refrigerant generated in a closed-loop gas expander refrigeration cycle.