A process for the production of ammonia synthesis gas and pure methane by cryogenic separation of a feed gas containing at least 75% hydrogen as well as methane and nitrogen, the feed gas is cooled in a heat exchanger and partially condensed, the partially condensed feed is sent to a phase separator, the gas from the phase separator is sent to a nitrogen wash column, liquid nitrogen is sent to the top of the nitrogen wash column and ammonia synthesis gas is removed from the top of the nitrogen wash column, the liquid from the phase separator is expanded and sent to a separation column, a nitrogen enriched gas stream is removed from the top of the column and a nitrogen depleted liquid stream rich in methane is removed from the bottom of the column and the nitrogen depleted liquid stream rich in methane is vaporized to form a pure methane product.