TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: Cooling and condensing of the methane vapor is performed in a dephlegmator to form high purity liquid methane product. A portion of the hydrocarbon liquid after cooling and condensing is removed as liquid product and vaporized higher order hydrocarbon is recycled and combined with the feed gas. The portion of hydrocarbon vapor is drawn from the heat exchanger and introduced into the dephlegmator drum. Subcooling of the hydrocarbon liquid is performed by reducing the pressure of hydrocarbon stream in dephlegmator and with indirect heat exchanger.Preferred Mechanism: A portion of the vaporized hydrocarbon in the heat exchanger is passed into a vertical passage such that hydrocarbon liquid flows down ward and vapor flows upward providing a stripping medium for mass transfer between the two phases.Preferred Unit: A portion of the refrigerant required to cool, and condense the purified liquid methane is provided by closed loop multicomponent refrigeration system.Preferred Refrigerant: The refrigerant comprises nitrogen, methane and hydrocarbon(s) higher than methane. A portion of the refrigerant required for cooling and condensing the methane vapor is provided by external refrigeration source.Preferred Purity: The high purity liquid methane product contains at least 98 mole % of methane and 0.5 mole % or less of higher order hydrocarbon. EXAMPLE - (In mole Percentage) Natural gas stream containing nitrogen (1.5), methane (95.4), ethane and higher order hydrocarbon was cooled to -121 degreesF in heat exchanger. The condensed liquid was transferred in dephlegmator drum and further cooled and condensed to remove remaining hydrocarbon. The subcooled hydrocarbon liquid was reduced to a pressure of 225 psi and partially vaporized as a supply for refrigeration. Methane enriched vapor stream at -713 degreesF was withdrawn from dephlegmator heat exchanger and condensed, subcooled to -261 degreesF to recover highly pure methane product containing nitrogen (1.8), methane (97.7), ethane (0.5). About 88 % of ethane and hydrocarbon(s) in the natural gas feed was removed and 80 % methane was recovered with high purity.