TECHNOLOGY FOCUS - CHEMICAL ENGINEERING - Preferred Process: The subcooling required in subcooling step may be provided by transfer of heat to overhead vapor from the fractionation column. The overhead vapor and the expanded stream are heated with first liquid stream or subcooled first liquid stream before the expansion step. A remainder of first liquid stream is subjected to subcooling and expanding steps. The gaseous stream is introduced into the fractionation column at a point above the liquid feed. The overhead vapor is rewarmed, compressed and cooled to provide a recycle stream and residue gas product. The separated lights fraction comprising a recycle stream derived overheads from the fractionation column is cooled by a net refrigeration available within the heat exchanger. The recycle stream is condensed or subcooled and returned to upper part of the fractionation column. The first gaseous and first liquid streams are fed to a reequilibration device to produce first and second outputs. The first output is richer in heavier hydrocarbons than the first liquid stream. The second output is leaner in heavier hydrocarbons than the first gaseous stream. The second output is cooled, partially condensed and (in)directly fed to upper part of the fractionation column as cooled stream. The first output is subjected to subcooling to recovering steps. The first gaseous stream is expanded before it is fed to the reequilibration device. The second output is partially condensed in heat exchange with the expanded stream, and is fed to a separator to produce additional gaseous and liquid streams. The additional liquid stream is fed to the reequilibration device and the additional gaseous stream is warmed to produce a residual gas product.    TECHNOLOGY FOCUS - MECHANICAL ENGINEERING - Preferred Apparatus: The apparatus further includes a mechanism for expanding the first liquid stream, and a mechanism for separating the first expanded liquid stream to further gaseous stream and further liquid stream. A reequilibration device is a high-pressure wash column, which is arranged to receive the expanded first gaseous stream and expanded first liquid stream.