(GB2350417-A)   NOVELTY - Under partially-loaded operation, a side stream (8) of pure methane product fraction (4) and/or a side stream (9) of residual gas fraction (5) is recycled to a point ahead of cryogenic fractionation (C). Quantities of methane and/or residual gas recycled are sufficiently large, that external sources of refrigeration are obviated.    USE - To produce methane and residual gases, especially from natural gas.    ADVANTAGE - There is no need for an external source of refrigeration, even when working under conditions of partial loading, with this process. Regardless of loading, purity is maintained constant. Capital costs of the plant are reduced. Purification separates CO2, to prevent blockages in lines and valves. The natural gas feedstock comprises in addition: methane (80 vol% or more), nitrogen (10-15 vol %) and higher hydrocarbons. Fractionation is standard, e.g. in two columns; represented by the black box (C). Because of recycling, the process essentially sees full loading at all times, regardless of the feedstock supply rate.    (NL1015065-C2)   NOVELTY - Under partially-loaded operation, a side stream (8) of pure methane product fraction (4) and/or a side stream (9) of residual gas fraction (5) is recycled to a point ahead of cryogenic fractionation (C). Quantities of methane and/or residual gas recycled are sufficiently large, that external sources of refrigeration are obviated.    USE - To produce methane and residual gases, especially from natural gas.    ADVANTAGE - There is no need for an external source of refrigeration, even when working under conditions of partial loading, with this process. Regardless of loading, purity is maintained constant. Capital costs of the plant are reduced. Purification separates CO2, to prevent blockages in lines and valves. The natural gas feedstock comprises in addition: methane (80 vol% or more), nitrogen (10-15 vol %) and higher hydrocarbons. Fractionation is standard, e.g. in two columns; represented by the black box (C). Because of recycling, the process essentially sees full loading at all times, regardless of the feedstock supply rate.