Abstract: The invention provides a process and apparatus for the separation of a gaseous feed comprising a mixture of hydrocarbons and nitrogen gas, the process comprising the steps of: (i) cooling and at least partially condensing the gaseous feed; (ii) feeding the cooled and at least partially condensed feed from step (i) to a fractionation column comprising reboil to produce an overhead hydrocarbon vapour stream enriched in nitrogen and a condensed hydrocarbon product stream low in nitrogen, wherein prior to the fractionation, the feed stream is divided into at least two streams including: a) a first stream which is expanded and fed to the fractionation column; b) a second stream which is expanded, heated and fed to a lower stage of the fractionation column than the first stream, (iii) removing a hydrocarbon product stream low in nitrogen from the fractionation column; and (iv) removing a hydrocarbon vapour stream enriched in nitrogen from the fractionation column.

Abstract: The invention provides a process and apparatus for the separation of nitrogen from a gaseous feed comprising a mixture of hydrocarbons and nitrogen gas, the process comprising the steps of: (i) cooling and at least partially condensing the gaseous feed; (ii) feeding the cooled and at least partially condensed feed from step (i) to a first fractionation to produce an overhead vapour stream having an enriched nitrogen content and a condensed product having a reduced nitrogen content which is subjected to a second fractionation, which comprises reboil, at a lower pressure than the first fractionation; (iii) partially condensing the overhead vapour stream, and separating to provide a liquid stream, which is used to provide reflux to the first fractionation, and a separated vapour stream, which is condensed to provide reflux to the second fractionation; and (iv) sub-cooling the condensed product of the first fractionation and dividing the resulting sub-cooled product into at least two streams: a first stream being

Abstract: The invention provides a process for the separation of a heavier hydrocarbon fraction from a gaseous feed comprising a mixture of hydrocarbons, which process comprises subjecting the feed to a first fractionation to form a condensed product; subjecting the condensed product to a second fractionation, at a lower pressure than the first fractionation pressure, to provide the heavier hydrocarbon fraction and distillate fraction; and withdrawing the produced heavier fraction wherein the distillate from the second fractionation is partially condensed to provide reflux streams for both the first and second fractionations. Running the second fractionation at a lower pressure than the first means that there is phased let-down of pressure in two stages, leading to an increased pressure at the suction of the residue gas compressor and reduces power consumption.

Abstract: A process is described for separating the heavier hydrocarbons from a gaseous hydrocarbon feed wherein a first separator is employed to separate partially condensed gaseous feed and wherein the vapour portion undergoes work expansion and is fed to a fractionation column. The liquid portion is subcooled in heat exchange with the overhead vapour from the fractionation column, expanded, evaporated to provide refrigeration at a low temperature level, and fed to the fractionation column. The rewarmed residual vapour is subsequently compressed to a pressure suitable for export, with a portion of the compressed gas being cooled, condensed and recycled back to reflux the top section of the fractionation column. Also described is a process wherein a first separator is employed to separate partially condensed gaseous feed and wherein the vapour portion undergoes work expansion and is fed to a high pressure wash column. The liquid portion is expanded and fed to the base of the high pressure wash column.