| abstract |
Abstract Nitrogen removal from natural gas The invention relates to a method for the separation of a hydrocarbon-rich, nitrogen-containing feed fraction (1, 101), preferably natural gas, wherein the feed fraction (1, 101) is at least in part liquefied (El, 10 E2) and divided by rectification (Ti) into a nitrogen enriched fraction (14, 110) and a hydrocarbon-rich, nitrogen-depleted fraction (11, 111) and wherein, in the upper region of the rectification (Tl), a nitrogen enriched stream (14) is taken off, cooled (E3) and 15 applied (20) at least in part to the rectification (Tl) as reflux and/or the nitrogen-enriched fraction (110) is cooled and partially condensed (E3), applied at least in part to the rectification (T1) as reflux (115) and the remaining stream (116) of the nitrogen-enriched 20 fraction (110) is subjected to a double-column process (T3). According to the invention, in the middle region of the rectification (Tl), a carbon-dioxide-poor stream (13, 25 113) which serves for cooling (E3) the nitrogen enriched substream (14) and/or cooling (E3) the nitrogen-enriched fraction (110) is taken off and the feed fraction is rectified (T1) in a separation column (T1) having a dividing wall (W), wherein the dividing 30 wall (W) is arranged at least in the region of the separation column (Ti) in which the feed fraction (2, 4, 5, 102, 104, 105) is fed to the separation column (Ti) and. the carbon-dioxide-poor stream (13, 113) is taken off. (Figure 1 is associated herewith.) |