| 摘要 |
<p>A process for separating nitrogen from e.g. natural gas 2 by separating the gas in a first distillation column K1 at superatmospheric pressure to obtain an overhead vapour stream 18 having a nitrogen content greater than that of the feed gas mixture, reducing the pressure of said overhead stream e.g. in valve 20, separating it in a second distillation column K2 and recovering a nitrogen depleted product stream from one or both of the condensate streams 16 and 42 from the distillation steps, and wherein part or all of the reboil for the second distillation column is provided by effecting indirect heat exchange between the liquid column bottoms 10 and the overhead vapour stream 18, with at least partial condensation of the latter. <IMAGE></p> |
