| 摘要 |
An improved process for separating gaseous materials from a mixture containing the same. The process is particularly useful for the separation of high concentrations of nitrogen or similar low boiling materials from hydrocarbon streams such as natural gas and comprises the steps of first liquifying a portion of said gas stream and thereafter separating said stream into a gas phase and a liquid phase in a separation column. The overhead gas stream from the separation column is then passed through one or more turbo-expanders to provide process refrigeration and process energy. In one embodiment, at least a portion of the energy recovered is employed to drive a feed compressor. In a second embodiment, where the feed is at or near the required process pressure, the energy will be available for other purposes. In a third embodiment, where the feed is available at pressures above the required process pressure, the feed may also be passed through one or more suitable turbo-expanders to thereby provide additional process refrigeration as well as additional energy. In all embodiments, the process permits low cost purification. Moreover, depending principally upon feed composition and pressure, surplus energy and refrigeration will be available for other purposes. As will be readily apparent, this constitutes a definite economic credit and thereby permits an even lower cost purification.
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