摘要 |
A process for economically recovering ethane, propane and heavier hydrocarbon components from methane and lighter constituents of natural gas streams is disclosed. The separation process of the natural gas stream is accomplished in two stages. The input gas stream (90) is first cooled by exchanger (58) using various streams of refrigerant. After cooling the stream (102) is partially condensed in a separator (104), with part of the methane and almost all of the ethane and heavier hydrocarbons within the stream being condensed. The condensed mixtures (112) are fed to a fractionation tower (116), where the methane and lighter gases are distilled from the other hydrocarbons. The cooling and condensation of the hydrocarbons in the feed stream and the heat source for the tower (116) are accomplished in indirect contact heat exchangers (26, 58, 68, 70, 210) with a multi-component hydrocarbon refrigerant in two streams (154, 220) and a slip stream (211) of the feed stream. The cooling of the feed stream is also accomplished by flashing of the process gases.
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