| 摘要 |
For separating a C2+-hydrocarbon fraction from compressed CO2-containing natural gas by rectification, wherein the compressed natural gas is, prior to rectification, subjected to partial condensation and engine-expansion steps to achieve the desired pressure and temperature conditions in the rectification column and wherein said column is fed by resultant condensate of natural gas, the improvement comprising: conducting the engine expansion of the natural gas to a point well above the temperature at which the CO2 would otherwise precipitate out, and recovering from the engine expansion step an unliquefied gaseous fraction, and passing said fraction in indirect heat exchange relationship with engine-expanded overhead product from said column, whereby peak cooling and partial condensation of said fraction is achieved, and feeding resultant partially condensed fraction to the top of said column.
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