| 摘要 |
For the fractionation of a hydrocarbon mixture, e.g., natural gas rich in a C2+ fraction, the hydrocarbon mixture is partially condensed and the thus-produced gas/liquid mixture is separated in a distillation column to produce a gaseous overhead fraction containing lighter hydrocarbons and a liquid bottoms product containing heavier hydrocarbons. In the upper column section, the gas is scrubbed with a physical scrubbing agent which is preferably a part of the bottoms product. A gaseous stream is withdrawn from the middle of the column to give the C4+ bottoms product the proper composition for scrubbing purposes. The scrubbing agent is also subcooled to lower the vapor pressure, preferably by a cooler liquid withdrawn from the column. |
