HYDROCARBON GAS PROCESSING

摘要

A PROCESS FOR THE RECOVERY OF ETHANE, ETHYLENE, PROPANE, PROPYLENE, AND HEAVIER HYDROCARBON COMPONENTS FROM A HYDROCARBON GAS STREAM IS DISCLOSED. THE STREAM IS COOLED AND IS THEREAFTER EXPANDED TO THE FRACTIONATION TOWER PRESSURE AND SUPPLIED TO THE FRACTIONATION TOWER AT A LOWER MID-COLUMN FEED POSITION. A DISTILLATION STREAM IS WITHDRAWN FROM THE COLUMN BELOW THE FEED POINT OF THE STREAM AND IS THEN DIRECTED INTO HEAT EXCHANGE RELATION WITH THE TOWER OVERHEAD VAPOR STREAM TO COOL THE DISTILLATION STREAM AND CONDENSE AT LEAST A PART OF IT, FORMING A CONDENSED STREAM. AT LEAST A PORTION OF THE CONDENSED STREAM IS DIRECTED TO THE FRACTIONATION TOWER AT AN UPPER MID-COLUMN FEED POSITION. A RECYCLE STREAM IS WITHDRAWN FROM THE TOWER OVERHEAD AFTER IT HAS BEEN WARMED AND COMPRESSED. THE COMPRESSED RECYCLE STREAM IS COOLED SUFFICIENTLY TO SUBSTANTIALLY CONDENSE IT, AND IS THEN EXPANDED TO THE PRESSURE OF THE FRACTIONATION TOWER AND SUPPLIED TO THE TOWER AT A TOP COLUMN FEED POSITION. THE QUANTITIES AND TEMPERATURES OF THE FEEDS TO THE FRACTIONATION TOWER ARE EFFECTIVE TO MAINTAIN THE OVERHEAD TEMPERATURE OF THE FRACTIONATION TOWER AT A TEMPERATURE WHEREBY THE MAJOR PORTION OF THE DESIRED COMPONENTS IS RECOVERED.