Process for the recovery of C.sub.2 + or C.sub.3 + hydrocarbons

In a low temperature separation process for the recovery of a heavy hydrocarbon product from a hydrocarbon containing gas stream comprising:

• (a) cooling the gas stream to effect the partial condensation thereof;
• (b) phase separating the partially condensed gas stream into its vapor and liquid components in a phase separator;
• (c) rectifying the vapor component from step (b) by low temperature dephlegmation to produce a light gas stream and a heavy liquid stream;
• and
• (d) stripping the liquid component from step (b) and the heavy liquid stream from step (c) in a stripping column containing a reboiler wherein the bottoms stream from the stripping column is the heavy hydrocarbon product;
• (e) providing the predominant amount of the refrigeration for the process from a single loop vapor recompression refrigerator employing a mixed refrigerant;
• the improvement for increasing the efficiency of said separation process comprising:
• (i) passing the liquid component from step (b) and the heavy liquid stream from step (c) directly to the stripping column of step (d);
• (ii) operating the stripping column at below ambient temperature;
• (iii) passing the overhead vapor from the stripping column directly to the phase separator of step (b) to be rectified with the vapor component from step (b);
• and
• (iv) using the mixed refrigerant employed in step (e) as a heating medium for the reboiler of the stripping column in order to provide at least a portion of the heat duty for the reboiler.