Patent ID: 8677780

Claim:
A method of conditioning a rich feed gas containing C1, C2 to C4, and C5+ in a conditioning unit, comprising: cooling and separating the rich feed gas into a liquid portion and a vapor portion; further cooling a first fraction of the vapor portion and separating the cooled vapor portion into a C5+ depleted vapor stream and a C5+ enriched liquid stream; separating the C5+ enriched liquid stream and the liquid portion in a refluxed fractionator into a C2-C5 enriched bottom product and an overhead product; compressing and cooling the overhead product and separating the compressed and cooled overhead product into a reflux liquid for the fractionator and a lean vapor; wherein the step of cooling the overhead product to obtain the reflux liquid is performed by reducing pressure of the C5+ enriched liquid stream and using refrigeration obtained from the step of reducing pressure in the step of cooling the overhead product; and combining a second fraction of the vapor portion, the lean vapor, and the C5+ depleted vapor stream to form a C2 to C4-containing combined stream, and feeding the combined stream to a downstream NGL recovery plant for separation of C2 to C4 from C1.