A process for separating a heavy key component from an inlet gas stream containing a mixture of methane, C 2 compounds, C 3 compounds, and heavier compounds, comprising the following steps: (a) at least partially condensing and separating the inlet gas stream to produce a first liquid stream (44; 144) and a first vapor stream (42; 142); (b) expanding at least a portion of the first liquid stream (44; 144) to produce a first fractionation feed stream (58; 158); (c) supplying a fractionation column with the first fractionation feed stream (58; 158) and a second fractionation feed stream (48; 148) to produce a fractionation overhead vapor stream (60; 160) and a fractionation bottom stream (72; 172); (d) expanding at least a portion of the first vapor stream (42; 142) to produce an expanded vapor stream (42a; 142a); (e) supplying an absorber with the expanded vapor stream (42a; 142a) and an absorber feed stream (70; 170) to produce an absorber overhead stream (46; 146) and an absorber bottom stream (45; 145), the absorber having an absorber pressure that is substantially greater than, and at a differential pressure from, a fractionation column pressure, the absorber pressure being at least about 34.47 bara (500 psia); (f) compressing at least a portion of the fractionation overhead vapor stream (60; 160) to the absorber pressure to produce a compressed second vapor stream (68; 168); and (g) at least partially condensing the compressed second vapor stream (68; 168) to produce the absorber feed stream (70; 170); whereby the fractionation bottom stream (72; 172) contains a majority of the heavy key component and heavier compounds, wherein the heavy key component is C 3 compounds and heavier compounds and wherein the process further comprises the following steps: (h) at least partially condensing the fractionation overhead vapor stream to produce a condensed fractionation overhead stream; (i) separating the condensed fractionation overhead stream to produce a second vapor stream and a fractionation reflux stream; (j) supplying the fractionation column with the fractionation reflux stream; (k) cooling the fractionation bottom stream and supplying the cooled portion of the fractionation bottom stream to the fractionation column as a fractionation reflux stream; and (l) warming at least a portion of the first liquid stream before producing the first fractionation feed stream from step (b). (a) at least partially condensing and separating the inlet gas stream to produce a first liquid stream (44; 144) and a first vapor stream (42; 142); (b) expanding at least a portion of the first liquid stream (44; 144) to produce a first fractionation feed stream (58; 158); (c) supplying a fractionation column with the first fractionation feed stream (58; 158) and a second fractionation feed stream (48; 148) to produce a fractionation overhead vapor stream (60; 160) and a fractionation bottom stream (72; 172); (d) expanding at least a portion of the first vapor stream (42; 142) to produce an expanded vapor stream (42a; 142a); (e) supplying an absorber with the expanded vapor stream (42a; 142a) and an absorber feed stream (70; 170) to produce an absorber overhead stream (46; 146) and an absorber bottom stream (45; 145), the absorber having an absorber pressure that is substantially greater than, and at a differential pressure from, a fractionation column pressure, the absorber pressure being at least about 34.47 bara (500 psia); (f) compressing at least a portion of the fractionation overhead vapor stream (60; 160) to the absorber pressure to produce a compressed second vapor stream (68; 168); and (g) at least partially condensing the compressed second vapor stream (68; 168) to produce the absorber feed stream (70; 170); (h) at least partially condensing the fractionation overhead vapor stream to produce a condensed fractionation overhead stream; (i) separating the condensed fractionation overhead stream to produce a second vapor stream and a fractionation reflux stream; (j) supplying the fractionation column with the fractionation reflux stream; (k) cooling the fractionation bottom stream and supplying the cooled portion of the fractionation bottom stream to the fractionation column as a fractionation reflux stream; and (l) warming at least a portion of the first liquid stream before producing the first fractionation feed stream from step (b).