Patent ID: 6278035
Filing Date: 2001-08-21
Classification: C07C,C10G,F25J,Y02P

Abstract:
In a process for separation of a gas stream containing methane, C.sub.2 and heavier hydrocarbon components into a volatile residue gas fraction and a relatively less volatile fraction containing said C.sub.2 components and heavier hydrocarbon components, in which process;(a) the feed gas is cooled in one or more heat exchangers and then directed to a separator providing thereby a first residue vapor and a first liquid which contains C.sub.2 and other lighter and heavier hydrocarbons; and(b) a first part of the first liquid containing C.sub.2 is directed into a heavy-ends fractionation column wherein said liquid is separated into a second residue containing lighter hydrocarbons and a liquid product containing C.sub.2 ;the improvements comprising;(1) cooling said second residue to partially condense it;(2) cooling a second part of said first liquid containing C.sub.2 from (b) and combining the same with said partially condensed second residue stream from (1) resulting in a third liquid stream and a third residue vapor;(3) dividing said third liquid produced in step (2) into first and second parts;(4) further cooling said first part of said third liquid;(5) directing said second part of the third liquid to the heavy-ends fractionation column;(6) intimately contacting at least part of said first residue vapor with said cooled first part of third liquid from step (4) in at least one contacting stage and thereafter separating a fourth residue vapor and fourth liquid containing C.sub.2 from said contacting device;(7) supplying the fourth liquid thereby recovered in step (6) above to a heat exchanger for heating the same and thereafter into the heavy-ends fractionation column as a feed thereto;(8) recovering as product the combined third residue vapor and the fourth residue vapor;(9) recovering as product the second liquid stream from the heavy-ends fractionation column.