摘要 |
In a process for the separation of C2+, C3+ or C4+ hydrocarbons from a gas stream containing light hydrocarbons and, if desired, of components boiling lower than methane, in which the gas stream, being under an elevated pressure, is cooled, partially condensed and separated in a phase separator into a liquid and a gaseous fraction; the gaseous fraction is engine expanded, and the liquid fraction is fractionated by rectification into a product stream containing substantially C2+, C3+ or C4+ hydrocarbons and a residual gas stream containing predominantly lower boiling components, the improvement comprising subjecting the gaseous fraction forming after partial condensation, before engine expansion thereof, to heat exchange with the engine expanded gaseous fraction, thereby cooling said gaseous fraction and separating additional components which condense out before the engine expansion stage. |