| 摘要 |
A fractionation process for gaseous hydrocarbon mixtures of high acid gas content is described, for separating at least a fraction containing ethane, propane and heavier hydrocarbons, a fraction containing essentially acid gases and a fraction containing essentially methane and possible inert gases, characterized by comprising the following stages: (a) feeding the gaseous hydrocarbon mixture after dehydration to a first distillation column to which a liquid hydrocarbon stream is fed, to obtain a gaseous overhead product stream containing methane, ethane, acid gases and possibly light inert gases, and a bottom product stream containing ethane and higher hydrocarbons; (b) feeding the overhead product of the first distillation column to a second distillation column to obtain a gaseous overhead product stream containing methane, the ethane-carbon dioxide azeotrope and possibly light inert gases, and a bottom product stream consisting essentially of acid gases; (c) feeding the overhead product of the second distillation column to a third distillation column the condenser of which is injected with a liquid hydrocarbon stream, to obtain a gaseous overhead product stream consisting essentially of methane and possibly inert gases, and a bottom product stream which is recycled to the first column and contains the ethane-carbon dioxide azeotrope and the liquid hydrocarbon stream injected into the condenser; (d) feeding the bottom product of the first distillation column to a fourth distillation column to obtain a gaseous overhead product stream containing ethane and a bottom product stream containing higher hydrocarbons than butane. |
