Method for producing a flow rich in methane and a flow rich in C₂⁺ hydrocarbons, and associated installation

摘要

This method comprises cooling the supply flow in a first heat exchanger, separation in a first separation flask in order to produce a light upper flow and a heavy lower flow and dividing the light upper flow into a supply fraction of a dynamic pressure reduction turbine and a supply fraction of a first distillation column.;The method comprises forming a cooled reflux flow from an effluent from a dynamic pressure reduction turbine, the portion of the effluent being cooled and at least partially liquefied in a heat exchanger.;It comprises introducing the cooled reflux flow from the heat exchanger into the first distillation column.

主权项

1. A method of producing a flow rich in methane and a flow rich in C2+ hydrocarbons from a supply flow containing hydrocarbons, the method comprising the following steps:
separating the supply flow into a first fraction of the supply flow and at least a second fraction of the supply flow; introducing the first fraction of the supply flow into a first heat exchanger; cooling the first fraction of the supply flow in the first heat exchanger; introducing the cooled first fraction of the supply flow into a first separation flask in order to produce a light upper flow and a heavy lower flow; dividing the light upper flow into a turbine supply fraction and a column supply fraction; pressure reducing the turbine supply fraction in a first dynamic pressure reduction turbine and introducing at least a portion of the turbine supply fraction subjected to pressure reduction into the first turbine in a middle portion of a first distillation column; cooling and at least partially condensing the column supply fraction and pressure reducing and introducing the cooled column supply fraction into an upper portion of the first distillation column; pressure reducing and partial vaporizing the heavy lower flow in the first heat exchanger and introducing the heavy lower flow subjected to pressure reduction into a second separation flask in order to produce an upper gas fraction and a lower liquid fraction; pressure reducing the lower liquid fraction and introducing the lower liquid fraction in the middle portion of the first distillation column; cooling and at least partially condensing the upper gas fraction and introducing the upper gas fraction into the upper portion of the first distillation column; recovering a lower column flow at the bottom of the first distillation column, the flow rich in C2+ hydrocarbons being formed from the lower column flow; recovering and reheating of an upper column flow rich in methane; compressing at least a fraction of the upper column flow in at least a first compressor coupled to the first dynamic pressure reduction turbine and in at least a second compressor; removing an extraction flow from the reheated and compressed upper column flow; cooling and introducing the cooled extraction flow into an upper portion of the first distillation column; introducing at least a portion of the second fraction of the supply flow into a second dynamic pressure reduction turbine, separate from the first dynamic pressure reduction turbine; forming an effluent from the second dynamic pressure reduction turbine; cooling and at least partly liquefying at least a portion of the effluent from the second dynamic pressure reduction turbine in a second heat exchanger so as to form a cooled reflux flow; and introducing the cooled reflux flow from the second heat exchanger into the first distillation column, wherein the portion of the second fraction of the supply flow introduced into the second dynamic pressure reduction turbine is conveyed from the separation point of the supply flow to the second dynamic pressure reduction turbine without passing through any heat exchanger.