FIELD: machine building.
SUBSTANCE: natural gas is partially combusted at cooling in E1 and separated in fractionating column 2 in methane-rich flow and that rich in hydrocarbons heavier than methane. Methane-rich flow is partially fludised in 3. Then separated condensates are cycled in cylinder 4 at column 2 via pipeline 7. Liquid fraction from cylinder 4 is liquefied in heat exchanger E2 to produce natural liquefied gas. Flow rich in hydrocarbons heavier than methane is separated in de-ethaniser into ethane-rich fraction and heavier hydrocarbons. In compliance with this invention, ethane-rich fraction is liquefied, at least, partially. Then, portion of liquefied ethane is recycled in cylinder 4 or to the line of low 7.
EFFECT: better propane extraction, increased critical pressure of liquefied gas.
11 cl, 4 tbl, 5 dwg
