METHOD OF LIQUEFYING A HYDROCARBON-RICH FRACTION Russian patent published in 2020 - IPC F25J1/00 

FIELD: chemical or physical processes.

SUBSTANCE: described is a method of liquefying a hydrocarbon-saturated fraction (A), in which a hydrocarbon-rich fraction is cooled by at least one circuit of a mixed refrigerant (E1, E2, E3). Refrigerating agent circulating in the mixed refrigerant circuit is compressed on at least two stages (C1, C2). Compressed refrigerant is divided into higher boiling point and lower boiling fraction of refrigerant. Higher-boiling fraction of refrigerant serves for preliminary cooling (E1), and lower-boiling fraction of refrigerant serves for liquefaction (E2) of fraction saturated with hydrocarbons. Liquefied fraction saturated with hydrocarbons (B) is overcooled in separate heat exchanger by means of a mixture of refrigerants from separate circuit of the expander, and a mixture of refrigerants from said contour of the dilator, in addition to N₂ and CH₄ components, contains at least one component of group O₂, Ar, Kr, Xe, C₂H₄ and C₂H₆, wherein the fraction of components N₂ and CH₄ is at least 80 mol %.

EFFECT: technical result is reduction of capital costs.

13 cl, 3 dwg