METHOD AND SYSTEM FOR LIQUEFACTION OF NATURAL GAS FEED FLOW Russian patent published in 2020 - IPC F25J1/00 

FIELD: technological processes.

SUBSTANCE: invention relates to liquefaction of natural gas stream. Provided is compressed process flow (25). First separated flow (32) is obtained from the compressed process flow and the first separated flow is expanded. Remaining portion of the compressed process flow (31) is cooled by an expanded first separated flow. Second separated flow (52) is obtained from pre-cooled process flow (41) and expanded. Remaining portion of the pre-cooled compressed process flow (51) is cooled by steam flow (56) obtained from the second separated flow. Additional cooled process flow (61) is expanded to produce flow (71) of liquefied natural gas. First separated flow (42) and steam flow (62) are passed into the repeated compression unit (200) to obtain recirculation flow (105), which must be combined with the natural gas feed flow to form a process flow.

EFFECT: reduced capital expenditures.

15 cl, 2 dwg