LIQUEFYING A HYDROCARBON-ENRICHED FRACTION Russian patent published in 2019 - IPC F25J1/00 

FIELD: gas processing.

SUBSTANCE: described is a method of liquefying and overcooling a hydrocarbon-rich fraction, particularly natural gas, in which, upon cooling, the fraction undergoes partial condensation to remove heavy hydrocarbons, particularly benzene. Partially condensed fraction (4) is separated into a liquid fraction containing heavy hydrocarbons and gas fraction (6) enriched with hydrocarbons. Gaseous fraction 6 is liquefied. Under normal conditions, liquefied hydrocarbon-rich fraction (7) is overcooled in separate heat exchanger (E3). In the cleaning mode, supply of liquefied hydrocarbon-rich fraction (7) to the heat exchanger (E3) is interrupted not later than the preset level of sedimentation of the solid residue in the heat exchanger. Solid residue is melted in heat exchanger (E3) by defrosting gas (10, 11) and extracted from heat exchanger (E3). Then, liquefied hydrocarbon-rich fraction (7) is returned to heat exchanger (E3).

EFFECT: technical result is providing reliable removal of heavy hydrocarbons.

6 cl, 2 dwg