GAS LIQUEFACTION METHOD WITH FRACTIONATING AT HIGH PRESSURE Russian patent published in 2013 - IPC F25J1/02 F25J3/02 

FIELD: machine building.

SUBSTANCE: method proposes to liquefy natural gas by implementing the following stages: natural gas is cooled; cooled natural gas is introduced to a fractionating column so that a gas phase saturated with methane and a liquid phase saturated with compounds that are heavier than ethane are separated; the above liquid phase is extracted from lower part of the fractionating column and the above gas phase is extracted from upper part of the separation column; the above gas phase is partially liquefied so that condensate and gaseous flow can be obtained; at that, condensate is returned to upper part of the column for fractionating as reflux; the above gaseous flow is liquefied due to heat exchange at the pressure of more than 50 bar. Working conditions of the fractionating column functioning at the pressure in the range of 40 to 60 bar are chosen so that the above liquid phase can contain molar content of methane at the interval of 10% to 150% of molar content of ethane contained in the above liquid phase.

EFFECT: use of the invention will allow improving liquefaction efficiency.

3 dwg, 1 tbl