NATURAL GAS LIQUEFACTION METHOD Russian patent published in 2012 - IPC F25J1/02 

FIELD: machine building.

SUBSTANCE: invention refers to gas liquefaction method with high methane content; it contains the stages at which gas flow is created; some portion of gas is extracted from the flow to be used as cooling agent; cooling agent is compressed; the obtained compressed cooling agent is cooled with cooling fluid medium having the ambient temperature; cooled compressed cooling agent is subject to additional cooling and expanded; cooling agent is supplied to heat exchange zone; gas flow is passed through the above heat exchange zone for cooling of at least some portion of gas by indirect heat exchange with expanded and additionally cooled cooling agent; thus forming the cooled fluid flow. As per the other versions, in order to improve the efficiency, in addition, auxiliary cooling can be performed after one or more other compression stages.

EFFECT: use of invention will allow reducing the consumed power of gas liquefaction plant.

12 cl, 3 dwg, 4 tbl