Process for liquefaction of natural gas and liquid recovery May natural gas comprising two refrigerant cycles semi-open to the natural gas and the refrigerant cycle refrigerant farm gas

The invention relates to a method of liquefying a natural gas comprising a mixture of hydrocarbons having predominantly methane, the method comprising a first refrigerant semi-open cycle gas turbine wherein the optional natural gas liquids which have been condensed are separated from the natural gas feed stream, the latter then through a main cryogenic heat exchanger (4) to contribute by heat exchange to precool a primary natural gas stream (FP) and cooling a flow initial refrigerant gas (G-0), a second refrigerant semi-open cycle gas turbine to contribute to precool natural gas and the refrigerant gas as well as the liquefaction of natural gas, and a refrigerant closed cycle gas refrigerant to provide subcooling of the liquefied natural gas and to provide additional refrigeration power to both other rings. The invention also relates to a natural gas liquefaction plant for implementing such a method.