Raw natural gas liquefaction method for producing liquid natural gas, involves recycling portion of fraction enriched in ethane by introducing portion of fraction in disengager, and liquefying gas phase to produce liquid natural gas

摘要

The method involves introducing raw natural gas into a fractionating column (2) to obtain gas fraction enriched in methane and liquid fraction impoverished in methane. The gas fraction is introduced in a disengager (4) to separate a gas phase and a liquid phase. A portion of the liquid phase is recycled in the column. The liquid fraction is separated to obtain a fraction enriched in ethane. A portion of the fraction enriched in ethane is recycled by introducing a portion of the fraction enriched in ethane in the disengager. The gas phase is liquefied to produce a liquid natural gas.