Method for liquefying hydrocarbon-rich fraction of natural gas stream, involves releasing gas fraction at pressure such that liquid fraction in entry region or immediately before inlet of heat exchanger, is mixed to released gas fraction

摘要

The method involves cooling and liquefying a hydrocarbon-rich fraction against a closed refrigerant mixture circuit. The refrigerant mixture is isolated into a liquid fraction (10) and a gas fraction (1) at the high circuit pressure. The gas fraction is released at pressure before combination with the liquid fraction such that the liquid fraction in the entry region or immediately before an inlet of a heat exchanger (E), is mixed to released gas fraction, where the heat exchanger is used for exchange of heat between a coolant mixture and a hydrocarbon-rich fraction.