Abstract: The invention is an absorption process for recovering C2+ components from a pressurized liquid mixture comprising C1 and C2+. The pressurized liquid mixture is at least partially vaporized by heating the liquid mixture in a heat transfer means. The heat transfer means provides refrigeration to an absorption medium that is used in treating the vaporized mixture in an absorption zone. The vaporized mixture is passed to an absorption zone that produces a first stream enriched in C1 and a second stream enriched in C2+ components. The pressurized liquid mixture is preferably pressurized liquid natural gas (PLNG) having an initial pressure above about 1,724 kPa (250 psia) and an initial temperature above −112° C. (−170° F.). Before being vaporized, the pressurized liquid mixture is preferably boosted in pressure to approximately the desired operating pressure of the absorption zone.
Type:
Grant
Filed:
June 20, 2002
Date of Patent:
May 20, 2003
Assignee:
ExxonMobil Upstream Research Company
Inventors:
Ronald R. Bowen, Moses Minta, E. Lawrence Kimble
Abstract: A process is disclosed for producing a displacement gas to be used in displacing a pressurized liquefied gas from one or more containers. A portion of the liquefied gas to be displaced is further pressurized and it is then separated into a first fraction and a second fraction. The first fraction is expanded by a suitable expansion means, and the expanded fraction is passed to a separation means to produce a liquid stream and a gas stream. The second fraction is heated to covert it to a vaporous product stream. A portion of the vaporous product stream is withdrawn, expanded, and passed to the separation means. A gas stream produced by the separation means is expanded, and it is then available for use as a displacement gas for displacing liquefied gas from one or more containers.
Abstract: A process is disclosed for liquefying natural gas to produce a pressurized liquid product having a temperature above −112° C. using two mixed refrigerants in two closed cycles, a low-level refrigerant to cool and liquefy the natural gas and a high-level refrigerant to cool the low-level refrigerant. After being used to liquefy the natural gas, the low-level refrigerant is (a) warmed by heat exchange in countercurrent relationship with another stream of the low-level refrigerant and by heat exchange against a first stream of the high-level refrigerant, (b) compressed to an elevated pressure, and (c) aftercooled against an external cooling fluid. The low-level refrigerant is then cooled by heat exchange against a second stream of the high-level mixed refrigerant and by exchange against the low-level refrigerant. The high-level refrigerant is warmed by the heat exchange with the low-level refrigerant, compressed to an elevated pressure, and aftercooled against an external cooling fluid.