Process for efficiently operating a natural gas liquefaction system with integrated heavies removal/natural gas liquids recovery to produce liquefied natural gas (LNG) and/or natural gas liquids (NGL) products.

The invention relates to a system, method and apparatus for removing heavies from natural gas. Natural gas and an external rich reflux gas feed are processed in a single column refluxed absorber. A bottoms stream is routed to a first heat exchanger and then to a stabilizer column where an overhead stream from the stabilizer column is routed through a condenser for partial separation into an overhead stream. A rich solvent may be introduced to the stabilizer column. The overhead stream is routed through a condenser for partial separation into a stabilizer reflux and a second overhead stream lights. The second overhead stream lights is routed to a heat exchanger and then routed to a partial condenser where the stream is separated into a heavies rich reflux stream, a distillate stream and heavies treated natural gas stream. The rich reflux is routed through a heat exchanger and the rich reflux is pumped to the single column refluxed absorber to be introduced into the single column refluxed absorber as the external rich reflux gas feed.

Systems and methods are provided for increasing the efficiency of liquefied natural gas production and heavy hydrocarbon distillation. In one embodiment, air within an LNG production facility can be utilized as a heat source to provide heat to HHC liquid for distillation in a HHC distillation system. The mechanism of heat transfer from the air can be natural convection. In another embodiment, heat provided by natural gas, or compressed natural gas, can be used for HHC distillation. In other embodiments, various other liquids can be used to transfer heat to HHC liquid for distillation.

A process for the purification of a gas rich in hydrocarbons and comprising at least 10 ppm by volume of hydrocarbons having at least six carbon atoms nitrogen.

The present invention relates to a method of cooling and separating a hydrocarbon stream: (a) passing an hydrocarbon feed stream (7) through a first cooling and separation stage to provide a methane enriched vapour overhead stream (110) and a methane depleted liquid stream (10); (b) passing the methane depleted liquid stream (10) to a fractionation column (200) to obtain a bottom condensate stream (210), a top stream enriched in C1-C2 (220) and a midstream enriched in C3-C4 (230), (c) cooling the upper part of the fractionation column (201) by a condenser (206), (d) obtaining a split stream (112) from the methane enriched vapour overhead stream (110) and obtaining a cooled split stream (112) by expansion-cooling the split stream (112), (e) providing cooling duty to the top of the fractionation column (201) using the cooled split stream (112).

The invention relates to various nonlimiting embodiments that include methods, apparatuses or systems for processing natural gas comprising a heavies removal column processing natural gas and light oil reflux. The overhead stream goes to heavies treated natural gas storage. The heavies removal column reboiler bottoms stream product is input to a debutanizer column. The debutanizer column overhead lights are input to a flash drum where the bottoms is pumped through a heat exchanger as a light oil reflux input to the heavies removal column, while the debutanizer reboiler bottoms product is stored as stabilized condensate. Alternatively, debutanizer column overhead lights are sent to heavies treated gas storage and the bottoms stream product goes to a depentanizer column, the overhead lights are pumped through a heat exchanger as a light oil reflux input to the heavies removal column, while the depentanizer reboiler bottoms product is stabilized condensate.

A system and method for liquefaction of natural gas using two distinct refrigeration circuits having compositionally different working fluids and operating at different temperature levels is provided. The turbomachinery associated with the liquefaction system are driven by a single three-pinion or four-pinion integral gear machine with customized pairing arrangements. The system and method of natural gas liquefaction further includes the conditioning of a lower pressure natural gas containing feed stream to produce a purified, compressed natural gas stream at a pressure equal to or above the critical pressure of natural gas and substantially free of heavy hydrocarbons to be liquefied.

A method comprising the cooling of the feed natural-gas (15) in a first heat exchanger (16) and the introduction of the cooled feed natural-gas (40) in separator flask (18). The method further comprising dynamic expansion of a turbine input flow (46) in a first expansion turbine (22) and the introduction of the expanded flow (102) into a splitter column (26). This method includes sampling at the head of the splitter column (26) a methane-rich head stream (82) and sampling in the compressed methane-rich head stream (86) a first recirculation stream (88). The method comprises the formation of at least one second recirculation stream (96) obtained from the methane-rich head stream (82) downstream from the splitter column (26) and the formation of a dynamic expansion stream (100) from the second recirculation stream (96).

A method comprising the cooling of the feed natural-gas (15) in a first heat exchanger (16) and the introduction of the cooled feed natural-gas (40) in separator flask (18). The method further comprising dynamic expansion of a turbine input flow (46) in a first expansion turbine (22) and the introduction of the expanded flow (102) into a splitter column (26). This method includes sampling at the head of the splitter column (26) a methane-rich head stream (82) and sampling in the compressed methane-rich head stream (86) a first recirculation stream (88). The method comprises the formation of at least one second recirculation stream (96) obtained from the methane-rich head stream (82) downstream from the splitter column (26) and the formation of a dynamic expansion stream (100) from the second recirculation stream (96).

Method and system for removing high freeze point components from natural gas. Feed gas is cooled in a heat exchanger and separated into a first vapor portion and a first liquid portion. The first liquid portion is reheated using the heat exchanger and separated into a high freeze point components stream and a non-freezing components stream. A portion of the non-freezing components stream may be at least partially liquefied and received by an absorber tower. The first vapor portion may be cooled and received by the absorber tower. An overhead vapor product which is substantially free of high freeze point freeze components and a bottoms product liquid stream including freeze components and non-freeze components are produced using the absorber tower.