Abstract: A process for liquefying natural gas in conjunction with producing a liquid stream containing predominantly hydrocarbons heavier than methane is disclosed. In the process, the natural gas stream to be liquefied is partially cooled, expanded to an intermediate pressure, and supplied to a distillation column. The bottom product from this distillation column preferentially contains the majority of any hydrocarbons heavier than methane that would otherwise reduce the purity of the liquefied natural gas. The residual gas stream from the distillation column is compressed to a higher intermediate pressure, cooled under pressure to condense it, and then expanded to low pressure to form the liquefied natural gas stream.

Abstract: An inverter (22) is provided between a power source (20) and a suction/discharge valve driving motor (14) that controls cycle time of suction and discharge of a refrigerator unit (10). An output frequency of the inverter (22) is controlled in accordance with output of a sensor (24) that detects temperature of a thermal load portion (11) of the refrigerator unit (10). This enables temperature adjustment of individual refrigerators with a highly reliable method without using an electric heater.

Abstract: A design for equipment and process for reliquefaction of LNG boiloff gas, primarily for shipboard installation, has high thermodynamic efficiency and lower capital cost, smaller size (volume, footprint), lower weight, and less need for maintenance than systems utilizing the prior art. The main refrigerant gas compressor is reduced to a single stage turbocompressor. Optional elements include: compression of boiloff gas at ambient temperature; compression of boiloff gas in one or two stages; turboexpansion of refrigerant gas incorporating one or two turboexpanders; turboexpander energy recovery by mechanical loading, compressor drive, or electric generator; refrigerant sidestream for cooling at the lowest temperatures.

Abstract: A design for equipment and process for reliquefaction of LNG boiloff gas, primarily for shipboard installation, has high thermodynamic efficiency and lower capital cost, smaller size (volume, footprint), lower weight, and less need for maintenance than systems utilizing the prior art. The main refrigerant gas compressor is reduced to a single stage turbocompressor. Optional elements include: compression of boiloff gas at ambient temperature; compression of boiloff gas in one or two stages; turboexpansion of refrigerant gas incorporating one or two turboexpanders; turboexpander energy recovery by mechanical loading, compressor drive, or electric generator; refrigerant sidestream for cooling at the lowest temperatures.

Abstract: Cryogenic liquefying/refrigerating method and system, wherein temperature of gas-to-be-liquefied at the inlet of the compressor for compressing the gas is reduced by cooling the gas discharged from the compressor using a high-efficiency chemical refrigerating machine and vapor compression refrigerating machine before the gas is introduced to a multiple stage heat exchanger thereby reducing power input to the compressor and improving liquefying/refrigerating efficiency.

Abstract: A method for liquefying natural gas using the pressure energy of the natural gas is provided, wherein flash vapor from natural gas depressurization is employed in a refrigeration cycle for subcooling high pressure natural gas prior to flashing.

Abstract: A method and system for the small-scale production of LNG.

Abstract: An apparatus and method for controlling temperature in a boil-off gas in a liquefaction plant prior to compression, wherein boil-off gas originating from an LNG storage tank is compressed and at least partially condensed, and wherein the condensed boil-off gas (LNG) is being returned to the storage tank. A heat exchanger (20) is connected to the boil-off gas feed line upstream of the compressor (10), and a first conduit (22) fluidly connects the line for returning LNG to the storage tank and the heat exchanger (20). A second conduit (26) fluidly connects the heat exchanger (20) to the boil-off gas feed line at a point upstream of the heat exchanger (20). Boil-off gas is heat exchanged against the cooler (24) prior to being fed into the compressor (10). Thus, the boil-off gas temperature is lowered downstream of the heat exchange.

Abstract: A method of liquefying a hydrocarbon stream such as natural gas from a feed stream, the method at least comprising the steps of: (a) providing a feed stream (10); (b) dividing the feed stream (10) of step (a) to provide at least a first feed stream (20) comprising at least 90 mass % of the initial feed stream (10), and a second feed stream (30); (c) liquefying the first feed stream (20) of step (b) at a pressure between 20-100 bar to provide a first liquefied natural gas (LNG) stream (40); (d) cooling the second feed stream (30) of step (b) to provide a cooled feed stream (50); (e) combining the first LNG stream (40) of step (c) with the cooled feed stream (50) of step (d) to provide a combined LNG stream (60); (f) reducing the pressure of the combined LNG stream (60) of step (e); and (g) passing the combined LNG stream (60) of step (f) through a flash vessel (12) to provide a product LNG stream (70) and a gaseous stream (80).

Abstract: A hydrocarbon stream is liquefied in a method wherein a feed stream is provided, from which feed stream a first stream and a second stream are produced. The first stream is liquefied in a main liquefaction system to provide a first liquefied stream, while the second stream is cooled separately to provide a cooled second stream. The first liquefied stream is combined with the cooled second stream to produce a combined stream, which is separated in a gas/liquid separator into a liquefied hydrocarbon product stream and a gaseous stream. The gaseous stream is warmed to a temperature of above ?40° C. by heat exchanging against any other stream used in the method, wherein the warming of the gaseous stream employs at least heat exchanging against the second stream to provide at least part of the cooling of the second stream.

Abstract: A method is proposed for converting a portion of associated gas generated during crude oil production into a liquid form which permits the transport of a large amount of methane at moderate temperatures.

Abstract: A method for liquefying natural gas using the pressure energy of the natural gas, wherein flash vapor from natural gas depressurization is employed in a refrigeration cycle for subcooling high pressure natural gas prior to flashing.

Abstract: In a method of condensing an unprocessed well stream from an offshore gas or gas condensate field the well stream taken from one or more wellheads is cooled and directly expanded, isentropically, or near isentropically, to a state in which the pressure is close to that of a storage tank. Part of the well stream is condensed and condensed fractions thereof is drawn off the expander and fed to the storage tank along with condensation products from the exit of the expander. Hence, without any preprocessing, a condensed well stream product is produced which comprises a mixture of liquids and solids which is collected in the storage tank for transport therefrom to land. A system for carrying out the method is also disclosed. The invention makes the condensation of an unprocessed well stream possible without any preprocessing thereof, such as extraction of solid particles, e.g. sands, removal of water, cleaning or drying.

Abstract: The present invention relates to a method of liquefying a natural gas stream, wherein the natural gas stream (10) is provided at a pressure of 10-80 bar, supplied to a gas/liquid separator (31), and separated into a vaporous stream (40) and a liquid stream (30). The vaporous stream (40) is compressed to a pressure of at least 70, 84 bar heat exchanged against the vaporous stream (40), and liquefied to obtain a liquefied natural gas stream (100).

Abstract: The present invention relates to a method of liquefying a natural gas stream, wherein the natural gas stream (10) is provided at a pressure of 30-80 bar, expanded to a pressure <35 bar, supplied to a gas/liquid separator (31) and therein into a vaporous stream (40) and a liquid stream (30). The pressure of the vaporous stream is increased to a pressure of at least 70 bar and the pressurized vaporous stream (90) is liquefied to obtain a liquefied natural gas stream.

Abstract: A variable speed liquid LNG expander (X1) and a variable speed two-phase LNG expander (X2) in line, downstream from X1. The rotational speed of both expanders can be controlled and changed independent from each other. The speed of expander X1 and expander X2 is determined in such way that the amount of liquid LNG downstream from the PHS compared to the feed gas supply is maximized and the amount of vapor and boil-off downstream of X2 is minimized.

Abstract: A gas liquefaction process, especially for producing LNG, maintains product flow rate and temperature by controlling the refrigeration so that variation to reduce any difference between actual and required product temperatures is initiated before variation of the product flow rate to reduce any difference between actual and required flow rates.

Abstract: Methods and systems for transportation and processing of a cryogenic fluid. The system includes a floating liquefaction unit receiving a gas from a source, a shuttle vessel for carrying liquefied gas away from the liquefaction unit, a floating regasification unit for receiving the liquefied gas from the vessel, regasifying the liquefied gas and providing the gas to a distribution system.

Abstract: A method for producing liquefied natural gas wherein high pressure liquid natural gas is subcooled and then flashed to form flash vapor and liquefied natural gas product, and the flash vapor is employed in a refrigeration cycle to generate refrigeration for subcooling the liquid natural gas.

Abstract: A process for the preparation of liquid hydrocarbons from a light hydrocarbonaceous feedstock in combination with a process for liquefying natural gas, which liquefaction process involves the steps of (a) passing the natural gas at liquefaction pressure through the product side of a main heat exchanger; (b) introducing cooled liquefied refrigerant at refrigerant pressure in the cold side of the main heat exchanger, allowing the cooled refrigerant to evaporate at the refrigerant pressure in the cold side of the main heat exchanger to obtain vaporous refrigerant at refrigerant pressure, and removing vaporous refrigerant from the cold side of the main heat exchanger; (c) removing the liquefied gas at liquefaction pressure from the product side of the main heat exchanger; (d) allowing the cooled liquefied gas to expand to a lower pressure to obtain expanded fluid; (e) supplying the expanded fluid to a separator vessel; (f) withdrawing from the bottom of the separator vessel a liquid product stream; (g) withdrawi

Abstract: A semi-closed loop system for producing liquefied natural gas (LNG) that combines certain advantages of closed-loop systems with certain advantages of open-loop systems to provide a more efficient and effective hybrid system. In the semi-closed loop system, the final methane refrigeration cycle provides significant cooling of the natural gas stream via indirect heat transfer, as opposed to expansion-type cooling. A minor portion of the LNG product from the methane refrigeration cycle is used as make-up refrigerant in the methane refrigeration cycle. A pressurized portion of the refrigerant from the methane refrigeration cycle is employed as fuel gas. Excess refrigerant from the methane refrigeration cycle can be recombined with the processed natural gas stream, rather than flared.

Abstract: The present invention relates to a process and apparatus for producing crude helium, liquefied natural gas product, and synthesis gas from natural gas. A natural gas comprising helium and methane is cooled to produce cooled natural gas. At least a portion of the helium and methane from the cooled natural gas is separated into a vapor comprising helium, from which crude helium is derived, and a liquid comprising methane. At least a portion of the methane from this liquid is separated into a vapor, which is reacted to produce synthesis gas, and a liquid, from which liquefied natural gas is derived. Additional heat exchange and separation steps may be included.

Abstract: An LNG plant is configured to receive rich LNG and to produce LPG, lean LNG, and power using at least one fractionation column, wherein the fractionation portion of the plant can be optionally thermally coupled to a power cycle utilizing residual refrigeration from the processed lean LNG. Most preferably, a liquid portion of the rich LNG is pumped to pressure and heated, and the pressurized and superheated portion is expanded to produce electric energy before being fed into the column. The column overhead vapor is partially condensed, providing column reflux for high NGL recoveries, and the residual vapor is further condensed using refrigeration content of the rich LNG forming the lean LNG product, that is further pumped to pipeline pressure and subsequently vaporized using heated working fluid of the power cycle.

Abstract: A refrigerant tank (40) holds a hydrocarbon refrigerant (42) used by refrigeration equipment (14) to cool natural gas to about ?163° C. to produce LNG (liquefied natural gas) (45). The refrigerant is stored on a floating structure (10) in a way that avoids dangers that would arise if the refrigerant were stored on deck with the refrigeration equipment. A refrigerant container (40) is stored in one of the LNG tanks (20) that holds LNG at about ?163° C.

Abstract: Natural gas liquefaction system employing an open methane cycle wherein the liquefied natural gas is flashed immediately upstream of the liquefied natural gas storage tank and boil off vapors from the tank are returned to the open methane cycle.

Abstract: A single LNG facility, and operating method therefor, capable of efficiently producing LNG products that meet the varying specifications of different LNG markets.

Abstract: A process and apparatus is provided for reducing the heating value of imported LNG by removing natural gas liquid products while condensing boil-off gas. The LNG is pumped from a storage container and is then heated by cross exchange to a dew point temperature. A portion of this heated LNG is sent out to be vaporized while the remaining portion is further heated by cross exchange with demethanizer overhead vapors and is then sent as feed to the demethanizer. NGL is recovered at the bottom of the demethanizer, and the overhead vapors are mixed with boil off gas coming from the LNG storage container. These mixed vapors are condensed by cross exchanging with the LNG feed portion and then pumped to pipeline pressure and sent to the gas pipeline through the vaporizers.

Abstract: An operating system of a liquefied natural gas ship for performing sub-cooled liquefaction of boil-off gas includes a boil-off gas compressor, a cryogenic heat exchanger connected to a refrigerator system, and a first check valve and a first pressure control valve, installed in a pipe between a liquefied natural gas phase separator and a gas combustion unit, and a second check valve and a second pressure control valve, installed in a parallel pipe connected to the pipe in parallel. The parallel pipe is connected to a pipe between the boil-off gas compressor and the cryogenic heat exchanger such that boil-off gas is supplied to an upper vapor region of the liquefied natural gas phase separator. Thus, pressure and level of the liquefied natural gas phase separator are stably controlled. Power consumption is effectively reduced, and economical efficiency is achieved by stable operating pressure and level of the liquefied natural gas phase separator.

Abstract: A method of increasing the production rate and operational flexibility of an LNG facility by overfiring one or more modular gas turbines employed to drive one or more refrigerant compressors in the LNG facility.

Abstract: Liquefied natural gas (LNG) facility employing an intermediate pressure distillation column for recovery of ethane and heavier components from the processed natural gas stream in a way that increases operational stability and minimizes capital and operating costs.

Abstract: Cascade-type natural gas liquefaction methods and apparatus are provided, having enhanced thermodynamic efficiencies, through the use of added refrigeration levels in one or both of the ethylene and methane refrigeration systems thereof.

Abstract: An improved apparatus and method for providing reflux to a refluxed heavies removal column of a LNG facility. The apparatus comprises stacked vertical core-in-kettle heat exchangers and an economizer disposed between the heat exchangers. The reflux stream originates from the methane-rich refrigerant of the methane refrigeration cycle. The liquid reflux stream generated by cooling the methane-rich stream in the vertical heat exchangers via indirect heat exchange with an upstream refrigerant.

Abstract: An LNG carrier for transporting LNG from one location to another that includes a vaporizer on board said LNG carrier for vaporizing the LNG to a gaseous state, one or more heat exchangers at least partially submerged in seawater, an intermediate fluid circulating between said vaporizer and said heat exchanger; and one or more pumps for circulating said intermediate fluid is disclosed.

Abstract: This process includes the following steps: (a) the feed natural gas (101) is introduced into a first distillation column (31) which produces, as top product, a pretreated natural gas (111), which pretreated natural gas (111) no longer contains practically any C6+ hydrocarbons; (b) the pretreated natural gas (111) is introduced into an NGL recovery unit (19) comprising at least a second distillation column (49), so as to produce, on the one hand, as column top product, a purified natural gas (151) and, on the other hand, an NGL cut (15); and (c) the said liquefiable natural gas (161) is formed from the purified natural gas (151) resulting from step (b).

Abstract: A method for liquefying methane-rich gas in the form of a feed gas comprising the steps of cooling the gas and partially liquefying the gas by expansion within an expansion device. The pressure of the gas at the inlet of the expansion device is in the range from 40 bar to 100 bar and pressure of the gas at the outlet of the expansion device is in the range from 2 bar to 10 bar.

Abstract: A method for producing liquefied natural gas employing two separate adsorption steps for removing water and carbon dioxide from natural gas and employing a subambient expansion to produce regeneration gas for the regeneration of the dehydration adsorption step in addition to supplying refrigeration for the cooling or liquefaction of clean natural gas.

Abstract: A method for producing liquefied natural gas wherein high pressure liquid natural gas is subcooled and then flashed to form flash vapor and liquefied natural gas product, and the flash vapor is employed in a refrigeration cycle to generate refrigeration for subcooling the liquid natural gas.

Abstract: An apparatus for and process for recovering LNG from reservoir natural gas which includes circulating a portion of the natural gas thru a gas cooling loop that includes heat exchanges, an expansion zone and compression zone. The process also includes removing liquids from the gas cooling loop, distilling those liquids to recover a distilled gas. The process also includes compressing and expanding various portions of the distilled gas and passing those portions thru heat exchangers shared with the gas cooling loop to effect heating/cooling as desired. The process also includes removing a portion of the LNG cooling loop as LNG product.

Abstract: A process for liquefying natural gas in conjunction with producing a liquid stream containing predominantly hydrocarbons heavier than methane is disclosed. In the process, the natural gas stream to be liquefied is partially cooled and divided into first and second streams. The first stream is further cooled to condense substantially all of it, expanded to an intermediate pressure, and then supplied to a distillation column at a first mid-column feed position. The second stream is also expanded to intermediate pressure and is then supplied to the column at a second lower mid-column feed position. A distillation stream is withdrawn from the column below the feed point of the second stream and is cooled to condense at least a part of it, forming a reflux stream. At least a portion of the reflux stream is directed to the distillation column as its top feed.

Abstract: An integrated process for producing LNG and GTL products is provided, wherein a CO2-containing natural gas feed to an LNG production zone is first pre-treated to separate at least a portion of the CO2 therefrom, and the resulting CO2 stream obtained thereby is then directed to a GTL production zone and utilized to make GTL products that include methanol and/or methanol derivatives.

Abstract: A cryogenic gas is liquefied using a refrigeration system [101] thermally coupled at an evaporator [125] to a cold end of a gas supply system [103] within a dewar [116]. The refrigerator has a minimum temperature at an evaporator [125] above the boiling point of the gas at atmospheric pressure but below the boiling point of the gas at a high pressure. Thus, the gas is compressed [128] to high pressure so it condenses when cooled by the evaporator [125]. As it expands at a flow restrictor [148], a portion evaporates and cools a fraction to the temperature of the boiling point of the gas at atmospheric pressure, producing liquefied gas. Opening a purge valve [142] sends warm gas upward through heat exchange section [146] and out through a three-way valve [138] for defrosting. To reduce clogging, the gas supply valve [138] is controlled by a gas purity sensor [158].

Abstract: A method for generating refrigeration for cooling a product gas wherein a first or working gas undergoes a staged expansion to a first temperature and a subsequent turboexpansion to a second higher temperature and both the expanded gas and the turboexpanded gas provide cooling to the product gas.

Abstract: Improved methodology for starting up a LNG facility employing a refluxed heavies removal column. The improved methodology involves varying the temperature of the feed to the heavies removal column between start-up and normal operation. This allows a larger amount of the stream produced from the top of the heavies removal column during start-up to be used to more rapidly start up the LNG facility.

Abstract: Method for liquefying a gas which comprises cooling a feed gas stream successively through first and second temperature ranges to provide a liquefied product, wherein refrigeration for cooling the feed gas stream in the first temperature range is provided by a first vaporizing refrigerant and refrigeration for cooling the stream in the second temperature range is provided by a second vaporizing refrigerant, and further wherein an auxiliary refrigerant derived from the second vaporizing refrigerant provides additional refrigeration by vaporization at temperatures above a lowest temperature in the first temperature range.

Abstract: The natural gas flowing in through line 1 is cooled, then expanded in turbine T1. The liquid at the bottom of drum D2 is the liquefied natural gas. The gas at the top of drum D2 is compressed by compressor K1, then fed into the treating plant using a Fischer-Tropsch process to convert the natural gas to natural gas liquid.

Abstract: A gas pressurization system comprising a gas inlet valve configured to receive an inlet gas stream. A clean-up system is coupled to the gas inlet valve. A recovery heat exchanger coupled to the clean-up system. The recovery heat exchanger is configured to remove thermal energy from the inlet gas stream and cool the inlet gas stream to one of a pre-cooled gas and liquid stream. An expander coupled to the recovery heat exchanger is configured to expand the pre-cooled liquid stream. A refrigeration unit coupled to the expander and configured to cool the expanded pre-cooled liquid stream to a liquid phase. A buffer storage unit is coupled to the refrigeration unit. A pump is coupled to the buffer storage unit at a pump suction and has a pump discharge coupled to the recovery heat exchanger. A high-pressure storage unit coupled to the pump discharge downstream of the recovery heat exchanger.

Abstract: A process for liquefying natural gas in conjunction with producing a liquid stream containing predominantly hydrocarbons heavier than methane is disclosed. In the process, the natural gas stream to be liquefied is partially cooled, expanded to an intermediate pressure, and supplied to a distillation column. The bottom product from this distillation column preferentially contains the majority of any hydrocarbons heavier than methane that would otherwise reduce the purity of the liquefied natural gas. The residual gas stream from the distillation column is compressed to a higher intermediate pressure, cooled under pressure to condense it, and then expanded to low pressure to form the liquefied natural gas stream.

Abstract: A process and apparatus for controlling or reducing the heating value or BTU content of NGL recovered from LNG streams. LNG pipelines have a maximum allowable heating value that LNG must be within prior to entering the pipeline. If the LNG heating value is too high, the components contributing to the high heating value must be removed prior to being introduced in the pipeline. The process controls the heating value of the residue LNG gas stream by splitting a feed stream and warming at least a portion of the feed stream. Substantial differences in enthalpy content and temperature between the two portions of the feed stream exist prior to being sent to a fractionation tower.

Abstract: The method for loading pressurized compressed natural gas into a storage element on a floating vessel entails introducing compressed natural gas from a source into a storage element located on the floating vessel raising the storage element pressure from about 800 psi to about 1200 psi at an ambient temperature; allowing a portion of the compressed natural gas to cool forming a liquid in the storage element; removing remaining vapor phase compressed natural gas from the storage element to a refrigeration plant, wherein the refrigeration plant is adapted to cool the vapor; removing the liquid from the storage element to the refrigeration plant; wherein the refrigeration plant is adapted to cool the liquid; mixing the cooled vapor phase with the cooled liquid phase and returning the mixture to the storage element; repeating the steps until the vapor has been cooled and is substantially a liquid.

Abstract: An apparatus and method for producing liquefied natural gas. A liquefaction plant may be coupled to a source of unpurified natural gas, such as a natural gas pipeline at a pressure letdown station. A portion of the gas is drawn off and split into a process stream and a cooling stream. The cooling stream passes through a turbo expander creating work output. A compressor is driven by the work output and compresses the process stream. The compressed process stream is cooled, such as by the expanded cooling stream. The cooled, compressed process stream is divided into first and second portions with the first portion being expanded to liquefy the natural gas. A gas-liquid separator separates the vapor from the liquid natural gas. The second portion of the cooled, compressed process stream is also expanded and used to cool the compressed process stream. Additional features and techniques may be integrated with the liquefaction process including a water clean-up cycle and a carbon dioxide (CO2) clean-up cycle.