Abstract: Natural gas liquefaction system employing an enhanced nitrogen removal system capable of removing nitrogen from a relatively warm natural gas stream.

Abstract: The inventive process and associated apparatus are ideally suited for the small-scale liquefaction of natural gas. The current invention provides a methodology and apparatus for the liquefaction of normally gaseous material, most notably natural gas, which reduces both the number of process vessels required and also the associated space requirements over convention apparatus while resulting in only a slight decrease in process efficiency.

Abstract: A process and associated apparatus for removing aromatics and/or higher molecular weight hydrocarbons from a methane-based gas stream comprising the steps of (a) condensing a minor portion of the methane-based gas stream thereby producing a two-phase stream, (b) feeding said two phase stream to the upper section of a column, (c) removing from the upper section of the column an aromatic- and/or heavies-depleted gas stream, (d) removing from the lower section of the column an aromatic- and/or heavies-rich liquid stream, (e) contacting via indirect heat exchange the aromatic- and/or heavies-rich liquid stream with a methane-rich stripping gas thereby producing a warmed liquid stream and a cooled stripping gas stream, (f) feeding said cooled stripping gas stream to the lower section of the column; and (g) contacting said two-phase stream and the cooled stripping gas stream in the column thereby producing the aromatic- and/or heavies-depleted gas stream and the aromatic- and/or heavies-rich liquid stream.

Abstract: This invention concerns a method and an apparatus for removing nitrogen and other low boiling point inorganic components from pressurized LNG-bearing streams and streams produced therefrom. The removal of such components is accomplished via a novel pressure reduction/stripping methodology thereby producing at least one low BTU nitrogen-rich gas stream and at least one high BTU methane-rich stream which is suitable for recycle to an open methane cycle liquefaction process and/or employment as a high quality fuel gas.

Abstract: A process and associated apparatus for removing aromatics and/or higher molecular weight hydrocarbons from a methane-based gas stream comprising the steps of (a) condensing a minor portion of the methane-based gas stream thereby producing a two-phase stream, (b) feeding said two phase stream to the upper section of a column, (c) removing from the upper section of the column an aromatic- and/or heavies-depleted gas stream, (d) removing from the lower section of the column an aromatic- and/or heavies-rich liquid stream, (e) contacting via indirect heat exchange the aromatic- and/or heavies-rich liquid stream with a methane-rich stripping gas thereby producing a warmed liquid stream and a cooled stripping gas stream, (f) feeding said cooled stripping gas stream to the lower section of the column; and (g) contacting said two-phase stream and the cooled stripping gas stream in the column thereby producing the aromatic- and/or heavies-depleted gas stream and the aromatic- and/or heavies-rich liquid stream.

Abstract: A process and apparatus for improving the efficiency of an open-cycle cascaded refrigeration process. Process efficiency is improved by the manner in which the compressed recycle stream is combined with the main process stream in the open refrigeration cycle.

Abstract: In multistage refrigeration compression, where liquid refrigerant withdraw from a core-in-shell type heat exchanger connected to a high compression stage is passed to a similar exchanger connected to a lower compression stage, liquid level stability in the higher compression stage exchanger is improved by providing an enlarged surge volume. A baffle plate transversing a lower portion of the shell divides the shell into a cooling zone that contains the cores, and a discharge zone that is part of the surge volume. The height of the baffle is selected to facilitate maintenance of at least a minimum functional liquid level in the shell. Liquid refrigerant withdraw from the discharge zone of the high-stage shell is supplied to the cooling zone of a shell connected to a lower compression stage. The liquid level in the shell is maintained by manipulating flow to liquid refrigerant that is flashed into the cooling zone of the higher compression stage shell.

Abstract: A process, apparatus and control methodology for transferring loads between drivers in adjacent refrigeration cycles in a cascaded refrigeration process has been developed thereby enabling more efficient driver operation. Load transfer is effected by cooling the higher boiling point refrigerant liquid prior to flashing via an indirect heat transfer with the lower boiling point refrigerant vapor in a adjacent cycle prior to compression of said stream.

Abstract: This invention concerns a novel process and apparatus for producing relatively small quantities of liquefied natural gas (LNG) by processing a side stream at a conventional NGL expander gas plant.

Abstract: A process for the liquefaction of natural gas having a pressure above atmospheric pressure, is disclosed in which a feed gas is cooled to sequentially lower temperatures, by passing the gas through a plurality of cooling stages, in heat exchange with at least three refrigerants, until the gas is substantially completely condensed in the last of the cooling stages. The pressure of the feed gas is reduced to near atmospheric pressure during the cooling of the feed gas by the use of hydraulic expanders which extract work during pressure reduction. Additionally, pressure reduction of the refrigerants within the refrigerant cycles is performed by similar hydraulic expanders. The work extracted by said hydraulic expanders is used to provide power to the liquefaction process, such as by helping to power compressors or pumps used in the liquefaction process.

Abstract: A process and apparatus for liquefying a natural gas, having a pressure above about 800 psig, in which the natural gas is introduced into an expander which operates to reduce the pressure of the natural gas and extract work from the expansion of the natural gas during the pressure reduction so that the resulting effluent from the expander can be cooled to sequentially lower temperatures by passing the gas through a plurality of cooling stages, in indirect heat exchange with at least one refrigerant, until the gas is substantially completely condensed in the last of the cooling stages.