Abstract: Method for the rejection of nitrogen from condensed natural gas which comprises (a) introducing the condensed natural gas into a distillation column at a first location therein, withdrawing a nitrogen-enriched overhead vapor stream from the distillation column, and withdrawing a purified liquefied natural gas stream from the bottom of the column; (b) introducing a cold reflux stream into the distillation column at a second location above the first location, wherein the refrigeration to provide the cold reflux stream is obtained by compressing and work expanding a refrigerant stream comprising nitrogen; and (c) either (1) cooling the purified liquefied natural gas stream or cooling the condensed natural gas stream or (2) cooling both the purified liquefied natural gas stream and the condensed natural gas stream, wherein refrigeration for (1) or (2) is obtained by compressing and work expanding the refrigerant stream comprising nitrogen.

Abstract: Compressor system comprising (a) a first compressor having a first stage and a second stage wherein the first stage of the first compressor is adapted to compress a first gas and the second stage of the first compressor is adapted to compress a combination of a fourth gas and an intermediate compressed gas from the first stage of the first compressor; and (b) a second compressor having a first stage and a second stage wherein the first stage of the second compressor is adapted to compress a second gas and the second stage of the second compressor is adapted to compress a combination of a third gas and an intermediate compressed gas from the first stage of the second compressor. The first gas is at a first pressure, the second gas is at a second pressure higher than the first pressure, the third gas is at a third pressure higher than the second pressure, and the fourth gas is at a fourth pressure higher than the third pressure.

Abstract: Liquid is distributed substantially uniformly in a liquid-vapour separation column 22 located on an off-shore floating platform using a liquid distributor 24 characterised in that (i) the distance between the two apertures that are furthest apart in the or each secondary distributor is such that the liquid distributor provides, at each angle of tilt, a standard deviation of liquid flow rates through the apertures of the or each secondary distributor that is less than a first predetermined maximum for all angles of tilt; and (ii) the difference in flow rate between the aperture having maximum liquid flow and the aperture having minimum liquid flow in the or each secondary distributor at each angle of tilt is less than a second predetermined maximum for all angles of tilt.

Abstract: A back-up quantity of a “first” gas is supplied temporarily to maintain the level of production of the first gas from a cryogenic separation of a gaseous mixture comprising the first gas and at least one other gas in the event of reduction in the level of production of said first gas from the separation. In the event of reduction in the level of production of said first gas from the separation, liquefied first gas inventory is withdrawn from the or at least one of said cryogenic distillation systems and vaporised to produce said back-up quantity of first gas. The invention has particular application to the production of gaseous oxygen (“GOX”) from the separation of air.

Abstract: Krypton and/or xenon is separated crudely from a mixture comprising oxygen and at least one rare gas selected from the group consisting of krypton and xenon in a process comprising feeding said mixture or a mixture derived therefrom to a rare gas recovery system and separating said mixture feed in said rare gas recovery system into rare gas-lean gaseous oxygen (“GOX”) and rare gas-enriched product. The process is characterized in that at least about 50 mol % of said mixture is fed to the rare gas recovery system in the gaseous phase provided that, when said mixture feed is separated by selective adsorption, the concentration of xenon in the mixture feed is no greater than 50 times the concentration of xenon in air. One advantage of a preferred embodiment of the present invention is that it can easily be retrofitted to existing pumped LOX cycle ASUs.

Abstract: In a process for the recovery of krypton and xenon, an oxygen-enriched stream containing krypton and/or xenon and hydrocarbons is removed from an air separation unit. A substantial portion of the hydrocarbons, especially methane, ethane, and acetylene, is removed from the oxygen-enriched stream prior to the distillation process. The hydrocarbon removal process includes, but is not restricted to, the hydrocarbons reacting with a portion of the oxygen present in the feed gas. The krypton and xenon are eventually recovered from the oxygen stream through a distillation process. The distillation process is performed in such a manner that at least a stream further enriched in both krypton and xenon is produced.

Abstract: In a plate-fin exchanger having a plurality of fins disposed between neighboring parting sheets, at least a portion of at least one of the fins has a textured surface. The textured surface is in the form of grooves or fluting formed on or applied to the surface of the fin material used in the plate-fin exchanger.

Abstract: Krypton and/or xenon is separated crudely from a mixture comprising oxygen and at least one rare gas selected from the group consisting of krypton and xenon in a process comprising feeding said mixture or a mixture derived therefrom to a rare gas recovery system and separating said mixture feed in said rare gas recovery system into rare gas-lean gaseous oxygen (“GOX”) and rare gas-enriched product. The process is characterized in that at least about 50 mol % of said mixture is fed to the rare gas recovery system in the gaseous phase provided that, when said mixture feed is separated by selective adsorption, the concentration of xenon in the mixture feed is no greater than 50 times the concentration of xenon in air. One advantage of a preferred embodiment of the present invention is that it can easily be retrofitted to existing pumped LOX cycle ASUs.

Abstract: An apparatus for distributing a liquid in an exchange column includes a plate and at least one elongated internal baffle. The plate has at least one elongated channel, which has a first longitudinal axis, a bottom, and at least one aperture in the bottom. At least a substantial portion of the internal baffle, which has a second longitudinal axis substantially parallel to the first longitudinal axis, is disposed in the channel.

Abstract: In a process for the production of a polyolefin, an olefin monomer is polymerised said polyolefin and residual monomer is recovered. A gas stream comprising the monomer and nitrogen is subjected to a PSA process in which said monomer is adsorbed on a periodically regenerated silica gel or alumina adsorbent to recover a purified gas stream containing said olefin and a nitrogen rich stream containing no less than 99% nitrogen and containing no less than 50% of the nitrogen content of the gas feed to the PSA process.

Abstract: Krypton and/or xenon is separated crudely from a mixture comprising oxygen and at least one rare gas selected from the group consisting of krypton and xenon in a process comprising feeding said mixture or a mixture derived therefrom to a rare gas recovery system and separating said mixture feed in said rare gas recovery system into rare gas-lean gaseous oxygen (“GOX”) and rare gas-enriched product. The process is characterized in that at least about 50 mol % of said mixture is fed to the rare gas recovery system in the gaseous phase provided that, when said mixture feed is separated by selective adsorption, the concentration of xenon in the mixture feed is no greater than 50 times the concentration of xenon in air. One advantage of a preferred embodiment of the present invention is that it can easily be retrofitted to existing pumped LOX cycle ASUs.

Abstract: A process for the production of synthesis gas from a hydrocarbon fuel and steam and/or oxygen gas wherein at least part of any steam requirement is provided by heat exchange against exhaust gas from a gas turbine driving an air separation unit supplying at least part of any oxygen requirement for the synthesis gas production. The process is particularly applicable when the synthesis gas is used to prepare a synfuel by methanol synthesis or a Fischer-Tropsch process.

Abstract: Liquid oxygen (“LOX”) product and a krypton- and xenon-enriched liquid product is produced from the cryogenic separation of air using a cryogenic distillation system. The process comprises separating feed air in the main distillation system into nitrogen-rich overhead vapor and said krypton- and xenon-enriched liquid product. At least a portion of said krypton- and xenon-enriched liquid product is removed from the main distillation system for further distillation, to produce at least one krypton- and/or xenon-rich product. Xenon-lean liquid is fed to the first additional distillation column and separated into oxygen-rich overhead vapor and said LOX product having a concentration of xenon less than that in said feed air. The xenon-lean liquid is usually also lean in krypton.

Abstract: Xenon and/or krypton are recovered from oxygen containing gas, typically derived from liquid oxygen bottoms in a cryogenic air separation plant, by selective adsorption on a Li and Ag exchange zeolite containing 5 to 40% Ag exchange capacity on an equivalents basis, with periodic thermal regeneration of the adsorbent.

Abstract: Oxygen-containing gas comprising no more than about 50 mol % oxygen is fed (150) to an auxiliary separation column (40) in a multiple column cryogenic air distillation system comprising at least a higher pressure (“HP”) column (10) and a lower pressure (“LP”) column (30) for separation into nitrogen-rich overhead vapor and oxygen-rich liquid. Oxygen-rich liquid is fed (154) from the auxiliary column (40) to an intermediate location in the LP column (30). The auxiliary column (40) is refluxed with a liquid stream from or derived from the HP column (10). One advantage of the invention is that the diameter of the upper sections (II, III) of the LP column (30) need no longer be larger than the diameter of the rest of the column system thereby increasing the capacity of the column system (under the constraint of a defined maximum column section diameter).

Abstract: A process for producing a nitrogen-enriched vapor product from a supply of a nitrogen-rich liquid uses a purifying device and a distillation column having a distillation zone. The process includes the steps of: feeding at least a portion of the supply of the nitrogen-rich liquid to the distillation zone at a first location; feeding a stream of a gas containing nitrogen and at least one contaminant to the purifying device, wherein the gas is cooled by a cryogenic liquid whereby at least a portion of the at least one contaminant condenses, solidifies, or dissolves; eventually feeding at least a portion of the cool gas from the purifying device to the distillation zone at a second location below the first location; withdrawing a stream of the nitrogen-enriched vapor product from the distillation zone; and withdrawing a stream of an oxygen-enriched liquid from the distillation zone.

Abstract: A process for generating power from the expansion of steam in a steam turbine system. The steam is generated by at least partially vaporizing pre-heated water by heat exchange against a first fuel gas that is generated exothermically. The at least partially vaporized water is then heated to produce the steam by heat exchange against expanded combustion product gas that is generated by the combustion of a second fuel gas in the presence of compressed oxygen-containing gas and the subsequent expansion of the combustion product gas. The steam is then expanded in a steam turbine system having more than one pressure stage to produce power and an expanded steam stream.

Abstract: A method of installing a structured packing in an exchange column, the structured packing having a surface area density in the range of about 500 m2/m3 to about 675 m2/m3 includes a plurality of corrugated plates disposed in vertically parallel relation. Each plate has at least one aperture and a plurality of regularly spaced and substantially parallel corrugations disposed in crisscrossing relation to the corrugations of an adjacent plate. The apertures have an equivalent diameter of less than about 4 millimeters but greater than about 2 millimeters. The corrugations have a corrugation angle (&agr;) relative to horizontal in the range of about 40° to about 60°. Each corrugation, when approximated to be substantially a triangular cross-section, has an included angle (&bgr;) defined by two sides of the corrugation in the range of about 90° to about 100°.

Abstract: A method of operating a thermal swing adsorption process by determining a parameter relating to the water content of a feed gas, selecting process conditions for regeneration of the adsorbent in the thermal swing adsorption process based on the parameter and modifying the regeneration process conditions to accord with the selected process conditions for regeneration is disclosed. Apparatus for effecting this adsorption method and apparatus in which regeneration conditions are modified based on the actual ambient water content of the feed gas are also disclosed.

Abstract: Pressurized gas containers 36 are refilled from a source of high pressure gas using a valve assembly 1,3 that comprise a first 1 and second 3 gas flow control unit, the control units having a first valve 6 and a second valve 42 respectively, in which assembly further comprises actuators 22, 56 for cooperatively opening the valves when the control units are provided in compressed engagement, preferably using a lever action.