Abstract: This disclosure describes a power system that includes a first compressor with an air inlet and a compressed air outlet; a nitrogen separator coupled to the compressed air outlet, the nitrogen separator comprising a nitrogen concentrate outlet and a byproduct outlet; a second compressor coupled to the nitrogen concentrate outlet, the second compressor having a high pressure outlet for supplying high pressure concentrated nitrogen to an underground storage; and a turbine generator with an inlet for high pressure concentrated nitrogen for coupling to an underground storage.

Abstract: A supply quantity adjustment device 500 comprises: a total demand quantity calculation unit 502 that calculates a total demand quantity used at a supply destination, based on plant information; an excess/deficit information setting unit 503 that compares the total demand quantity and a flow rate set value and sets a first calculated pressure value; a backup coefficient setting unit that sets a backup coefficient set value based on a reference gasholder pressure, the first calculated pressure value, a reference backup pressure set value, and a measured gasholder pressure value; and a production coefficient setting unit that compares a production pressure set value obtained by adding the reference gasholder pressure and a first pressure output value with the measured gasholder pressure value, and sets a production coefficient so as to modify a variation in the quantity of product gas produced by the air separation apparatus.

Abstract: This disclosure describes a power system that includes a first compressor with an air inlet and a compressed air outlet; a nitrogen separator coupled to the compressed air outlet, the nitrogen separator comprising a nitrogen concentrate outlet and a byproduct outlet; a second compressor coupled to the nitrogen concentrate outlet, the second compressor having a high pressure outlet for supplying high pressure concentrated nitrogen to an underground storage; and a turbine generator with an inlet for high pressure concentrated nitrogen for coupling to an underground storage.

Abstract: A process and apparatus for the recovery of heavier hydrocarbons from a liquefied natural gas (LNG) stream is disclosed. The LNG feed stream is heated to vaporize at least part of it, then supplied to a fractionation column at a mid-column feed position. A vapor distillation stream is withdrawn from the fractionation column below the mid-column feed position and directed in heat exchange relation with the LNG feed stream, cooling the vapor distillation stream as it supplies at least part of the heating of the LNG feed stream. The vapor distillation stream is cooled sufficiently to condense at least a part of it, forming a condensed stream. At least a portion of the condensed stream is directed to the fractionation column as its top feed. The quantities and temperatures of the feeds to the column are effective to maintain the column overhead temperature at a temperature whereby the major portion of the desired components is recovered in the bottom liquid product from the column.

Abstract: The refrigeration system for an ethylene plant comprises a closed loop tertiary refrigerant system containing methane, ethylene and propylene. The tertiary refrigerant from a compressor final discharge is separated into a methane-rich vapor fraction and two levels of propylene-rich liquids so as to provide various temperatures and levels of refrigeration in various heat exchange stages while maintaining a nearly constant refrigerant composition flowing back to the compressor and with the bulk of the total return refrigerant flow going to the first stage compressor section. This tertiary system can also be applied to an ethylene plant with a high pressure demethanizer.

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: The refrigeration system for an ethylene plant comprises a closed loop tertiary refrigerant system containing methane, ethylene and propylene. The tertiary refrigerant from a compressor final discharge is separated into a methane-rich vapor fraction and two levels of propylene-rich liquids so as to provide various temperatures and levels of refrigeration in various heat exchange stages while maintaining a nearly constant refrigerant composition flowing back to the compressor and with the bulk of the total return refrigerant flow going to the first stage compressor section. This tertiary system can also be applied to an ethylene plant with a high pressure demethanizer.

Abstract: The process and the apparatus serve for separating a gas mixture in a separation plant. A feed gas (18) is introduced into a compressor system (6, 16) and then into the separation plant. In the event of loss or partial loss of the compressor system (6, 16) of the first feed gas compressor (6), a first auxiliary stream (91, 92) which has approximately the composition of the first product stream or approximately the composition of the feed gas is compressed (78, 89) to at least approximately the first pressure and is recirculated to the separation plant.

Abstract: A process and apparatus for the production of low pressure gaseous oxygen (“GOX”) in which compressed and purified feed air (1) is cooled and at least partially condensed in heat exchange means (E1) having a warm end and a cold end and the cooled and at least partially condensed feed air (2) is then distilled in a cryogenic distillation column system (C1, C2). A liquid oxygen (“LOX”) product stream (8) is removed from the column system (C1, C2) and vaporized and warmed by heat exchange (E1) to produce GOX. LOX refrigerant (10) from an external source is used to provide a portion of the refrigeration duty required for the cooling and at least partial condensation of the feed air stream (1).

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 method of producing a gaseous product, for instance gaseous oxygen in accordance with a cyclical demand pattern having high and low periods of demand. During periods of high demand, liquid is vaporized against condensing air which is in turn stored. During low demand periods, product is accumulated and previously stored liquid air is introduced into the column. During both high and low periods of demand liquid product is drawn to reduce the percentage variance in the required flow rate to the booster compressor used in producing the air to be liquefied. Preferably, during periods of high demand, a turbine used in generating refrigeration can be turned down to increase the amount of air available for condensation and with a reduction in production of liquid product.

Abstract: A film-type vaporizer in a vaporization enclosure, for example the upper column of a double air-distillation column, is associated with a measurement and analysis box where a polished surface and a spillway reconstruct the flow of liquid in the vaporizer in order to check for the absence of the deposition of impurities in the liquid that is to be evaporated. If deposition occurs, the impurities involved are quantified and analyzed and appropriate action taken on the settings of the machine.

Abstract: The invention relates to a method for liquefying a stream rich in hydrocarbons, especially a stream of natural gas, by the indirect exchange of heat with the refrigerants in a closed-circuit cascade of mixed refrigerants. According to the invention, said closed-circuit cascade of mixed refrigerants consists of at least 3 circuits of mixed refrigerants, with each circuit comprising different refrigerants. The first of the three mixed refrigerant circuits is used for pre-cooling (E1), the second for liquefying E2), and the third for super-cooling (E3) the hydrocarbon-rich stream (1) to be liquefied. The method provided for in the invention reduces specific energy consumption and investment costs since the three circuits of mixed refrigerants are or can be optimally adjusted to the enthalpy temperature curves of the hydrocarbon-rich stream to be liquefied and the refrigerant mixtures.

Abstract: A high pressure nitrogen pipeline, oxygen or plant air is diverted around a pressure letdown station to liquefy the gas or a portion of the gas for storage or air separation assist, with the remaining unused gaseous portion being returned to the pipeline downstream the letdown station. One or more heat exchangers and one or more expanders are used to cool down the gas and liquefy it. A generator or compressor may be coupled to the expanders employing companders for generating power or for further compression of the pipeline gas. In a further embodiment, natural gas is cooled to assist in liquefying the nitrogen by drying the natural gas and forming two streams wherein carbon dioxide is removed from a smaller stream which is applied to cascaded heat exchangers and the larger stream is expanded to further cool it. The two streams are applied to the heat exchangers for cooling and liquefying nitrogen gas or other merchant gas applied to the heat exchangers from a pipeline or other source.

Abstract: In an air distillation apparatus having a main heat exchanger 7 for cooling down feed air, a rectification column 9S comprising a rectifying portion 13 for separating the thus-cooled feed air to an oxygen-enriched component and a nitrogen component and a condenser 35S for partially condensing the latter, and a liquid nitrogen storage tank 31S for supplying liquid nitrogen by way of a supply valve V3, anda transport route 18 for transporting an oxygen-enriched liquid flowing down from said rectifying portion 13 to the bottom into said condenser 35S, the said oxygen-enriched liquid is not reserved at the bottom of the column.

Abstract: A conventional air separator unit separates nitrogen, oxygen or argon merchant gas to be liquefied. Input pressurized natural gas is processed through a pressure letdown liquefaction system including gas separators for removing moisture and for drying the gas. The dried gas is then separated into large and small gas stream portions wherein CO.sub.2 in the smaller portion is removed. The two portions are passed through a first heat exchanger from which the larger portion is expanded which cools it and then passed through two heat exchangers including the first exchanger, used to regenerate the CO.sub.2 separator and drier and then returned to the input stream.

Abstract: A method and apparatus for separating out is used to produce an oxygen product in which an air stream after having been compressed and purified is introduced into a bottom reblower located in a bottom region of the distillation column to produce boil up in such distillation column. The resultant air stream liquefies to produce a liquid air stream. The liquid air stream after having been valve expanded is stripped within the distillation column to produce a column bottoms which can be extracted as a product stream that is vaporized within a main heat exchanger. Product stream can be pressurized by being pumped to atmospheric a pressure hence liquefying a further compressed air stream to produce further liquid air is also stripped within the distillation column. The distillation column operates at near atmospheric pressures that is pressures between 1 and 1.3 bar absolute. Refrigeration is introduced into the plant by injecting liquid preferably liquid oxygen into a bottom region of the distillation column.

Abstract: A method of separating air in a liquid nitrogen assist plant in which oxygen rich waste stream produced by the plant is used to partially pressurize adsorbent beds in a pre-purification unit operating in accordance with a pressure swing adsorption cycle.

Abstract: Feed air is fed to a rectifying system (14, 15) for low-temperature separation, from which a liquid fraction (31, 32) is taken off and introduced into a first reservoir tank (33). The pressure of a variable rate of the liquid fraction (34) is increased (35). The liquid fraction (36) is evaporated under the elevated pressure by indirect heat exchange (12) and obtained as a gaseous pressurized product (37). A heat-transport medium circulates in a refrigeration cycle which has a cycle compressor (41, 42). A first partial stream (45) of the heat-transport medium (44) compressed in the cycle compressor (41, 42) is fed to the indirect heat exchange (12) to evaporate the liquid fraction (36) and is liquefied, at least in part, in the course of this. A second partial stream (59) of the heat-transport medium (44) compressed in the cycle compressor (41, 42) is expanded (43) so as to perform work. Liquefied heat-transport medium (45, 48) is buffered in a second reservoir tank (49).

Abstract: A refrigerating mixture is compressed in the penultimate stage of a plurality of stages of a compression unit. The mixture is partially condensed in order to cool it substantially to ambient temperature; the condensed mixture is separated in order to obtain a vapour fraction and a liquid fraction; the vapour fraction is cooled and partially condensed; the resultant vapour fraction is sent to the final compression stage at least the high pressure vapour fraction and the liquid fraction are cooled, expanded, and circulated in at least first heat exchange means (5) with the fluid to be cooled.Moreover, according to the invention, during condensation of the vapour fraction, the vapour fraction produced by separating the condensed mixture is cooled by circulating it in heat-exchange relationship with a refrigerating fluid, in second heat exchange means.

Abstract: A process and installation for the separation of air in a cryogenic distillation apparatus (24) comprising a distillation column (30, 42) and in which the supplied air is separated to produce a fraction rich in oxygen and a fraction rich in nitrogen as products. The purities of these products are maintained substantially constant during variations of demand of either product or of the flow rate or of the pressure of the supplied air by introducing an excess of liquid rich in nitrogen into the distillation apparatus when the demand for the product or the flow rate of the supplied air increases, and by withdrawing an excess of liquid rich in nitrogen from the distillation apparatus, and storing this liquid, when the demand for the product or the flow rate of the supplied air decreases.

Abstract: Compressed, purified, vaporous air and liquid air streams are introduced into a higher pressure rectification column. A stream of oxygen-enriched liquid flows from an outlet of the higher pressure rectification column via a reboiler and an expansion valve into a vessel. The oxygen-enriched liquid is partially vaporised in a boiler located in the vessel. The residual liquid flows from the vessel and a condenser to a lower pressure rectification column in which oxygen and nitrogen products are separated. A stream of vapour flows from the boiler through an outlet from the vessel to a pipeline which leads the air back for compression with incoming air. A greater yield of oxygen, and, if separated, argon is made possible by this recycle.

Abstract: Ultra-high purity nitrogen is generated by removing, from feed air, carbon dioxide, moisture and catalyst poisons of an oxidation catalyst contained therein by a decarbonating drier (4). The feed air is then introduced into a low-pressure rectification column (6), where it is roughly rectified to further remove the carbon dioxide, moisture and catalyst poison. Then raw nitrogen gas obtained in the low-pressure rectification column (6) is introduced into an oxidation column (8) so that carbon monoxide in the raw nitrogen gas is converted to carbon dioxide and hydrogen also contained therein to water. Thereafter the raw nitrogen gas is introduced into an adsorption column (10) so that carbon dioxide and water are removed by adsorption to provide feed raw nitrogen gas, which is fed into an intermediate-pressure rectification column (11), where it is rectified.

Abstract: A method for producing ultra high purity liquid oxygen from standard grade liquid oxygen which integrates the oxygen purification process with a nitrogen purification process by utilizing the condensing duty of liquid nitrogen, thereby causing the nitrogen to vaporize which is desirable prior to delivery to a nitrogen purification unit. The method of the present invention includes pressurizing a source of liquid nitrogen and vaporizing at least a portion of the pressurized liquid nitrogen. The resulting high pressure gaseous nitrogen stream is introduced to at least one bottom reboiler/condenser of a high purity liquid oxygen unit, which also purifies standard grade liquid oxygen into ultra high purity liquid oxygen. The gaseous nitrogen provides the needed heat to the distillation columns of the high purity liquid oxygen unit.

Abstract: A system for processing nitrogen-containing effluent from an industrial process wherein the effluent is cooled and liquid nitrogen is added directly to the cooled effluent. The direct contact and heat exchange produces gaseous nitrogen and liquid organics which are both used to cool the effluent and are subsequently recovered.

Abstract: A high purity nitrogen gas generator is provided which can be rapidly returned to a stable state when boil-off gas is generated in a liquid nitrogen storage tank 10. The high purity nitrogen gas generator includes a liquid nitrogen storage tank 10, a rectification column 7, a liquid nitrogen introduction pipe P15 for supplying liquid nitrogen from the liquid nitrogen storage tank to the rectification column, an inverted U-type pipe P13 whose upper end is positioned at a height in the vicinity of the top portion of said liquid nitrogen storage tank connected to the bottom portion of said liquid nitrogen storage tank 10, said liquid nitrogen storage tank 10 and said liquid nitrogen introduction pipe P15 being connected with each other by way of said inverted U-type pipe, the upper end of the inverted U-type pipe and the top portion of said liquid nitrogen storage tank are connected with each other by means of a pipe P17 and a control valve V3 provided on the way of said pipe P17.

Abstract: A method for the control of the operation of an installation for the separation of air by cryogenic distillation comprising a double distillation column wherein the top of a medium pressure column and the base of a low pressure column are thermally interconnected by a vaporizer-condenser supplied with liquid oxygen from a bath of liquid oxygen in the base of the low pressure column. Liquid oxygen from the bath is continuously tested to detect the content of nitrous oxide in the bath, and upon the detection of a fall in the nitrous oxide content of the bath when the installation is operating under equilibrium conditions, the flow of liquid oxygen to the vaporizer-condenser is increased to raise the detected nitrous oxide content of the bath. But when the detected nitrous oxide level falls, then either a liquid oxygen purge line is opened farther, or else the operating time or pressure of switching adsorbers in the air supply is changed.

Abstract: An air separation process of the "pumped" type, in which liquid oxygen is removed from a double distillation column and is pumped to a higher production pressure and then vaporized under that pressure. The incoming air is divided into several streams. A first stream is compressed to the medium pressure, cooled and sent to the double distillation column (7). A second stream is compressed above about 25 bars, but below its condensation pressure during vaporization of the liquid oxygen under pressure, then cooled to an intermediate temperature, at which a portion of the air continues its cooling and is liquified (in 20A), then expanded (in 21A) and sent to the double column, while the rest is work expanded (in 4). Use in large size installations for the production of oxygen.

Abstract: A process and apparatus for the liquefaction of hydrogen, of the type using a refrigeration cycle whose cycle fluid comprises mostly hydrogen, and a closed liquid nitrogen refrigeration cycle. The cycle fluid is hydrogen and a mixture of C.sub.2 + hydrocarbons. The hydrocarbons are liquefied and expanded to form fluids which vaporize in a substantially continuous manner between a temperature of the order of -120.degree. C. and a temperature adjacent ambient temperature. More particularly, the mixture of hydrocarbons is saturated C.sub.2, C.sub.3, and C.sub.5 hydrocarbons, and if desired C.sub.4, and separated liquefied fractions of these hydrocarbons are expanded at respective temperatures before expansion of the order of 0.degree. C. to -10.degree. C., -40.degree. C. to -50.degree. C. and -110.degree. C. to -120.degree. C., to form refrigerant liquids adapted to be vaporized.

Abstract: In a process for the production of gaseous oxygen under pressure at a variable flow rate, of the type in which air is distilled in an air distillation installation comprising a distillation apparatus (7) and a heat exchange line (6) to cool the air by heat exchange with the products from the distillation apparatus; liquid oxygen is withdrawn from this apparatus, brought to a vaporization pressure, vaporized and reheated under this pressure in the heat exchange line, this vaporization and this reheating being accompanied by a liquefaction of air in the air liquefaction passages (21; 21,21A) of the heat exchange line.

Abstract: Process and installation for the production of gaseous oxygen and/or gaseous nitrogen under pressure, of the type in which the air is distilled in a double distillation column (10) comprising a low pressure column (12) operating under a low pressure, and a medium pressure column (11) operating under a medium pressure. All the air to be distilled is compressed (in 1,4) to at least one high pressure of air substantially greater than the medium pressure, and the compressed air is cooled to an intermediate temperature. A portion of it is expanded in a turbine (5) to the medium pressure, before introducing it into the medium pressure column (11). The non-work-expanded air is liquified, then introduced after expansion (in 19, 20), into the double column; and at least one liquid product withdrawn from the double column is brought to the production pressure, and this liquid product is vaporized by heat exchange with the air.