Abstract: Process and apparatus for the separation of a compressed feed air stream to produce an oxygen product using a distillation column having a lower-pressure column and a higher-pressure column, a higher-pressure heat exchanger and a lower-pressure heat exchanger where the gaseous nitrogen expander receives a nitrogen-enriched fraction from a position intermediate the warmer end and the colder end of the higher-pressure heat exchanger.

Abstract: An apparatus for drying or conditioning bulk solids, includes a housing including an inlet for receiving the bulk solids, and an outlet for discharging the bulk solids, a plurality of spaced apart heat transfer plates assemblies disposed in the housing between the inlet and the outlet for passage of the bulk solids that flow from the inlet, through spaces between the heat transfer plates, and a sweep gas delivery system for the flow of sweep gas in a first direction across the direction of flow of the bulk solids. The sweep gas delivery system includes at least one valve for reversing the flow of the sweep gas from the first direction to a second direction, opposite to the first direction.

Abstract: A method and apparatus for producing compressed nitrogen and liquid nitrogen. A separation system has a high-pressure column, a low-pressure column with a top condenser and a main condenser. Air is compressed in an air compressor, purified, cooled in a heat exchanger and introduced into the high-pressure column. A first part of the gaseous top nitrogen from the low-pressure column becomes compressed nitrogen product. A second part of the gaseous top nitrogen is condensed in the condensing space of the top condenser and vapor is drawn off as a residual gas stream. The vapor is expanded in a first expansion machine. A second compressed nitrogen stream from the top of the high-pressure column is expanded in a second expansion machine and then drawn off as compressed nitrogen product. A part of the nitrogen condensed in the top condenser is drawn off as liquid nitrogen product.

Abstract: Method for the liquefaction of nitrogen using the recovery of cold energy deriving from the evaporation of liquefied natural gas comprising the steps of: sending a flow of nitrogen (100) to be liquefied to a precooler (101); sending a flow (107) of nitrogen gas exiting said precooler (101) to a heat exchanger (108) of the high pressure recirculation compressor; sending a flow (114) of nitrogen exiting said heat exchanger (108) to a high pressure recirculation compressor (115, 117); sending a flow (120) of nitrogen exiting said compressor (115, 117) to a liquefaction heat exchanger (121); sending to said liquefaction heat exchanger (121) a flow (123) of natural gas, countercurrent to the flow (120) exiting said compressor (115, 117); sending a flow (126, 150) of nitrogen exiting said liquefaction heat exchanger (121) to said heat exchanger (108) countercurrent to said flow (107) of nitrogen gas and to said flow (114) of nitrogen; sending a flow (151, 152) of nitrogen exiting said heat exchanger (108) to said p

Abstract: A method and apparatus for separating air in which an argon refining column of a distillation column system is reboiled with a liquid air stream. The argon refining column further refines crude argon produced by a crude argon column connected to a lower pressure column of the distillation column system. At least one intermediate reflux stream is formed, at least indirectly, from at least part of the liquid air stream, and is introduced into the lower pressure column at a level thereof above where a crude liquid oxygen column bottoms of a higher pressure column of such system is further refined to increase a liquid to vapor ratio below said level and therefore, argon recovery from the argon refining column.

Abstract: A simple and inexpensive gas separation device is provided.

Abstract: A method and apparatus for producing high pressure nitrogen is provided.

Abstract: An air stream is compressed in multiple stages using refrigeration derived from a refrigerant comprising natural gas for inter-stage cooling. The possibility of natural gas leaking into the air stream is reduced by use of an intermediate cooling medium (“ICM”) to transfer the refrigeration from the refrigerant to the inter-stage air stream. The compressed air stream can be fed to a cryogenic air separation unit that includes an LNG-based liquefier unit from which a cold natural gas stream is withdrawn for use as said refrigerant.

Abstract: There is provided a method of generating nitrogen which includes cryogenically separating compressed air introduced into a high-pressure column 11, storing liquid air 13 in a bottom portion of the high-pressure column 11 and taking nitrogen in gaseous form from an upper portion of the high-pressure column 11, introducing the liquid air 13 stored in the bottom portion of the high-pressure column 11 into a low-pressure column 12, cryogenically separating the liquid air 13 introduced into the low-pressure column 12 and storing oxygen-enriched liquid air 22 in a bottom portion of the low-pressure column 12 and taking nitrogen in gaseous form from an upper portion of the low-pressure column 12 as a product gas. Liquid air 13 taken through an extraction pipe 20 is introduced into a portion of a rectification part 12a of the low-pressure column 12 in which the number of theoretical plates from a column bottom side is set within the range of one to ten.

Abstract: The invention relates to a method and device for obtaining compressed oxygen and compressed nitrogen by the low-temperature separation of air in a distillation column system for nitrogen-oxygen separation, said distillation column system having at least one high-pressure column (8) and one low-pressure column (460), wherein the low-pressure column (460) is in a heat-exchanging connection with the high-pressure column (8) by means of a main condenser (461) designed as a condenser-evaporator. Feed air is compressed in an air compressor (2). The compressed feed air (6, 734, 802, 840) is cooled down in a main heat exchanger (20) and at least partially introduced into the high-pressure column (8). An oxygen-enriched liquid (462, 465) is removed from the high-pressure column (8) and fed to the low-pressure column (460) at a first intermediate position (464, 467, 906).

Abstract: A method of producing a liquid product stream, for example, a liquid nitrogen product stream, at a production rate that is selectively varied. This variation is produced in either a waste expansion or air expansion process by increasing the pressure and flow rate of the feed stream during periods in which a high rate of liquid production is desired without substantially increasing the pressure of the exhaust stream produced by a variable speed turboexpander. This increases the expansion ratio across the turboexpander and therefore the refrigeration supplied to increase liquid production. At the same time, the increase in flow rate prevents a decrease in the performance of the variable speed turboexpander.

Abstract: Method and apparatus of separating a nitrogen from a compressed and purified feed stream in a cryogenic rectification plant that employs a distillation column to produce a nitrogen-rich vapor as a column overhead and an oxygen-rich liquid column bottoms. Reflux is generated for the column by condensing part of the nitrogen-rich vapor within a down-flow heat exchanger. A stream of the oxygen-rich liquid column bottoms is introduced into an ejector which draws a stream of an oxygen-rich liquid phase produced from the outlet of a down-flow heat exchanger. The combined oxygen-rich liquid exiting the ejector is fed to the down-flow heat exchanger to condense the nitrogen-rich vapor. In such manner, part of the oxygen-rich liquid phase is recirculated to prevent dry-out of the down-flow heat exchanger outlet and to maintain effective condensation of the nitrogen-rich vapor.

Abstract: A hybrid system which utilizes high purity oxygen from a local pipeline, which is blended with low purity oxygen from an on-site or local cryogenic distillation system, thus resulting in a blend of intermediate quality which satisfies the needs of the customer. In order to offset the operating and energy costs associated with this fairly low profit margin intermediate purity oxygen, high purity nitrogen at high pressure is simultaneously exported to the local pipeline, thereby acting as a credit to the overall system.

Abstract: A process for carrying out cryogenic air separation wherein liquid oxygen is pressurized and vaporized against condensing feed air to produce oxygen gas product wherein excess plant refrigeration is generated such that the aggregate warm end temperature difference of the process exceeds the minimum internal temperature difference of the primary heat exchanger by at least 2K.

Abstract: A distillation apparatus and method in which first and second compressed streams are formed from a compressed feed stream, for example, compressed air. The first compressed stream is fully cooled within a main heat exchanger so that it is substantially condensed. The second compressed stream is partly cooled within the main heat exchanger and then introduced into a turboexpander at a temperature such that the turboexpander exhaust stream is superheated. Part of the first compressed stream is mixed with the exhaust stream to produce a combined stream that is no more than 10° C. above saturation temperature at the pressure of the exhaust stream. The combined stream is introduced into a distillation column unit to produce one or more products that are enriched in components of the feed to be separated. In such manner the turboexpansion can occur at a higher temperature and with increased refrigerating effect.

Abstract: A process and apparatus for producing nitrogen by which product nitrogen can be efficiently supplied.

Abstract: A cryogenic air separation process is set forth wherein, in order to provide the refrigeration necessary when at least a portion of the oxygen product is desired as liquid oxygen, LNG-derived refrigeration is used to liquefy a nitrogen stream in the process. A key to the present invention is that, instead of feeding the liquefied nitrogen to the distillation column, the liquefied nitrogen is heat exchanged against the air feed to the distillation column system.

Abstract: Nitrogen gas at a single pressure is produced from a two-column cryogenic distillation of air. The bottoms liquid product from the high pressure column is divided into two portions, one of which is vaporized and then turboexpanded before its entry into the low pressure column as a feed stream. By these means, no stream bypasses the double distillation process, further enhancing nitrogen recovery and achieving low specific energy consumption for nitrogen product.

Abstract: A process and apparatus for highly efficient production of industrial gases by the cryogenic distillation of air, wherein a feed stream of compressed air, is supercharged to high pressure, cooled, and mixed with various recycle streams of supercharged air, to regulate the expander turbine operating temperature. The need for pre-cooling equipment downstream of the supercharger, which is widely employed in industry to manage the temperature of the incoming compressed air stream, is eliminated.

Abstract: The invention concerns a method for generating energy, which consists in conveying to an air separation apparatus (5) air from a compressor (1) coupled to an expansion machine (3). A nitrogen-enriched gaseous flow (11) containing between 3 and 18% of oxygen is conveyed to a combustion chamber (19) with a combustible flow (17) and the combustion gases (33) are expanded in the expansion machine. Optionally air from an auxiliary compressor (21) can be conveyed to the combustion chamber.

Abstract: The invention concerns a method for generating energy, which consists in conveying to an air separation apparatus (5) air from a compressor (1) coupled to an expansion machine (3). A nitrogen-enriched gaseous flow (11) containing between 3 and 18% of oxygen is conveyed to a combustion chamber (19) with a combustible flow (17) and the combustion gases (33) are expanded in the expansion machine. Optionally air from an auxiliary compressor (21) can be conveyed to the combustion chamber.

Abstract: High-purity nitrogen is generated by low-temperature fractionation of air in a rectification system for nitrogen/oxygen separation having at least a first rectifier column (4). Cycle nitrogen (24) in gas form is removed from the upper region of the first rectifier column (4) and is compressed in a cycle compressor (30). A first part (35) of the compressed cycle nitrogen is liquefied. A nitrogen fraction (52) from the rectification system for nitrogen/oxygen separation is introduced (52) into a high-purity nitrogen column (39) having a top condenser (54). High-purity nitrogen (56) is removed from the upper region of the high-purity nitrogen column (39). The refrigeration demand of the top condenser (54) is at least partially covered by liquefied cycle nitrogen (38).

Abstract: Oxygen and nitrogen are produced by low-temperature separation of air in a rectification system that has a pressure column (4) and a low-pressure column (5). Charging air (1, 3) is introduced into pressure column (4). An oxygen-containing liquid fraction (8, 10) is removed from pressure column (4) and fed into low-pressure column (5). Gaseous nitrogen (17) from low-pressure column (5) is at least partially condensed in a top condenser (7) by indirect heat exchange with an evaporating cooling fluid (15). A nitrogen product stream (19) is removed from low-pressure column (5) and/or pressure column (4). An oxygen product stream (61, 62, 63) is pulled off from low-pressure column (5). The cooling fluid for top condenser (7) of low-pressure column (5) is formed by an intermediate liquid (15) that is drawn off from an intermediate point on low-pressure column (5).

Abstract: Oxygen and nitrogen are produced by low-temperature separation of air in a rectification system that has a pressure column (4) and a low-pressure column (5). Charging air (1, 3) is introduced into pressure column (4). An oxygen-containing liquid fraction (8, 10) is removed from pressure column (4) and fed into low-pressure column (5). Gaseous nitrogen (17) from low-pressure column (5) is at least partially condensed in a top condenser (7) by indirect heat exchange with an evaporating cooling fluid (15). A nitrogen product stream (19) is removed from low-pressure column (5) and/or pressure column (4). An oxygen product stream (61, 62, 63) is pulled off from low-pressure column (5). The cooling fluid for top condenser (7) of low-pressure column (5) is formed by an intermediate liquid (15) that is drawn off from an intermediate point on low-pressure column (5).

Abstract: Nitrogen is produced by separation of it from air. Nitrogen so separated is condensed. Most or all of the nitrogen is separated by rectification. At least some of the condensed nitrogen is employed as reflux in the rectification. The nitrogen is both separated and condensed at three or more different pressures.

Abstract: Air is separated in a double rectification column comprising a higher pressure column and a lower pressure column, the latter operating at pressures of less than 2 bar absolute. An oxygen product is withdrawn from the column by a pump. A first vaporous nitrogen stream is taken from the top of the higher pressure column, is compressed in a compressor and is used in a gas turbine. Feed to the lower pressure column is derived from a stream of the bottom oxygen-enriched liquid fraction obtained in the higher pressure column. To this end, this stream is subjected to further separation (typically in further rectification column) to form a vaporous nitrogen fraction (a flow of which is condensed and is used as reflux in the lower pressure column) and an oxygen-containing feed to the lower pressure column which flows via an outlet and a condenser to the column. At least 60% of the nitrogen product flowing to the gas turbine is taken from the higher pressure column.

Abstract: The process and the apparatus serve to produce pressurized nitrogen by low-temperature fractionation of air in a rectification system which has a pressure column (4) and a low-pressure column (5). Feed air (1, 3) is passed into the pressure column (4). An oxygen-containing liquid fraction (11) is taken off from the pressure column (4) and fed into the low-pressure column (5). Gaseous nitrogen (18) from the low-pressure column (5) is at least partially condensed in a top condenser (17) by indirect heat exchange with an evaporating liquid (13). Nitrogen from the low-pressure column is produced as gaseous pressurized nitrogen product (24, 25, 29) at a pressure which is higher than the operating pressure of the low-pressure column (5). Liquid nitrogen (20) withdrawn from the low-pressure column is brought (21) in the liquid state to a pressure which exceeds the pressure of the low-pressure column (5).

Abstract: A cryogenic air separation system wherein feed air is initially processed to produce a vapor and a liquid, the vapor is then processed in the rectifying section of a reflux condenser to produce moderate purity nitrogen, and the liquid is processed in the stripping section of the reflux condenser to produce moderate purity oxygen.

Abstract: The present invention relates to an elevated pressure air separation cryogenic process wherein feed air is compressed, treated to remove water and carbon dioxide, cooled to cryogenic temperature in a main heat exchanger having a cold end and a warm end and fed to a distillation column system having at least two (2) distillation columns for separation into at least a nitrogen-enriched product, an oxygen-enriched product and a gaseous waste stream characterized in that at least a portion of said waste stream is (isentropically) expanded to produce work and work produced by the expansion is used to provide at least a portion of the work required to compress a process stream other than the gaseous waste stream at a temperature warmer than the temperature of the cold end of said main heat exchanger. The alternative process streams to be compressed can be: at least a portion of the feed air, at least a portion of the oxygen-enriched product or at least a portion of the nitrogen-enriched product.

Abstract: Oxygen is produced by compressing air to provide a first and a second pressurized air stream, separating the first pressurized air stream into an oxygen-rich product stream and a nitrogen-rich byproduct stream, and combining the nitrogen-rich byproduct stream with the second pressurized air stream. The resulting combined stream is heated by indirect heat exchange with a hot process stream and is work expanded in a gas turbine expander. At least a portion of the expander shaft work is utilized for the air compression step. Fuel is combusted with the expander discharge stream to provide the hot process stream for heating the combined stream prior to expansion. The use of this integrated indirectly-fired gas turbine to provide pressurized feed air for the air separation system improves the availability and reliability of the integrated system compared with conventional directly-fired gas turbine systems.

Abstract: The present invention relates to a process for the cryogenic distillation of air in a distillation column system that contains at least one distillation column wherein the boil-up at the bottom of the distillation column producing the oxygen product is provided by condensing a stream whose nitrogen concentration is equal to or greater than that in the feed air stream. The process of the present invention comprises the steps of: (a) generating work energy which is at least ten percent (10%) of the overall refrigeration demand of the distillation column system; (b) work expanding a process stream to produce additional work energy such that the total work generated along with step (a) exceeds the total refrigeration demand of the cryogenic plant; and (c) using the work which is generated in excess of the refrigeration need of the distillation column system to cold compress a process stream at a temperature lower than the ambient temperature.

Abstract: In the method and device, nitrogen is obtained by two-stage rectification of air in a double column. Double column contains a high-pressure column and a medium-pressure column that are in a heat-exchange relationship with each other. Entering air is compressed, purified, cooled in a main heat exchanger against separation products, and fed to rectification. At least one nitrogen product fraction is taken from high-pressure column. A nitrogen gas fraction from double column is heated, expanded, and brought into indirect heat exchange with an oxygen-enriched liquid from the lower region of medium-pressure column. In this way, the nitrogen gas fraction is at least partially condensed and the oxygen-enriched liquid is at least partially evaporated. The condensate formed in the indirect heat exchange is at least partially fed to medium-pressure column.

Abstract: An improved efficiency system for producing low purity oxygen by rectification of air employs a high pressure column and a low pressure column and includes the steps of: turboexpanding a flow of nitrogen-rich gas from the high pressure column to provide a cooled nitrogen-rich gas flow; condensing the cooled nitrogen-rich gas flow to a nitrogen-rich liquid against a flow of a vaporizing oxygen-rich liquid flow taken from the low pressure column; passing the nitrogen-rich liquid as a reflux flow to the low pressure column; returning the vaporizing oxygen liquid to the low pressure column; and employing energy derived from the turboexpanding step to compress feed air.

Abstract: A process and apparatus are used for liquefying a low-boiling gas, 1, 507, particularly nitrogen. Gas to be liquified is cooled 12 under an increased pressure, is expanded 14 and is then obtained as a liquid product 16. In a refrigeration cycle, cycle medium is compressed to a first pressure 4, 6, 8, 10. A first partial flow 101 of the cycle medium is expanded while carrying out work in a first expansion machine 102. A second partial flow 201 of the cycle medium is cooled 12a and is expanded while carrying out work in a second expansion machine 202. In addition, a third partial flow 301 of the cycle medium is cooled and is expanded in a third expansion machine 302 while carrying out work. All three expansion machines 102, 202, 302 have essentially the same inlet pressure. The cooling of the gas to be liquified is carried out at least partially by the indirect heat exchange with expanded cycle medium 103, 203, 17 in a cycle heat exchanger 12.

Abstract: A method and apparatus of separating air in which the air is rectified wig a single column nitrogen generator which produces a nitrogen stream which is expanded into a refrigerant stream and then taken as a medium pressure product. Oxygen enriched air can be taken as low pressure and medium pressure enriched air products. A stream of oxygen enriched air can be used to regenerate the pre-purification unit and also taken as a wet product.

Abstract: A double column cryogenic rectification system for producing low purity oxygen and high purity nitrogen, preferably at elevated pressure, wherein nitrogen-rich vapor from the higher pressure column is turboexpanded and condensed against lower pressure column intermediate liquid prior to being passed into the lower pressure column.

Abstract: A cryogenic rectification system for producing low purity oxygen and high purity nitrogen, preferably at elevated pressure, wherein nitrogen-rich vapor from a higher pressure column is turboexpanded and condensed against lower pressure column intermediate liquid prior to being passed into the lower pressure column and low purity oxygen is produced in an auxiliary side column driven by fluid from the higher pressure column.

Abstract: In order to precool a flow of gas to be distilled, before a purification stage, it is sent into an exchanger (5) where it is cooled by heating a flow of refrigerant (13B). At least a part of this refrigerant has its pressure reduced before cooling the unpurified gas and may be a fraction of the gas to be distilled or a product of the distillation. It is preferably a cycle gas of the system. This arrangement makes it possible to obviate a refrigerating unit.