Abstract: A cryogenic air separation method and apparatus in which first and second liquid streams are produced. The first liquid stream has a higher oxygen content than air and can consist of a higher pressure distillation column bottoms and the second liquid stream, for instance, air, has a lower oxygen content than the first liquid stream and an argon content no less than the air. The second liquid stream is subcooled through indirect heat exchange with the first liquid stream and both of such streams are introduced into the lower pressure column. The second liquid stream is introduced into the lower pressure column above that point at which the crude liquid oxygen column bottoms or any portion thereof is introduced into the lower pressure column to increase a liquid to vapor ratio below the introduction of the second liquid stream and therefore, reduce the oxygen present within the column overhead.

Abstract: Separation method and apparatus for separating a gaseous mixture, for example, air, in a cryogenic rectification plant in which a compressed stream is divided into subsidiary streams that are extracted from a main heat exchanger of the plant at higher and lower temperatures. The two streams are then combined and expanded in a turboexpander to generate refrigeration for the plant. The flow rates of the two streams are adjusted to control inlet temperature of a turboexpander supplying plant refrigeration and to minimize potential deviation of the turboexpander exhaust from a saturated vapor state. Control of the expansion ratio can advantageously be applied to allow variable liquid production from the rectification plant.

Abstract: A method and apparatus for separating a mixture, for example air, within a cryogenic rectification plant that utilizes a banked heat exchanger arrangement. In such arrangement, a lower pressure heat exchanger is used to cool part of the mixture and a higher pressure heat exchanger is used to heat one or more pumped liquid streams composed of separated nitrogen-rich and oxygen-rich fractions and thereby produce pressurized product streams. A boosted pressure stream, that can be part of the air, is utilized to supply most of the heat exchange duty in the higher pressure heat exchanger. In addition, a heat exchange stream, that can also be part of the mixture, can be partially cooled in the higher pressure heat exchanger and then further cooled in the lower pressure heat exchanger to decrease the warm end temperature difference of the higher pressure heat exchanger and therefore, the required refrigeration for the plant.

Abstract: A method and apparatus for producing an oxygen product in which air is separated in an installation including air separation units having higher and lower pressure columns. A pumped liquid stream generated within the installation, that can be a pumped liquid oxygen stream, is warmed within a main heat exchanger through indirect heat exchange with a compressed air stream to produce a liquid air stream. An impure oxygen stream is rectified within an auxiliary column to produce an oxygen containing stream that is introduced into the lower pressure column of each of the air separation units and intermediate liquid streams, composed of the liquid air stream or another air-like stream, reflux the lower pressure columns and the auxiliary column and optionally the higher pressure column of each of the air separation units.

Abstract: A method and apparatus for producing an oxygen product in which air is separated in an installation including one or more air separation units having higher and lower pressure columns. An exhaust stream produced from a turboexpander and optionally an impure oxygen stream such as that derivable from higher pressure column bottoms is rectified within an auxiliary column to produce an oxygen containing stream that is introduced into the lower pressure column of each of the air separation units to increase the capacity of such columns. The pressure within the auxiliary column is set by the pressure of the exhaust stream such that a nitrogen-rich vapor stream extracted from the top of the auxiliary column can be used in regenerating adsorbent within a pre-purification unit utilized in connection with the installation.

Abstract: A method of producing a carbon dioxide product stream from a synthesis gas stream formed within a hydrogen plant having a synthesis gas reactor, a water-gas shift reactor, located downstream of the synthesis gas reactor to form the synthesis gas stream and a hydrogen pressure swing adsorption unit to produce a hydrogen product recovered from the synthesis gas stream. In accordance with the method the carbon dioxide from the synthesis gas stream by separating the carbon dioxide from the synthesis gas stream in a vacuum pressure swing adsorption system, thereby to produce a hydrogen-rich synthesis gas stream and a crude carbon dioxide stream and then purifying the crude carbon dioxide stream by a sub-ambient temperature distillation process thereby to produce the carbon dioxide product. A hydrogen synthesis gas feed stream to the hydrogen pressure swing adsorption unit is formed at least in part from the hydrogen rich stream.

Abstract: The present invention relates to a method and apparatus for producing a pressurized product stream product by cryogenic rectification. A main heat exchanger, used in the cryogenic rectification, warms a pumped product stream composed of oxygen-rich or nitrogen-rich liquid and thereby produces the pressurized product stream. Layers of the main heat exchanger are designed such that a reduction in the heat transfer area provided within the main heat exchanger for warming the pumped product stream occurs at a location at which the temperature of the pumped product stream exceeds either the critical or a dew point temperature of such stream. The reduction in heat transfer area leaves regions of the layers able to heat or cool another stream that is used in connection with the cryogenic rectification. Such other stream can be a refrigerant stream that allows the introduction of additional refrigeration to increase production of liquid products.

Abstract: A plate-fin heat exchanger having alternating layers for exchanging heat between fluids to be warmed against fluids to be cooled. One or both of the layers is subdivided into flow passages to allow for the flow of two or more fluids flowing through one of the layers to engage in indirect heat transfer with one or more fluids flowing through another adjacent layer. The flow through the heat exchanger is parallel to the width of the heat exchanger. The first and second layers provide a greater cross-sectional flow area for each of the fluids than otherwise would have been provided had the fluids flow been parallel to the length of the heat exchanger with layers thereof dedicated to the flow of each of the fluids.

Abstract: An Apparatus for purifying a feed stream containing carbon dioxide in which the feed stream, after having been compressed and dried, is partly cooled and then used to reboil a stripping column. Thereafter, the feed stream is further cooled and expanded to a lower operational temperature of the stripping column. A carbon dioxide product stream composed of the liquid column bottoms of the stripping column is expanded at one or more pressures to generate refrigeration, then fully vaporized within the main heat exchanger and compressed by a compressor to produce a compressed carbon dioxide product. Refrigeration is recovered in the main heat exchanger from a column overhead stream extracted from the stripping column within the main heat exchanger either directly or indirectly by auxiliary processing in which carbon dioxide is further separated and optionally recycled back to the main compressor used in compressing the feed stream.

Abstract: A method of supplying refrigeration to air separation plants within an air separation plant facility in which a refrigerant stream is produced at cryogenic temperature within a centralized refrigeration system. Streams of the refrigerant at the cryogenic temperature are introduced into the air separation plants such that all or a part of the refrigeration requirements of the air separation plants are supplied by the streams of the refrigerant.

Abstract: Air separation method in which air is separated within cryogenic rectification processes conducted in first and second cryogenic air separation plants. The first cryogenic air separation plant is designed to produce an oxygen-rich product stream and the second cryogenic air separation plant is designed to produce an impure oxygen vapor stream. At least part of the impure oxygen vapor stream is introduced into a lower pressure column of the first cryogenic air separation plant and oxygen contained in such stream along with air separated within the first air separation plant is used in producing the oxygen-rich product stream.

Abstract: Method of purifying a feed stream containing carbon dioxide wherein the feed stream after having been compressed and dried is partly cooled and then used to reboil a stripping column. Thereafter, the feed stream is further cooled and expanded to a lower operational temperature of the stripping column. A carbon dioxide product stream composed of the liquid column bottoms of the stripping column is expanded at one or more pressures to generate refrigeration, then fully vaporized within the main heat exchanger and compressed by a compressor to produce a compressed carbon dioxide product. Refrigeration is recovered in the main heat exchanger from a column overhead stream extracted from the stripping column within the main heat exchanger either directly or indirectly by auxiliary processing in which carbon dioxide is further separated and optionally recycled back to the main compressor used in compressing the feed stream.

Abstract: The present invention relates to cryogenic air separation processes and systems that employ a pressure swing adsorption (PSA) prepurification process. It is advantageous to operate the PSA process at a pressure comparable to or below the operating pressure of the highest pressure column in the cryogenic separation unit. Following PSA prepurification, the air can be split into at least two fractions, with at least a portion of the air being directed to the cryogenic separation unit and at least a portion of the remaining air being further pressurized in at least one stage of compression.

Abstract: A cryogenic plant having at least two direct phase separation devices such as distillation columns whose circular perimeters serve to define the perimeter of the cold box encompassing the direct phase separation devices and ancillary equipment for the process.

Abstract: Method and apparatus of separating an oxygen and nitrogen containing feed stream, for example, air, in higher and lower pressure columns. A crude liquid oxygen stream condenses nitrogen vapor in the higher pressure column for reflux purposes and results in the partial vaporization of the crude liquid oxygen stream to produce vapor and liquid fractions thereof. The liquid fraction condenses a lower pressure part of the feed stream and results in the liquid fraction being at least partially vaporized. Both the vapor fraction of the crude liquid oxygen stream and the liquid fraction after having been at least partially vaporized are introduced into the lower pressure column. Boil-up is produced within a bottom region of the lower pressure column by partially vaporizing an oxygen-rich liquid column bottoms against condensing a higher pressure part of the feed stream and then utilizing vapor or residual liquid as an oxygen product.

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: Argon, oxygen and nitrogen contained within an incoming air feed is fractionated within an air separation system having a multiple column arrangement that includes a higher pressure column and a lower pressure column to produce oxygen and nitrogen-rich fractions and an argon column to produce an argon-rich fraction for recovery of the argon as an argon product. A two-phase stream can be formed by either expanding at least part of a liquid air stream or by a liquid oxygen column bottoms formed within a higher pressure column of the multiple column arrangement. The liquid air stream is formed by liquefying part of the air feed to be fractionated against vaporizing a pumped liquid stream composed of nitrogen and/or oxygen. The diversion of the nitrogen vapor contained in the nitrogen-rich fraction increases the liquid to vapor ratio within the lower pressure column to increase the argon recovery.

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: 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 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.