Abstract: Methods and apparatus for the integration of a fractionation process and an olefin refrigeration system, wherein the fractionation process olefin effluent is supplied to the refrigeration system, can eliminate a fractionation process condenser and reflux drum typically present. A plurality of bottoms streams can be collected from the fractionation process. The olefin refrigerant can be supplied to alternate olefin refrigerant consumers, as desired. A column in the fractionation process can be refluxed with an olefin stream from refrigeration system, and olefin product can be collected or exported via line.

Abstract: A first contaminant selected from oxygen and carbon monoxide is removed from impure liquid carbon dioxide using a mass transfer separation column system which is reboiled by indirect heat exchange against crude carbon dioxide fluid, the impure liquid carbon dioxide having a greater concentration of carbon dioxide than the crude carbon dioxide fluid. The invention has particular application in the recovery of carbon dioxide from flue gas generated in an oxyfuel combustion process or waste gas from a hydrogen PSA process. Advantages include reducing the level of the first contaminant to not more than 1000 ppm.

Abstract: The present invention relates to an apparatus and method for recovering volatile liquids collected in volatile storage tanks (T). The apparatus comprises absorption and condensation chambers (3, 8, 9, 10, 11) with transverse evaporation elements (12) and metallic elements having a high surface area, through which the gas mixture flows, is condensed and recirculated both internally and externally. These features make it possible to reduce the size of and increase the heat exchange efficiency and yield of the apparatus (R).

Abstract: The invention relates to a process for separating chlorine from a gas stream I comprising oxygen and chlorine, in which the gas stream I is fed into a lower part of a column K1 and a separately provided liquid, hydrogen chloride stream II is fed into an upper part of the same column and the ascending gaseous stream I is brought into contact with the descending liquid stream II, with chlorine condensing out from the stream I and hydrogen chloride vaporizing from the stream II to give an essentially chlorine-free gas stream III comprising hydrogen chloride and oxygen and a liquid stream IV comprising chlorine.

Abstract: A system for removing acid gases from a raw gas stream includes an acid gas removal system (AGRS) and a sulfurous components removal system (SCRS). The acid gas removal system receives a sour gas stream and separates it into an overhead gas stream comprised primarily of methane, and a bottom acid gas stream comprised primarily of carbon dioxide. The sulfurous components removal system is placed either upstream or downstream of the acid gas removal system. The SCRS receives a gas stream and generally separates the gas stream into a first fluid stream comprising hydrogen sulfide, and a second fluid stream comprising carbon dioxide. Where the SCRS is upstream of the AGRS, the second fluid stream also includes primarily methane. Where the SCRS is downstream of the AGRS, the second fluid stream is principally carbon dioxide. Various types of sulfurous components removal systems may be utilized.

Abstract: In one embodiment, a method for cooling a reaction effluent gas includes feeding a sufficient amount of a suitable silicon source cooling gas into a stream of the reaction effluent gas, wherein the reaction effluent gas is produced by a thermal decomposition of at least one silicon source gas in a reactor, and wherein sufficient amount of the suitable silicon source cooling gas is defined based a concentration of the at least one chemical species in the reaction effluent gas; cooling the reaction effluent gas to a sufficient temperature so that: the cooled reaction effluent gas is capable of being handled by a material that is not suitable for handling the reaction effluent gas.

Abstract: One embodiment of the present invention is a gas discharge system utilizing a temperature-actuated valve. The temperature-actuated valve uses a temperature-measuring device to sense the temperature of the natural gas after it pass through an expansion valve and after leaving a heat exchanger inside the discharge station. This temperature-measuring device sends a signal to a valve that is automatically actuated. If the temperature of the gas is too low, the valve is tightened, increasing the residence time in the heat exchanger and increasing the gas temperature. If the gas temperature is too high, the valve is opened, reducing the residence time in the heat exchanger, decreasing gas temperature. Using this temperature-actuated valve to control the temperature of a wet gas discharge station is also disclosed.

Abstract: A process for separating a gas mixture in a separation unit of the type in which the gas mixture comes from a reaction unit and comprises, as main constituents, hydrogen (H2) and/or carbon monoxide (CO).

Abstract: A system for scrubbing acid gases from a gas stream, and particularly adapted for scrubbing CO2 from flue gas and recovering the CO2 at high pressure and good purity using an aqueous scrubbing medium such as aqueous ammonia scrubbing solution. A scrubber, regenerator, and stripper are provided, with each having two parts that are each multistage countercurrent vapor-liquid contactors. The required compression energy is minimized by providing necessary refrigeration from an ammonia absorption refrigeration plant that is powered by heat extracted from the gas being scrubbed. The amount of reboil required for the regenerator and stripper is minimized by providing internal heat exchangers (non-adiabatic distillation) in those components.

Abstract: The invention provides a method and a system for extracting a substance comprised in a gaseous mixture, the extraction being carried out in a cyclic manner in 2N chambers (AA, BB, CC, DD), each provided with a heat-exchanger (A, B, C, D), N being an integer greater than or equal to 3. Each chamber carries out a cycle comprising the following four steps in succession: a frosting step, a defrosting step, a step of recovering the liquid phase and the residual gas phase, and a temperature-reduction step of reducing the temperature of the heat-exchanger. Further, sequencing the passage from one step to another in each of the chambers is such that the number of chambers carrying out the frosting step and also the total number of chambers carrying out the defrosting, recovery, and temperature-reduction steps are both equal to N.

Abstract: A power plant for the generation of electrical energy with a system (1) for processing flue gases resulting from a combustion of fossil fuels comprises, according to the invention, an adiabatic compressor (5) for a first low-pressure compression of the flue gases and a second multi-stage, low-pressure flue gas compression system (14) and a multi-stage, high-pressure CO2 compression system (15), where both the low-pressure flue gas compression system and the high-pressure CO2 compression systems are combined in one single machine (C2) and are arranged on one common shaft (16) driven by one common driver (17). A heat exchanger (8) facilitates an improved recovery of heat resulting from the cooling of the adiabatically compressed flue gases. The invention allows an improvement of the overall power efficiency of a power plant integrated with this processing system as well as a reduction of investment cost.

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: The present invention provides a method and system for separating CO2 from a gas stream containing CO2. A gas stream having an initial pressure is compressed and subsequently cooled. The compressed and cooled gas stream has an increased pressure and reduced temperature at which the CO2 in the gas stream is at least partially converted to the liquid phase. The liquid phase is separated from the compressed and cooled gas stream, to provide a liquid phase stream and a gas phase stream, wherein the output pressure of the liquid phase stream is higher than the initial pressure of the gas stream.

Abstract: The present invention relates to a method for purifying a gas stream including CO2, elemental mercury (Hg0) and nitrogen oxides (NOx).

Abstract: In order to provide an improved multistage oil separator, in particular for the use with compressors in cryogenics, the oil separator includes a housing (10) having a gas inlet (18) and a gas outlet (20), and at least two filter elements (26, 28) arranged as a cascade in the housing between the gas inlet (18) and the gas outlet (20).

Abstract: A process for removing harmful substances from a gas steam which includes carbon dioxide and substances of value, such as at least one of the gases hydrogen H2 carbon monoxide CO, nitrogen N2 or noble gases, and harmful substances such as a substance from the group of mercury, sulphur, mercury compounds or sulphur compounds, wherein a carbon dioxide condensation is performed in order to obtain liquid carbon dioxide, adsorptive removal of the harmful substances from the condensed carbon dioxide is performed to remove the harmful substances from the carbon dioxide. A process temperature of less than ?30° C. but great than ?70° C. is maintained.

Abstract: This invention relates to thioetherification processes for the removal of mercaptans in charge gas streams. In particular, the invention relates to thioetherification processes for the removal of mercaptans using a catalyst comprising palladium and silver.

Abstract: A system and method for capturing and separating carbon dioxide from mixed gas streams. The gas stream is processed in a structure including a compression module comprising a plurality of compressors, intercoolers and inter-stage condensate separators. The flow path from the compression module includes a plurality of flow separators, gas stream splitters, heat exchangers and at least a first mixer and a first expander. The gas stream is sequentially compressed and cooled to form process condensate and separate it from the compressed gas stream. The gas stream is further dried and cooled to liquefy carbon dioxide and separate it from the non-condensable portion. Selective expansion of liquid carbon dioxide streams provides cooling for the system, and further energy efficiency is achieved by selective recycling of portions of gas streams, allowing for compact equipment and economical operation, while providing for high purity product streams of carbon dioxide.

Abstract: Disclosed herein are processes for removing water from organic solvents, such as ethanol. The processes include distillation in two columns operated at sequentially higher pressure, followed by treatment of the overhead vapor by one or two membrane separation steps.

Abstract: The invention relates to a method for producing carbon monoxide consisting, during an adsorption step, in using N adsorbers (4A, 4B), wherein N is equal to greater than two, each of which follows, at an offset; the same period T cycle during which adsorption and regeneration phases succeed each other, in exposing, at the beginning of the adsorption phase, each adsorber to an eluting phase during which only a part of a nominal flowrate of the mixture is transferred to the adsorber until said adsorber is substantially carbon monoxide saturated while at least the second adsorber is maintained in the adsorption phase and a purified gaseous mixture is partially liquefied for producing a liquefied gaseous mixture, in storing said mixture in a capacity (7) and in transferring the liquefied gaseous mixture from the capacity to at least one column (11) for the separation thereof into a carbon monoxide rich product and, during at least one part of the adsorber eluting phases, the liquid level in the container is decrea

Abstract: Purified SiHCl3 and/or SiCl4 are used as a sweep gas across a permeate side of a gas separation membrane receiving effluent gas from a polysilicon reactor. The combined sweep gas and permeate is recycled to the reactor.

Abstract: Methods and systems of purifying an acetylene process gas are described. The methods may include the steps of providing an acetylene vessel containing source acetylene mixed with a solvent impurity, and flowing the source acetylene through a purification container that holds a cooled purifying medium, where at least a portion of the solvent impurity in the source acetylene separates as a liquid impurity on the purifying medium. The method may also include removing the liquid from the purification container and flowing a purified acetylene gas from the purification container. The purified acetylene gas has a concentration of the solvent impurity of about 5 vol. % or less, and the separated liquid impurity is removed without interrupting the flow of the acetylene while the purified acetylene gas flows from the purification container to keep the concentration of the solvent impurity substantially constant in the purified acetylene gas.

Abstract: A process for separating a mixture of gases into a relatively condensable first component and a relatively non-condensable second component is provided. The first component comprises one or more gases selected from the group consisting of carbon dioxide, carbonyl sulphide and hydrogen sulphide and the second component one or more gases selected from the group consisting of hydrogen, methane, ethane, carbon monoxide, nitrogen, oxygen and synthesis gas.

Abstract: A system for isolating a greenhouse gas from an exhaust gas includes a vessel having an inlet to receive an exhaust gas, and an outlet to discharge a process stream, an adsorbent contained in the vessel to selectively adsorb the greenhouse gas from the exhaust gas under suitable conditions, and a heat source to heat the adsorbent and desorb the adsorbed greenhouse gas therefrom to produce a process stream of greenhouse gas for release through the outlet.

Abstract: A process is described for separating a gas stream containing hydrogen sulfide (H2S) impurities into a hydrogen (H2) rich vapour stream, a carbon dioxide (CO2) stream and an H2S rich vapour stream in an apparatus that comprises a compression and/or cooling system comprising at least one compressor and/or heat exchanger and a gas-liquid separator vessel, and an H2S recovery unit.

Abstract: The invention relates to a device for separating a gas mixture into product gas and offgas by way of gas permeating on, comprising at least two membrane units (1) and (2) and a condenser (3) connected upstream of the first membrane unit (1), which membrane units (1) and (2) have a gas inlet (1a, 2a), a retentate outlet (1b, 2b) and a permeate outlet (1c, 2c), wherein the retentate outlet (1b) of the first membrane unit (1) is connected to the gas inlet (2a) of the second membrane unit (2), the permeate outlet (2c) of the second membrane unit (2) is connected on the intake side to the condenser (3) or the gas supply leading into the condenser, and the condenser (3) is connected to the gas inlet (1a) of the first membrane unit (1), the connection in each case being by way of lines, product gas is obtained via the permeate outlet (2a) and offgas via the retentate outlet (1c), wherein the permeate outlet (4c) of an upstream membrane unit (1) is connected to the gas supply of the condenser (3) by way of lines, whe

Abstract: A heat exchanger with brazed plates including a stack of parallel plates defining a plurality of generally flat fluid circulating passages, closure bars which delimit the passages and distributing means for distributing a fluid to each passage of a first series of passages and means for conveying another fluid to a second series of passages where at least one passage contains organized exchanging structures which form a plurality of channels in the width of the passage and also at least three channels in the height of the passage is provided. The invention is useful for air separation by cryogenic distillation.

Abstract: A concentrated carbon dioxide stream is produced during a hydrogen pressure swing adsorption unit cycle by fractionating the carbon dioxide removed from the adsorbent in the adsorption beds during the regeneration of the adsorption beds. Thereby providing a cost efficient process for producing merchant carbon dioxide.

Abstract: A power plant includes a gas turbine unit adapted to feed whose flue gases into a boiler of a steam turbine unit, to be then diverted into a recirculated flow and discharged flow. The recirculated flow is mixed with fresh air forming a mixture that is fed into a gas turbine unit compressor. The discharged flow is fed into a CO2 capture unit that is an amine based or chilled ammonia based CO2 capture unit.

Abstract: Methods and apparatus for an oxy-fuel combustion power cycle are provided, including converting gaseous carbon dioxide to liquid and/or supercritical carbon dioxide which may include the use of a cryogenic pump, removing a portion of the liquid and/or supercritical carbon dioxide from the cycle, combusting oxygen and a combustion fuel with the remaining liquid and/or supercritical carbon dioxide in an oxy-fuel combustor to generate steam and additional liquid and/or supercritical carbon dioxide which replaces the portion of the liquid and/or supercritical carbon dioxide sequestered from the cycle.

Abstract: A distillation system for separating components fluid feed includes a stripper and a rectifier. The stripper includes an inlet to receive a feed of fluid a compressor in fluid communication with a more volatile portion of the fluid within the stripper to provide an output feed, and a reboiler in fluid communication with a less volatile portion of fluid within the stripper. The rectifier receives the output feed and includes a condenser in fluid communication with a more volatile portion of the output feed from the compressor, the condenser including an exit to remove at least one component from the more volatile portion of the output feed, and an outlet to recycle a less volatile portion of the output feed back to the stripper. Heat pipes transfer thermal energy from the rectifier to the stripper.

Abstract: The invention relates to a method and to a device for separating argon from a gas mixture. The method comprises the method steps of collecting the gas mixture, separating the oxygen present in the gas mixture, drying the gas mixture, and cryogenically purifying the remaining gas mixture for separating the argon in liquid form. The device for performing the method according to the invention comprises a collector for the gas mixture, a component for catalytic and/or adsorptive separation of oxygen from the gas mixture, a component for drying the gas mixture, and a system for cryogenically purifying the gas mixture and separating the argon in liquid form.

Abstract: A slug-containing vapor recovery system wherein pressure and/or fluid level sensors are provided which monitor for conditions caused by the entry of a slug of hydrocarbon liquid, including that caused by a plunger-lift system. The system can be configured to accommodate virtually any anticipated slug-events.

Abstract: The invention relates to a gas scrubbing process, as well as a method for the operation thereof, in which during normal operation in an absorber column, gas components are separated from a gas mixture (feed gas) by scrubbing with a scrubbing liquid. The scrubbing liquid, loaded with separate gas components during the scrubbing process, is regenerated in a regeneration system that comprises at least one regeneration device equipped with a liquid level control. The regenerated scrubbing liquid is then recycled into the absorber column. When the feed gas is lost/reduced, the nominal value of the liquid level control is raised, and the resultant additional storage volume provided in the regeneration device is used for storing scrubbing liquid.

Abstract: The invention relates to a method for producing an argon-enriched fluid and an oxygen-enriched fluid from a fluid resulting from a method for purifying of oxy-fuel combustion fumes, wherein said method comprises purifying the residual gas by a purification method in order to produce a gas enriched with carbon dioxide and a residual gas lean in carbon dioxide, pre-treating the residual gas lean in carbon dioxide in order to obtain a flow enriched with carbon dioxide and a flow lean in carbon dioxide, treating the flow lean in carbon dioxide by a cryogenic technique so as to extract at least an argon-enriched fraction, an oxygen-enriched fraction, and a fraction lean in argon and/or oxygen.

Abstract: A process for dehydrating a hydrofluorocarbon or hydrochlorofluorocarbon, which can be done by simple equipment, and a continuous process of producing 1,3,3,3-tetrafluoropropene using the dehydration process. The dehydration process includes cooling the hydrofluorocarbon or hydrochlorofluorocarbon in gaseous form containing water with a heat exchanger, thereby condensing and liquefying the hydrofluorocarbon or hydrochlorofluorocarbon while freezing and solidifying the water.

Abstract: The invention relates to a valve including a circuit for a fluid conveyed into a valve body, a stopper that is movable between a rest position and an operative position from among an open position and a closed position of said circuit, and a resilient annular bellows system connecting said stopper and said body and sealingly closing said circuit in relation to a chamber, wherein the chamber is open towards the outside of the valve via a vent formed in the body, the vent being provided with means for preventing the ingress of wet gas into the body.

Abstract: A water recovery process for a steam assisted gravity drainage system for a heavy oil recovery facility, the process comprising a flash drum and a flash drum heat exchanger/condenser, wherein the water recovery process receives hot water produced by a facility at a temperature above the water atmospheric boiling point and cools it to a temperature below the water atmospheric boiling point before transferring it to the remaining section of the water recovery process.

Abstract: A gas separation or gas transportation process forms a gas hydrate from an aqueous feed and a gas feed having a hydrate P-T stability envelope. While in the presence of the aqueous feed, the gas feed is initially pressurized to an operating pressure and cooled to an operating temperature which are inside the hydrate P-T stability envelope to form a gas hydrate from at least a portion of the gas feed and at least a portion of the aqueous feed. The resulting gas hydrate is readily separable from any remaining gas and stable for transport.

Abstract: An off gas extraction system cleans common sources of off gas, such as storage tanks and polluted soils. Off gas is extracted, followed by compression and condensation. Compression and condensation produce an off gas that can be reintroduced as a treated gas into the off gas source. Alternatively, a regenerative absorber cleans the treated gas by adsorbing residual chemical vapor and concentrates the removed chemical vapors and reprocesses them. If the treated gas is not reintroduced into the off gas source, conventional scrubbers may used on the back end of the system to produce a final exhaust as prescribed by environmental regulation. Methods of accomplishing the same are similarly provided, including novel methods for degassing storage tanks and treating polluted soils to meet current environmental regulations, as well as green technology and sustainability initiatives.

Abstract: An apparatus and process for removing gaseous contaminants from a feed gas comprising methane and gaseous contaminants, in which the feed gas is cooled to obtain a slurry comprising solid contaminant, liquid contaminant and a methane enriched gaseous phase. The slurry is introduced into a separation device from which the methane enriched gaseous phase is removed. The slurry is diluted with liquid contaminant and passed through a heat exchanger wherein solid contaminant is melted into liquid contaminant. A stream comprising liquid contaminant is removed from the separation device at a position below the slurry level in the separation device by means of a pump and at least part of the removed liquid contaminant is recovered as a stream product and at least part is recycled and introduced into the separation device to dilute the slurry inside the separation device.

Abstract: A system for removing acid gases from a raw gas stream the system includes a cryogenic distillation tower. The tower receives and separates the raw gas stream into an overhead methane stream and a bottom liquefied acid gas stream. Refrigeration equipment downstream of the cryogenic distillation tower cools the overhead methane stream and returns a portion of the overhead methane stream to the cryogenic distillation tower as liquid reflux. The system also may include a first molecular sieve bed upstream of the distillation tower and a second molecular sieve bed downstream of the distillation tower. The first molecular sieve bed adsorbs water while the second molecular sieve bed adsorbs additional acid gases from the cooled overhead methane stream.

Abstract: The present disclosure relates to the separation of CO2 from a gas mixture. The CO2 may be removed by cooling the gas mixture such that the CO2 can be removed as a solid or liquid. In various embodiments the gas mixture from which the CO2 is removed may include exhaust gases generated as part of a combustion process, such as may be employed in a power generation process, though the gas mixture may be any gas mixture that includes CO2.

Abstract: The present disclosure relates to the separation of CO2 from a gas mixture. The CO2 may be removed by cooling the gas mixture such that the CO2 can be removed as a solid or liquid. In various embodiments the gas mixture from which the CO2 is removed may include exhaust gases generated as part of a combustion process, such as may be employed in a power generation process, though the gas mixture may be any gas mixture that includes CO2.

Abstract: A heat exchanger for a fuel cell includes first and second heat exchanger portions that provide a fluid flow passage. The second heat exchanger portion is arranged downstream from the first heat exchanger portion. The first and second heat exchanger portions include a coolant flow passage, which is provided by tubes in one example. The first and second heat exchanger portions are configured to transfer heat between the fluid flow and coolant flow passages. The first heat exchanger portion is configured to provide a first heat transfer rate capacity. The second heat exchanger portion includes a second heat transfer rate capacity that is greater than the first heat transfer rate capacity. In one example, the first heat exchanger portion includes tubes and does not include any fins, and the second heat exchanger includes spaced apart fins supporting the tubes.

Abstract: An energy-efficient method of recovering carbon dioxide (CO2) in a high-pressure liquid state from a high-pressure gas stream. The method includes cooling, condensing, and/or separating CO2 from a high-pressure gas stream in two or more separation zones and further purifying the resulting sub-critical pressure liquid CO2 streams in a third purification zone to thereby provide purified CO2. The purified liquid CO2 may be pumped to above the critical pressure for further utilization and/or sequestration for industrial or environmental purposes.

Abstract: A process and apparatus for separating at least part of a gaseous product from a feed stream which comprises contaminants. The process comprises: 1) providing the feed stream; 2) cooling the feed stream to a temperature at which a slurry stream is formed which comprises solid contaminant, liquid phase contaminant and the gaseous product; 3) introducing the slurry stream as obtained in step 2) via a plurality of tangentially directed inlet means into an upper part of a separation device, thereby creating a swirl of the slurry stream which allows at least part of the gaseous product to flow upwardly and solid contaminant and liquid phase contaminant to flow downwardly; 4) removing at least part of the gaseous product from the upper part of the device; and 5) removing a stream comprising liquid phase contaminant from a lower part of the device.

Abstract: A process is described for removing carbon dioxide from a synthesis gas feed stream in a cryogenic separation plant. In an example described the synthesis gas feed stream (3) comprises 40 to 65 mole % hydrogen and is fed to a single stage or a first stage of a series of separation stages (120, 103, 104) at a pressure in the range of 46 to 90 bar absolute. The single stage or a stage of the series is operated at a temperature in the range of ?53 to ?48° C. and a pressure in the range of 44 to 90 bar absolute. In some examples, the single stage or the combined stages of the series remove 70 to 80% of the total moles of carbon dioxide in the synthesis gas feed stream. Liquefied C02 product stream(s) discharged from the stage (s) (7,10,13) of the cryogenic separation plant may be sequestrated and/or used in a chemical process (71).

Abstract: The invention relates to cryogenic engineering, in particular to purifying krypton-xenon mixture and is usable in the chemical and oil-and-gas industries. The inventive method comprises purifying and separating the mixture in rectification columns, wherein coolant is removed and returned to a cooling cycle, additionally removing radionuclides from krypton and xenon fractions and from krypton and xenon production flows by means of filtration and/or adsorption and/or rectification and/or absorption and/or chemical and/or physicochemical methods in apparatuses for additional removing radionuclides. Balloons for reception of the separated products are certified with respect to radionuclides content and/or activity prior to and after the filling thereof.

Abstract: The present invention is a process for recovering rare gases from a multiple column oxygen plant, wherein the multiple column oxygen plant comprises a higher pressure column, a lower pressure column, a middle pressure intermediate column, and a low pressure intermediate column, said middle pressure intermediate column comprising a first bottom reboiler and said low pressure intermediate column comprising a second bottom reboiler. The process includes providing a first oxygen rich liquid stream containing rare gases from the higher pressure column, wherein said first oxygen rich liquid stream is introduced to the first bottom reboiler. The process also includes removing a second oxygen rich liquid stream rich in rare gases from the bottom of the middle pressure intermediate column, wherein said second oxygen rich liquid stream is introduced to the low pressure intermediate column.