Abstract: The invention relates to a method for dehumidifying air and to an air dehumidifier. To this end, a filter element is provided that is filled with granular material that can be regenerated by baking out. For effecting this baking out, a heating device is provided that is only actuated when both a humidity sensor indicates that a humidity limit value has been exceeded as well as a relative pressure sensor or a comparable technical means indicates that, at the moment, no flow toward the oil expansion tank is recorded.

Abstract: The adsorption of CO2 from flue gas streams using temperature swing adsorption. Adsorbent contactors are used in the temperature swing adsorption unit that contain a plurality of substantially parallel channels comprised of or coated with an adsorbent material that is selective for adsorbing CO2 from flue gas.

Abstract: A water production unit is provided having two modes of operation for extracting water from exhaust and air.

Abstract: An apparatus and method of conditioning humidity and temperature in the process airstream of a desiccant dehumidifier used to dry moisture-laden spaces and structures by replacing moisture-laden air with dehumidified air to increase the rate of water evaporation within the affected areas. A heat-modulating dehumidifier comprises a dehumidification assembly having a desiccant rotor assembly, a post-process pre-reactivation heat exchanger assembly, a reactivation air bypass damper, a reactivation heater, and a control system. The apparatus regulates the temperature level of the dehumidified air exiting the apparatus by extracting heat from the dehumidified air prior to its ejection into an affected area, using a bypass damper that controls the amount of heat transfer from the dehumidified air to a second airstream entering the apparatus.

Abstract: Apparatus and methods useful for removal or reduction of moisture from fluids are described. In one embodiment the apparatus comprises a moisture separation unit comprising a thermally regenerable moisture adsorption material having feed and waste sides, and means for regenerating the thermally regenerable moisture adsorption material. The feed fluid contacts the feed side, while a dry, preferably heated purge gas flows past the waste side. The thermally regenerable moisture adsorption material is regenerated by contacting with the heated dry purge gas. The apparatus and methods are particularly useful in supplying dehydrated electronic specialty gases to semiconductor tools.

Abstract: A dehydrator breather is provided that includes automatic purging of accumulated moisture by detecting absorbed moisture in the breather, and closing an intake air channel, while opening an exit moisture channel. Adjustment of a default time-based purging cycle is adjusted to account for fluctuations in the detected moisture. An external communication capability is provided to enable off-site monitoring of the breather or the tank the breather is attached to.

Abstract: Process for drying wet F32, which comprises placing a stream of the said F32 in continuous contact with a feed stock of a composition comprising a molecular sieve chosen from a 3A type sieve, at a temperature of between 5 and 78° C. and at a pressure of between 0.5 and 25 atm.

Abstract: A warm-up system is provided for an internal combustion engine equipped with a CO2 absorbing and releasing agent that absorbs CO2 at a temperature in a first temperature range and releases the CO2 at a temperature in a second temperature range that is higher than the first temperature range. The warm-up system increases a temperature of the CO2 absorbing and releasing agent to reach the second temperature range such that the CO2 released from the CO2 absorbing and releasing agent is supplied to a component of the internal combustion engine such as an intake manifold and an exhaust gas purification catalyst.

Abstract: An improved thermal swing adsorption process is set forth which addresses the problem of water ingress into the adsorbent by periodically heating the adsorbent to a temperature greater than the temperature used in the normal regeneration cycle.

Abstract: A continuous method of producing a process fluid gas from a feed stream that includes the process fluid and impurities. The method includes: (a) providing a first and second vessel, each vessel containing one or more regenerable purifier materials for removing at least one of the impurities from the feed stream; (b) removing at least one of the impurities by passing the feed stream through one or the other of the vessels to provide a purified process fluid gas, with the vessel being maintained at a first temperature during the removal of impurities; and (c) regenerating the purifier materials in the vessels at a second temperature and during the time when it is not purifying the feed stream by flowing a portion of the purified process fluid or the feed stream or a separate source of the process fluid gas therethrough.

Abstract: Disclosed embodiments address contaminant management challenges that arise during production of desirably contaminant free product fluid in the operation of PSA equipment, and further address the more serious challenges that arise under intermittent operation of PSA equipment. One disclosed embodiment of a PSA apparatus, intended primarily for normal operating cycle speeds of at least 3 cycles per minute, includes a breather fluidly coupled to a feed end of an adsorber with a contaminant-sensitive adsorbent. The breather can be coupled to the feed end through a shutoff valve closed during production and open during shutdown. Other disclosed embodiments of the PSA apparatus used particular sealing strategies for additional sealing of the apparatus, or at least components thereof, from contaminant ingress.

Abstract: A method for the regeneration of humidity-laden drying cartridges includes heating to 220 to 300° C. and introducing it into a drying cartridge for regeneration. Subsequent cooling of the drying cartridge is achieved by a partial stream of air diverted from the dried process air. An arrangement suitable for carrying out the method is also disclosed.

Abstract: A method and apparatus for the extraction of water from a gas stream, such as atmospheric air. The method includes contacting the gas stream with a porous adsorbent material having a surface modifying agent adsorbed on the surface of a porous support. The surface modifying agent creates a hydrophilic surface for the adsorption of the water. After the water is adsorbed into the pores, the surface modifying agent is selectively desorbed from the surface. The water then evaporates from the pore and can be collected in a condenser. The method and apparatus of the present invention advantageously operate in a substantially isothermal manner, thereby reducing the size and power consumption of the device. The device can advantageously be used to extract potable drinking water from atmospheric air.

Abstract: A purge and trap concentrator and a method for drying a stream of sample gas in a gas analysis instrument. A dryer tube has an inlet that receives a stream of sample gas during a drying interval and receives a stream of dry gas during a regeneration interval. The dryer tube also has an outlet and an interior passageway between the inlet and an outlet. Support material comprising polymer sorbent is placed in the interior passageway and provides a support surface area for a hygroscopic coating comprising lithium chloride. A controller controls a heater to increase the temperature of the dryer tube to between 100 and 300 degrees centigrade during the regeneration interval and controls the heater to decrease the temperature of the dryer tube to below 100 degrees centigrade during the drying interval.

Abstract: A system for recovering water from the atmosphere includes water sorbent assembly composed of a water adsorbent material and a heat exchanger. The water adsorbent material traps water present within the air drawn through the sorbent assembly. Once the sorbent assembly is fully saturated, exhaust gases generated from a power plant are routed through a heat exchanger in thermal contact with the water adsorbent material to remove water within the sorbent assembly into a condenser, and from the condenser to a water storage container.

Abstract: A purge and trap concentrator and a method for drying a stream of sample gas in a gas analysis instrument. A dryer tube has an inlet that receives a stream of sample gas during a drying interval and receives a stream of dry gas during a regeneration interval. The dryer tube also has an outlet and an interior passageway between the inlet and an outlet. Support material comprising polymer sorbent is placed in the interior passageway and provides a support surface area for a hygroscopic coating comprising lithium chloride. A controller controls a heater to increase the temperature of the dryer tube to between 100 and 300 degrees centigrade during the regeneration interval and controls the heater to decrease the temperature of the dryer tube to below 100 degrees centigrade during the drying interval.

Abstract: An adsorbent, method, and apparatus involving same for the removal of moisture from a fluoride-containing fluid such as gaseous nitrogen trifluoride are disclosed herein. In certain preferred embodiments, the adsorbent of the present invention comprises an organic support having a porosity of 30% or greater and a pore size of 2 &mgr;m or less; and at least one metal fluoride disposed within at least a portion of the organic substrate.

Abstract: An HFBD purification process includes: (a) contacting a composition containing HFBD with an adsorbent to remove from the HFBD at least two impurities selected from the group consisting of water, an alcohol, hydrofluoric acid and a fluorinated olefin, wherein the adsorbent is a solid having an average pore diameter of about 5 Å and the adsorbent is contacted with the HFBD at a rate of at least 2.7 kg of the HFBD per hour; and (b) recovering from the adsorbent a purified HFBD product containing at least 99.9 vol. % HFBD, a reduced amount of the impurities and less than 0.1 vol. % hexafluoro-2-butyne. Alternatively, the process can be conducted at any contacting rate to produce 99.96 vol. % HFBD. The process can also be conducted at any contacting rate in a bed within a column having a length of at least 30 cm and an inner diameter of at least 2.5 cm.

Abstract: The present invention provides compact adsorption systems that are capable of rapid temperature swings and rapid cycling. Novel methods of thermal swing adsorption and thermally-enhanced pressure swing adsorption are also described. In some aspects of the invention, a gas is passed through the adsorbent thus allowing heat exchangers to be very close to all portions of the adsorbent and utilize less space. In another aspect, the adsorption media is selectively heated, thus reducing energy costs. Methods and systems for gas adsorption/desorption having improved energy efficiency with capability of short cycle times are also described. Advantages of the invention include the ability to use (typically) 30-100 times less adsorbent compared to conventional systems.

Abstract: A seal for an opening defined by a sidewall portion of the pressurizable tank. The tank contains desiccant for drying gases which pass through the desiccant. An elongate antenna extends from an interior portion to an exterior portion of the tank and is used for carrying microwave energy to the desiccant for regeneration of the desiccant. The seal has an insulator with an interior surface for receiving engagement with the antenna at the opening of the tank. In one embodiment, the interior surface of the insulator is tapered such that a distance between opposing portions of the insulator reduces as the insulator extends in a direction through the opening toward the exterior of the tank. The antenna has a cross sectional dimension which reduces in size as the antenna extends in the direction through the opening toward the exterior of the tank.

Abstract: The present invention provides for methods and compositions for gas separation and purification utilizing a metallo-organic polymer adsorbent in processes for separating carbon dioxide, water, nitrogen oxides and hydrocarbons from gas streams.

Abstract: A heat exchanger, perhaps a cross flow heat exchanger, has first and second passages. During dehumidification (adsorption of moisture) in the first passages, water is evaporated from the second passages. This water can be introduced to the second passages during reactivation (desorption of moisture) in the first passages or at another time. If the water is introduced to the second passages during reactivation, the first and second passages have therein first and second moisture adsorbents. During a first time period, air to be dehumidified is passed through the first passages of the heat exchanger and cooling air is passed through the second passages of the heat exchanger to remove heat generated in the first passages and to desorb moisture adsorbed by the second moisture adsorbent. During a second time period, a heating fluid is passed through the second passages of the heat exchanger to heat the first passages and supply moisture for adsorption to the second moisture adsorbent.

Abstract: The present invention is a method for separating condensable substances from gases or gas mixtures with the use of porous materials including the steps of employing as adsorbents substances or materials suitable for capillary condensation and cyclically performing the method. The method can be used to separate water from air. The porous materials have a pore structure adapted to the environmental or climatic conditions present at the site of utilization of the method. The step of cyclically performing the method can be performing a plurality of times in succession separation by capillary condensation of the condensable substances in the porous materials and desorption of the condensed substances from the porous materials.

Abstract: A robust, relatively simple air quality control system that can control the air quality in buildings during both the heating and cooling seasons. In one illustrative embodiment, a first air stream is directed through an air treatment module and back into the inside space. A desiccant in the air treatment module adsorbs water, volatile organic compounds and/or particulate material from the first air stream. A second air stream is then directed through the air treatment module to a location outside of the inside space. The second air stream is preferably heated relative to the first air stream so that at least a portion of the adsorbed water, volatile organic compounds and/or particulate material are desorbed from the desiccant into the second air stream. The second air stream carries the desorbed water, volatile organic compounds and/or particulate material to a location outside the inside space.

Abstract: Nitrogen oxides and low molecular weight hydrocarbons are removed from air by subjecting the air to a temperature swing adsorption process using as the adsorbent a composite zeolite product containing both zeolite type A and zeolite type X. The composite zeolite product is prepared by crystallizing a sodium ion- or sodium ion- and potassium ion-containing alumina-silica hydrogel under conditions which result in the production of a zeolitic composite which contains both zeolite type A and zeolite type X crystal domains. In a preferred embodiment, calcium ions constitute a substantial number of the composite's exchangeable cations and the type X portion of the composite zeolite product has a silicon-to-aluminum atomic ratio in the range of 0.9 to less than 1.15. The nitrogen oxide- and hydrocarbon-selective adsorbent can be incorporated into an atmospheric air prepurification plant downstream of a water vapor-selective adsorbent and a carbon dioxide-selective adsorbent.

Abstract: A method for removing trace moisture from a gas is disclosed. The method involves heating a zeolite having a high silica-to-alumina ratio to about 400° C. to remove physically adsorbed water from the zeolite, followed by heating the zeolite to a temperature in excess of 650° C., to form a superheated zeolite. The superheated zeolite is contacted with the gas, thereby adsorbing water from the gas. A dehydroxylated zeolite for removing trace moisture from a gas wherein the zeolite has a high silica-to-alumina ratio and a low level of metallic impurities is also disclosed. A method for removing metallic impurities from a gas using the low metals zeolite is also disclosed. The zeolites and methods of the invention are particularly useful for removing trace water and trace metal impurities from acid gases such as hydrogen chloride and hydrogen bromide.

Abstract: A VOC removal or destruction system incorporates a regenerator/reactivator having a cylindrical ceramic tube for receiving contaminated adsorbent activated carbon. Electrodes are provided in the ceramic tube in contact with the activated carbon and a programmable logic controller is connected to control the voltage applied to the electrodes and the current flowing through the activated carbon within the tube. The temperature of the material in the tube is controlled by the programmable controller to maintain a temperature within one of two temperature ranges for regenerating the activated carbon and for reactivating the activated carbon. An inert gas is supplied through the tube in contact with the contaminated adsorbent material; the effluent gas including the stripped VOC's is supplied to an oxidizer for destruction. The oxidizer includes a stoichiometric burner providing combustion products for oxidizing the gaseous adsorbate and for providing carrier gas to the regenerator/reactivator.

Abstract: A humidity control system. The system comprises a housing containing one or more hygroscopic monoliths to provide, and passively sustain, the capacity to control the humidity on an intermittent basis. The present invention may be employed either independently or as part of a larger climate control system.

Abstract: A ventilation and dehumidification system for ventilating fresh air to a conditioned space. The system is comprised of a unitary heat transfer desiccant wheel for dehumidifying incoming air by exchanging moisture from an inflow current of air with an outflow current of air. The unitary heat recovery wheel is able to transfer heat between the two air currents when the wheel is spun at a faster speed. The unitary heat transfer desiccant wheel is both regenerated and defrosted by a regenerative heater which is placed to heat the outflow current of air before the outflow current passes through the unitary heat transfer desiccant wheel. The unitary heat transfer desiccant wheel is spun at a slow speed to accomplish more dehumidification, and at a fast speed to accomplish more heat recovery. The system includes at least two blowers in order to motivate the inflow and outflow currents of air.

Abstract: Carbon dioxide is removed from gas streams comprised predominantly of gases that are less strongly adsorbed than is carbon dioxide by passing the gas stream through a bed of type X zeolite having a silicon to aluminum atomic ratio not greater than about 1.15 and at least 75% of the exchangeable cations of which are potassium ions, thereby adsorbing the carbon dioxide from the gas stream. The process is particularly advantageous when applied to the removal of low levels of carbon dioxide from gas streams at temperatures of about 0 to 80° C.

Abstract: The present invention provides a method and apparatus to purify various gases utilizing the superior performance a heated getter process in a smaller package than previous multiple stage, heated getter processes. The smaller package includes inner and outer enclosures, and an integral, regenerative heat exchanger to simultaneously increase heater efficiency and cool the purified gas. The invention also includes a particle filter to remove particles from the gas flow. The invention further provides an interface to various modular gas stick substrate designs with an inlet and an outlet in one end of the integrated heated getter purifier system. The inlet gas is preheated by the integral heat exchanger and then heated to operating temperature of 200-400° C. The heated getter removes various impurities from the gas. The heated gas is then cooled in the integral heat exchanger. The cooled gas is exposed to a second quantity of cooler getter to remove residual impurities.

Abstract: A method and device for drying a gas by means of adsorption on a desiccant able to be regenerated (11), whereby a portion of the dried gas is used for regenerating the desiccant. The gas portion used for the regeneration is heated in at least two successive steps, said steps being performed in different zones (30,31 or 33-36) situated successively in the flow direction of the gas portion through the regenerating desiccant (11) and by stopping the heating in a zone (30,31 or 33-36) as soon as the desiccant (11) in this zone (30,31 or 33-36) is regenerated, so that this zone (30,31 or 33-36) may already cool down by the gas portion for regeneration while a successive zone (30,31 or 33-36) is still regenerated by the heated gas. In each vessel (7, 8) at least two individually controllable heating elements (25-26; 27-28; 38-41) are present.

Abstract: A method and apparatus for compressing and drying a gas, typically air, are provided in which a multistage compressor is employed to produce interstage and final stage compressed gas. Regenerative adsorbent is employed to dry the final stage compressed gas. Interstage gas is used to regenerate the saturated adsorbent. Preferably, two beds of regenerable adsorbent are provided, each operable in a drying mode and a regeneration mode. In the drying mode, final stage compressed gas is passed through the bed of adsorbent in order to be dried, until the adsorbent is saturated. In the regeneration mode, moisture is removed from the saturated adsorbent by a stream of interstage compressed gas. The two beds are preferably alternately operated in the drying mode and the regeneration mode, in order to provide a continuous process.

Abstract: A method for removing trace moisture from a gas is disclosed. The method involves heating a zeolite having a high silica-to-alumina ratio to about 400.degree. C. to remove physically absorbed water from the zeolite, followed by heating the zeolite to a temperature in excess of 650.degree. C., to form a superheated zeolite. Heating to temperatures of 650.degree. C. or above is believed to cause dehydroxylation of the zeolite. A method for the preparation of a dehydroxylated zeolite is also disclosed. The superheated zeolite is contacted with the gas, thereby adsorbing water from the gas. A dehydroxylated zeolite for removing trace moisture from a gas wherein the zeolite has a high silica-to-alumina ratio and a low level of metallic impurities is also disclosed. The zeolite and methods of the invention are particularly useful for removing trace water from acid gases such as hydrogen chloride and hydrogen bromide.

Abstract: Carbon dioxide, water, nitrous oxide and optionally ethylene are removed from a feed air stream by a temperature swing adsorption using a first adsorbent such as alumina to adsorb water, a second adsorbent such as 13X zeolite to adsorb carbon dioxide, and a third adsorbent such as binderless calcium exchanged X zeolite to adsorb nitrous oxide and optionally ethylene, prior to cryogenic separation of the purified air stream.

Abstract: A sorbent material, an activated carbon canister and a method are described which can be utilized to remove organic compounds from a vaporous stream with a relatively greater degree of safety, as compared to previously known methods. In the invention, essentially dry and wetted activated carbon particles are intermixed in a substantially homogeneous mixture which inhibits accidental combustion. The heat capacity of wetted carbon particles retards the heating of nearby unwetted particles, so as to inhibit the ignition of the nearby unwetted particles. The presence of wetted particles intermixed in the substantially homogeneous mixture has relatively little effect on the hydrocarbon adsorption performance of the mixture.

Abstract: The purge and trap procedure commonly used for analysis of volatile organic compounds in water or air can be significantly improved using traps employing clays and modified clays as adsorbents. Examples of clays include attapulgite clay, attapulgite clay modified with tetrasodiumpyrophosphate, carboxymethylcellulose and the combination thereof, kaolin clay, kaolin clay modified with tetrasodiumpyrophosphate, carboxymethylcellulose or the combination thereof, and mixtures of the above clays.

Abstract: A gas phase adsorption process in which a gas phase containing water vapor or a basic gas is brought into contact with activated carbon fiber to adsorb the water vapor or basic gas. The activated carbon fiber comprises pitch-based oxidized activated carbon fiber having oxygen-containing functional groups and an oxygen content of 3-18% by weight, based on the weight of the fiber. The oxidized activated carbon fiber is prepared by oxidizing pitch-based activated carbon fiber having a specific surface area of 200-2500 m.sup.2 /g.

Abstract: Method for drying a gas which has been compressed by a compressor (1) wherein compressed gas (2) from the compressor is driven through an amount of drying agent (3) until a dried, compressed gas (4) is obtained. An amount of used drying agent (7) is regenerated by driving a part (5) of dried compressed gas (4), which is heated first by the compression heat of compressor (1), through used drying agent (7). Moisture is absorbed from used drying agent (7) by a part (5) of the dried compressed gas (4), which is then condensed and separated by cooling. Part (5) of dried compressed gas (4) is then mixed with compressed gas (2) from the compressor to be dried.

Abstract: In a method for recovering and/or purifying water which is absorbed from a humid atmosphere, the moisture from the air is adsorbed on a suitable medium (3) in a defined space, whereupon by the application of heat the moisture is brought to a condenser (1) where it passes into a liquid state (10) and is collected in a suitable manner. In order to improve the efficiency of this method the defined, sealed space is opened for the adsorbing medium (3), for free access to air at night-time and is closed during the hot day-time period. Condensed water is passed out through a collecting funnel (2) and a channel (5) to a collection container (6). A device is also described in the form of a housing with walls (7) which can be opened and closed, in which there is located an adsorbing medium (3). In the upper part of the housing there is provided a condenser (1). The condenser (1) is equipped with a drop collector (2) which is connected to an outlet pipe (5) to a collection container (6).

Abstract: A moisture control unit is made up of a housing and a moisture absorption rotor is rotatably supported in the housing. A fan is provided in an exterior wall of the housing and it feeds air into the housing. A heater is contained within the housing adjacent the rotor to evaporate moisture therefrom and a heat exchanger is also provided in the housing. The heat exchanger has a first passageway through which a portion of the air from the fan flows to absorb moisture from the rotor and a second passageway through which moisture-laden air flows from the rotor, the first and second passageways being in heat exchange relationship with each other.

Abstract: A desiccant dehumidifier is provided in which a desiccant material is applied to a first end of a heat pipe heat exchanger. During the sorption phase, a supply air stream is exposed to the desiccant material on the first end of the heat pipe heat exchanger and a second air stream, which could be ambient atmosphere, is exposed to the second end of the heat pipe heat exchanger. The moisture from the supply air stream is transferred to the desiccant material. However, the heat pipe heat exchanger acts as a heat sink and adsorbs the heat generated by the moisture transfer and transfers it to the second end of the heat pipe heat exchanger. At the second end of the heat pipe heat exchanger, the heat is transferred to the second air stream. As a result, both the supply air stream and the desiccant material remain at a substantially constant temperature during the sorption phase.

Abstract: A pre-compression dehydration system optimizes the gas flow parameters which are essential to the performance of a radial or spherical desiccant dryer. When used in conjunction with a low pressure dryer, the system protects the desiccant bed from channeling, which can cause the gas to flow unevenly through the desiccant bed and fail to make effective contact with the desiccant. The system provides a multiple zone, or divided, desiccant bed adsorption unit to maintain a proper flow distribution as required by the demand of the air compressor and to eliminate the potential for channeling. The system may also include a controller for automatically opening and closing the port access doors of the adsorption unit to control the amount of desiccant utilized to dry the air. A thermostatically controlled precooler may be provided for cooling the ambient air prior to adsorption to insure that the temperature of the effluent air will not exceed 100.degree. F. (37.8.degree. C.

Abstract: An air compressor (1) is cooled by a water circuit (5) which comprises a buffer tank (6) and an air cooled cooler (7) provided with a fan (8) of adjustable speed. The buffer tank is supplied by makeup water and includes a purge (16) which serves, when the ambient temperature is relatively high, to cool the preliminarily separated compressed air from cooling water. Application in processes for separation of air by adsorption or permeation.

Abstract: A microtrap sample concentrator useful for concentrating a sample of purged gas containing analytes for delivery to an analytical instrument, including: a tube containing at least one sorbent material which retains or traps analytes; where greater than 30% of all trapped analytes are directly delivered to an analytical instrument at a desorption flow rate of one to three cc/min, without splitting or cryogenic focusing the trapped analytes; where delivery of the trapped analytes to the analytical instrument is achieved by passing the trapped analytes through a passage being selectively connectable between the microtrap and the analytical instrument, the passage connected to a vent; where the temperature of the passage is not lower than ambient room temperature; and where the passage is heated to a temperature sufficient to vaporize water in the passage and to expel the vaporized water out of the vent.

Abstract: An improved rotary concentrator separates the desorption gas flow into two flow portions. The first flow portion is sent to a final processing system. The second portion is recycled to the rotary concentrator. In a first embodiment, gas is recycled to the process gas inlet. In a second embodiment, the recycled gas is reused as desorption inlet gas. Most preferably, the recirculated gas is relatively clean compared to the gas in the first portion which is sent to the final processing system. In this way, the improved rotary concentrator is more efficient and reduces the amount of gas which must be processed by the final processing system.

Abstract: A process for the adsorption of at least carbon dioxide, water and oxides of nitrogen and preferably acetylene from a feed gas, comprises contacting the feed gas with an adsorbent mixture of a zeolite and an alumina. The process may be operated as a swing adsorption process comprising contacting the gas with the adsorbent at a first temperature and pressure to adsorb at least carbon dioxide, water and oxides of nitrogen therefrom and periodically regenerating the adsorbent by reducing the pressure and or increasing the temperature to which the adsorbent is exposed.

Abstract: Multiple thermal pulses are employed to regenerate segments of an adsorber bed simultaneously in thermal swing adsorption processes. The invention is particularly applicable to air purification as it helps to reduce purge flow and improve regeneration efficiency.

Abstract: Particulate adsorbents composed of inorganic oxides impregnated with an indicator dye selected from the group consisting of phenolphthalein, cresol red and thymol blue; a method for the production thereof, and a method for adsorptive drying of neutral gases using the aforementioned particulate adsorbents, whereby the degree of water absorption by the adsorbent particles is indicated by a reversible color change.

Abstract: A system for drying a gas, such as air, includes a source of gas to be dried, a multistage compressor having an inlet connected to the source, and a dryer connected interstage to the compressor and to the outlet of the compressor. The dryer is connected interstage to the compressor between a compression stage and a heat exchanger of one of the compressor stages for regenerating a first desiccant filled tower. The dryer is also connected to the outlet of the compressor for drying the gas using a second desiccant filled tower. A communication structure can be activated to connect the first tower to the outlet of the compressor for drying the gas using the first tower, and to connect the second tower interstage to the compressor for regeneration of the second tower.