Abstract: A carbon dioxide (CO2) adsorption membrane or bed is operative to separate metabolic CO2 from an exhaust stream from a breathable atmosphere which is discharged from a closed habitable environment. The habitable environment is in a low ambient pressure surrounding. A portion of the scrubbed exhaust gas stream is diverted from the habitable environment and passed through a desorption chamber. The desorption chamber is open to the low ambient pressure surrounding to maintain a pressure which is slightly greater than the pressure in the ambient surrounding so that the desorption chamber gas stream will exit the system into the ambient surroundings. When the diverted exhaust gas enters the low pressure desorption pressure chamber its CO2 partial pressure content is reduced. The reduced CO2 partial pressure content of the gas stream in the desorption chamber enables the desorption chamber gas stream to remove CO2 from the adsorption membrane or bed.

Abstract: Modification, neutralization and/or decontamination of airborne biological and/or chemical contaminants from a breathable atmosphere by subjecting the breathable atmosphere to a filter which is formed from a plurality of polymeric multilobal fibers. These fibers include a central core with T-shaped lobes projecting therefrom, wherein each T-shaped lobe has a leg and a cap. The lobes define a longitudinally extending internal cavity between two adjacent legs that extends the entire length of the fiber. The filter is impregnated with a biological and/or chemical decontamination reagent for chemically modifying, neutralizing and/or decontaminating airborne biological and/or chemical contaminants from a breathable atmosphere. A filter projection preferably extends into an external reservoir containing a supply of biological and/or chemical decontamination reagent. This configuration increases the capacity and efficiency of the filter, and causes a lower pressure differential across the filter.

Abstract: In a process for the production of a polyolefin, an olefin monomer is polymerised said polyolefin and residual monomer is recovered. A gas stream comprising the monomer and nitrogen is subjected to a PSA process in which said monomer is adsorbed on a periodically regenerated silica gel or alumina adsorbent to recover a purified gas stream containing said olefin and a nitrogen rich stream containing no less than 99% nitrogen and containing no less than 50% of the nitrogen content of the gas feed to the PSA process.

Abstract: The present invention provides a method and apparatus for removing trace contaminants from a gas stream or flue gas. In one embodiment, the present invention an apparatus for removing a trace contaminant from a gas stream, comprising a gas duct configured to receive a gas stream comprising a trace contaminant; a plurality of substrates disposed within the gas duct; a trace contaminant sorbent disposed on at least a portion of each of the substrates; an isolation device for separating the portion of each of the substrates from the gas stream; and a regenerator for regenerating the trace contaminant sorbent. In another embodiment, the present invention provides a method for removing a trace contaminant from a gas stream.

Abstract: Using a distillation separator, a gas to be treated is separated into a plurality of gas groups having different boiling points. Then, the specific gases included in each of the plurality of gas groups separated at the first separator and having similar boiling points are separated using a chromatographic separator. In this manner, specific gases can be separated from the gas to be treated containing a plurality of specific gases.

Abstract: An ion exchange scrubber has a housing, and a partition plate installed within the housing. The partition plate partitions an inner space of the housing in longitudinal direction into two chambers that are filled with a predetermined amount of aqueous solution. The upper end portions of the two partitioned chambers communicate with each other. At least one cartridge is installed at the upper portion and has an ion exchange resin. The ion exchange resin removes a harmful substance contained in the gas. By repeatedly pumping the aqueous solution from one side chamber to the other side chamber, and immersing and cleaning the contaminated ion exchange resin in the aqueous solution, the contaminated gas can be effectively processed even with a small amount of water.

Abstract: A capacity increase and/or pressure decrease of gas in a gas storage and dispensing vessel is achieved by use of a physical adsorbent having sorptive affinity for the gas. Such approach enables conventional high pressure gas cylinders to be redeployed with contained sorbent, to achieve substantial enhancement of safety and capacity.

Abstract: The present invention includes two beds of activated alumina or similar material, which can remove moisture during a PSA cycle. One bed is placed in series in each drive air line for the pressure intensifier or boost pump. The beds are sized such that there is sufficient material to adsorb the moisture contained in the volume of gas required to move the drive piston through a complete stroke.

Abstract: Apparatus, materials, and methods for removing ammonia from fluids using metal hydroxides (e.g. zinc hydroxide) and metal loaded media (e.g. zinc loaded ion exchange resins); the metal hydroxides and metal loaded media may be regenerated with a weak acid (pKa between 3 and 7). Alternatively, ammonia is removed from fluids by using H2SO4 and ZnSO4 and metal loaded media; the metal loaded media may be regenerated with H2SO4 and ZnSO4; the ammonia containing H2SO4 and ZnSO4 may be concentrated as necessary to form (NH4)2SO4.ZnSO4.6H2O (ammonium zinc sulfate hexahydrate) crystals. These crystals are removed from the mother liquor and heated to temperatures exceeding 200° C. releasing NH3 and H2O vapor upon the decomposition of the crystals.

Abstract: A cargo or bulk product off-load system includes a compressor (10) that pressurizes air. The air is dried by a dryer (12, 14) and routed to a supply tank (16). From the supply tank, the air is either used to pressurize service reservoirs (24, 26) or to assist the off-load system. Air stored in the service reservoirs (24, 26) is used to pressurize purge volumes associated with the dryers (12, 14). The compressor (10) operates at a lower pressure when supplying air to assist the off-load system than when pressurizing the service reservoirs (24, 26). Controllers (30, 40) coordinate switching of airflow, and alternating purging and drying of the dryers.

Abstract: The present invention is a gas separator for separating a gas mixture into a product gas. The gas separator has an adsorbent bed including a separation chamber with first and second ports and a molecular sieve material contained in the separation chamber. A first pumping chamber is connected to the first port. A first valve regulates a flow of the gas mixture between the first port and the first pumping chamber. A first piston is located in the first pumping chamber. A second pumping chamber is connected to the second port. A second valve regulates a flow of the product gas between the second port and the second pumping chamber. A second piston is located in the second pumping chamber. A drive system coordinates operation of the first and second pistons and the first and second valves in a cycle including a pressurization stage, a gas shift stage, and a depressurization stage.

Abstract: The invention relates to adsorbing chemical samples onto inert carriers to form highly stable free flowing solid for long term storage in, for example, a proprietary compound collection.

Abstract: A hydrogen peroxide vapor generation unit (10) receives hydrogen peroxide and water solution at an interface (20) and interconnects with an air dryer (14) by way of nipples (72, 92). In one embodiment, the dryer includes a clamping assembly (42) which is latched (74, 94) with the nipples and which receives a disposable desiccant cartridge (40). In an alternate embodiment, a reusable desiccant cartridge (40′) is connected directly to the nipples (72, 92). When the desiccant cartridge (40′) is saturated, it is removed and placed in a regenerator unit (120). A regenerated cartridge is installed in its place.

Abstract: A molecular sieve apparatus and magnetic/adsorbent material composition that facilitate molecular absorption and separation using a magnetic field to hold, move, cool, and/or heat a magnetoadsorbent composed of an adsorbent (1) that is bonded to a magnetic material (3) by a binder (2). The ability to move the magnetoadsorbent using a magnetic field increases the efficiency of the absorption cycle, because the magnetoadsorbent can be moved to a location in the cycle having the most optimized conditions.

Abstract: A passive air sampler is designed to facilitate emptying granular or particulate adsorbent from it directly into a thermal desorption tube or other vessel for use in an analytical instrument. The preferred form has an adsorbent container in a conical or funnel-like shape.

Abstract: An exhaust gas processing apparatus is provided. The apparatus includes a rotor concentrator installed in an inlet, an active carbon adsorption system installed in an outlet, and a switch located between the zeolite rotor concentrator and the active carbon adsorption system for selecting any one (or both) of the two systems to process exhaust gases.

Abstract: A device for absorbing atmospheric moisture includes a support member with a net extending therefrom. The net includes a super absorbent polymer that has the property of being able to absorb a multiple of the polymer mass in atmospheric water and to thereafter release the water in response to an external stimulus. The device is in this way reusable. The device has particular application in the clearing of fog, manure odor clearance, and collection of potable water in remote locations. A process for extracting atmospheric moisture is also detailed that includes the step of extending a super absorbent polymer net into contact with an atmosphere. Thereafter, with that being in contact with the atmosphere for a sufficient amount of time moisture is absorbed from the atmosphere. The application of a stimulus to the super absorbent polymer containing atmospheric moisture causes the release of liquid water therefrom. The super absorbent polymer is then suitable for reuse to again absorb atmospheric water.

Abstract: A method of operating a thermal swing adsorption process by determining a parameter relating to the water content of a feed gas, selecting process conditions for regeneration of the adsorbent in the thermal swing adsorption process based on the parameter and modifying the regeneration process conditions to accord with the selected process conditions for regeneration is disclosed. Apparatus for effecting this adsorption method and apparatus in which regeneration conditions are modified based on the actual ambient water content of the feed gas are also disclosed.

Abstract: An adsorber for cleaning raw gas has at least one filter element wherein the at least one filter element is made of electrically conducting adsorber material. A filter module has a module housing in which such an adsorber is arranged. The housing has at least one inlet opening for the raw gas entering the filter module and at least one outlet opening for the clean gas exiting the filter module. A first ventilation damper unit closes the inlet opening as needed and a second ventilation damper unit closes the outlet opening as needed for performing regeneration and adsorption phases.

Abstract: A Diesel particulate filter cartridge system for filtering particulate matter and nitrogen oxide from a flow of air containing particular matter includes a filter support plate with a plurality of cylindrical electrically regenerable filter media members connected thereto. A NOx trap is also provided that is either incorporated directly into the filter media members or provided as a separate structure in close proximity to the filter media members. A valve assembly includes a number of independently actuatable damper valves that correspond to a number of through holes in the filter support plate. When actuated, the damper valves limiting flow of air through a corresponding through hole and filter media member connected thereto. An outer housing is disposed about the valve assembly and filter media members to contain them in a compact package. A programmable computer control module shuts off the flow of air through a filter media member and selectively electrically regenerates it.

Abstract: An apparatus and method are disclosed for purifying a contaminated fluid stream, for example an air stream contaminated with volatile organic compounds. A sorption media is directed between narrowly spaced plates which control the depth of sorbant flow. In an adsorber the plates are porous to allow the contaminated air to pass into an adsorption chamber where the media removes the contaminates from the fluid stream. In a desorber the plates may be transmissive or reflective of microwave energy and porous to a purging gas in a desorption chamber where the media releases the contaminates to refresh the media. An inclined plane or conical surface is contemplated for a desorber which can be coupled to an adsorber in a closed loop system.

Abstract: A method and apparatus for controlling the heating of adsorbent materials in a vessel including the utilization of electrodes in direct contact with the adsorbent material to induce a current in the material. The electrical contacts are spaced apart and receive a potential for inducing the electrical current; one of the electrodes is a different size to thereby induce a radial component in the electrical current to thus modify the current density flowing through the adsorbent material as the current traverses the distance between the electrodes. The resulting modified current density causes the temperature gradient across the transverse section of the vessel to decrease, thus rendering the temperature more uniform across the vessel.

Abstract: An advanced medical concentrator process and system is provided using fast cycle and advanced adsorbent. Significant improvements achieved results in a smaller, lighter and more efficient system in comparison with the current commercial stationary concentrators. Integrated with a conserver, a small portable concentrator is achieved.

Abstract: Pressure swing adsorption process for the recovery of high purity oxygen from a feed gas comprising oxygen, nitrogen, and argon. The process includes a forward flow stage which comprises (a) passing the feed gas into a first adsorption zone containing an adsorbent selective for the adsorption of nitrogen over oxygen and argon, and withdrawing therefrom a nitrogen-depleted intermediate gas; (b) passing the nitrogen-depleted intermediate gas into a second adsorption zone containing an adsorbent which is selective for the adsorption of nitrogen over argon and selective for the adsorption of argon over oxygen; (c) withdrawing an oxygen-enriched product gas from the second adsorption zone; and (d) terminating the passing of feed gas into the first adsorption zone and withdrawing an oxygen-enriched depressurization gas from the second adsorption zone in the same flow direction as (c).

Abstract: A gas supply system including a gas cabinet defining an enclosure including therein a gas dispensing manifold and one or more adsorbent-based gas storage and dispensing vessels mounted in the enclosure and joined in gas flow communication with the gas dispensing manifold. The enclosure may be maintained under low or negative pressure conditions for enhanced safety in the event of leakage of gas from the gas storage and dispensing vessel(s) in the enclosure. The gas supply system may be coupled to a gas-consuming unit in a semiconductor manufacturing facility, e.g., an ion implanter, an etch chamber, or a chemical vapor deposition reactor.

Abstract: A pressure swing process and system for purifying a first gas, preferably argon, from a crude feed gas stream containing the first gas and second gas(es) utilizes two adsorption beds and continuously promotes the crude feed gas to the bed during the process and simultaneous equalization of pressure in the two beds in top-to-top end and bottom-to-bottom end equalizations in each bed following purging of each bed.

Abstract: A method and system for retrofitting an integrated scrubber to provide maximum oxygen content in a controlled decomposition oxidation (CDO) abatement process including a thermal/wet integrated scrubber, and a compressed air supply for supplying air to an oxygen separation device that separates the air into a nitrogen-enriched component and an oxygen-enriched component. The oxygen separation device includes a module, such as a vessel containing ceramic-materials arranged in an adsorbent bed or coated on a substrate. The present invention uses a ceramic oxide material through which only oxygen can diffuse. The composition of the ceramic oxide adsorbent material is such that a significant number of oxygen vacancies exist in the material. By placing either a voltage potential or a pressure gradient across the membrane, oxygen is selectively diffused in and through the oxide material to separate the air supply into an oxygen component for introduction into the integrated scrubber.

Abstract: In order to aim at shortening the time of refueling by maintaining the function of prevention of discharge of vapor, similar to that of a conventional canister in the case of other than refueling during resting of an engine while the flow resistance in the canister becomes smaller during refueling, there is provided a canister in which a plate is vertically arranged in a chamber charged therein with absorbent in the canister, and filter support pins are projected from opposite surfaces of the plate while filters are arranged at the tip end faces of the filter support pins, and in which a plurality of constriction passages are formed being arranged in a horizontal direction only in the upper part of the plate.

Abstract: Gas separation by pressure swing adsorption (PSA) and vacuum pressure swing adsorption (VPSA), to obtain a purified product gas of the less strongly adsorbed fraction of the feed gas mixture, is performed with an apparatus having a plurality of adsorbers. The adsorbers cooperate with first and second valves in a rotary PSA module, with the PSA cycle characterized by multiple intermediate pressure levels between the higher and lower pressures of the PSA cycle. Gas flows enter or exit the PSA module at the immediate pressure levels as well as the higher and lower pressure levels, under substantially steady conditions of flow and pressure. The PSA module comprises a rotor containing laminated sheet adsorbers and rotating within a stator, with ported valve faces between the rotor and stator to control the timing of the flows entering or exiting the adsorbers in the rotor.

Abstract: The present invention is a gas separator for separating a gas mixture into a product gas. The gas separator has an adsorbent bed including a separation chamber with first and second ports and a molecular sieve material contained in the separation chamber. A first pumping chamber is connected to the first port. A first valve regulates a flow of the gas mixture between the first port and the first pumping chamber. A first piston is located in the first pumping chamber. A second pumping chamber is connected to the second port. A second valve regulates a flow of the product gas between the second port and the second pumping chamber. A second piston is located in the second pumping chamber. A drive system coordinates operation of the first and second pistons and the first and second valves in a cycle including a pressurization stage, a gas shift stage, and a depressurization stage.

Abstract: An improved pressure swing adsorption process and system for producing a high recovery of a highly purified product gas, such as argon, from a feed gas stream containing the product gas and impurity gases employs first and second adsorption stages with beds for adsorbing impurity gases. The system and process provides for sequential steps of: feed pressurization; simultaneous feed pressurization and product pressurization; adsorption; adsorption and purge; adsorption in the absence of purge; pressure equalization between beds; evacuation and depressurization of adsorbent bed; evacuation with product purge; evacuation without purge; and pressure equalization between beds.

Abstract: A system for storage and dispensing of a sorbate fluid, in which a sorbate fluid is sorptively retained on a sorbent medium and desorption of sorbate fluid from the sorbent medium is facilitated by inputting energy to the sorbent medium including one or more of the following energy input modes: (a) thermal energy input including inductive heating of the sorbent medium, resistive heating of the sorbent medium and/or chemical reaction heating of the sorbent medium; (b) photonic energy input to the sorbent medium; (c) particle bombardment of the sorbent medium; (d) mechanical energy input to the sorbent medium; and (e) application of a chemical potential differential to the sorbate fluid on the sorbent medium.

Abstract: The invention is based upon the recognition that intrinsic sorption rates of adsorbent materials have a significant impact upon process performance. In a preferred embodiment an adsorption process uses an adsorbent zone comprising an adsorbent selected from the group consisting of A-zeolite, Y-zeolite, NaX, mixed cation X-zeolite, LiX having a SiO2/Al2O3silica/alumina ratio of less than 3.0, chabazite, mordenite, clinoptilolite, silica-alumina, alumina, silica, titanium silicates and mixtures thereof, wherein the adsorbent has a mass transfer coefficient for nitrogen of kN2≧12 s−1 and an intrinsic diffusivity for N2, when measured at 1.5 bar and 300K, of Dp≧3.5×10−6 m2/s. Other embodiments include the development of process parameters around which such materials should be used and methods of making such materials.

Abstract: A system and method for improving the efficiency of a gas fractionalization system of the type having a compressor having an inlet for receiving air from the ambient environment. The system includes a sensor for sensing a parameter indicative of the flow of concentrated gas delivered from the gas fractionalization system to a patient. A multi-positional valve is disposed in line with the compressor for regulating the flow of air from the ambient environment into the compressor. A valve control manipulates the position of the multi-positional valve depending on the value of the parameter sensed by the sensor for regulating the quantity of air received from the ambient environment into the compressor inlet.

Abstract: A desorbable sorption filter, in particular for a heating or air-conditioning system of a motor vehicle, has a metallic support (12) which can be heated by flow of current and an adsorber (14) mounted at or on the support (12). To provide an improved, directly heatable sorption filter which particularly enables inexpensive production and good electrical and thermal conductive contact without the use of adhesives, it is proposed for the adsorber (14) to be of planar design and to be mechanically connected to the support (12, 112) by means of holding elements (26) formed integrally on the support (12, 112).

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 apparatus of the present invention for treating a gas containing a substance to be decomposed comprises adsorption means equipped with an adsorbent for adsorbing the substance to be decomposed, steam introduction means for bringing steam into contact with the adsorbent, condensation means for obtaining a condensed liquid containing the substance to be decomposed from the steam containing the substance, a reaction tank, condensed liquid supply means for supplying the condensed liquid to the reaction tank, hypochlorous acid supply means for supplying a solution containing hypochlorous acid to the reaction tank, and light irradiation means for irradiating the reaction tank with light.

Abstract: The present invention involves a vacuum-pressure swing adsorption process for the separation of components of a fluid mixture. The process includes (a) transferring a fluid mixture through an adsorbent bed at an elevated pressure Ph so as to produce a purified product fluid; (b) venting the adsorbent bed down to an ambient fluid pressure Pa; (c) applying a vacuum force to the adsorbent bed to bring the adsorbent bed to a reduced pressure Pl; and (d) venting the adsorbent bed up to an ambient fluid pressure Pa.

Abstract: A fuel adsorption layer formed in a canister is partitioned into an upper adsorption layer and a lower adsorption layer by a partition plate in which a heater is embedded. The relation between a heating value of the heater and thickness X of the upper and lower adsorption layers is set so that the temperature of a part closest to the heater heating face of the fuel adsorption layer is lower than a fire point of the fuel, and the temperature of a part farthest from the heater heating face is higher than the boiling point of the fuel. With the configuration, by heating the fuel adsorption layer by the heater, the desorption performance of activated carbon is improved, and almost all of the fuel vapors adsorbed can be desorbed. As a result, the fuel vapors do not remain in the canister, so that all of the fuel vapors which flow in at the time of adsorption can be adsorbed with reliability.

Abstract: A regenerable air cleaning device is disclosed which comprises a filter holder supporting a regenerable filter that includes activated carbon fibers (ACF) and a control system that is adapted to determine when to regenerate the regenerable filter. The device exhibits high performance and longevity over many regeneration cycles.

Abstract: A compression machine (compressor 4 and/or pump 5) of the plant (1) for the treatment of a fluid, typically by pressure swing adsorption, comprises at least one detector (7) for detecting clearance between a moving part (6) and a stator and delivering a measurement signal used so as to vary, depending on this measurement, the operation of the plant and especially to automatically shorten the phases during which the machine is running at an excessively high speed.

Abstract: The invention relates to the use of adsorbent materials that have been selected on the basis of their relationship between that material's intrinsic rate and equilibrium properties.

Abstract: A method for purifying a minority constituent and concentrating it in a majority constituent of a gas mixture that also contains one or more other minority constituent(s) employs (i) a selective permeation step, (ii) next, a purification step, and (iii) finally a concentration step. In the selective permeation step, an initial gas mixture is passed through a membrane to yield a gas mixture that is enriched in the first minority constituent. In the purifying step, the first minority constituent is absorbed by a solid adsorbent which has a strong affinity for the first minority constituent, then following an elution step, a gas mixture that contains essentially only the majority constituent and the first minority constituent is formed.

Abstract: An air dryer system for a trailer braking assembly is modified to provide a purge flow when the park brakes are actuated. An air reservoir, either the main air tank or a separate reservoir, is in operative communication with the trailer air dryer. A valve disposed at a supply end of the trailer air dryer selectively vents a purge flow to atmosphere in response to a park brake application. A restricting orifice limits the purge flow through the trailer air dryer to extend the purge time and maximize the removal of moisture from the air dryer.

Abstract: A method and apparatus for initiating regeneration in a particulate trap including the steps of locating microwave-absorbing material in the particulate trap in areas that particulates build up, generating microwaves, absorbing microwaves with the microwave-absorbing material, and controlling the microwaves to initiate a burn-off of particulates.

Abstract: In a method for regenerating an electrically conducting adsorbent laden with organic substances the adsorbent is heated by passing electric current through the adsorbent while not passing a flushing gas through the adsorbent. Subsequently, the flushing gas is passed through the adsorbent while not heating the adsorbent by passing electric current through the adsorbent so that the adsorbed organic substances are flushed from the adsorbent and the adsorbent is simultaneously cooled by the flushing gas.

Abstract: A gas supply system including a gas cabinet defining an enclosure including therein a gas dispensing manifold and one or more adsorbent-based gas storage and dispensing vessels mounted in the enclosure and joined in gas flow communication with the gas dispensing manifold. The enclosure may be maintained under low or negative pressure conditions for enhanced safety in the event of leakage of gas from the gas storage and dispensing vessel(s) in the enclosure. The gas supply system may be coupled to a gas-consuming unit in a semiconductor manufacturing facility, e.g., an ion implanter, an etch chamber, or a chemical vapor deposition reactor.

Abstract: A molecular sieve apparatus and magnetic/adsorbent material composition facilitate molecular adsorption and separation using a magnetic field to hold, move, cool, and/or heat an adsorbent 1 that is bonded to magnetic materials 3 that are moveable by a magnetic field. An adsorbent 1 is bonded to a soft magnetic material 3 with a binder 2 into a powder composite material adsorbent attractable by a magnetic field (magnetoadsorbent 4). Magnetoadsorbent 4 functions to adsorb and desorb working substances, causing a molecular separation; thereby increasing the efficiency of the adsorption cycle by moving the adsorbent 1 to a location that optimally processes the adsorbent 1. Magnetic field manipulation of adsorbents 1 enables delivery of molecules to locations within systems. Magnetoadsorbents 4 of the present invention further increase the efficiency of the adsorption cycle by combining materials with functions including: catalyst, buoyancy, suspension, magnetic heating, and sinking in liquid.

Abstract: An exhaust gas cleaning system for an engine capable of judging the amount of trapped NOx and the oxygen storage capacity of an NOx trap agent and which can diagnose the deterioration of the NOx trap agent. The NOx trap is arranged in an exhaust gas passage and the air-fuel ratio of the exhaust gas is temporally changed from a lean air-fuel ratio to the stoichiometric air-fuel ratio or a rich air-fuel ratio with a predetermined cycle. The NOx trapping occurs by absorbing or adsorbing NOx in the exhaust gas when an air-fuel ratio of the exhaust gas is a lean air-fuel ratio and by releasing or reducing NOx when the air-fuel ratio is a rich air-fuel ratio. The amount of trapped NOx is judged from the oxygen concentration and the oxygen concentration in the exhaust gas is detected in the exhaust gas passage in the downstream side of the NOx trap and determined by taking the oxygen storage capacity when the air-fuel ratio of the exhaust gas changes to the stoichiometric air-fuel ratio or the rich air-fuel ratio.

Abstract: An adsorbing device comprising a main body having an intake port and an exhaust port and accommodating therein an adsorbing composition capable of adsorbing a gaseous specific substance; regenerating means attached to the main body for releasing the specific substance from the adsorbing composition; a sensor capable of detecting the specific substance arranged at least near the exhaust port of the main body; and a control unit for instructing the regenerating means to operate when the sensor detects the specific substance at a higher value than a predetermined value. The present invention intends to facilitate an operation to regenerate the adsorbing composition by heating and enable automation of the operation, thereby to prevent deterioration of the adsorbing composition.