Abstract: A valve for use with an ultra high purity gas comprising a valve body defining a valve chamber having a valve outlet through which gas is discharged and containing a reciprocable sealing member, characterized in that the valve chamber is in fluid communication with a source of the gas and in that the sealing member is reciprocable along an axis substantially parallel to the direction of flow of gas discharged from the valve outlet and into and out of sealing contact with a sealing face located within the valve chamber and circumscribing the inlet end of a valve outlet pipe, the opposite, outlet end of which pipe forms the valve outlet. The valve has a low wetted area and is thus easy to purge, and the valve design both reduces wear and restricts it to a single component which is easily replaced when necessary.

Abstract: The present invention provides for a multi-composite adsorbent mixture which will remove H2O, CO2 and nitrogen oxides and/or hydrocarbons from a feed gas stream. The improvement lies in the use of a third adsorbent which is selective for nitrogen oxides, hydrocarbons or both.

Abstract: Sulfur vapor is formed by partial oxidation of hydrogen sulphide. A burner is operated so as to establish a flame in a furnace in or into which the burner fires. There is supplied to the flame from the first region of the mouth of the burner at least one flow of a first combustible gas comprising hydrogen sulfide. At least one second flow of a first oxidizing gas is caused to issue from the mouth of the burner and mix in the flame with the first combustible gas. There is supplied to the flame from a second region of the mouth of the burner surrounding and spaced from the said first region at least one third flow of a second combustible gas comprising hydrogen sulfide. At least one fourth flow of a second oxidizing gas is caused to issue from a region or regions of the mouth of the burner surrounded by said second region and mix in the flame with the second combustible gas. At least one fifth, outermost flow of a third oxidizing gas is caused to mix in the flame with the second combustible gas.

Abstract: Novel compositions of molecular sieve adsorbents are provided in which at least 50% of the exchangeable cations are selected from those of Li, Ca, Ag and Cu and which have within their pore system metal oxide, metal oxide precursors or mixtures thereof. These compositions are useful for the separation of gases and, in particular, the separation of nitrogen from air to produce oxygen or oxygen-enriched gas.

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: An improved restraining clip for holding fragile substrates has been invented. The clip can be used to provide a force on the backside of substrates during processing. The invention has a compound spring mechanism, effectively uncoupling the force used to hold the substrate from that applied by an operator to move the clip. The preferred configuration incorporates a multiple leaf spring for providing force to the substrate, a coil spring to hold the clip in place, and a lever arm for the operator to provide lifting and turning forces on the clip. This combination of features allows the clip to be used on fragile substrates, such as Ga—As, which are easily damaged by other clips.

Abstract: A gas separation process comprising feeding a gaseous mixture comprising at least two components having different adsorption characteristics into an adsorption vessel containing at least one adsorbent material capable of preferentially adsorbing at least one of the gaseous components in the gaseous mixture and subjecting the gaseous mixture to non-cryogenic conditions which enable the preferentially adsorbable gaseous component in the gaseous mixture to adsorb onto the adsorbent material and separate from the non-adsorbed component in the gaseous mixture which pass through the adsorbent vessel wherein at least one adsorbent material in the adsorbent vessel comprises a composite particle having an inner core comprising a non-porous, non-adsorbent material and at least one outer layer comprising the adsorbent material. In another embodiment of the process of the present invention a hollow particulate adsorbent material is utilized.

Abstract: Liquid in which oxygen-containing gas is to be dissolved is pumped through a main and distributed into faster-moving subsidiary streams. Each subsidiary stream passes through a turbulence-inducing means and air or oxygen is introduced into the turbulent region of alternate streams. The relative proportions of air to oxygen introduction are varied so as economically and efficiently to oxygenate the liquid. The gas-containing liquid passes through nozzles back into the volume of the liquid at sufficient velocity to cause further turbulence, making gas bubbles shear into smaller bubbles and also agitating the body of liquid.

Abstract: Substantially all of the carbon dioxide is removed from a gas containing up to about 1% by volume carbon dioxide by subjecting the gas to a pressure swing adsorption process using a two layer adsorption system, wherein the first layer contains activated alumina and the second layer is a zeolite or a combination of zeolites having a silicon to aluminum atomic ratio of at least 1.5. The process is particularly suitable for removing substantially all carbon dioxide and water vapor contained in air prior to subjecting the air to cryogenic distillation.

Abstract: A method of separating a first gaseous component from a gas mixture comprising the first gaseous component and a second gaseous component comprising passing the gaseous mixture into an adsorption zone containing an adsorbent material capable of preferentially adsorbing at least one of the gaseous components in the gaseous mixture, to separate the first gaseous component from the second gaseous component wherein the adsorbent material is a monolith having a plurality of channels throughout, the channels being aligned parallel to the direction of flow of the gaseous mixture and having a wall thickness of less than 1 mm and (b) recovering the non-preferentially adsorbed gaseous component from the adsorption zone. Preferably, the adsorption zone comprises multiple layers of monolithic structures in the shape of a wheel stacked one upon the other in a direction parallel to the direction of the flow of the gaseous mixture and form by spirally winding a sheet of corrugated adsorbable material about a hub.

Abstract: Nitric oxide is removed from a gas stream by contacting the gas stream with oxygen in the presence of a metal-cation exchanged zeolite, thereby oxidizing the nitric oxide to nitrogen dioxide, then contacting the resulting nitrogen dioxide-containing gas stream with ozone, thereby converting the nitrogen dioxide to nitric acid, nitric acid precursors or mixtures thereof, then contacting the gas stream with an aqueous liquid, thereby scrubbing the nitric acid, nitric acid precursors or mixtures thereof from the gas stream. Contact of the gas stream with oxygen in the presence of a zeolite is carried out at a temperature above the temperature at which significant adsorption of nitrogen dioxide occurs, and the aqueous liquid used as scrubbing agent preferably has a pH greater than 7.

Abstract: Iron ore is reduced to molten iron by introducing the ore into a reactor while combusting coal with pure oxygen in the reactor. The molten iron phase, which forms at the bottom of the reactor, is stirred by injecting carbon monoxide into the molten iron. In a preferred embodiment, finely pulverized iron ore is injected with pure oxygen tangentially into a cyclone section of the furnace situated on top of a converter section, thereby causing melting and preliminary reduction of the ore to take place in the cyclone section. Primary reduction of the iron oxide occurs in the converter section of the furnace.

Abstract: Ethene is separated from a gas mixture containing ethane by a pressure swing adsorption process carried out at a temperature in the range of about 50 to about 200° C., wherein the adsorption step of the process is conducted by passing the gas mixture through an adsorption zone containing type A zeolite whose exchangeable cations are preferably made up of at least about 60 but not more than 75% sodium ions and more than 25 and up to about 40 percent potassium ions.

Abstract: Nitrogen oxides are removed from a waste gas stream by contacting the waste gas stream with ammonia, thereby reducing the nitrogen oxides to nitrogen. Residual nitrogen oxides and unreacted ammonia in the waste gas stream leaving the nitrogen oxides reducing step are oxidized to nitrogen pentoxide or nitric acid by contacting this gas stream with ozone. Contact of the ozone and waste gas is preferably carried out in the presence of an aqueous solution at a pH above about 9 and at a temperature above about 75° C., and this step is preferably carried out in the presence of an ammonia-oxidizing catalyst.

Abstract: An ozone-oxygen gas stream produced by passing oxygen into an ozone generator is introduced into a membrane separation unit containing an ozone-permeable membrane. Ozone-enriched gas passes through the membrane and is recovered or it contacts a liquid or gas stream which contains ozone-reactive substances, thereby oxidizing the substances. The oxygen-enriched gas stream produced on the feed side of the membrane by permeation of ozone through the membrane is recycled to the ozone generator. Prior to being recycled, the oxygen-enriched stream may be purified to remove gaseous impurities which permeate through the membrane from the liquid or gas stream being treated.

Abstract: An ozone-oxygen gas stream is introduced into feed side of a membrane separation unit containing an elastomeric polymer membrane. Ozone-enriched gas passes through the membrane to a permeate zone and is contacted with an ozone-reactive substance-containing gas stream in the permeate zone, thereby oxidizing the substances or is removed from the permeate zone. Removal of the ozone-enriched gas from the permeate zone may be effected by purging the permeate zone with an inert gas and/or evacuating the permeate zone. Ozone-enriched gas removed from the permeate zone may be mixed with a liquid or gas stream which contains ozone-reactive substances in, for example, a venturi device, thereby oxidizing the substances.

Abstract: Adsorbent composites composed of microparticulate zeolites at least 90% of whose particles have a characteristic particle dimension not greater than about 0.6 micron and a macropore inert binder. The composites are useful for separating strongly adsorbed gas components from gas mixtures. Microparticulate type X zeolites composites are particularly useful for separating nitrogen or carbon dioxide from air.

Abstract: Partial oxidation of hydrocarbons to produce hydrogen and carbon monoxide is carried out by a fluidized bed process which includes the steps of passing air through a perovskite-type ceramic mixed conductor in an adsorption zone at an elevated temperature, thereby at least partially saturating the mixed conductor with oxygen, and subsequently contacting the hot, at least partially oxygen-saturated mixed conductor with a hydrocarbon in a partial oxidation reaction zone. During the partial oxidation reaction phase of the process, the sorbed oxygen reacts with the hydrocarbon, thereby producing hydrogen, carbon monoxide or mixtures of these. The oxygen-depleted mixed conductor is recycled to the adsorption zone.

Abstract: Temperature rise during the exothermic reduction of nitrogen oxides contained in a carbon dioxide-rich gas stream to nitrogen by contacting the gas stream with ammonia in a reactor containing a reduction catalyst is controlled by recycling a portion of the gaseous effluent from the reactor to the gas stream prior to its introduction into the reactor, thereby cooling the reactor contents without diluting the carbon dioxide in the effluent.

Abstract: Methods and apparatus for filling containers with a gas or gas mixture under pressure are disclosed. The apparatus comprises a fixed volume vessel for containing the gas at a pressure P.sub.1, a line extending from the fixed volume vessel to a buffer volume vessel which has a capacity greater than the volume of the container to be filled, a pressure controller for controlling the pressure of the gas in the line so that the gas reaches the buffer volume vessel at a pressure P.sub.2 which is less than P.sub.1, a further line extending from the buffer volume vessel to at least one filling nozzle, and a valve located in the further line for controlling the flow of gas from the buffer volume vessel to the gas capsule to be filled.