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: Ammonia is purified by a membrane unit to concentrate ammonia and/or ammonia and moisture. Moisture is removed in a temperature-swing adsorption unit. The resultant product of such purification is then partially condensed to remove light components of other impurities and then partially vaporized to produce a pressurized ammonia product lean in heavy components. If the feed stream is processed through the membrane unit first, the permeate stream will be lean in such impurities as carbon dioxide, nitrogen and methane. Moisture and any carbon dioxide not removed in the membrane unit is then removed by the adsorption unit. The resultant stream produced by action of the membrane and adsorption units is then partially condensed to produce a liquid lean in light impurities. Such liquid is then partially vaporized within a product pressure vessel to produce ammonia vapor lean in heavy impurities and at a required operational pressure.

Abstract: A method of processing semiconductor manufacturing exhaust gases for recovering at least hexafluoroethane in which a feed stream composed of the exhaust gases is passed through an adsorbent bed selected to adsorb oxygen, and also nitrogen if present, but not to appreciably adsorb the hexafluoroethane. As a result, a product stream, discharged from the adsorbent bed, has a higher concentration of hexafluoroethane than in the feed stream. In one embodiment, only a single adsorbent such as carbon molecular sieve is provided to adsorb the oxygen or a modified 4A zeolite could be used to adsorb both oxygen and nitrogen. When nitrogen is a potential constituent, layers of carbon molecular sieve and zeolite are provided to adsorb the oxygen and then the nitrogen, respectively. A third adsorbent, preferably 5A zeolite may be provided in addition to the foregoing two adsorbents to also adsorb any carbon tetrafluoride produced as a by-product.

Abstract: An apparatus and method for recovering one or more components from the vapor feed in which the component is recovered from the vapor feed at a lower pressure within a lower pressure cold trap. Thereafter, a higher pressure cold trap is connected to the lower pressure cold trap and the component revaporizes in the lower pressure cold trap and resolidifies in the higher pressure cold trap. The higher pressure cold trap is then isolated and the component is allowed to thaw to build up a vapor pressure such that the component can be delivered for recovery at a high pressure. Two or more components having higher and lower boiling points can be recovered by low pressure cold traps set in series. Low pressure cold traps can be provided to operate in an out of phase relationship so that components are frozen on one set of lower pressure cold traps while being vaporized from the other set of cold traps.

Abstract: A system for controlling the atmosphere of a container for use in the storage and/or transportation of perishable goods which includes adsorption apparatus for the selective adsorption in whole or in part and in a predeterminded order of any water vapor, carbon dioxide, oxygen or ethylene contained within the atmosphere, a blower for urging the atmosphere to the adsorption apparatus, and a conduiting for returning the controlled atmosphere to the container.

Abstract: A membrane gas separation apparatus, typically for separating air, includes a gas separation cell containing an array of membranes in the form of hollow fibres. The cell has a first gas port and a second gas port. Flow of gas to and from the ports is controlled by a four-port, two-position valve. In one position, the valve admits incoming air to the first port and allows product nitrogen to flow out of the second port. In the other position the roles of the ports are reversed and hence the direction of flow of the gas is reversed. During prolonged operation, there is a tendency for contaminants to affect disproportionately the feed gas inlet of the membrane fibres. By periodically changing the position of the valve, different ends of the membrane fibres are presented to the feed gas, and thus the operating life of the membranes is lengthened.

Abstract: A gas treatment or separation apparatus includes a vessel (2) containing a bed (18) of particulate material. Within the bed (18) there is located a plurality of distensible hollow members (30) each capable of being placed in communication with a source of fluid under pressure. The members (30) restrain movement of the particulate material.

Abstract: A compressed gas mixture, particularly air, is separated in absorbent beds 6 and 8 in turn. The adsorbent adsorbs a first component in preference to, or more rapidly than, second and third components. Accordingly, product gas rich in the second component is delivered to the pipeline 44. While one bed adsorbs the first component from compressed gas mixture, the other is regenerated by being placed in communication with the atmosphere through vent pipe 30. At the end of each adsorption step, the respective bed 6 or 8 is placed in communication with a bed 12 of adsorbent that adsorbs the second component more rapidly than, or in preference to, the first and third components, and the pressure between the two beds is equalized. The pressure between the beds 6 and 8 is then equalized. Unadsorbed gas comprising the first and third components is vented from bed 12 to the atmosphere and then the bed 12 is placed in communication with either bed 6 or bed 8 to cause the desired product, i.e.