Abstract: Commonly available carbon dioxide may contain unacceptable amounts of compounds containing greater than about ten carbon atoms, sulfur-containing materials, and nitrogen-containing materials which are particularly detrimental to semiconductor and silicon wafer processing-related uses of carbon dioxide. These impurities can be effectively removed by a combination of metal oxide, silica gel, and activated carbon, thus permitting an on-site, on-demand, convenient, and economic method of purifying carbon dioxide ranging from laboratory scale operations to tank car scale operations.

Abstract: Air in a compressed air system is cleaned by consecutively passing the air through a pre-filter (6), silica gel with large pores (7), silica gel with fine pores (8), a molecular sieve (9), and a fine filter (10).

Abstract: The present invention is a two stage PSA process for producing high purity oxygen from a feed air stream. Water, carbon dioxide and nitrogen are removed in a first stage. An oxygen selective adsorbent is used to adsorb oxygen in the second stage. High purity oxygen product is recovered during regeneration of the second stage. Importantly, the high purity of the oxygen product is achieved without inclusion of an oxygen rinse step in the process cycle. The high purity oxygen product is obtained by collecting the middle cut of the second stage effluent stream during regeneration.

Abstract: A process for the purification of a gaseous hydrogen flow containing one or more gaseous impurities from the group consisting of carbon monoxide, water vapor, nitrogen, H2S, chlorine, C1-C3 light alcohols, ammonia, carbon dioxide and linear, branched or cyclic hydrocarbons, saturated and unsaturated, C1-C8. The hydrogen flow is placed in contact with a porous carbonated adsorbent having an adsorption limit volume (W0) and an energy parameter of (E0) according to the Dubinin relationship, such that: 0.18 ml.g−1≦W0≦1.50 ml.g−1 and 15 kJ.mole−1≦E0≦45 kJ.mole−1. The porous carbonated adsorbent is selected from active carbons. The gas rich in hydrogen is a reforming gas, an electrolysis gas, a gas from ammonia cracking or from alcohol cracking.

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: This invention is directed to a method and system for purifying hexafluoroethane near its critical temperature and pressure, particularly where the hexafluoroethane contains at least about 1 ppb by weight of a non-volatile residue. A combination of a sand trap, an adsorption assembly made of a glass wool-molecular sieve-glass wool combination, and a filter is used.

Abstract: A method and apparatus for preventing contamination of a substrate or a substrate surface, and particularly relates to prevention of contamination of raw materials, semi-finished products, base materials of products and substrate surface in a high-tech industry such as in the production of semiconductors and liquid crystals. A gas coming into contact with a base material or substrate is purified by dust removing apparatus and adsorption and/or absorption apparatus so that the concentration of fine particles in the gas is below class 1,000 and a non-methane hydrocarbon concentration is below 0.2 ppm. Thereafter, the base material or the substrate surface is exposed to this gas.

Abstract: In this process for purifying a gas by adsorption of a first impurity and of a second impurity, at least two main adsorbers (5A, 5B) and at least one auxiliary adsorber (6A, 6B) are used, the main adsorbers comprising a packing (8A, 8B, 9A, 9B) for adsorbing the first and second impurities. During at least a first step, the gas is purified by adsorbing the two impurities by passing through at least a first (5A, 5B) of the main adsorbers without passing through a first auxiliary adsorbers (6A, 6B), and simultaneously the second main adsorber (5A, 5B) and the or each auxiliary adsorbers (6A, 6B, 6) is regenerated in parallel, then, during a second step, at least some of the gas flow is purified by adsorption of the two impurities by passing in series through the first main adsorber (5A, 5B) and through the first auxiliary adsorber (6A, 6B). Application, for example, to the purification of air for the purpose of its distillation.

Abstract: A low energy cost process for the co-production of oxygen and nitrogen employing a fuel tube extending into the first oxygen selective ion transport membrane whereby fuel is introduced adjacent to the closed end and flows cocurrently with oxygen containing gas in the annulus and an oxygen selective ion transport membrane having a separator section and a reactor section. An oxygen-containing feedstock, typically air, is compressed and then contacts the cathode side of the separator section where a portion of the oxygen contained within the feedstock is transported to the anode side of the separator section and recovered as an oxygen product gas. Substantially the remainder of the oxygen contained within the feedstock is transported from the cathode side of the reactor section to the anode side and exothermically reacted with a fuel. Following the exothermic reaction, hot nitrogen rich product gas is expanded in a turbine to generate the power necessary to compress the feedstock.

Abstract: Industrial grade carbon dioxide may contain unacceptable amounts of sulfur-containing materials, oxygen, and organic materials particularly detrimental to food-related uses of carbon dioxide. These can be effectively removed by a bed of silver-exchanged faujasite and an MFI-type molecular sieve. This permits an on-site, on-demand method of purifying carbon dioxide ranging from laboratory to tank car seals.

Abstract: A process for removing sulfur-containing compounds and halocarbons such as fluorocarbons and chlorocarbons from gases to provide gas streams which contain these compounds at unprecedentedly low levels using an adsorption train of four beds has been developed. The first bed serves to remove water, the second and third beds remove sulfur-containing compounds generally, and the fourth adsorbent bed removes sulfur-containing compounds and halocarbons such as chlorocarbons and fluorocarbons to very low levels.

Abstract: A process, composition and apparatus for the removal of water from moist non-corrosive gases (such as those containing oxygen or CO.sub.2) down to .ltoreq.10-20 ppb water concentration are described. The dehydrating agent is an oxide or salt of an electropositive metal and has a surface area of at least 140 m.sup.2 /g, preferably 140-500 m.sup.2 /g, is compatible with the gas, and preferably is capable of dehydrating such gases to .ltoreq.1 ppb, preferably to as low as 500 ppt. The electropositive metal will be a Group 3b, 4b or lanthanide metal or vanadium. The preferred agent is a high surface area titania, zirconia, yttria or vanadia, with titania most preferred. The dehydrating agent can be in the form of a pelleted or granular bulk material or a coating on or within the pores of a substrate. The agent is retained in a simple container which is easily installed in a gas supply line for the gas, such as to a gas- or vapor-deposition manufacturing unit.

Abstract: A system for the ultrapurification of organic solvents comprising (1) a membrane-based vapor permeation step for selective removal of water vapor from the solvent, wherein a countercurrent sweep stream is used that has a particular partial pressure of water vapor, (2) a filtration step for selective removal of particulates, and (3) an ion exchange step for selective removal of ionic species.

Abstract: A method and apparatus for preventing contamination of a substrate or a substrate surface, and particularly relates to prevention of contamination of raw materials, semi-finished products, base materials of products and substrate surface in a high-tech industry such as in the production of semiconductors and liquid crystals. A gas coming into contact with a base material or substrate is purified by dust removing apparatus and adsorption and/or absorption apparatus so that the concentration of fine particles in the gas is below class 1,000 and a non-methane hydrocarbon concentration is below 0.2 ppm. Thereafter, the base material or the substrate surface is exposed to this gas.

Abstract: A process for preparing ultrafine aluminum silicate salt particles, said process comprising the steps of admixing a solution of aluminum chloride with water glass to form an aluminum silicate gel, adding a suspension of calcium and magnesium hydroxides into said aluminum silicate gel to form a calcium and magnesium salt of aluminum silicate, aging said calcium and magnesium salt of aluminum silicate by heating and agitating, neutralizing a mixture of a solution of sodium aluminate and water glass by adding hydrochloric acid to form another aluminum silicate gel, and admixing said another aluminum silicate gel into with aged calcium and magnesium salt of aluminum silicate, and simultaneously heating and agitating the resulting mixture.

Abstract: Apparatus for drying flowing gas includes a generally cylindrical vessel having a gas inlet and a gas outlet, two perforated plates of different metals in contact with each other transverse the interior of the vessel, and a third perforated plate downstream from the two mutually contacting plates.

Abstract: Vacuum pressure swing adsorption (VPSA) processing is carried out employing a processing sequence of ten steps that serves to enhance the productive capacity thereof for air separation and other desirable applications.

Abstract: Processes and systems for purifying high purity helium group gas which may have been contaminated with water, oxygen and/or hydrogen during its transmission to customers' sites.