Abstract: An oxygen selective adsorbent and a method for making an oxygen selective adsorbent wherein a porous carbon substrate such as a carbon molecular sieve, activated carbon, carbon black, coal, or petroleum coke, is impregnated with a solution of an acidic species and the impregnated substrate is dried. The oxygen selective adsorbent can be used in a pressure swing adsorption process for the separation of oxygen from nitrogen, for example, in air.

Abstract: The present invention is directed to active compositions, such as adsorbents and catalysts, which comprise cuprous compounds dispersed on amorphous oxide or carbon macroporous supports. The compositions are prepared by impregnating cupric compounds on pretreated supports with the aid of an aqueous solution of an ammonium salt of a di- or polycarboxylic acid dispersant, such as ammonium citrate, followed by activation of the cupric compound or reduction of the cupric compound to the corresponding cuprous compound. Methods of synthesis and processes utilizing the compositions are also disclosed.

Abstract: The present invention is directed to a process for adsorptive separation of carbon monoxide or olefins from gas mixtures using adsorbents, which comprise cuprous compounds dispersed on amorphous oxide or carbon macroporous supports. The compositions are prepared by impregnating cupric compounds on, preferably pretreated, supports with the aid of an aqueous solution of an ammonium salt of a di- or polycarboxylic acid dispersant, such as ammonium citrate, followed by reduction of the cupric compound to the corresponding cuprous compound. The reduction can be performed either by the use of elevated temperature or by the use of a reducing gas preferably carbon monoxide at relatively low temperatures up to 150.degree. C. Methods of synthesis are also disclosed.

Abstract: Nitrogen is economically recovered from the flue gas evolved in a hydrocarbon steam reforming furnace by hydrogenation of free oxygen therein and removal of carbon dioxide and other minor impurities from the flue gas by pressure swing adsorption with recovery of high purity nitrogen is unsorbed effluent. The process is utilized to highest advantage in the production of ammonia syngas wherein natural gas or other hydrocarbon feed is subjected to steam reforming in a fuel-fired furnace. The nitrogen obtained by purification of the flue gas is combined with the purified hydrogen separated from the reformate providing the syngas for conversion to ammonia. In a preferred embodiment, the steam reforming is carried out in two stages, the first stage being performed in a conventional fuel-fired steam reforming furnace to which a major portion of the fresh hydrocarbon feed is charged.

Abstract: The present invention is directed to a process for adsorptive separation of carbon monoxide or olefins from gas mixtures using adsorbents, which comprise cuprous compounds dispersed on amorphous oxide or carbon macroporous supports. The compositions are prepared by impregnating cupric compounds on, preferably pretreated, supports with the aid of an aqueous solution of an ammonium salt of a di- or polycarboxylic acid dispersant, such as ammonium citrate, followed by reduction of the cupric compound to the corresponding cuprous compound. The reduction can be performed either by the use of elevated temperature or by the use of a reducing gas preferably carbon monoxide at relatively low temperatures up to 150.degree. C. Methods of synthesis are also disclosed.

Abstract: Multicomponent gas mixtures containing: (1) hydrogen as the primary component, (2) a secondary key component that is more strongly sorbed by the adsorbent than hydrogen, and (3) a minor quantity of one or more dilute tertiary components less strongly sorbed than the secondary key component, are subject to selective adsorption in an adiabatic pressure swing adsorption (PSA) cycle for the separate recovery of high purity hydrogen and the secondary component. A given example is the treatment of the effluent gas from a shift converter in a hydrocarbon reformer plant, wherein hydrogn and carbon dioxide are separately recovered as key components substantially freed of minor dilute components such as methane, carbon monoxide and nitrogen.

Abstract: The present invention is directed to active compositions, such as adsorbents and catalysts, which comprise cuprous compounds dispersed on amorphous oxide or carbon macroporous supports. The compositions are prepared by impregnating cupric compounds on pretreated supports with the aid of an aqueous solution of an ammonium salt of a di- or polycarboxylic acid dispersant, such as ammonium citrate, followed by activation of the cupric compound or reduction of the cupric compound to the corresponding cuprous compound. Methods of synthesis and processes utilizing the compositions are also disclosed.

Abstract: Nitrogen is economically recovered from the flue gas evolved in a hydrocarbon steam reforming furnace by hydrogenation of free oxygen therein and removal of carbon dioxide and other minor impurities from the flue gas by pressure swing adsorption with recovery of high purity nitrogen as unsorbed effluent. The process is utilized to highest advantage in the production of ammonia syngas wherein natural gas or other hydrocarbon feed is subjected to steam reforming in a fuel-fired furnace. The nitrogen obtained by purification of the flue gas is combined with the purified hydrogen separated from the reformate providing the syngas for conversion to ammonia. In a preferred embodiment, the steam reforming is carried out in two stages, the first stage being performed in a conventional fuel-fired steam reforming furnace to which a major portion of the fresh hydrocarbon feed is charged.

Abstract: Dilute impurities are removed from a hydrogen stream by selective adsorption in a bed of an X-type zeolite comprising barium cation.

Abstract: An improved pressure swing adsorption process is disclosed for the recovery of two individual components from a multicomponent gas mixture. The process utilizes a first group of adsorbent beds selective for the secondary component product and a second group of beds selective for tertiary impurities in the mixture. The gas mixture is passed through the first and second beds in series and high purity primary component product is discharged from the second beds. The secondary component product is recovered by desorption from the first beds. Product recovery is improved by recycling depressurization gas from the first beds and by several novel pressure equalization steps. The process can be used to recover high-purity hydrogen and carbon dioxide from a gas mixture containing these components along with minor amounts of methane, carbon monoxide, and nitrogen.

Abstract: A pressure swing adsorption process is provided for the direct production from ambient air of a moderately enriched oxygen product gas. The production of a product gas having an oxygen concentration of 23 to 30% is effected by a three step cycle wherein (1) the feed air is charged to a bed of nitrogen selective adsorbent until the bed is brought from atmospheric pressure to a pressure in the range of up to 10 atmospheres, (2) reducing the bed pressure to an intermediate level by withdrawal of oxygen enriched product gas therefrom and (3) finally venting the bed to restore atmospheric pressure. By an alternative mode including a fourth step of purging the bed following the venting step, a product of 23 to 45% oxygen concentration is obtained.

Abstract: A simplified low-cost system designed for home use in the direct administration of high purity oxygen to a patient, utilizes a single adsorption column containing successive layers of adsorbent. The first layer is composed of a molecular sieve adsorbent for removal of water and CO.sub.2 from the air feed stream. The second layer is a molecular sieve adsorbent which preferentially retains nitrogen. The sequence and conditions of the several steps of the operating cycle are designed to recover a therapeutic gas stream of about 90% oxygen content.

Abstract: A process is set forth for the removal of carbon dioxide from air in an adsorption bed wherein the regeneration energy is reduced by the use of a heat recuperator and a purge sequence which avoids the removal of heat from the adsorption bed during regeneration.

Abstract: Moisture and CO.sub.2 are removed from atmospheric air by adsorption of these respectively in separate beds. The moisture laden bed is regenerated by pressure swing adsorption in a relatively short operating cycle while the CO.sub.2 -laden bed is regenerated thermally at considerably longer time intervals. The described method is of particular advantage in connection with the pretreatment of air prior to cryogenic distillation for separation of oxygen and nitrogen therein.