Abstract: Disclosed is a method for subjecting feed air to fractionation for recovery of a product oxygen fraction therefrom in a pressure swing adsorption (PSA) process utilizing a nitrogen-selective adsorbent (“NSA”) that is sensitive to water. The PSA process includes the steps of feed pressurization, production, equalization, and blowdown. The improvement to this PSA process commences with placing a bed of pre-treatment adsorbent between feed air and a bed of NSA. Next, a controllable valve is interposed between the pre-treatment adsorbent bed and the NSA bed. Finally, the controllable valve is kept closed during the steps of production, equalization, and when the process is idle. An advantageous NSA is LiX zeolite, Li-LSX zeolite, CaX zeolite, and similar adsorbents, particularly highly hydrophilic zeolites. Another feature of the disclosed PSA cycle is that the pre-treatment adsorbent bed blows-down while the NSA bed equalizes.

Abstract: Disclosed is a method for subjecting feed air to fractionation for recovery of a product oxygen fraction therefrom in a pressure swing adsorption (PSA) process utilizing a nitrogen-selective adsorbent (“NSA”) that is sensitive to water. The PSA process includes the steps of feed pressurization, production, equalization, and blowdown. The improvement to this PSA process commences with placing a bed of pre-treatment adsorbent between feed air and a bed of NSA. Next, a controllable valve is interposed between the pre-treatment adsorbent bed and the NSA bed. Finally, the controllable valve is kept closed during the steps of production, equalization, and when the process is idle. An advantageous NSA is LiX zeolite, Li-LSX zeolite, CaX zeolite, and similar adsorbents, particularly highly hydrophilic zeolites. Another feature of the disclosed PSA cycle is that the pre-treatment adsorbent bed blows-down while the NSA bed equalizes.

Abstract: An improved sieve bed design to manage breakthrough and the mass transfer zone by way of volumetric division. An empty space in the product end is separated from adsorbent-filled sieve space in the feed end by a mid-diffuser plate. The ratio of the empty product end void space to the adsorbent filled sieve space within a sieve bed may be determined by the relative percentages of the gasses to be separated and the bulk loading factor of the molecular sieve. A product end void space of the correct volume may ensure the maximum volume of nitrogen has been adsorbed before breakthrough occurs. In operation, pressure in the sieve bed empty space and sieve filled space may be equal at any instant. This contains breakthrough to the location of the mid-diffuser plate. The mass transfer zone may be static at the point of the mid-diffuser plate and as such, gas separation is a function of pressure within the bed.

Abstract: An improved sieve bed design to manage breakthrough and the mass transfer zone by way of volumetric division. An empty space in the product end is separated from adsorbent-filled sieve space in the feed end by a mid-diffuser plate. The ratio of the empty product end void space to the adsorbent filled sieve space within a sieve bed may be determined by the relative percentages of the gasses to be separated and the bulk loading factor of the molecular sieve. A product end void space of the correct volume may ensure the maximum volume of nitrogen has been adsorbed before breakthrough occurs. In operation, pressure in the sieve bed empty space and sieve filled space may be equal at any instant. This contains breakthrough to the location of the mid-diffuser plate. The mass transfer zone may be static at the point of the mid-diffuser plate and as such, gas separation is a function of pressure within the bed.

Abstract: A component gas concentrator includes an air compressor, an air-tight first container containing a molecular sieve bed, the first container in fluid communication with the compressor through a first gas conduit, and an air-tight second container in fluid communication with the first container through a second gas conduit. A gas flow controller such as PLC controls actuation of valves mounted to the gas conduits.

Abstract: A component gas concentrator includes an air compressor/vacuum pump, an air-tight first container containing a molecular sieve bed, the first container in fluid communication with the compressor/vacuum pump through a first gas conduit, and an air-tight second container in fluid communication with the first container through a second gas conduit. A gas flow controller such as PLC controls actuation of valves mounted to the gas conduits.