Modular pressure swing adsorption apparatus

Abstract

A rotary module for implementing a high frequency pressure swing adsorption process comprises a stator and a rotor rotatably coupled to the stator. The stator includes a first stator valve surface, a second stator valve surface, a plurality of first function compartments opening into the first stator valve surface, and a plurality of second function compartments opening into the second stator valve surface. The rotor includes a first rotor valve surface in communication with the first stator valve surface, a second rotor valve surface in communication with the second stator valve surface, and a plurality of flow paths for receiving adsorbent material therein. Each flow path includes a pair of opposite ends, and a plurality of apertures provided in the rotor valve surfaces and in communication with the flow path ends and the function ports for cyclically exposing each said flow path to a plurality of discrete pressure levels between the upper and lower pressures for maintaining uniform gas flow through the first and second function compartments.

We claim:  
     
         1 . A rotary module for implementing a pressure swing adsorption process having an operating pressure cycling between an upper pressure and a lower pressure for extracting a first gas fraction and a second gas fraction from a gas mixture including the first and second fractions, the rotary module comprising: 
 a stator including a first stator valve surface, a second stator valve surface, a plurality of first function compartments opening into the first stator valve surface, and a plurality of second function compartments opening into the second stator valve surface; and    a rotor rotatably coupled to the stator and including a first rotor valve surface in communication with the first stator valve surface, a second rotor valve surface in communication with the second stator valve surface, a plurality of flow paths for receiving adsorbent material therein, each said flow path including a pair of opposite ends, and a plurality of apertures provided in the rotor valve surfaces and in communication with the flow path ends and the function ports for cyclically exposing each said flow path to a plurality of discrete pressure levels between the upper and lower pressures for maintaining uniform gas flow through the first and second function compartments.    
     
     
         2 . The rotary module according to  claim 1 , wherein the function compartments are shaped to provide uniform gas flow through the flow paths.  
     
     
         3 . The rotary module according to  claim 1 , wherein at least one of the valve surfaces includes a sealing strip for reducing gas flow loss between the valve surfaces, the sealing strip including a tapered portion for providing uniform gas flow through the flow paths.  
     
     
         4 . The rotary module according to  claim 3 , wherein the sealing strip is shaped to provide rapid closing of the flow paths.  
     
     
         5 . The rotary module according to  claim 1 , wherein each said function compartment simultaneously communicates with at least two flow paths for providing uniform gas flow through the function compartments.  
     
     
         6 . The rotary module according to  claim 1 , wherein each said function compartment is coupled immediately adjacent to a respective end of a respective one of the flow paths for implementing high frequency pressure swing adsorption.  
     
     
         7 . The rotary module according to  claim 6 , wherein the function compartments are positioned a distance from the respective flow path ends sufficient for implementing the pressure swing adsorption process at a rotor rotational speed of at least 20 revolutions per minute.  
     
     
         8 . The rotary module according to  claim 1 , wherein the function compartments include a plurality of pressurization compartments for subjecting the flow paths to a plurality of incremental pressures increases.  
     
     
         9 . The rotary module according to  claim 8 , wherein the pressurization compartments comprise gas feed compartments opening into the first stator valve surface for delivering the gas mixture to the flow paths at a plurality of incrementally different pressures.  
     
     
         10 . The rotary module according to  claim 8 , wherein the pressurization compartments comprise light reflux return compartments opening into the second stator valve surface for delivering light reflux gas to the flow paths at a plurality of incrementally different pressures.  
     
     
         11 . The rotary module according to  claim 1 , wherein the first function compartments include a plurality of blowdown compartments for subjecting the flow paths to a plurality of incremental pressure drops.  
     
     
         12 . The rotary module according to  claim 11 , wherein the blowdown compartments comprise light reflux exit compartments opening into the second stator valve surface for removing light reflux gas from the flow paths at a plurality of incrementally different pressures.  
     
     
         13 . The rotary module according to  claim 11 , wherein the blowdown compartments comprise countercurrent blowdown compartments opening into the first stator valve surface for removing heavy product gas from the flow paths at a plurality of incrementally different pressures.  
     
     
         14 . The rotary module according to  claim 1 , wherein the second function compartments include a plurality of cocurrent blowdown compartments for subjecting the flow paths to a plurality of incremental pressure drops, and a plurality of light reflux return compartments communicating with the cocurrent blowdown compartments for subjecting the flow paths to a plurality of incremental pressure increases, and the stator includes pressure let-down means coupled between the cocurrent blowdown compartments and the light reflux return compartments for delivering gas removed from the cocurrent blowdown compartments at reduced pressure to the light reflux return compartments.  
     
     
         15 . The rotary module according to  claim 14 , wherein the pressure let-down means comprises one of mechanical expansion stages, restrictor orifices and throttle valves.  
     
     
         16 . The rotary module according to  claim 14 , wherein the second function compartments include a light product compartment, and the pressure let-down means comprises an expander coupled to the cocurrent blowdown compartments and the light reflux return compartments, and a compressor coupled to the light product compartment and to the expander for boosting light product gas pressure.  
     
     
         17 . The rotary module according to  claim 1 , wherein the first function compartments include a plurality of countercurrent blowdown compartments for subjecting the flow paths to a plurality of incremental pressure drops, and a heavy reflux return compartment communicating with at least one of the countercurrent blowdown compartments, and the stator includes a reflux compressor coupled between the countercurrent blowdown compartments and the heavy reflux return compartment for delivering gas removed from the countercurrent blowdown compartments at increased pressure to the heavy reflux return compartments.  
     
     
         18 . The rotary module according to  claim 1 , wherein the function compartments are disposed around the respective valve surfaces for conveying gas along the flow paths in a common predetermined sequence for each flow path, the sequence for each flow path comprising delivering the gas mixture at the upper pressure from a gas feed function compartment to the flow path end adjacent the first rotor valve surface while removing light product gas at the upper pressure from the flow path end adjacent the second rotor valve surface to a light product function compartment, removing heavy product gas at the lower pressure from the flow path end adjacent the first rotor valve surface to a heavy product gas function compartment, and delivering gas at a pressure intermediate the upper and lower pressure from a repressurization function compartment to the flow path end adjacent the first rotor valve surface ahead of the gas feed function compartment.  
     
     
         19 . The rotary module according to  claim 1 , wherein the function compartments are disposed around the respective valve surfaces for conveying gas along the flow paths in a common predetermined sequence for each flow path, the sequence for each flow path comprising delivering the gas mixture at the upper pressure from a gas feed function compartment to the flow path end adjacent the first rotor valve surface while removing light product gas at the upper pressure from the flow path end adjacent the second rotor valve surface to a light product function compartment, removing gas at a pressure intermediate the upper and lower pressures from the flow path end adjacent the second rotor valve surface to a cocurrent blowdown function compartment, and removing heavy product gas at the lower pressure from the flow path end adjacent the first rotor valve surface to a heavy product gas function compartment.  
     
     
         20 . The rotary module according to  claim 1 , wherein the function compartments are disposed around the respective valve surfaces for conveying gas along the flow paths in a common predetermined sequence for each flow path, the sequence for each flow path comprising delivering the gas mixture at the upper pressure from a gas feed function compartment to the flow path end adjacent the first rotor valve surface while removing light product gas at the upper pressure from the flow path end adjacent the second rotor valve surface to a light product function compartment, removing gas at a pressure intermediate the upper and lower pressures from the flow path end adjacent the first rotor valve surface to a countercurrent blowdown function compartment, and removing heavy product gas at the lower pressure from the flow path end adjacent the first rotor valve surface to a heavy product gas function compartment.  
     
     
         21 . The rotary module according to  claim 1 , wherein each said flow path includes a laminated sheet adsorber.  
     
     
         22 . A rotor module for use with a stator for implementing a pressure swing adsorption process having an operating pressure cycling between an upper pressure and a lower pressure, the rotor module comprising: 
 an annular rotor including a first rotor valve surface for communicating with a first stator valve surface of the stator, a second rotor valve surface for communicating with a second stator valve surface of the stator, a plurality of flow paths spaced around the rotor and extending between the rotor valve surfaces, and a plurality of apertures provided in the rotor valve surfaces in communication with the flow paths for cyclically exposing each said flow path to a plurality of discrete pressure levels between the upper and lower pressures; and    a plurality of adsorbent beds disposed in the flow paths in communication with the apertures.    
     
     
         23 . The rotor module according to  claim 22 , wherein each said adsorbent bed comprising at least two laminated adsorbent sheets, each said sheet including a reinforcement matrix, an adsorbent material deposited therein, a binder for securing the adsorbent material to the binder, and a spacer provided between the two laminated sheets for providing a flow channel therebetween.  
     
     
         24 . The rotor module according to  claim 23 , wherein the reinforcement material is selected from glass fiber, metal wire matrix, metal foil, inorganic fiber and organic fiber.  
     
     
         25 . The rotor module according to  claim 23 , wherein the adsorbent material comprises zeolite crystallites.  
     
     
         26 . The rotor module according to  claim 22 , wherein the rotor has an inner circumference and an outer circumference, and the adsorbent beds have a width, the width being greater adjacent the outer circumference than adjacent the inner circumference and increasing in magnitude with distance from the inner circumference.  
     
     
         27 . The rotor module according to  claim 22 , wherein the adsorbent beds have a curved shape.  
     
     
         28 . The rotor module according to  claim 22 , wherein the adsorbent beds comprise a plurality of adsorbent pellets, each said pellet comprising an inert core coated with an adsorbent material.  
     
     
         29 . The rotor module according to  claim 28 , wherein the inert core is selected from iron group metals and oxides thereof.  
     
     
         30 . The rotor module according to  claim 28 , wherein the pellet has a volume, and the inert core comprises half of the volume.  
     
     
         31 . The rotor module according to  claim 22 , wherein the flow paths include a pair of opposite ends, and each said aperture is disposed immediately adjacent to a respective one of the opposite ends.  
     
     
         32 . A pressure swing adsorption system for extracting a first gas fraction and a second gas fraction from a gas mixture including the first and second fractions, the pressure swing adsorption system comprising: 
 a rotary module coupled to a gas feed manifold, a heavy product manifold, and a light product manifold, the rotary module comprising: 
 stator including a first stator valve surface, a second stator valve surface, a plurality of first function compartments opening into the first stator valve surface, and a plurality of second function compartments opening into the second stator valve surface; and  
 a rotor rotatably coupled to the stator and including a first rotor valve surface in communication with the first stator valve surface, a second rotor valve surface in communication with the second stator valve surface, a plurality of flow paths for receiving adsorbent material therein, each said flow path including a pair of opposite ends, and a plurality of apertures provided in the rotor valve surfaces and in communication with the flow path ends and the function ports; and  
   compression/expansion machinery coupled to the rotary module for maintaining the function ports at a plurality of discrete pressure levels between an upper pressure and a lower pressure for maintaining uniform gas flow through the first and second function compartments.    
     
     
         33 . The pressure swing adsorption system according to  claim 32 , wherein the function compartments include a plurality of gas feed compartments, and the compression/expansion machinery comprises a multi-stage compressor including a plurality of pressure output ports, each said pressure output port being coupled to a respective one of the feed compartments for delivering feed gas to the flow paths at a plurality of pressure increments.  
     
     
         34 . The pressure swing adsorption system according to  claim 33 , wherein the multi-stage compressor comprises a centrifugal compressor having a plurality of stages, each said stage including a gas inlet, a diffuser, and an impeller coupled to the gas inlet and having an axis of rotation for accelerating gas from the gas inlet towards the diffuser.  
     
     
         35 . The pressure swing adsorption system according to  claim 33 , wherein the multi-stage compressor comprises a multi-stage axial flow split stream compressor including a plurality of annular stator rings of progressively decreasing diameter, each said stator ring including an annular flow area and a plurality of stator blades, and a rotor having an axis of rotation and including a plurality of rotor blades cooperating with the stator blades for compressing gas flow through the flow area, at least one of the said stator rings further including a collector and a diffuser for apportioning the compressed gas flow between the collector and the flow area of a subsequent one of the stator rings.  
     
     
         36 . The pressure swing adsorption system according to  claim 33 , wherein the function compartments include a plurality of blowdown compartments, and the compression/expansion machinery includes a multi-stage vacuum pump coupled to the compressor, the vacuum pump including a plurality of pressure inlet ports, each said pressure inlet port being coupled to a respective one of the blowdown compartments for receiving blowdown gas from the flow paths at a plurality of pressure increments.  
     
     
         37 . The pressure swing adsorption system according to  claim 33 , wherein the function compartments include a plurality of blowdown compartments, and the pressure swing adsorption system includes a plurality of throttle orifices coupled to the blowdown compartments for releasing blowdown gas from the flow paths at a plurality of pressure increments.  
     
     
         38 . The pressure swing adsorption system according to  claim 32 , wherein the function compartments include a plurality of countercurrent blowdown compartments and a plurality of cocurrent blowdown compartments, and the compression/expansion machinery comprises a first expander coupled to the countercurrent blowdown compartments and a second expander coupled to the first expander and to the cocurrent blowdown compartments.  
     
     
         39 . The pressure swing adsorption system according to  claim 36 , wherein the function compartments include a plurality of gas feed compartments, and the compression/expansion machinery includes a compressor coupled to the gas feed compartments and to the first and second expanders.  
     
     
         40 . The pressure swing adsorption system according to  claim 33 , wherein the multi-stage turbine is coupled to a plurality of said rotary modules, and the gas feed manifold, the heavy product manifold, and the light product manifold are coupled to the plurality of rotary modules.  
     
     
         41 . A multi-stage axial flow split stream compressor comprising: 
 a plurality of annular stator rings of progressively decreasing diameter, each said stator ring including an annular flow area and a plurality of stator blades; and    a rotor having an axis of rotation and including a plurality of rotor blades cooperating with the stator blades for compressing gas flow through the flow area, at least one of the stator rings further including a collector and a diffuser for apportioning the accelerated gas flow between the collector and the flow area of a subsequent one of the stator rings.