Compressible Fluid Separation Pump

Abstract

The compressible fluid separation pump includes a crankshaft, four cylinders, and four pistons. Each cylinder includes an inlet including an inlet valve for a mixed fluid including a target component and a reject component, a reject outlet including a reject valve for a reject fluid, and a select outlet for a select fluid, each including a separation member that favors the target component over the reject component such that the target component is in a higher concentration in the select fluid than in the mixed fluid and the reject fluid. Each piston is connected to the crankshaft and located in one of the four cylinders, and the crankshaft is configured to place two of the pistons at top dead center when the other two of the pistons are at bottom dead center.

Description

[Technical field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to compressible fluid separation pumps, and more particularly to gas separation pumps with gas membranes or sorbents. [Background technology]

[0002] Separation of trace gases from other, more common gases can be an important process step for many applications, including natural gas extraction, chemical refinery manufacturing, production of special gases (i.e., oxygen (O2)) in medical environments, and removal of greenhouse gases (i.e., carbon dioxide (CO2)) from combustion products or the atmosphere. One method of separation is filtration, where a mixture of trace and common gases at relatively high pressure is on one side of a selective membrane. This forces the trace gas through the membrane into a collection vessel, while the common gas is exhausted.

[0003] In some systems, the upstream side of the membrane is pressurized to force the trace gas through the membrane, but the energy required for such filtration can be roughly the product of the compression force multiplied by the forced distance. A significant portion of the compression energy is wasted in compressing the general gas before filtration, since the partial pressure of the trace gas in the mixture must exceed the partial pressure of the same trace gas after filtration. In other systems, the downstream side of the membrane has a vacuum pressure to force the trace gas through the membrane. In such systems, less energy is required because the pressure drop across the membrane is limited to atmospheric pressure (e.g., the difference between atmospheric pressure and about zero pressure). However, the flow rate of such systems can be low, so the process requires substantially more time to perform.

[0004] Another separation method is gas sorption (i.e., absorption or adsorption) using pressure swing technology. In such a process, a gas mixture is compressed at high pressure into a sorption material, where trace gases are captured and then released into a vessel at low pressure. Like membrane separation, pressure swing sorption separation also involves compressing common gases, which can waste energy. Summary of the Invention

[0005] According to one embodiment of the present disclosure, a compressible fluid separation pump includes a crankshaft, four cylinders, and four pistons. Each cylinder includes an inlet including an inlet valve for a mixed fluid including a target component and a reject component, a reject outlet including a reject valve for a reject fluid, and a select outlet for a select fluid, each including a separation member that favors the target component over the reject component such that the target component is in a higher concentration in the select fluid than in the mixed fluid and the reject fluid. Each piston is connected to the crankshaft and located in one of the four cylinders, and the crankshaft is configured to place two of the pistons at top dead center when the other two of the pistons are at bottom dead center.

[0006] According to one embodiment of the present disclosure, a method of operating a compressible fluid separation pump includes rotating a crankshaft connected to four pistons, each piston located in one of four cylinders, each cylinder including an inlet including an inlet valve for a mixed fluid including a target component and a reject component, a reject outlet including a reject valve for a reject fluid, and a select outlet for a select fluid, each including a separation member that favors the target component over the reject component such that the target component is in a higher concentration in the select fluid than in the mixed fluid and the reject fluid. The method also includes opening an inlet valve for one of the four cylinders while its piston is moving toward bottom dead center to draw the mixed fluid into the one cylinder, closing the inlet valve for the one cylinder, compressing the mixed fluid against a separator member of the one cylinder while its piston is moving toward top dead center, and depressurizing the one cylinder while its piston is moving toward bottom dead center to assist in rotating the crankshaft to compress the mixed fluid against a separator member of another cylinder while its piston is moving toward top dead center.

[0007] According to one embodiment of the present disclosure, a compressible fluid separation pump includes a crankshaft, eight cylinders, and eight pistons. Each cylinder includes a first inlet including a first inlet valve for a mixed fluid including a target component and a reject component, a first selection outlet having a first outlet valve for a select fluid, each including a first separation member that favors the target component over the reject component such that the target component is in a higher concentration in the select fluid than in the mixed fluid and the reject fluid, and a second selection outlet having a second outlet valve for the select fluid, each including a second separation member that favors the target component over the reject component such that the target component is in a higher concentration in the select fluid than in the mixed fluid and the reject fluid. Each piston is connected to the crankshaft and located in one of the eight cylinders, and the crankshaft is configured to place four of the pistons at top dead center when the other four of the pistons are at bottom dead center.

[0008] According to one embodiment of the disclosure, a method of operating a compressible fluid separation pump includes rotating a first crankshaft connected to eight pistons, each piston being located in one of eight cylinders, each cylinder including a first inlet including a first inlet valve for a mixed fluid including a target component and a reject component, a first selection outlet including a first outlet valve for a select fluid, each including a first separation member that favors the target component over the reject component such that the target component is in a higher concentration in the select fluid than in the mixed fluid and the reject fluid, and a second selection outlet including a second outlet valve for the select fluid, each including a second separation member that favors the target component over the reject component such that the target component is in a higher concentration in the select fluid than in the mixed fluid and the reject fluid. The method also includes opening a first inlet valve for one of the first cylinders while its piston is moving toward bottom dead center to draw the mixed fluid into the one of the cylinders, closing the first inlet valve for the one of the first cylinders, opening a first selective outlet valve, compressing the mixed fluid against a separator member of the one of the first cylinders while its piston is moving toward top dead center, and depressurizing the one of the first cylinders while its piston is moving toward bottom dead center to assist in rotating the first crankshaft to compress the mixed fluid against a separator member of another of the first cylinders while its piston is moving toward top dead center.

[0009] According to one embodiment of the present disclosure, a compressible fluid separation pump having a Wankel type configuration includes a housing, a rotatable shaft, and an eccentric rotor. The housing includes a cavity, an inlet for a mixed fluid fluidly connected to the cavity, the mixed fluid including a target component and a reject component, a reject outlet for a reject fluid fluidly connected to the cavity, and a select outlet for a select fluid fluidly connected to the cavity, the select outlet including a separation member that favors the target component over the reject component such that the target component is in a higher concentration in the select fluid than in the mixed fluid and the reject fluid, the inlet and the reject outlet being on one side of the housing and the select outlet being on an opposite side of the housing. The rotatable shaft passes through the housing, and the eccentric rotor is rotatably connected to the shaft and has a triangular shape with curved sides, the eccentric rotor orbiting within the housing such that decompression of the reject fluid on one side of the eccentric rotor assists in compression of the mixed fluid on another side of the eccentric rotor. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic diagram of a compressible fluid separation system including a compressible fluid separation pump according to an embodiment of the present disclosure. [Diagram 2] 1 is a schematic cross-sectional view of a compressible fluid separation pump according to an embodiment of the present disclosure. [Diagram 3] FIG. 2 is a transparent perspective view of a portion of a compressible fluid separation pump according to an embodiment of the present disclosure. [Figure 4] 1A-1C are schematic diagrams of a sequence of operations of a compressible fluid separation pump in accordance with an embodiment of the present disclosure. [Diagram 5] 4 is a table illustrating the operation of a compressible fluid separation pump according to an embodiment of the present disclosure. [Figure 6] FIG. 2 is a schematic cross-sectional view of an alternative compressible fluid separation pump according to an embodiment of the present disclosure. [Figure 7] FIG. 2 is a schematic cross-sectional view of an alternative compressible fluid separation pump according to an embodiment of the present disclosure. [Figure 8] FIG. 1 is a schematic diagram of a two-stage compressible fluid separation system including two series compressible fluid separation pumps according to an embodiment of the present disclosure. [Figure 9]FIG. 1 is a schematic cross-sectional view of a two-stage compressible fluid separation system including two series compressible fluid separation pumps according to an embodiment of the present disclosure. [Figure 10] FIG. 2 is a schematic cross-sectional view of an alternative two-stage compressible fluid separation system including two series compressible fluid separation pumps according to an embodiment of the present disclosure. [Figure 11] FIG. 2 is a schematic cross-sectional view of an alternative compressible fluid separation pump according to an embodiment of the present disclosure. [Figure 12] 12 is a table illustrating the operation of the alternative compressible fluid separation pump of FIG. 11 in accordance with an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Various embodiments of the present disclosure are described herein with reference to the associated drawings. Alternative embodiments may be devised without departing from the scope of the present disclosure. It should be noted that in the following description and drawings, various connections and positional relationships between elements (e.g., above, below, adjacent, etc.) are shown. These connections and / or positional relationships can be direct or indirect unless otherwise specified, and the present disclosure is not intended to be limited in this respect. Thus, the coupling of entities refers to either direct coupling or indirect coupling, and the positional relationship between entities can be a direct positional relationship or an indirect positional relationship.

[0012] The following definitions and abbreviations are used in the interpretation of the claims and the specification. As used herein, the terms "comprises," "comprises," "includes," "includes," "has," "having," "containing," "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, mixture, process, method, article, or device that includes a list of elements is not necessarily limited to only those elements, and may include other elements not expressly stated or inherent to such composition, mixture, process, method, article, or device. In addition, any numerical ranges included herein include the boundaries of those numerical ranges unless expressly stated otherwise.

[0013] Hereinafter, for purposes of explanation, the terms "top", "bottom", "right", "left", "vertical", "horizontal", "upper", "lower" and their derivatives shall refer to the described structures and methods as oriented in the drawings. The terms "overlying", "atop", "on top", "positioned on" or "positioned atop" mean that a first element, such as a first structure, is on a second element, such as a second structure, and that an intervening element, such as an interface structure, may be between the first and second elements. The term "direct contact" means that a first element, such as a first structure, and a second element, such as a second structure, are connected without any intermediate components at the interface between the two elements.

[0014] FIG. 1 is a schematic diagram of a compressible fluid separation system 100 ("system 100"), which includes a gas source 102, a mixing pump 104, a compressible fluid separation pump 106 ("separator 106"), a select pump 108, and a reject pump 110. In some embodiments, the gas source 102 is some type of combustion system, e.g., a power plant. In such embodiments, the composition of the mixed exhaust gas generated therefrom may be essentially, e.g., 5-15% carbon dioxide (CO2) and 95-85% nitrogen (N2) (and possibly other trace gases). In some situations, it may be beneficial to separate the mixed gas into a target component and an exhaust component in order to collect the target component. In other embodiments, the gas source 102 is absent and the mixing pump 104 draws air (which is a mixed gas) from the atmosphere. In such embodiments, the concentration of carbon dioxide is 0.04%. In other embodiments, the system 100 operates on different compressible mixed fluids.

[0015] In the illustrated embodiment, the mixing pump 104 draws some or all of the exhaust from the gas source 102. The mixed gas then enters the separator 106 where it is separated into a select gas and a reject gas. The separator 106 functions to filter the mixed gas such that the concentration of the target component is higher in the select gas than in the mixed gas and the reject gas, and the concentration of the exhaust component is lower in the select gas than in the mixed gas and the reject gas. Conversely, the concentration of the exhaust component is higher in the reject gas than in the mixed gas and the select gas, and the concentration of the target component is lower in the reject gas than in the mixed gas and the select gas. In some embodiments, the target component is carbon dioxide and the exhaust component is nitrogen, so that the select gas has a higher concentration of carbon dioxide than the mixed gas. The select gas exits the separator 106 separately from the reject gas, but the select gas is not limited to being carbon dioxide. Instead, it may include some of the exhaust component (e.g., nitrogen). Similarly, the reject gas may include some of the target component (e.g., carbon dioxide), even though carbon dioxide is the target for the selection.

[0016] In the illustrated embodiment, the select gas may be pumped by a select pump 108 for collection (e.g., compressed to a supercritical fluid and sent off-site). The reject gas may be pumped out of the system 100 (e.g., vented to atmosphere) by a reject pump 110. This allows the system 100 to separate low concentration or trace gases from common gases. Although the system 100 includes pumps 104, 108, and 110, the system 100 (or portions thereof) may operate at ambient pressure. In such an embodiment, the pumps 104, 108, and / or 110 are optional or absent.

[0017] Figure 2 is a schematic cross-sectional view of the separator 106. Figure 3 is a transparent perspective view of a portion of the separator 106. Figures 2 and 3 will now be described together. In general, the separator 106 resembles an in-line four-stroke reciprocating internal combustion engine, although there are significant differences between the two machines.

[0018] In the illustrated embodiment, separator 106 includes block 112 (having cylinders 114A-114D, collectively "cylinders 114"), pistons 116A-116D (collectively "pistons 116"), crankshaft 118, motor 120, flywheel 122, inlet manifold 124, selection manifold 126, and reject manifold 128. Cylinders 114A-114D each include inlets 130A-130D (collectively "inlets 130"), selection outlets 132A-132D (collectively "selection outlets 132"), and reject outlets 134A-134D (collectively "reject outlets 134"). The inlets 130A-130D include inlet valves 136A-136D (collectively "inlet valves 136"), the selection outlets 132A-132D include selection valves 138A-138D (collectively "selection valves 138") and separation members 140A-140D (collectively "separation members 140"), and the reject outlets 134A-134D include reject valves 142A-142D (collectively "reject valves 142"), respectively.

[0019] In the illustrated embodiment, each piston 116 is slidably disposed in its corresponding cylinder 114 and is movable between bottom dead center (for piston 116A) and top dead center (for piston 116B). Movement of the pistons 116 is effected by a crankshaft 118 to which each piston 116 is rotatably connected. More specifically, the crankshaft 118 has a series of eccentrics on which the pistons 116 each ride such that rotation of the crankshaft 118 can be translated into linear reciprocating translation of the pistons 116. Two of these eccentrics are at the same radial location on the crankshaft 118 and the other two are at opposite sides thereof (i.e., 180 degrees apart). The crankshaft 118 is also connected to a motor 120 (which may be, for example, an electric motor or an internal combustion engine) and a flywheel 122. The rotation of the crankshaft 118 may be powered in part by a motor 120, and a flywheel 122 increases the rotational inertia of the crankshaft 118 to smooth its rotation throughout the operation of the separator 106.

[0020] In the illustrated embodiment, the top of each cylinder 114 includes an inlet 130, a select outlet 132, and a reject outlet 134. Each inlet 130 is fluidly connected to an inlet manifold 124, each select outlet 132 is fluidly connected to a select manifold 126, and each reject outlet 134 is fluidly connected to a reject manifold 128. In some embodiments, the inlet manifold 124 is fluidly connected to the mix pump 104 (shown in FIG. 1), the select manifold 126 is fluidly connected to the select pump 108 (shown in FIG. 1), or the reject manifold 128 is fluidly connected to the reject pump 110 (shown in FIG. 1), or a combination thereof.

[0021] In the illustrated embodiment, valves 136, 138, 142 control the flow of gas from inlet manifold 124 through cylinder 114 to manifolds 126, 128. Valves 136, 138, and 142 can be controlled, for example, electronically by an actuator (not shown) with sensors or mechanically by a camshaft (not shown), although in some embodiments, selection valve 138 is a check valve that is not controlled by another system. Additionally, separation member 140 is located between cylinder 114 and selection manifold 126. Separation member 140 controls the type of fluid that enters manifold 126. More specifically, separation member 140 may be a polymer or graphene selective membrane that favors certain component materials (e.g., atoms or molecules) over others. In this context, when selection member 140 favors a component, that component is more likely to pass through separation member 140 than other components, or other components are less likely to pass through separation member 140 than the favored component, or both. For example, the separation member 140 may be configured to selectively favor carbon dioxide over nitrogen when carbon dioxide is the target component and nitrogen is the exhaust component. Such a separation member 140 may still pass some nitrogen, but the select gas downstream of the separation member 140 will have a higher concentration of carbon dioxide and a lower concentration of nitrogen than the gas mixture upstream. The degree to which the target component is favored (and thus passed through the separation member in higher proportions) while the exhaust component is disliked (and thus not passed through the separation member 140 in the same proportions) may be application specific, such that a level of preference that is satisfactory in one application may be unsatisfactory in another application.

[0022] FIG. 4 is a series of schematic diagrams of the operation of the separator 106. Since the separator 106 operates in a four-stroke cycle, FIG. 4 includes four diagrams I-IV. FIG. 5 is a table explaining the operation of the separator 106. Since the separator 106 operates in a four-stroke cycle, FIG. 5 includes four columns I-IV. Next, FIG. 4 and FIG. 5 will be explained together.

[0023] In general, the four-stroke cycle that each cylinder 114 / piston 116 pair completes (and repeats) is composed of the following operations: I) intake, II) compression, III) decompression, and IV) exhaust. At a given time, each of the pistons 116 completes a different operation. The intake and exhaust operations do not require much energy to complete (i.e., the input from the motor 120 shown in FIG. 2 simply needs to overcome friction and gas flow losses), while the compression operation requires a significant amount of energy input. However, each compression operation occurs simultaneously with a decompression operation on a different cylinder 114 / piston 116 pair, and the energy made available during the decompression operation can be transferred to the compression cylinder 114 / piston 116 via the crankshaft 118. This provides a significant portion of the energy input for the compression operation, reducing the energy input from the motor 120.

[0024] In the illustrated embodiment of FIG. I, piston 116A is moving toward bottom dead center (BDC) drawing mixed gas from inlet manifold 124 (shown in FIG. 2) into cylinder 114A. Thus, column I indicates that inlet valve 136A is open and valves 138A and 142A are closed. Piston 116B is moving toward top dead center (TDC) exhausting reject gas from cylinder 114B into reject manifold 128 (shown in FIG. 2). Thus, column I indicates that reject valve 142B is open and valves 136B and 138B are closed. Piston 116C is moving toward BDC during the decompression of cylinder 114C to assist the compression being performed by piston 116D in cylinder 114D. Thus, column I indicates that valves 136C and 138C are closed. However, reject valve 142C is shown closed and open because reject valve 142C is initially closed and opens toward the end of the stroke to prevent a vacuum from building up in cylinder 114C. Piston 116D is moving toward TDC during compression of cylinder 114D to increase the differential pressure across separation member 140D. Urged by the force thus applied, the target component moves through the selective membrane and into selection manifold 126 (shown in FIG. 2). Thus, column I shows that selection valve 138D is open and valves 136D and 142D are closed.

[0025] In the illustrated embodiment of FIG. II, piston 116B is moving toward BDC drawing mixed gas from inlet manifold 124 into cylinder 114B. Thus, column II indicates that inlet valve 136B is open and valves 138B and 142B are closed. Piston 116C is moving toward TDC exhausting rejected gas from cylinder 114C into reject manifold 128. Thus, column II indicates that reject valve 142C is open and valves 136C and 138C are closed. Piston 116D is moving toward BDC during the decompression of cylinder 114D to assist the compression being performed by piston 116A in cylinder 114A. Thus, column II indicates that valves 136D and 138D are closed. However, reject valve 142D is shown closed and open because reject valve 142D is initially closed and then opens toward the end of the stroke to prevent a vacuum from building up in cylinder 114D. Piston 116A is moving toward TDC during compression of cylinder 114A to increase the pressure differential across separation member 140A. Urged by the force thus applied, the target component moves through the selective membrane to selection manifold 126. Thus, column II shows that selection valve 138A is open and valves 136A and 142A are closed.

[0026] In the illustrated embodiment of FIG. III, piston 116C is moving toward BDC drawing mixed gas from inlet manifold 124 into cylinder 114C. Thus, row III indicates that inlet valve 136C is open and valves 138C and 142C are closed. Piston 116D is moving toward TDC exhausting rejected gas from cylinder 114D into reject manifold 128. Thus, row III indicates that reject valve 142D is open and valves 136D and 138D are closed. Piston 116A is moving toward BDC during cylinder 114CA decompression to assist the compression being performed by piston 116B in cylinder 114B. Thus, row III indicates that valves 136A and 138A are closed. However, reject valve 142A is shown closed and then opened because reject valve 142A is initially closed and then opens toward the end of the stroke to prevent a vacuum from building up in cylinder 114A. Piston 116B is moving toward TDC during compression of cylinder 114B to increase the pressure differential across separation member 140B. Urged by the force thus applied, the target component moves through the selective membrane to selection manifold 126. Thus, column III shows that selection valve 138B is open and valves 136B and 142B are closed.

[0027] In the illustrated embodiment of FIG. IV, piston 116D is moving toward BDC drawing mixed gas from inlet manifold 124 into cylinder 114D. Thus, row IV indicates that inlet valve 136D is open and valves 138D and 142D are closed. Piston 116A is moving toward TDC exhausting rejected gas from cylinder 114A into reject manifold 128. Thus, row IV indicates that reject valve 142A is open and valves 136A and 138A are closed. Piston 116B is moving toward BDC during the decompression of cylinder 114B to assist the compression being performed by piston 116C in cylinder 114C. Thus, row IV indicates that valves 136B and 138B are closed. However, reject valve 142B is shown to be closed and open because reject valve 142B is initially closed and then opens toward the end of the stroke to prevent a vacuum from building up in cylinder 114B. Piston 116C is moving toward TDC during compression of cylinder 114C to increase the pressure differential across separation member 140C. Urged by the force thus applied, the target component moves through the selective membrane to selection manifold 126. Thus, column IV shows that selection valve 138C is open and valves 136C and 142C are closed.

[0028] In the illustrated embodiment, the partial pressure of the target component in the mixed gas needs to be higher than the partial pressure of the target component in the select gas in order for the target component to pass through the separation member 140. In some embodiments, the greater the difference in partial pressures of the mixed gas and the select gas, the greater the power required to pass the target component through the separation member 140. The separator 106 can be compared to a system (not shown) that uses only a vacuum on the select gas without compressing the mixed gas. Because such a system only has a pressure difference of (at most) one atmosphere, the compression action of the separator 106 removes more of the target component from the mixed gas in a given period of time. Alternatively, the separator 106 can be smaller than a purely vacuum-based system, yet remove the same amount of the target component from the mixed gas. This is because, in some embodiments, the peak pressure during the compression action is 50 times greater than the pressure of the mixed gas at the inlet manifold 124 (i.e., the compression ratio of the cylinder 114 / piston 116 is 50:1). Thus, the separator 106 may be 50 times faster or 50 times smaller than a purely vacuum-based system. Alternatively, a balance can be made between prioritizing speed alone and number alone. Additionally, the speed of operation of the separator 106 may be adjusted by the motor 120 based on, for example, the permeability of the separating member 140 or the flow rate of gas entering the inlet manifold 124, or both (e.g., due to changes in the operating conditions of the gas source 102, shown in FIG. 1). For example, the speed of the motor 120 may be selected to optimize the average speed at which the target components pass through the separating member 140. In such an embodiment, when the permeability of the separating member 140 is low, it may be beneficial to increase the time that the mixed gas is compressed. Thus, a lower speed of the motor 120 may be utilized. In some embodiments, the motor 120 may be a type of motor other than a constant speed motor, such as, for example, a stepper motor. In such an embodiment, the piston 116 may be moved rapidly between TDC and BDC and stopped at TDC and BDC, respectively. By holding the compressing piston 116 at the TDC position for a longer period of time, more of the target components may traverse the separating member 140.

[0029] As mentioned above, the compression action in one cylinder 114 is assisted by the simultaneous decompression action in another cylinder 114. Because the separator 106 is a positive displacement machine, recovery of the energy stored in the compression cylinder 114 through decompression is simpler and more efficient compared to a system (not shown) that uses a viscosity-based turbine for energy recovery. However, some input from the motor 120 is required during the operation of the separator 106. Besides friction and viscous losses due to moving parts and fluids, the decompression energy is not equal to the compression energy. This is because a part of the mixed gas (i.e., the selected gas) escapes from the cylinder 114 through the separating member 140 during compression. Therefore, the amount of the remaining mixed gas (i.e., the rejected fluid) for decompression is smaller in volume than the mixed gas compressed in the other cylinder 114. The motor 120 can input the energy required to make up the difference between the compression action and the decompression action. In addition, by opening the reject valve 142 before the piston 116 reaches the BDC, a loss of pressure due to the absence of the selected gas can occur. This avoids a situation where the vacuum cylinder 114 is at a lower pressure than normal at BDC, which would otherwise require more energy input from the motor 120 .

[0030] The four-cylinder, four-stroke configuration of separator 106 allows the energy expended in compressing the reject gas to be recovered and used to compress more of the mixed gas, which would otherwise be wasted, for example, in a system having only one cylinder / piston (not shown). This allows separator 106 to operate efficiently even when the concentration of the target component is very low (e.g., when extracting carbon dioxide from air).

[0031] 4 and 5 show an embodiment of the present disclosure, with alternatives. For example, the crankshaft 118 may have a different configuration in which two adjacent eccentrics have the same orientation. In such an embodiment, two adjacent pistons 116 move together. In another example, adjacent cylinders 114 / pistons 116 may be in non-adjacent motion. In such an embodiment, for example, cylinder 114A / piston 116A may be performing intake while cylinder 114C / piston 116C is performing exhaust.

[0032] FIG. 6 is a schematic cross-sectional view of an alternative compressible fluid separation pump 206 ("separator 206"). Some of the components and features of separator 206 may be similar to or correspond to those of separator 106 (shown in FIGS. 2-5), and larger reference numbers may be used to indicate so. In the illustrated embodiment, cylinders 114 and pistons 116 are arranged in an H-pattern (as opposed to in-line as in separator 106). Pistons 116 are connected to a bar 218, which translates left and right (towards and away from cylinders 114). Bar 218 is connected at either end to two linear actuators 220A and 220B (collectively "actuators 220"). Actuators 220 provide input energy that is lost to friction and collection of select gases.

[0033] In the illustrated embodiment, separator 206 operates substantially similarly to separator 106. This allows the separator to transfer energy from the depressurizing cylinder 114 to the compressing cylinder 114, thus conserving energy that would otherwise be wasted in compressing the reject gas.

[0034] FIG. 7 is a schematic cross-sectional view of an alternative compressible fluid separation pump 306 ("separator 306"). Some of the components and features of separator 306 may be similar to or correspond to those of separator 106 (shown in FIGS. 2-5), and 200 larger reference numbers may be used to indicate so. In the illustrated embodiment, separator 306 has a Wankel-type configuration. Separator 306 includes a housing 314, an eccentric rotor 316, and a drive shaft 318. Housing 314 includes a hollow cavity 344, and an inlet 330, a select outlet 332, and a reject outlet 334 fluidly connected to hollow cavity 344. Inlet 330 includes an inlet valve 336, select outlet 332 includes a select valve 338 and a separation member 340, and reject outlet includes a reject valve 342.

[0035] In the illustrated embodiment, the rotor 316 has a triangular shape with curved sides and is slidably positioned in a hollow cavity 344. The rotor 316 is rotatably connected to a drive shaft 318 via a gear set 346, with the rotor 316 being eccentric relative to the drive shaft 318. Thus, the rotor 316 rotates and revolves within the housing 314. As this occurs, each side of the rotor 316 draws in and compresses the mixed gas against the select outlet 332 (passing the select gas through the select outlet 332) and expels the reject gas out the reject outlet 334.

[0036] In the illustrated embodiment, each of the three sides of the rotor 316 is operating differently in the intake, compression, decompression, and exhaust cycles at a given time. Thus, decompression on one side can provide energy for compression on another side. In addition, a motor (not shown) can be connected to the drive shaft 318 to compensate for the energy lost during each cycle. In some embodiments, additional housings 314 and rotors 316 are stacked on the same drive shaft 318. In such embodiments, the rotors 316 can be offset by a measure corresponding to the number of housings 314 / rotors 316 present. For example, if there are three housings 314 / rotors 316, each rotor 316 can be 120 degrees from each other.

[0037] 8 is a schematic diagram of a two-stage compressible fluid separation system 400 ("system 400") that includes two series compressible fluid separation pumps 406A and 406B (collectively "separators 406"). Some of the components and features of system 400 and separator 406 may be similar to or correspond to the components and features of system 100 and separator 106 (shown in FIGS. 1-5), and 300 larger reference numbers may be used to indicate such.

[0038] In the illustrated embodiment, the system 400 includes the gas source 102, the mix pump 104, the separator 406, the select pump 108, the reject pumps 410A and 410B (collectively "reject pumps 410"), and the interstage pump 448. The select gas from the separator 406A is sent to the separator 406B, where the select gas is further purified to a higher concentration of the target component. This is particularly useful for membranes with low selectivity (i.e., membranes that pass a significant amount of the effluent component to the select gas). For example, a membrane may have a selectivity of 11, so if the mixed gas is 90% nitrogen and 10% carbon dioxide, the select gas at the interstage pump 448 will be 45% nitrogen and 55% carbon dioxide. This results in the governing equation being S=((1-C M ) / C M )*(C S / (1-C S )), where "S" is selectivity, "C M ” is the incoming concentration of the target component in the gas mixture, “C S " is the exiting concentration of the target component in the select gas. In such an embodiment, the select gas at the select pump 108 will be 6.9% nitrogen and 93.1% carbon dioxide, since enrichment has occurred twice.

[0039] After the second concentration, the select gas may be pumped by the select pump 108 for collection (e.g., compressed to a supercritical fluid and sent off-site). The reject gas may be pumped out of the system 400 by the reject pump 410 (e.g., vented to atmosphere). This allows the system 400 to separate low concentration or trace gases from common gases. Although the system 400 includes pumps 104, 108, 410, and 448, the system 400 (or portions thereof) may operate at ambient pressure. In such embodiments, the pumps 104, 108, 410, or 448, or combinations thereof, are optional or absent.

[0040] 9 is a schematic cross-sectional view of a portion of a system 400 that includes two in-line separators 406. Some of the components and features of system 400 and separators 406A and 406B may be similar to or correspond to the components and features of system 100 and separator 106 (shown in FIGS. 1-5), and reference numbers 300 larger may be used to indicate such.

[0041] In the illustrated embodiment, the reject outlets and reject manifolds for separators 406A and 406B have been omitted for clarity. Additionally, interstage pump 448 is not present in this embodiment. Instead, selection manifold 426 of separator 406A is fluidly connected directly to inlet manifold 424 of separator 406B. The select gas being collected is then from selection manifold 126 of separator 406B. Thus, the mixed gas entering inlet manifold 124 of separator 406A is doubly separated before exiting system 400.

[0042] In the illustrated embodiment, the pistons 416A and 416B of separator 406A and separator 406B are connected to a single crankshaft 418. Thus, the separators 406 are synchronized with each other and there is only one motor 120, although in some embodiments there are separate crankshafts and motors. In addition, the displacement of separator 406B is substantially smaller than that of separator 406A. This can be achieved, for example, by using a smaller cylinder 414B and / or a shorter stroke piston 416B.

[0043] This difference in size between the separators 406 is due to the stage disconnect associated with the amount of mixed gas entering separator 406B being only a fraction of the amount of mixed gas entering separator 406A. In some embodiments, if the interstage select gas is only 15% of the initial mixed gas amount, then cylinder 414 may be only 15% of that in separator 406A, assuming the pressures at inlet manifolds 124 and 424 are the same. In some embodiments, these pressures may be different. For example, if the mixed gas is pressurized to 506 kilopascals (kPa) (5 atmospheres (atm)) with 8% carbon dioxide and separator 406A has a compression ratio of 10:1, the pressure of the select gas at selection manifold 426 will be 405 kPa (4 atmospheres) (assuming perfect selectivity such that the select gas is substantially composed of the target component). This is because the partial pressure of carbon dioxide on the upstream side of the separation member will be the same as on the downstream side.

[0044] In some embodiments, the separator has more than two stages (e.g., four stages). In such an embodiment, the incoming gas to the later separator stage may be highly enriched in the target component (e.g., 90% target component and 10% exhaust component). In such a situation, recovering the energy compressing the reject gas may be significantly less than the energy expended in pushing the select gas through the separator. Thus, such a system may use a separator that favors the target compound in the early stages, and then a separator that favors the exhaust component in the later stages. In such an embodiment, the reject gas would exit through the separator during the compression operation, and the select gas would exit the cylinder during the exhaust operation. This allows more energy to be transferred during decompression in the above example where the incoming gas mixture is already composed of 90% target component. Such a switch in the preference of the separator may occur between stages where the select gas has a concentration of the target component greater than 50%. In other words, the separator can be configured to always favor the component / fluid with the lower flow rate.

[0045] 10 is a schematic cross-sectional view of a portion of an alternative two-stage compressible fluid separation system 500, including two series compressible fluid separation pumps 506A and 506B (collectively "separator 506"). Some of the components and features of system 500 and separator 506 may be similar to or correspond to components and features of systems 100, 400, or separators 106, 206, 306, 406, or combinations thereof (shown in FIGS. 1-9), and reference numerals 400 or 100 greater, respectively, may be used to indicate such.

[0046] In the illustrated embodiment, the inlet manifold, reject outlet, and reject manifold are omitted for clarity, but an inlet 530 to each cylinder 514A and a select outlet 532 from each cylinder 514B are shown. The system 500 has two separators 506 in series, but each cylinder 514A is fluidly connected only to its corresponding cylinder 514B by one of the couplers 550. Each coupler 550 includes a select valve 538 and a separator member 540. In addition, separator 506A is controlled by crankshaft 518A and separator 506B is controlled by crankshaft 518B. Both crankshafts 518A and 518B (collectively "crankshafts 518") are connected to a timing mechanism 552, comprised of, for example, two sprockets and a chain. A timing mechanism 552 synchronizes the separators 506 so that when a cylinder 514A is compressing, its corresponding cylinder 514B is decompressing.

[0047] In the illustrated embodiment, the displacement of separator 506A is substantially less than the displacement of separator 506B. In some embodiments, the displacement of separator 506B can be ten times greater than the displacement of separator 506A, which can be accomplished, for example, by a wider cylinder 514B and / or a longer travel of piston 516B. Such a configuration can increase rarefaction downstream of separator member 540 and increase the dynamics of the select gas passing therethrough.

[0048] Due to the components and configuration of the system 500, the separator 506A applies a positive pressure on the upstream side of the separation member 540, and the separator 506B simultaneously draws a negative pressure on the downstream side of the separation member 540. The corresponding selection valve 538 is then opened so that the combination of upstream compression and downstream rarefaction is multiplicative. For example, if the compression ratio of the piston 516A is 100:1 and the compression ratio of the piston 514B is 1:100, the pressure ratio generated by the system 500 across the separation member 540 is 10,000:1. Such a high ratio can be beneficial, for example, when separating carbon dioxide from air, since its concentration is very low (0.04%). Thus, while the partial pressure of carbon dioxide is only 1 / 2500 of atmospheric pressure, the ratio of 10,000:1 is four times greater. Thus, the system 500 can separate carbon dioxide from air while still allowing the transfer of energy from one decompression cylinder 514A to another compression cylinder 514A. Furthermore, there is an energy transfer from one compression cylinder 514B (i.e., the de-leaching cylinder 514B) to the decompression cylinder 514B (i.e., the de-leaching cylinder 514B). This allows most of the compression and de-leaching energy to be conserved, and the remaining energy can be input by the motor 120.

[0049] 11 is a schematic cross-sectional view of an alternative compressible fluid separator pump 606. Some of the components and features of separator 606 may be similar to or correspond to the components and features of separators 106, 406, or 506, or combinations thereof (shown in FIGS. 2-5, 9, and 10), and reference numerals 500, 200, or 100 greater, respectively, may be used to indicate such. Generally, separator 606 has two banks of cylinders 614 with a fluid lock 654 between them, but despite its similarity to system 500, separator 606 is a single stage device operating on an eight stroke cycle.

[0050] In the illustrated embodiment, separator 606 includes blocks 612A and 612B (collectively "blocks 612") (each having eight cylinders 614A1-614A8 (collectively "cylinders 614A") and 614B1-614B8 (collectively "cylinders 614B"), respectively), piston 616, crankshafts 618A and 618B (collectively "crankshaft 618"), motor 120, flywheel 122, and lock 654. Separator 606 may also include an inlet manifold, a reject manifold, and a reject outlet in cylinder 614A (but not in cylinder 614B), although these components have been omitted for clarity. Cylinders 614A each include an inlet 630, and cylinders 614B each include a select outlet 632. Each corresponding pair of cylinders 614A and 614B (which can be identified by their shared final digit, e.g., "Cylinder 1" of the leftmost pair) are fluidly connected to one another by locks 654A and 654B (collectively, "locks 654"). Lock 654A includes an inlet valve 656A, a separation member 640A, and an outlet valve 658A. Similarly, lock 654B includes an inlet valve 656B, a separation member 640B, and an outlet valve 658B. These features are shown in the inset, which shows the center of cylinder 1, although the centers of each of cylinders 2 through 8 may be represented.

[0051] In the illustrated embodiment, the separation member 640 is a solid or liquid sorbent that prefers the target component. The separation member 640 may, for example, comprise xeolite, a metal-organic framework material, or choline-2-pyrrolidine carboxylic acid ([Cho][Pro]) combined with polyethylene glycol (PEG). Unlike selective membranes, sorbents function by trapping the target component on or within themselves. For this reason, the separation member 640 is placed in the lock 654 so that the separation member 640 can be exposed to a pressurized gas mixture (when the piston 616A performs a compressing action) to sorb the target component. The inlet valve 656 is then closed and the outlet valve 658 is opened, allowing the target component to be released from the separation member 640 into the cylinder 614B (when the piston 616B performs a decompressing action).

[0052] In the illustrated embodiment, valves 636, 638, 656, 658, and a reject valve (not shown) control the gas flowing into the separator 606, through cylinders 1-8, and out of the separator 606. Valves 636, 638, 656, 658, and a reject valve can be controlled, for example, electronically by an actuator (not shown) with a sensor, or mechanically by a camshaft (not shown). Although the separating member 640 prefers the target component, some of the exhaust component may still pass through the lock 654 during operation of the separator 606. This may be because some of the exhaust component sorbs on the separating member 640, but it may also be because the lock 654 has a dead volume that is not occupied by the separating member 640. When the outlet valve 658 is opened to reduce pressure, the mixed gas in the dead volume becomes part of the selected gas. However, the select gas downstream of the separation member 640 still has a higher concentration of the target component (eg, carbon dioxide) and a lower concentration of the exhaust component (eg, nitrogen) than the upstream gas mixture.

[0053] FIG. 12 is a table illustrating the operation of separator 606. Because separator 106 operates in a four stroke cycle, FIG. 12 includes eight rows I-VIII. To properly correlate FIG. 11 with FIG. 12, it should be recognized that FIG. 11 is shown in stroke II or VI. Additionally, for compactness (as there are a significant number of cells in the table), inlet valve 636 is designated using the reference letter "J", inlet valve 656 is designated using the reference letter "K", reject valve (not shown) in cylinder 614B is designated using the reference letter "L", outlet valve 658 is designated using the reference letter "M", and select valve 638 is designated using the reference letter "N". For example, inlet valve 656A is designated "KA".

[0054] In general, each cylinder 614A / piston 616A pair completes (repeatedly) eight stroke cycles consisting of the following operations: I) intake, II) compression A or B, III) decompression, IV) exhaust, V) intake, VI) compression B or A, respectively, VII) decompression, VIII) exhaust. At a given time, each of the pistons 616A is completing a different operation. The intake and exhaust operations do not require much energy to complete (i.e., the input from the motor 120 simply needs to overcome friction and gas flow losses), while the compression operation requires a significant amount of energy input. However, each compression operation occurs simultaneously with a decompression operation on a different cylinder 614A / piston 616A pair, and the energy made available during the decompression operation can be transferred to the compression cylinder 614A / piston 616A via the crankshaft 618A. This provides a significant portion of the energy input for the compression operation, reducing the energy input from the motor 120.

[0055] In the illustrated embodiment, the crankshaft 618B is connected to the crankshaft 618A and the motor 120 by a timing mechanism 652. Thus, the motion of the piston 616B is synchronized with the piston 616A such that the piston 616B is at BDC when the piston 616A is at TDC. Thus, the eight stroke cycles that each cylinder 614B / piston 616B pair completes (repeatedly) are made up of the following operations: I) exhaust, II) lean B, III) de-lean, IV) reverse flow, V) exhaust, VI) lean A, VII) de-lean, and VIII) reverse flow. At a given time, each of the pistons 616B is completing a different operation. While the exhaust and reverse flow operations do not require much energy to complete (i.e., input from the motor 120 is simply required to overcome friction and gas flow losses), the rarefaction operation (i.e., drawing negative pressure) requires a significant amount of energy input. However, each lean operation occurs simultaneously with a de-lean operation (i.e., return to normal pressure) in a different cylinder 614B / piston 616B pair, and the energy made available during the de-lean operation can be transferred to the lean cylinder 614B / piston 616B via the crankshaft 618B, thereby providing a significant portion of the energy input for the compression operation and reducing the energy input from the motor 120.

[0056] In the illustrated embodiment, an eight stroke cycle is utilized because compression against the separator member 640 cannot occur simultaneously with rarefaction such that the mixed gas does not flow past and through the separator member 640. Thus, only one side of each lock 654 is open at a time, which causes cylinder 614B to undergo a reverse flow stroke since it only sees select gas (and, like cylinder 614A, does not see any reject gas during the exhaust stroke that needs to be exhausted through the reject valve). In some embodiments, there is only one lock 654 for cylinders 1-8, but in such embodiments, there are four dead strokes of each piston 614 per cycle, wasting time and energy. Thus, the separator 606 has two locks 654 for each cylinder 1-8.

[0057] In the illustrated embodiment, the displacement of block 612A is substantially less than that of block 612B. In some embodiments, the displacement of block 612B can be ten times greater than that of block 612A, which can be achieved, for example, by a wider cylinder 614B or a longer travel of piston 616B, or both. Such a configuration can increase the rarefaction downstream of lock 654 and increase the force for the target compound to escape from separation member 640. This is because the partial pressure of the desorbed target compound is proportional to the partial pressure of the target compound when it is sorbed, so the lower the atmospheric pressure in cylinder 614B, the better. However, in some embodiments, block 612B (including cylinder 614B, piston 616B, etc.) and crankshaft 618B are absent. In such an embodiment, the outlet valve 658 releases the select gas to a selection manifold (not shown), which may include a vacuum pump (as shown in FIG. 1, at select pump 108) to reduce the pressure in the selection manifold to approximately the minimum level that occurs in cylinder 614B during lean A / B operation (i.e., when piston 616B is at BDC). Such an embodiment may be less efficient in terms of time or energy, or both, but is simpler.

[0058] 12, in the illustrated embodiment of stroke I, piston 616A1 is performing an intake operation. Piston 616A1 is moving toward BDC to draw mixed gas into cylinder 614A1. Thus, row I indicates that inlet valve 636 / J is open and inlet valve 656 / K and reject valve / L are closed. Additionally, piston 616B1 is performing an exhaust operation and is moving toward TDC to push selected gas out of select outlet 632. Thus, row I indicates that select valve 638 / N is open and outlet valve 658 / M is closed.

[0059] In the illustrated embodiment of stroke I, piston 616A2 is performing an exhaust operation. Piston 616A2 is moving toward TDC to push the reject gas out of cylinder 614A2. Thus, row I indicates that reject valve / L is open and inlet valve 636 / J and inlet valve 656 / K are closed. Additionally, piston 616B2 is performing a reverse flow operation and is moving toward BDC to pull the select gas back into cylinder 614B2. Thus, row I indicates that select valve 638 / N is open and outlet valve 658 / M is closed.

[0060] In the illustrated embodiment of stroke I, piston 616A3 is performing a decompression operation. Piston 616A3 is moving toward BDC to assist the compression being performed by pistons 616A4 and 616A8. Thus, row I indicates that valves 636 / J, 656 / K, and reject / L are closed. In addition, piston 616B3 is performing a de-rarefaction operation and is therefore moving toward TDC to assist the rarefaction being performed by pistons 616B4 and 616B8. Thus, row I indicates that valves 658 / M and 638 / N are closed.

[0061] In the illustrated embodiment of stroke I, piston 616A4 is performing a compression B operation. Piston 616A4 is moving toward TDC to push mixed gas into lock 654B. Thus, row I indicates that inlet valve 656B / KB is open and valves 636 / J, 656A / KA, and reject / L are closed. Additionally, piston 616B4 is performing a rarefaction A operation and is therefore moving toward BDC to draw select gas from lock 654A. Thus, row I indicates that outlet valve 658A / MA is open and outlet valve 658B / MB and select valve 638 / N are closed.

[0062] In the illustrated embodiment of stroke I, piston 616A5 is performing an intake operation. Piston 616A5 is moving toward BDC to draw mixed gas into cylinder 614A5. Thus, row I indicates that inlet valve 636 / J is open and inlet valve 656 / K and reject valve / L are closed. Additionally, piston 616B5 is performing an exhaust operation and is moving toward TDC to push select gas out of select outlet 632. Thus, row I indicates that select valve 638 / N is open and outlet valve 658 / M is closed.

[0063] In the illustrated embodiment of stroke I, piston 616A6 is performing an exhaust operation. Piston 616A6 is moving toward TDC to push the reject gas out of cylinder 614A6. Thus, row I indicates that reject valve / L is open and inlet valve 636 / J and inlet valve 656 / K are closed. Additionally, piston 616B6 is performing a reverse flow operation and is moving toward BDC to pull the select gas back into cylinder 614B6. Thus, row I indicates that select valve 638 / N is open and outlet valve 658 / M is closed.

[0064] In the illustrated embodiment of stroke I, piston 616A7 is performing a decompression operation. Piston 616A7 is moving toward BDC to assist the compression being performed by pistons 616A4 and 616A8. Thus, row I indicates that valves 636 / J, 656 / K, and reject / L are closed. In addition, piston 616B7 is performing a de-rarefaction operation and is therefore moving toward TDC to assist the rarefaction being performed by pistons 616B4 and 616B8. Thus, row I indicates that valves 658 / M and 638 / N are closed.

[0065] In the illustrated embodiment of stroke I, piston 616A8 is performing a compression A operation. Piston 616A8 is moving toward TDC to push mixed gas into lock 654A. Thus, row I indicates that inlet valve 656A / KA is open and valves 636 / J, 656B / KB, and reject / L are closed. Additionally, piston 616B8 is performing a rarefaction B operation and is therefore moving toward BDC to draw select gas from lock 654B. Thus, row I indicates that outlet valve 658B / MB is open and outlet valve 658A / MA and select valve 638 / N are closed.

[0066] In the illustrated embodiment, the subsequent seven strokes of the eight stroke cycle are completed as shown in rows II through VIII of the table, after which the cycle begins again (as shown in row I).

[0067] As mentioned above, the compression action in two of the cylinders 614A is aided by the simultaneous decompression action in the two other cylinders 614A, and the rarefaction action in two of the cylinders 614B is aided by the simultaneous de-rarefaction action in the two other cylinders 614B. Because the separator 606 is a positive displacement machine, recovery of the energy stored in the compressed cylinder 614A via decompression and in the rarefied cylinder 614B via de-rarefaction is simpler and more efficient compared to a system using a viscosity-based turbine for energy recovery (not shown). However, some input from the motor 120 is required during the operation of the separator 606. Other than frictional and viscous losses due to moving parts and fluids, decompression energy is not equal to compression energy, and de-rarefaction energy is not equal to rarefaction energy. The former is because a part of the mixed gas (i.e., the select gas) is trapped in the lock 654 (either by being sorbed by the separating member 640 or by being trapped in the dead space) when the inlet valve 656 closes after compression, and the amount of the remaining mixed gas (i.e., the reject gas) for decompression is smaller in volume than the mixed gas compressed in the other cylinder 614A. The latter is because a large part of the select gas from the lock 654 desorbs / enters the cylinder 614B when the outlet valve 658 is opened, and the volume available for de-rarefaction is smaller since the outlet valve 658 is closed after de-rarefaction. The motor 120 can input the energy required to bridge the difference between the compression and de-rarefaction operations, and between the de-rarefaction and de-rarefaction operations. Although omitted from FIG. 12 for compactness, the reject valve / L is opened before the piston 616A reaches BDC during the de-rarefaction operation to account for the loss of pressure due to the absence of the select gas. This avoids a situation where the decompression cylinder 114 is below normal pressure at BDC, which would otherwise require more energy input from the motor 120. Similarly, the select valve 638 / N is opened before the piston 616B reaches TDC during the de-leaning operation to allow for pressure gain from the additional select gas.This avoids a situation where the de-lean cylinder 614 is at higher than normal pressure at BDC, which would otherwise require more energy input from the motor 120 .

[0068] The 16 cylinder / 8 cylinder pair, 8 stroke configuration of separator 606 allows the energy expended in compressing the reject gas to be recovered and used to compress more of the mixed gas, and the energy expended in diluting select gas from one lock to be recovered and used to dilute select gas from another lock, allowing separator 106 to operate efficiently even when the concentration of the target component is very low (e.g., when extracting carbon dioxide from air). Further consideration of some illustrative embodiments

[0069] The following is a non-exclusive description of several exemplary embodiments of the present disclosure.

[0070] A compressible fluid separation pump, according to an exemplary embodiment of the present disclosure, includes, among other things, a crankshaft; four cylinders, each including an inlet including an inlet valve for a mixed fluid including a target component and a reject component, a reject outlet including a reject valve for a reject fluid, and a select outlet for a select fluid, each including a separation member that favors the target component over the reject component such that the target component is in a higher concentration in the select fluid than in the mixed fluid and the reject fluid; and four pistons, each connected to the crankshaft and located in one of the four cylinders, the crankshaft configured to place two of the pistons at top dead center when the other two of the pistons are at bottom dead center.

[0071] The compressible fluid separation pump of the preceding paragraph may additionally and alternatively, or additionally or alternatively, optionally include any one or more of the following features, configurations, or additional components, or combinations thereof.

[0072] A further embodiment of the compressible fluid separation pump described above, wherein the target component is carbon dioxide (CO2) and the separation member is a CO2-loving membrane.

[0073] A further embodiment of any of the above-mentioned compressible fluid separation pumps, wherein the selective outlet further comprises a selective valve.

[0074] A two-stage compressible fluid separation system comprising any of the compressible fluid separation pumps described above and another compressible fluid separation pump constructed from any of the compressible fluid separation pumps described above, wherein a selected outlet of each cylinder of the compressible fluid separation pump is fluidly connected to an inlet of a corresponding cylinder of the other compressible fluid separation pump.

[0075] A further embodiment of any of the compressible fluid separation pumps described above, wherein each inlet is configured to be fluidly connected to an inlet manifold.

[0076] A further embodiment of any of the above described compressible fluid separation pumps, wherein the inlet manifold is configured to be fluidly connected to an exhaust of a combustion system.

[0077] A further embodiment of any of the compressible fluid separation pumps described above, wherein each selection outlet is configured to be fluidly connected to a selection manifold.

[0078] A further embodiment of any of the compressible fluid separation pumps described above, further comprising a motor connected to the crankshaft to assist in moving the piston.

[0079] A further embodiment of any of the above compressible fluid separation pumps, further comprising a flywheel connected to the crankshaft.

[0080] A method of operating a compressible fluid separation pump, according to an exemplary embodiment of the present disclosure, includes, among other things, rotating a crankshaft connected to four pistons, each piston located in one of four cylinders, each cylinder including an inlet including an inlet valve for a mixed fluid including a target component and a reject component, a reject outlet including a reject valve for a reject fluid, and a select outlet for a select fluid, each including a separation member that favors the target component over the reject component such that the target component is in a higher concentration in the mixed fluid than in the reject fluid; opening an inlet valve for one cylinder while its piston is moving toward bottom dead center to draw the mixed fluid into the one cylinder, closing the inlet valve for the one cylinder, compressing the mixed fluid against a separator member of the one cylinder while its piston is moving toward top dead center, and depressurizing one cylinder while its piston is moving toward bottom dead center to assist in rotating the crankshaft to compress the mixed fluid against a separator member of another cylinder while its piston is moving toward top dead center.

[0081] The method of the preceding paragraph may additionally and alternatively, or additionally or alternatively, optionally include any one or more of the following features, configurations, or additional components, or combinations thereof.

[0082] A further embodiment of the above method, wherein the target component is carbon dioxide (CO2), the separating member is a carbon dioxide preferential membrane, and the carbon dioxide passes through the separating member by compressing the mixed fluid against the separating member.

[0083] A further embodiment of any of the above methods, further comprising opening a reject valve for one cylinder before its piston reaches bottom dead center during decompression such that reject fluid enters the one cylinder.

[0084] A further embodiment of any of the preceding methods, further comprising opening an inlet valve to one cylinder before its piston reaches bottom dead center during decompression such that the mixed fluid enters the one cylinder.

[0085] A compressible fluid separation pump, according to an exemplary embodiment of the present disclosure, includes, among other things, a first crankshaft and eight first cylinders, each having a first inlet including a first inlet valve for a mixed fluid including a target component and a reject component, a first selection outlet including a first outlet valve for a select fluid, each including a first separation member that favors the target component over the reject component such that the target component is in a higher concentration in the select fluid than in the mixed fluid and the reject fluid, and a second selection outlet including a second outlet valve for the select fluid, the first cylinder including a second selection outlet, each including a second separation member that favors the target component over the rejected component such that the target component is in a higher concentration in the selection fluid than in the mixed fluid and the reject fluid; and eight first pistons, each connected to a first crankshaft and positioned in one of the eight first cylinders, the first crankshaft configured to position four of the first pistons at top dead center when the other four of the first pistons are at bottom dead center.

[0086] The compressible fluid separation pump of the preceding paragraph may additionally and alternatively, or additionally or alternatively, optionally include any one or more of the following features, configurations, or additional components, or combinations thereof.

[0087] A further embodiment of the compressible fluid separation pump described above, further comprising a second crankshaft; eight second cylinders, each including a second inlet including a second inlet valve for receiving a select fluid from a corresponding first separation member, a third inlet including a third inlet valve for receiving a select fluid from a corresponding second separation member, and a third select outlet including a third outlet valve for the select fluid; and eight second pistons, each connected to the second crankshaft and located in one of the eight second cylinders, wherein the second crankshaft is synchronized with the first crankshaft such that a first piston is at top dead center when a corresponding second piston is at bottom dead center.

[0088] A further embodiment of any of the compressible fluid separation pumps described above, wherein the target component is carbon dioxide (CO2) and the separation member is a carbon dioxide preferential sorption material.

[0089] A further embodiment of any of the compressible fluid separation pumps described above, wherein each of the first cylinders includes a reject outlet including a reject valve for the reject fluid.

[0090] A further embodiment of any of the compressible fluid separation pumps described above, wherein each inlet is fluidly connected to an exhaust pipe of a combustion system.

[0091] A further embodiment of any of the compressible fluid separation pumps described above, further comprising a motor connected to the crankshaft to assist in moving the piston.

[0092] A method of operating a compressible fluid separation pump, according to an exemplary embodiment of the present disclosure, includes, among other things, rotating a first crankshaft connected to eight first pistons, each first piston being located in one of eight first cylinders, each first cylinder including a first inlet including a first inlet valve for a mixed fluid including a target component and a reject component, a first selection outlet including a first outlet valve for a select fluid, each including a first separation member that favors the target component over the reject component such that the target component is in a higher concentration in the select fluid than in the mixed fluid and the reject fluid, and a second selection outlet including a second outlet valve for the select fluid, each including a first separation member that favors the target component over the reject component such that the target component is in a higher concentration in the select fluid than in the mixed fluid and the reject fluid. the first cylinder includes a second selective outlet, the first selective outlet includes a second separator member having a second selective outlet, the first selective outlet includes a second separator member having a second selective outlet, the first selective outlet includes a second selective outlet, the first selective outlet includes a second separator member having a second selective outlet, the first selective outlet includes a second selective outlet, the first selective outlet includes a second selective outlet, the first selective outlet includes a second selective outlet, the first selective outlet includes a second selective outlet, the first selective outlet includes a second selective outlet, the first selective outlet includes a second selective outlet, the first selective outlet includes a second selective outlet, the first selective outlet includes a second selective outlet

[0093] The method of the preceding paragraph may additionally and alternatively, or additionally or alternatively, optionally include any one or more of the following features, configurations, or additional components, or combinations thereof.

[0094] A further embodiment of the above-mentioned method includes rotating a second crankshaft connected to eight second pistons, each second piston being located in one of eight second cylinders, each second cylinder including a second inlet including a second inlet valve for receiving the selected fluid from a corresponding first separation member, a third inlet including a third inlet valve for receiving the selected fluid from a corresponding second separation member, and a third selection outlet including a third outlet valve for the selected fluid; removing the selected fluid through the third outlet valve of one of the second cylinders while the piston is moving towards top dead center; opening a second inlet valve for one of the second cylinders, leaning one of the second cylinders while its piston is moving toward bottom dead center to draw the selected fluid from the first separation member, and closing the second inlet valve for the one of the second cylinders, de-leaning one of the second cylinders while its piston is moving toward top dead center to assist in rotating the second crankshaft to draw the selected fluid from another of the first separation members corresponding to the other of the second cylinders being leaned.

[0095] A further embodiment of any of the aforementioned methods, wherein the second crankshaft is synchronized with the first crankshaft such that the first piston is at top dead center when the corresponding second piston is at bottom dead center.

[0096] A further embodiment of any of the above methods, wherein the target component is carbon dioxide (CO2), the separating member is a carbon dioxide preferential sorption material, and the carbon dioxide is sorbed by the separating member by compressing the mixed fluid against the separating member of one first cylinder.

[0097] A further embodiment of any of the aforementioned methods, further comprising opening a first inlet valve during decompression and before the first cylinder piston reaches bottom dead center such that the mixed fluid enters the first cylinder.

[0098] A compressible fluid separation pump having a Wankel type configuration, according to an exemplary embodiment of the present disclosure, includes, among other things, a housing, a cavity, an inlet for a mixed fluid fluidly connected to the cavity, the mixed fluid including a target component and a reject component, a reject outlet for a reject fluid fluidly connected to the cavity, and a select outlet for a select fluid fluidly connected to the cavity, the select outlet including a separation member that favors the target component over the reject component such that the target component is in a higher concentration in the select fluid than in the mixed fluid and the reject fluid, the inlet and the reject outlet being on one side of the housing and the select outlet being on an opposite side of the housing, a rotatable shaft passing through the housing, and an eccentric rotor rotatably connected to the shaft and having a triangular shape with curved sides, the eccentric rotor orbiting within the housing such that reduced pressure of the reject fluid on one side of the eccentric rotor assists in compression of the mixed fluid on another side of the eccentric rotor.

[0099] The description of various embodiments of the present invention is presented for illustrative purposes, but is not intended to be exhaustive and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terms used in this specification are selected to best explain the principles of the embodiments, practical applications, or technical improvements over the technology found in the market, or to enable those skilled in the art to understand the embodiments disclosed herein.

Claims

1. 1. A compressible fluid separation pump, comprising: A crankshaft, four cylinders, each including an inlet including an inlet valve for a mixed fluid including a target component and a reject component, a reject outlet including a reject valve for a reject fluid, and a select outlet for a select fluid, each including a separating member that favors the target component over the reject component such that the target component is in a higher concentration in the select fluid than in the mixed fluid and the reject fluid; four pistons, each connected to the crankshaft and located in one of the four cylinders; 2. A compressible fluid separation pump, wherein the crankshaft is configured to place two of the pistons at top dead center when two other of the pistons are at bottom dead center.

2. The target component is carbon dioxide (CO ２ ) and The separation member is CO ２ 2. The compressible fluid separation pump of claim 1, wherein the membrane is

3. 3. The compressible fluid separation pump of claim 1, wherein the selective outlet further comprises a selective valve.

4. 4. A compressible fluid separation pump as claimed in any preceding claim, wherein each inlet is configured to be fluidly connected to an inlet manifold.

5. The compressible fluid separation pump of claim 4 , wherein the inlet manifold is configured to be fluidly connected to an exhaust of a combustion system.

6. 6. A compressible fluid separation pump as claimed in any preceding claim, wherein each selection outlet is adapted to be fluidly connected to a selection manifold.

7. 7. A compressible fluid separation pump as claimed in any preceding claim, further comprising a motor connected to said crankshaft for assisting in moving said piston.

8. 8. The compressible fluid separation pump of claim 7, further comprising a flywheel connected to said crankshaft.

9. 1. A two-stage compressible fluid separation system comprising: The compressible fluid separation pump according to any one of claims 1 to 8; and another compressible fluid separation pump constructed according to any one of claims 1 to 8, A two stage compressible fluid separation system, wherein a selected outlet of each cylinder of said compressible fluid separation pump is fluidly connected to an inlet of a corresponding cylinder of said another compressible fluid separation pump.

10. 1. A method of operating a compressible fluid separation pump, comprising: rotating a crankshaft connected to four pistons, each piston being located in one of four cylinders, each cylinder including an inlet including an inlet valve for a mixed fluid including a target component and a reject component, a reject outlet including a reject valve for a reject fluid, and a select outlet for a select fluid, each including a separating member that favors the target component over the reject component such that the target component is in a higher concentration in the selected fluid than in the mixed fluid and the reject fluid; opening an inlet valve for one of the four cylinders while its piston is moving toward bottom dead center to draw mixed fluid into the one cylinder; closing the inlet valve for the one cylinder; compressing a mixed fluid against the separator member of one of the cylinders while the piston thereof is moving toward top dead center; depressurizing said one cylinder while its piston is moving toward bottom dead center to assist in said rotating said crankshaft to compress a mixed fluid against a separating member of another cylinder while its piston is moving toward top dead center.

11. The target component is carbon dioxide (CO ２ ) and the separation member being a carbon dioxide preferential membrane; The method of claim 10 , wherein carbon dioxide passes through the separating element by compressing the mixed fluid against the separating element.

12. 12. The method of claim 10, further comprising opening the reject valve for the one cylinder during the decompression and before its piston reaches bottom dead center so that rejected fluid enters the one cylinder.

13. 13. The method of claim 10, further comprising opening the inlet valve to the one cylinder during the decompression and before its piston reaches bottom dead center so that mixed fluid enters the one cylinder.

14. 1. A compressible fluid separation pump, comprising: A first crankshaft; eight first cylinders, each including a first inlet including a first inlet valve for a mixed fluid including a target component and a reject component, a first selection outlet including a first outlet valve for a select fluid, each including a first separating member that favors the target component over the reject component such that the target component is in a higher concentration in the select fluid than in the mixed fluid and the reject fluid, and a second selection outlet including a second outlet valve for the select fluid, each including a second separating member that favors the target component over the reject component such that the target component is in a higher concentration in the select fluid than in the mixed fluid and the reject fluid; eight first pistons, each connected to the first crankshaft and located in one of the eight first cylinders; 11. A compressible fluid separation pump, wherein the first crankshaft is configured to place four of the first pistons at top dead center when other four of the first pistons are at bottom dead center.

15. A second crankshaft; eight second cylinders, each including a second inlet including a second inlet valve for receiving a select fluid from a corresponding first separation member, a third inlet including a third inlet valve for receiving a select fluid from a corresponding second separation member, and a third select outlet including a third outlet valve for the select fluid; eight second pistons, each connected to the second crankshaft and located in one of the eight second cylinders; 15. The compressible fluid separation pump of claim 14, wherein the second crankshaft is synchronized with the first crankshaft such that a first piston is at top dead center when a corresponding second piston is at bottom dead center.

16. The target component is carbon dioxide (CO ２ ) and 16. A compressible fluid separation pump as claimed in any one of claims 14 to 15, wherein the separating member is a carbon dioxide preferential sorption material.

17. 17. A compressible fluid separation pump as claimed in any one of claims 14 to 16, wherein each of the first cylinders includes a reject outlet including a reject valve for the reject fluid.

18. 18. A compressible fluid separation pump as claimed in any one of claims 14 to 17, wherein each inlet is fluidly connected to an exhaust pipe of a combustion system.

19. 19. A compressible fluid separation pump as claimed in any one of claims 14 to 18, further comprising a motor connected to the crankshaft for assisting in moving the piston.

20. 1. A method of operating a compressible fluid separation pump, comprising: rotating a first crankshaft connected to eight first pistons, each first piston being located in one of eight first cylinders, each first cylinder including a first inlet including a first inlet valve for a mixed fluid including a target component and a reject component, a first selection outlet including a first outlet valve for a select fluid, each including a first separating member that favors the target component over the reject component such that the target component is in a higher concentration in the select fluid than in the mixed fluid and in the reject fluid, and a second selection outlet including a second outlet valve for the select fluid, each including a second separating member that favors the target component over the reject component such that the target component is in a higher concentration in the select fluid than in the mixed fluid and in the reject fluid; opening a first inlet valve for a first one of the cylinders while its piston is moving toward bottom dead center to draw mixed fluid into the one of the cylinders; closing the first inlet valve for the one first cylinder; opening a first select outlet valve; compressing a mixed fluid against the separating member of the one first cylinder while a piston thereof is moving toward top dead center; depressurizing one of the first cylinders while a piston thereof is moving toward bottom dead center to assist in the rotating of the first crankshaft to compress a mixed fluid against a separating member of another first cylinder while a piston thereof is moving toward top dead center.

21. rotating a second crankshaft connected to eight second pistons, each second piston being located in one of eight second cylinders, each second cylinder including a second inlet including a second inlet valve for receiving a select fluid from a corresponding first separation member, a third inlet including a third inlet valve for receiving a select fluid from a corresponding second separation member, and a third select outlet including a third outlet valve for said select fluid; removing selected fluid through the third outlet valve of one second cylinder while its piston is moving toward top dead center; opening a second inlet valve to the one second cylinder; diluting said one second cylinder while its piston is moving toward bottom dead center to draw selected fluid from said first separating member; closing the second inlet valve for the one second cylinder; 21. The method of claim 20, further comprising: de-leaning the one second cylinder while its piston is moving toward top dead center to assist in the rotating of the second crankshaft to draw selected fluid from another first separation member corresponding to another second cylinder that is being leaned while its piston is moving toward bottom dead center.

22. 22. The method of claim 21, wherein the second crankshaft is synchronized with the first crankshaft such that a first piston is at top dead center when a corresponding second piston is at bottom dead center.

23. The target component is carbon dioxide (CO ２ ) and the separating member being a carbon dioxide preferential sorbent material; 23. The method of any of claims 20 to 22, wherein carbon dioxide is sorbed by the separating member by compressing the mixed fluid against the separating member of the one first cylinder.

24. 24. The method of any of claims 20 to 23, further comprising opening the first inlet valve during the decompression and before the first cylinder piston reaches bottom dead center so that mixed fluid enters the first cylinder.

25. 1. A compressible fluid separation pump having a Wankel type configuration, comprising: a housing comprising: a cavity; an inlet for a mixed fluid fluidly connected to the cavity, the mixed fluid including a target component and a reject component; a reject outlet for a reject fluid fluidly connected to the cavity; and a select outlet for a select fluid fluidly connected to the cavity, the select outlet including a separating member that favors the target component over the reject component such that the target component is in a higher concentration in the select fluid than in the mixed fluid and the reject fluid, the inlet and the reject outlet being on one side of the housing and the select outlet being on an opposite side of the housing; a rotatable shaft passing through the housing; an eccentric rotor rotatably connected to the shaft and having a triangular shape with curved sides, the eccentric rotor orbiting within the housing such that reduced pressure of rejected fluid on one side of the eccentric rotor assists in compressing mixed fluid on another side of the eccentric rotor.

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