PULSED ABSORPTION CONTACTOR

Pulsed absorption contactor systems and methods are provided. The systems include a vessel having inlet and outlet ends and a pulse generator system, a gas inlet configured to direct an input gas stream into the vessel, a gas outlet configured to receive an output gas stream and direct the output gas stream out of the vessel, a liquid inlet configured to direct an input liquid stream into the vessel, and a liquid outlet configured to receive an output liquid stream and direct the output liquid stream out of the vessel. The pulse generator system is configured to induce a fluctuation in the input gas stream, the input liquid stream, and/or a combination of the input gas stream and the input liquid stream.

BACKGROUND

In industrial processing, power generation, and other similar industries, capture of various byproducts and/or generated gases may be necessary or desirable. For example, capture of environmentally threatening gasses such as CO2from the exhaust streams of hydrocarbon-fueled processes has become a necessity. Regulation of allowable CO2emissions now limits the economic viability of power generation and other large scale industrial facility operations. Furthermore, such capture technologies may be used for other chemicals and/or processes, including, without limitation: natural gas production, sweetening, and the like.

Typical absorbers may utilize a static, fixed surface area on which the absorption occurs. For example, a common absorber design is a “shaped packing” design. In this design, packing elements with complex surface shapes are placed in a fixed-size chamber. A liquid solvent is typically caused to flow downwardly through the chamber and wet the exterior surfaces of the packing elements. With a liquid solvent present, a gas is then driven upwardly through the packing elements. The aim of such packing elements is to increase a surface area for mass transfer between the solvent and the gas that are directed into/through the fixed-size chamber, and a selected component of the gas is absorbed into a surface of the solvent. The surface area of the packing elements remains fixed and static. The three commercial types of packing are random, structured trays, and spray towers.

A common limitation of such absorbers is the relatively short amount of time in which the two fluids (gas to be captured and liquid solvent) are in surface contact with each other. The static, fixed surface area designs typically use a counter-flow arrangement wherein the solvent flows downwardly and the gas flows upwardly. Such counter-flow technique is utilized to maximize the concentration gradient between the two fluids but has the inherent limitation of minimizing the time in which the surfaces of the two fluids are in contact. Accordingly, to accommodate such limitation on duration of contact, this conventional system may require a significant height of packing elements required (e.g., vertically stacked) to facilitate the absorption process.

Recent advancements in continuous post-combustion capture technologies have demonstrated that the size and cost of equipment can be dramatically reduced through development of new processes (e.g., chemical and/or mechanical). One of such technologies is the Regenerative Froth Contactor (RFC) which may be able to increase the mass-transfer between carbon-rich flue gasses and absorbent liquid solvents by a factor greater than five. The primary mechanism allowing increased mass transfer is the generation of a pulsating flow regime inside a gas-liquid contactor such that the majority of the internal volume of the contactor is occupied by a pulsating froth of micro-scale gas bubbles and liquid droplets.

U.S. Pat. No. 11,484,860 discloses an apparatus for enhancing a yield and a transfer rate of a packed bed that includes a packed bed (e.g., packing elements), a vessel having a reaction chamber, a support frame and acoustic attenuator for holding the packed bed in the reaction chamber, at least one acoustic transducer adapted to transmit acoustic energy into the packed bed, and an acoustic generator. The acoustic transducer is located within and part of the packed bed and/or arranged on the outside of the packed bed. The acoustic generator has impedance matching functionality. The system disclosed therein is directed to applying the acoustic transducer directly to the packed bed and is designed for adsorption by vibrating the packed bed with the acoustic energy. The system employs a counter-flow arrangement where a gas and a liquid are directed in opposite directions through a vessel that includes the packed beds with integrated acoustic transducers.

The prior solution systems may require relatively expensive materials in their construction and may require very large and/or vertically tall processing towers/facilities. The large surface area of the packing element, which is required to facilitate absorption, also makes such systems susceptible to build up of contaminates within the contactor (e.g., dirt, impurities from the gas and/or liquid, or precipitation products from the absorption itself). Accordingly, improved systems for gas absorption into a solvent may be desirable to provide various advantages, such as reduced costs, increased efficiencies, and reduced facility size (with accompanying benefits thereof).

SUMMARY

In accordance with some embodiments, pulsed absorption contactor systems are provided. The systems include a vessel having an inlet end and an outlet end. The vessel includes at least one gas inlet arranged at the inlet end of the vessel and configured to direct an input gas stream into the vessel, at least one gas outlet arranged at the outlet end of the vessel and configured to receive an output gas stream and direct the output gas stream out of the vessel, at least one liquid inlet arranged at the inlet end of the vessel and configured to direct an input liquid stream into the vessel, and at least one liquid outlet arranged at the outlet end of the vessel and configured to receive an output liquid stream and direct the output liquid stream out of the vessel. A pulse generator system is configured to induce a fluctuation in at least one of the input gas stream, the input liquid stream, or a combination of the input gas stream and the input liquid stream. An induced pulse from the pulse generator system creates a compression wave of a mixture of a gas of the input gas stream and a liquid of the input liquid stream within the vessel.

In accordance with some embodiments, methods for capturing a target component from a gas within a liquid are provided. The methods employ a pulsed absorption contactor system having a vessel with an inlet end and an outlet end and a pulse generator system. The methods include supplying an input gas into the vessel through a gas inlet at the inlet end of the vessel, supplying an input liquid into the vessel through a liquid inlet at the inlet end of the vessel, and inducing a pressure wave within the vessel using the pulse generator system configured to induce a pulse in at least one of the input gas, the input liquid, and a mixture of the input gas and the input liquid, wherein an induced pulse from the pulse generator system creates a compression wave of a mixture of the input gas and the input liquid within the vessel.

DETAILED DESCRIPTION

Referring toFIG.1, an example of a gas absorber10that may be modified to incorporate embodiments of the present disclosure is shown. The gas absorber10includes a reaction or absorber vessel20which, as shown, is a cylindrical, vertically extending vessel. Due to the nature of gas absorption systems, as described above, the absorber vessel20may, in some uses and configurations, exceed 15 meters in diameter and may be significantly taller in the vertical direction. Although illustrated as a cylinder, it will be appreciated that the absorber vessels described herein may be virtually any shape, and have cross-sections which are circular, oval, rectangular, polyhedral, or other shape.

In operation, an incoming flow gas stream30such as flue gas from a power plant (e.g., fossil fuel or other fuel source), flows into an inlet duct31connected to an inlet port33at the top or upper end of the absorber vessel20. The gas stream30contains a selected component, chemical, compound, or the like. The incoming flowing gas stream30flows downwardly through the absorber vessel20, and after being subjected to an absorption process described herein, the processed gas is discharged through an outlet duct32.

In this illustrative configuration, the absorber vessel20has a first chamber25and a second chamber26separated by a bulkhead plate21extending horizontally across the absorber vessel20. The first chamber25is fluidly connected to the gas inlet duct31to allow a flow of the gas stream30into the first chamber25. The bulkhead plate21extends across an outlet end25bof first chamber25and separates the first chamber25from the adjacent second chamber26, which is arranged vertically beneath the first chamber25.

An array of discrete, vertically oriented absorption tubes40are arranged in respective flow ports40aformed through the bulkhead plate21. Each of the absorption tubes40extends through the bulkhead plate21in an upward direction and into first chamber25to define a respective conduit for the flow of the gas stream30from the first chamber25into the second chamber26. The absorption tubes40may be arranged in any one of a number of possible geometric shapes, as will be appreciated by those of skill in the art (e.g., circular, square, oval, polygonal, etc. in cross-section). The flow ports40aand the absorption tubes40are sized and positioned to equalize a flow speed of the gas stream30downwardly through each absorption tube40from the first chamber25into the second chamber26.

In this illustrative configuration, a fan97is provided within the inlet duct31. The fan97provides means for pressurizing the gas stream30in the first chamber25and to cause a back pressure in the first chamber25, which in turn causes the gas stream30to flow at substantially the same, equal flow rates through each of the absorption tubes40into the second chamber26. It will be appreciated that the fan97may be arranged at other locations and/or may be configurated as some other type of pressure generator (e.g., pump, compressor, controlled valve, etc.). As shown inFIG.1, an optional second bulkhead plate23(similar to bulkhead plate21) is arranged vertically below the first bulkhead plate21to form an additional set of chambers, including a third chamber27and a fourth chamber28, which are substantially the same as the configuration of the first and second chambers25,26.

The array of discrete, vertically oriented absorption tubes40are densely mounted to and arranged in the flow ports40ain the bulkhead plates21,23. The absorption tubes40are mounted perpendicular to the bulkhead plates21,23and arranged parallel with a vertical axis of the absorber vessel20. The number of absorption tubes40required on each stage (e.g., mounted to each bulkhead plate21,23) may be dependent upon the gas flow, a liquid flow through the absorber vessel20, and/or based on other factors. For example, depending on the specific configuration and desired use, each stage may include as few as a single absorption tube40or may include many thousands of such absorption tubes40. Each of the absorption tubes40extends through the respective bulkhead plate21,23to define a respective conduit for the flow of gas stream30from first chamber25into second chamber26or from the third chamber27into the fourth chamber28. The absorption tubes40and the associated flow ports40aholding or carrying the absorption tubes40are sized and positioned to equalize a flow speed of the gas stream30downwardly through each absorption tube40from the respective upstream chambers25,27to respective downstream chambers26,28.

The mechanism to absorb the desired chemical, compound, or material to be captured, is provided by introducing a liquid solvent into the absorber vessel20. For example, a lean liquid solvent50may be fed into the absorber vessel20above the first bulkhead plate21through one or more inlet lines51to flood the space above the first bulkhead plate21. Such liquid solvent will surround and fill the space between the absorption tubes40and thus form a solvent reservoir56. The liquid solvent50may be any solvent capable of absorbing the selected component, chemical, compound, etc.

Each absorption tube40may be arranged with a screen assembly60arranged therein. The screen assembly60may be a packing material or packing elements with complex surface shapes (e.g., complex screens). For example, each screen assembly60may be formed of a stack of screens or mesh material that provide a high level of surface area while providing through paths therethrough to permit a liquid-gas mixture to flow through and interact with the material/structures of the screen assembly60. Further, each absorption tube40may include fluid inlets for receiving both a portion of the gas stream30and a portion of the liquid solvent50. The fluid inlets on the absorption tubes40for permitting the liquid solvent50to enter the absorption tubes40may be arranged as holes41(e.g., holes, slots, apertures, or the like). The gas stream30may be directed through open tops of the absorption tubes40, or may flow through one or more holes, apertures, slots or the like.

In operation, the liquid solvent50flows through the holes41into each of the absorption tubes40. With the liquid solvent50within the absorption tube40, and the gas stream30being directed therethrough, the two fluids may interact within the absorption tubes40. For example, the liquid solvent50may interact with the screen assembly60(also referred to as a “froth generator”) to mix with the gas stream30and establish froth droplets and bubbles (both not shown for clarity). In other configurations, the liquid solvent50may simply flow over the top of the absorption tubes40, and enter through an open top thereof, thus negating the need for the holes41. In such configurations, the top of the absorption tubes40may have notches to allow the liquid solvent50to drain at set points into the absorption tube40or a lip of the absorption tube40may be smooth (e.g., without notches) to create an even flow of the liquid solvent50over the entire top of the absorption tubes40. Each of these techniques injects the liquid solvent50into each of the absorption tubes40and through a plurality of screen assemblies60provided in each absorption tube40to form an aqueous bubbly froth from the liquid solvent inside each of the absorption tubes40as the gas stream30flows through the absorption tubes40.

The screen assemblies60may be formed of one or more (e.g., a set) of mesh screens Each mesh screen extends transversely between side walls of each tube40. As such, the mesh screens of the screen assemblies60provide a tortuous flow path through which the mixture of the gas stream30and the liquid solvent50may interact. In some configurations, the screen assemblies60may include an array of screens. The screens of the screen assemblies60are configured to burst, shatter, fragment, or break up the bubbles of the aqueous froth into a myriad of droplets and micro-droplets of different radii. Such treatment of the mixture may create a very large, rapidly changing solvent surface, as described in detail in U.S. Pat. No. 7,854,791, the contents of which are incorporated herein in their entirety. The screen assemblies60may include plurality of vertically spaced apart mesh screens (e.g., a stack). Each screen may have any of a variety of cross-sectional geometries or shapes, including ridge shaped screens, undulating screens, flat mesh screens, etc. A mesh or screen size may be selected to permit the fluid mixture to pass through but with sufficient obstruction to such flow of fluid mixture to cause the treatment of the gas-liquid mixture to increase a surface area of the liquid to absorb the gas, as will be appreciated by those of skill in the art.

The injection or introduction of the liquid solvent50into each of the absorption tubes40may be done by various techniques as will be appreciated by those of skill in the art. The introduction and/or injection of the liquid solvent50into the absorption tubes40will form an aqueous froth in each absorption tube40. With the inclusion of the screen assemblies60, bubbles that are present in the froth will burst, reform, and burst repeatedly to form numerous micro-droplets of different radii, thereby creating a rapidly changing surface area for absorption of the component, chemical, or compound of interest. In some configurations, in order to deliver the leanest liquid solvent50to each stage, the liquid solvent50may be fed directly to each stage through a dedicated inlet line51,52.

In configurations where separation of the gas and liquid is required, multiple liquid/gas separators24may be mounted directly below the absorption tubes40(e.g., in the second chamber26). One possible form of these liquid/gas separators24is shown, but various other configurations may be employed without departing from the scope of the present disclosure. The liquid/gas separators24may be supported or mounted on a separator bulkhead plate22. The separator bulkhead plate22may also substantially separate the second chamber26from the third chamber27, with the liquid/gas separators24providing fluid connection therebetween. For example, the passageways through the liquid/gas separators24establish fluid (gas) communication between an initial dewatering chamber (e.g., second chamber26) and a next absorber stage (e.g., third chamber27) of the gas absorber10. In this operation, the liquid falls and settles into the space between around the liquid/gas separators24and on the separator bulkhead plate22and can be drawn off as a continuous liquid stream through a rich solvent drain line53to be regenerated into lean solvent, which may be recycled back into the gas absorber10at the inlet lines51,52. The gas stream30, in turn, passes through the liquid/gas separator24and into the next absorber stage (e.g., third chamber27). It will be appreciated that the need to remove the liquid solvent (absorbent) after each stage may be dependent on the requirements of each application, and thus such separator stage may be omitted or additional separator stages may be provided, as will be appreciated by those of skill in the art.

Although a specific configuration of the gas absorber10is illustrated, various other configurations are possible without departing from the scope of the present disclosure. For example, in other configurations, all of the liquid solvent may be directed to enter the absorber vessel20via a single line at the top of the absorber vessel20and will pass through the multiple stages of the absorber vessel20to be removed at the bottom thereof (e.g., by an absorber sump or the like). As illustratively shown, the gas stream30and the liquid solvent50leaving the absorber tubes40flows into the next stage in the absorber vessel50. In applications where liquid absorbent removal is not required, the partially spent absorbent from the first stage may be directed to fall or be pumped into a liquid-absorbent reservoir of the next stage, and in-turn enter the absorber tubes40of the subsequent stage.

A final dehydration stage may be provided within the fourth chamber28. The dehydration stage may include a rich-solvent reservoir29in the bottom of the absorber vessel20. A horizontal gas outlet duct32may be arranged to project through the vessel wall of the absorber vessel20in the fourth chamber28to allow the gas stream30to leave the absorber vessel20.

As noted above, fresh or lean liquid solvent50may be delivered to the absorber vessel20through the inlet line51and/or in the case of multiple inlets, the inlet lines51,52. Rich solvent55(the solvent already used to absorb components from the gas) may exits through a drain57at the bottom of absorber vessel20and/or through the solvent drain line53at an intermediate stage of the processing through the gas absorber10. The rich solvent55may be directed to a solvent regeneration system and then recycled and/or reused within the gas absorber10or may be used for other purposes, as will be appreciated by those of skill in the art. For example, a solvent regeneration system may employ heat and/or a vacuum to strip the component, compound, or chemical which has been removed from the gas stream30from the rich solvent55so that the regenerated solvent can in turn be reused in the gas absorber10.

Although illustrated as a substantially co-current flow with both the liquid solvent50and the gas stream30traveling in a vertically downward direction, other configurations are possible. For example, a counter-current configuration may be arranged to direct one of the liquid solvent and the gas stream in a downward direction and the other of the liquid solvent and the gas stream in an upward direction. This counter-current configuration may be used to increase the froth and absorption of the target gas within the liquid solvent. Such systems may be relatively more complex and/or require additional components or features to achieve such counter-current operation.

For example, referring toFIG.2, a schematic illustration of a counter-current absorber200is shown. The counter-current absorber200includes an absorber vessel202that is configured to receive a gas at a gas inlet204which is arranged at a bottom end of the vertically oriented absorber vessel202. The gas is then directed to flow upward toward a gas outlet206arranged at a top end of the absorber vessel202. At the same time, a liquid solvent is introduced to the absorber vessel202at the top end at a liquid inlet208and the liquid solvent then flows downward and in a direction opposite the flow direction of the gas to a liquid outlet210. Arranged within the absorber vessel202are a series or stack of packing elements212. The packing elements212may be arranged as conventional screens or the like.

However, recent advancements in continuous post-combustion capture technology have demonstrated that the size and cost of equipment can be dramatically reduced through development of new processes (e.g., chemical and/or mechanical). One technology that can increase the mass-transfer between a gas stream (e.g., carbon-rich flue gasses) and an absorbent liquid solvent is called a Regenerative Froth Contactor (RFC). The primary mechanism of an RFC system allows increased mass transfer through the generation of a pulsating flow regime inside a gas-liquid contactor such that the majority of the internal volume of the contactor is occupied by a pulsating froth of micro-scale gas bubbles and liquid droplets. An RFC system may be substantially passive in the sense that the frothing is achieved by suppling a substantially constant pressure and flowrate of the gas and liquid solvent through a vessel having a series of packing elements (e.g., screens or the like).

An RFC may employ specialized Corrugated Screen Packing (CSP) to produce a pulsing gas/liquid flow regime inside an absorber vessel. Corrugated Screen Packing and arrangements thereof are described in European Patent No. 2,675,548, the contents of which are incorporated herein in their entirety. Such pulsing of the gas/liquid mixture may be dependent on the geometric architecture of the packing arrangement (CSP) and the particular flowrates of liquid and gas used. Arrangements of CSP with flowrates of liquid and gas sufficiently high enough to achieve a high mass-transfer rate requires significant pumping power to overcome undesirable pressure drops due to the nature of the CSP. That is, the complex nature of the CSP may require additional pressure and/or flow rate production to ensure that the liquid-gas mixture is sufficiently passed through the CSP. Such configurations may result in large liquid pumping and gas compression equipment that is costly to install, maintain, and operate.

Referring toFIG.3, a schematic illustration of a co-current absorber300is shown. The co-current absorber300includes an absorber vessel302that is configured to receive a gas at a gas inlet304which is arranged at a top end of the vertically oriented absorber vessel302. The gas is then directed to flow downward toward a gas outlet306arranged at a bottom end of the absorber vessel302. At the same time, a liquid solvent is introduced to the absorber vessel302at the top end at a liquid inlet308and the liquid solvent then flows downward and in a direction parallel or the same as the flow direction of the gas to a liquid outlet310. Arranged within the absorber vessel302are a series or stack of packing elements312. The packing elements312may be arranged as Corrugated Screen Packing (CSP), as described above. As shown in the enlarged view ofFIG.3, the introduction of the packing elements312in the form of CSP may result a froth pulsation that is achieved through a combination of flow rate, flow pressure, characteristics of the absorber vessel302, and, primarily, characteristics of the packing elements312.

Although the co-current absorber vessel302of the configuration using CSP, shown inFIG.3, may be smaller than counter-current absorber vessel202ofFIG.2, to achieve the desired absorption, various alternative operational parameters may be required to be adjusted with the co-current absorber vessel302of the configuration using CSP, shown inFIG.3. For example, increased pressure and/or flow rate of the gas stream and/or the liquid solvent may be required to ensure that sufficient absorption occurs during the passage of the two fluids through the absorber vessel302.

The ability to generate the desired pulsating and/or fluctuating flow regime fundamental to an RFC with less restriction on packing design could reduce the size, cost, and power required to drive fluids through the contactor. Accordingly, in some embodiments of the present disclosure, fluctuations are introduced to the pressure of a liquid and/or a gas flow passage and/or within the absorber vessel. Such fluctuations may be introduced, in accordance with some non-limiting embodiments, through passive mechanisms, such as paddlewheels, restricted orifices, and/or active mechanisms, such as fast-acting control valves, electromagnetic solenoids (e.g., voice coils and/or acoustic drivers), or the like.

In accordance with embodiments of the present disclosure, the generation and perpetuation of highly mixed gas-liquid flows may be enhanced. Further, in accordance with some embodiments, a dependence of the flow regime on the geometric configuration of the contactor internal packing elements (e.g., screen assemblies) may be reduced. As a result, in accordance with some embodiments of the present disclosure, the internal packing elements may then be formed of a less restrictive architecture, and thus the pressure drop and the associated costs of equipment required to circulate fluids may be reduced.

In accordance with some embodiments of the present disclosure, a gas and/or liquid inlet stream feeding a co-current RFC absorber are introduced with a prescribed fluctuation in pressure and/or flowrate. This is in contrast to the nearly constant pressure and flowrates used by existing RFC systems. Further, in some embodiments, the frequency and/or magnitude of the fluctuations may be tuned according to internal flow dynamics of the absorber vessel (e.g., tower) and components arranged therein (if any). Considering the pressure waves that generate micro-bubble froth pulsations or fluctuations in a repeating pattern along the length of the absorber vessel, a standing-wave may be maintained by exciting a natural frequency of the compressible fluid mixture (e.g., mixture of gas and liquid solvent) within the absorber vessel. In some such configurations, the energy required to maintain a desired set of high-pressure/low-pressure mixture pulsations or fluctuations is thereby reduced. As a result, the absorber vessel and use thereof may be described as a resonator or resonating system, as described herein.

In accordance with some embodiments of the present disclosure, a regenerative froth contactor (RFC) able to produce high mass-transfer rates using energy-efficient resonator principles instead of energy-intensive pumping devices is provided. Such configurations may offer similar reductions in absorber contactor/vessel size and cost at a lower overall operational cost and may provide increased efficiency. Additional benefits, without limitation, may include increased operating range(s), and/or improved turndown. For example, in contrast to traditional RFC configurations, which rely on a particular arrangement of internal packings and require liquid and gas flowrates within a limited range in order to produce pulsing or fluctuating froth, the use of fluctuating liquid/gas pressures, as described herein, can produce pulsing or fluctuating froth to allow a broader range of liquid and gas flowrates. This additionally allows, for example, efficient capture of gaseous elements from a plant from maximum power (e.g., 100% power) down to less than 50% power (e.g., 50%, 40%, 30%, etc. power), which may be referred to as “turndown.”

Referring now toFIG.4, a schematic illustration of a pulsed absorption contactor400in accordance with an embodiment of the present disclosure is shown. The pulsed absorption contactor400is arranged as a co-current flow system including an absorber vessel402having a gas inlet404, a gas outlet406, a liquid inlet408, and a liquid outlet410. The co-current flow is achieved by the gas inlet404and the liquid inlet408being arranged at a top end (or inlet end403) of the absorber vessel402and the gas outlet406and the liquid outlet410being arranged at a bottom end (or outlet end405) of the absorber vessel402.

As shown, gas is supplied to the gas inlet404from a gas source412along a gas supply line414. Similarly, liquid is supplied to the liquid inlet408from a liquid source416along a liquid supply line418. The gas source414may be an industrial processing plant, equipment for industrial processing, or any other type of source for a gas that may require removal of one or more target compounds (e.g., CO2, methane, oxides of nitrogen, oxides of sulfur, etc.). The liquid source418may be a source of a solvent or the like that is used in the pulsed absorption contactor400and selected to absorb the target compound(s). In some configurations, the sources414,418may be part of a closed-loop or partially closed-loop system, such that the output at the outlets406,410may be recycled or recirculated back to the respective source414,418. It will be appreciated that the gas at the gas inlet404may be compositionally different than the gas at the gas outlet406. As such, the gas inlet404may be configured to receive an input gas and the gas outlet406may be configured to direct an output gas out of the absorber vessel402. Similarly, due to the absorption of a target compound, chemical, or component, an input liquid at the liquid inlet408may be different from a composition of an output liquid at the liquid outlet410. For example, the input gas may include a high proportion of a target component (e.g., chemical, compound, composition of matter, etc.) and, the output gas may have a relatively low proportion of the target component. In contrast, the input liquid may have a relatively low proportion of the target component, but the output liquid may comprise a relatively high proportion of the target component, due to the absorption of the target component into the liquid solvent.

The pulsed absorption contactor400is configured to actively induce or produce a fluctuation in a mixture of the gas and the liquid within the absorber vessel402. To generate such fluctuations, in this configuration, a gas pulser420is arranged along the gas supply line414and a liquid pulser422is arranged along the liquid supply line418. The gas pulser420is configured to impart a fluctuation into the flow of the gas as it flows through the gas supply line414and such fluctuation generates a pulse or fluctuation that continues as the gas flows into and through the absorber vessel402. Similarly, the liquid pulser422is configured to impart a fluctuation into the flow of the liquid as it flows through the liquid supply line418and such fluctuation generates a pulse or fluctuation that continues as the liquid flows into and through the absorber vessel402.

The fluctuations that are generated by the respective pulsers420,422may be sourced from or controlled by at least one pulse generator424. The pulse generator424may be configured to control the pulsers420,422such that a flow of the fluid (e.g., gas or liquid) is imparted with a pulse of different pressure (e.g., compression pulse, pressure wave, etc.), such that a consistent pulse pattern is imparted to the respective fluid. Such fluctuations may be introduced, in accordance with some non-limiting embodiments, through passive mechanisms, such as paddlewheels, restricted orifices, etc. and/or active mechanisms, such as fast-acting control valves, electromagnetic solenoids (e.g., voice coils, acoustic drivers, etc.), etc. and/or combinations thereof (e.g., combination of both active and passive fluctuation generators). When the pulsed fluid enters the absorber vessel402, the pulsed fluid will interact with the other fluid, which can be another pulsed fluid or a non-pulsed fluid. For example, a specific pulse regime may be imparted to the gas flow through the gas pulser420. As the gas flows along the gas supply line414it will then enter the absorber vessel402with the pulse and then propagate through the absorber vessel402from inlet end403toward the outlet end405. Similarly, a pulsed liquid will enter and propagate through the absorber vessel402with an imparted pulse signal from the liquid pulser422.

In this non-limiting configuration, due to the imparted pulses or fluctuations in the gas and the liquid, a standing wave426may be generated within the absorber vessel402. Due to the compression and condensing of the particles of the fluids at the peaks of the standing wave426, sufficient agitation may occur to cause bursting, shattering, fragmenting, or breaking up bubbles of the aqueous froth into a myriad of droplets and micro-droplets of different radii. This may result in a high efficiency of absorption of the gas into the liquid solvent. In some non-limiting configurations, the absorber vessel402may include one or more packing elements428. The packing elements428may be similar to the screens and meshes described with respect to the configuration ofFIGS.1-2and/or similar to the Corrugated Screen Packing (CSP) system described with respect to the configuration ofFIG.3. In other embodiments, packing elements may be omitted entirely. Further, various combinations of multiple similar or different packing elements may be employed in combination with the pulsed fluids described herein.

In operation, the pulsed absorption contactor400will supply pulsed fluids into the absorber vessel402where a mixture will froth and allow the liquid portion (e.g., solvent) to absorb gas molecules of the gas portion (e.g., CO2-rich gas). In a non-limiting example, the gas and/or liquid inlet streams (e.g., supply lines414,418) feeding a co-current RFC absorber (e.g., absorber vessel402) are introduced with a prescribed fluctuation in pressure and flowrate (e.g., pulsers420,422in combination with pulse generator424). Such configuration is in comparison to the nearly constant pressure and flow used by existing contactors (e.g., similar to that described inFIGS.2-3).

To impart or cause the generation of the pulses or fluctuations within the fluids (gas and/or liquid), the pulse generator424may, in some embodiments, be an electronic controller. The pulse generator424may define a gas pulse signal430and a liquid pulse signal432, which are transmitted to the respective pulsers420,422, along communication lines434,436, respectively. The transmission of the pulse signals430,432may be through a wired or wireless connection, if such signals are electronic. However, in other embodiments, the pulse signals may be hydraulic signals or pulses, mechanical signals (e.g., based on a clock or the like), or through some other mechanism(s) as will be appreciated by those of skill in the art. Further, in some embodiments, the gas pulser420may include an integral or integrated pulse generator and the liquid pulser422may include an integral or integrated pulse generator, and thus the pulse generator424illustrated inFIG.4may be omitted. The pulse signals430,432may be used to control the pulsers420,422to impart a pressure wave into the flow of the respective fluid. In such cases, the pulsers420,422may be electronically controlled or operated valves, turbines, paddle wheels, fan, adjustable orifice, gate/door controlling a controlled volume of the respective fluid, or the like. Such control may be referred to as active pulse generation.

In accordance with some embodiments of the present disclosure, the pulse generator424may be configured to impart the same frequency, amplitude, waveform or other feature into both the gas and liquid streams. In other embodiments, the two imparted pulses may be different in one or more aspects of the imparted waveform. Further, for example, the pulse signal of one of the gas or liquid streams may be a harmonic of the other, such that the two pulse signals are related, but may not be identical or substantially similar. The tuning of each pulse signal430,432may be selected to achieve a desired agitation and intermixing of the mixed fluid within the absorber vessel402.

In other embodiments, the pulse generation may be referred to as passive pulse generation. In such configurations, the system is designed to naturally generate the desired pressure waves, fluctuations, pulses, etc. within the respective fluid(s). It will be appreciated by those of skill in the art that the terms pulse and fluctuations may be used interchangeably herein, and the specific terminology of “pulse” is not intended to impart a specific type of pulse or fluctuation, but rather is intended to capture an induced change in pressure or flowrate in the subject fluid(s). For example, a turbine, paddle wheel, fan, orifice, and/or a controlled volume of the fluids may be used in a passive manner. For example, such turbines, wheels, fans, rotating baffle(s), and the like may be configured to rotate due to the supply of the respective fluid through the supply lines414,418. As the fluid interacts with the passive device within the supply line, a pressure pulse may be generated and then propagated into and through the absorber vessel402. Similarly, pulses may be generated by selecting an orifice of sufficient size or properties to cause a restriction within the flow of the fluid, and upon reaching a predetermined pressure, the orifice may open to permit a compressed portion of the fluid to pass through and into the absorber vessel402. A fixed volume may similarly be used. It will be appreciated that the above are merely examples of means and mechanisms for imparting a pressure pulse to a fluid, whether actively or passively.

Although shown inFIG.4with both the gas and the liquid having respective pulsers420,422, such configuration is not intended to be limiting. For example, in some embodiments, only one of the two fluids may have the pulse generated therein. For example, in one non-limiting example, the liquid solvent may be sprayed (e.g., as a fine mist) into the inlet end403of the absorber vessel402. However, the gas may have a gas pulser420that imparts a pressure wave into the gas along the gas supply line414and/or as the gas is introduced into the absorber vessel402at the gas inlet404. In such a configuration, the pulse imparted into the gas is the primary driving mechanism for generating the froth and mixture to agitate sufficiently for absorption of the target compound into the liquid solvent. In such a configuration, a standing wave may still be formed, but such standing wave is generated solely by the gas portion of the system. In other embodiments, the reverse may be true, with the pulse imparted to the liquid solvent, and the gas not having a pulse imparted thereto. As such, it will be appreciated that various different configurations are possible without departing from the scope of the present disclosure.

As shown inFIG.4, the pulsed absorption contactor400is arranged as a co-current flow system including an absorber vessel402having a gas inlet, a gas outlet406, a liquid inlet408, and a liquid outlet410. A pulse generator system438is provided to induce the above-described pressure waves426along the supply lines of the liquid and/or gas that are input to the absorber vessel402. The pulse generator system438of this illustrative configuration includes, at least, the pulse generator424, the pulsers420,422, and the packing elements428. It will be appreciated that the pulse generator system438may be configured with various other components and/or arrangements thereof, as will be appreciated in view of the teachings herein.

Referring now toFIG.5, a schematic illustration of a pulsed absorption contactor500in accordance with an embodiment of the present disclosure is shown. The pulsed absorption contactor500is arranged as a co-current flow system including an absorber vessel502having a gas inlet504, a gas outlet506, a liquid inlet508, and a liquid outlet510. The co-current flow is achieved by the gas inlet504and the liquid inlet508being arranged at a top end (or inlet end503) of the absorber vessel502and the gas outlet506and the liquid outlet510being arranged at a bottom end (or outlet end505) of the absorber vessel502.

In this configuration, the imparted pressure wave is introduced within the absorber vessel502itself, and not along the supply lines of the liquid or gas that are input into the absorber vessel502. As such, the gas and/or liquid may be deposited or injected into the absorber vessel502through spray nozzles, duct openings, gas nozzles, or the like, as will be appreciated by those of skill in the art. With the gas and liquid portions introduced into the absorber vessel502, the two fluids will mix. To increase the mixing and absorption of the gas into the liquid, a pressure wave may be introduced into the system with one or more pulsers512,514. The pulsers512,514are arranged on or in the absorber vessel502and are configured to generate pressure waves516within the absorber vessel502.

The pulsers512,514may be acoustic wave generators, vibration generators or the like. As shown, the pulsers512,514are arranged in sets, with a first set of pulsers512arranged at the inlet end503of the absorber vessel502and a second set of pulsers514arranged between the inlet end503and the outlet end505of the absorber vessel502. In some embodiments, only one set of pulsers512may be provided at the inlet end503of the absorber vessel502. The second set of pulsers514may be optionally included to ensure that the generated pressure wave (e.g., a standing wave) is maintained for the full length of the absorber vessel502from the inlet end503to the outlet end505. The second set of pulsers514may be arranged within an interior of the absorber vessel502, and may optionally be configured with or associated with a packing element or the like. The pulsers512,514may be controlled, for example, by a pulse generator518, which may be in wired or wireless communication with the pulsers512,514. As a result, a standing pressure wave may be generated within the absorber vessel502and cause the mixture of gas and liquid bubbles to burst, shatter, fragment, or break up into a myriad of droplets and micro-droplets, and the gas may be absorbed into the liquid. Although shown with two first pulsers512and two second pulsers514, it will be appreciated that the number of pulsers in a given set and/or the number of sets of pulsers may be adjusted to fit the particular application, and such specific number and arrangement as shown inFIG.5is not intended to be limiting.

Similar to the above-described embodiments, the absorber vessel502may include one or more packing elements428. The packing elements428may be similar to the screens and meshes described with respect to the configuration ofFIGS.1-2and/or similar to the Corrugated Screen Packing (CSP) system described with respect to the configuration ofFIG.3. In other embodiments, packing elements may be omitted entirely. Further, various combinations of multiple similar or different packing elements may be employed in combination with the pulsed fluids described herein. In some embodiments, due to the induced pressure waves, the number and features of packing elements may be reduced or simplified, and thus additional costs and complexity savings may be achieved. For example, rather than a corrugated screen, in some embodiments, a simple mesh or screen or even a plate with holes may be employed. These more simplistic packing elements may be configured merely as nucleation devices to provide surfaces upon which the fluid may collect and then cause absorption of the target gas, compound, chemical, or component within the liquid portion of the mixture.

Although the configuration ofFIG.5locates the pulsers512,514on or in the absorber vessel, such configuration of vibration inducing systems (e.g., acoustic, hydraulic, mechanical, etc.) is not intended to be limiting. For example, in some configurations, similar pulsers that generate pressure waves through vibrations may be arranged along supply lines of the gas and/or liquid that are injected or supplied into the absorber vessel. Further, in other embodiments, the pulsers may be integrated into or arranged to impart vibrations into one or more packing elements that are positioned within the absorber vessel (e.g., packing elements428shown inFIG.4). As such, the vibration-type pulsers may be used at various locations on pulsed absorption contactor systems, and the illustrated configurations are merely provided for illustrative and explanatory purposes.

As discussed above, embodiments of the present disclosure are directed to actively generating a pressure wave (e.g., compression wave, fluctuations, vibrations, etc.) within the gas, the liquid solvent, and/or the mixture thereof. Such a pressure wave, when actively induced, may cause regions of compression within an absorber vessel. These compressed regions, in combination with the flow of the fluid mixture through the absorber vessel (e.g., from inlet to outlet in a co-current manner) will cause the two fluids to intermix and interact such that the gas or a constituent thereof (e.g., target compound(s)) will be captured by the liquid solvent. This induced pressure wave system may be augmented by the inclusion of one or more packing elements, which may be CSP or the like, as described above. Whether such packing elements are included or not, the induced pressure wave could be a standing wave or a traveling wave. To achieve the induced standing wave, various factors have to be considered, such as the fluids employed (both gas and liquid), the nature of the injection of the fluids (e.g., mist, atomized, etc.), the flow rate(s) of the fluids, the pressure of the fluids, and the geometry and other features of absorber vessel itself.

Because such tuning is possible, the pulsed absorption contactors of the present disclosure may be configured as harmonic resonators. That is, in some embodiments of the present disclosure, the frequency and magnitude of the pressure waves (e.g., fluctuations, compression waves, vibrations, etc.) may be tuned according to the internal flow dynamics of the contactor system. Considering the pressure waves that generate micro-bubble froth pulsations in a repeating pattern along the length of the tower (i.e., absorber vessel), a standing-wave is maintained by exciting the natural frequency of the compressible fluid mixture (combination of gas and liquid) within the absorber vessel. By tuning the induced pressure waves to match harmonic frequencies of the physical system, the energy required to maintain the desired set of high-pressure/low-pressure mixture pulsations is thereby reduced. It will be appreciated that absorption contactor systems that are so tuned may be referred to as resonator absorption contactors. Such resonator absorption contactors may provide additional increased efficiencies and/or reduced costs associated with operation thereof, on top of the systems that may not have such tuned pressure waves.

Advantageously, embodiments of the present disclosure provide for improved capture systems for capturing target compounds from a gas stream. In accordance with some embodiments, an actively induced pressure wave is introduced into at least one of a gas stream, a liquid stream, or a mixture thereof. The induced pressure wave will result in regions of high compression between a liquid solvent and a gas within an absorber vessel. The induced pressure wave thereby increases the mixing and interaction of gas bubbles and liquid droplets, increasing the surface area of contact between the two fluids, and thereby increasing the absorption rate or capacity of a liquid solvent. Accordingly, a high extraction and capture of a target compound may be achieved through implementation of embodiments of the present disclosure.

Furthermore, advantageously, embodiments of the present disclosure may enable reduced size and/or cost of a contactor system, as compared to systems without induced pressure waves, as described herein. For example, and without limitation, the systems described herein may achieve a reduced pressure drop as compared to systems without such induced pressure waves. With a reduced pressure drop, pumps, blowers, piping, ducting and other components of the systems may be reduced in size and/or power, or may be eliminated entirely. Accordingly, a lower cost of equipment and lower operating costs may be achieved. Additionally, through a combination with a regenerative froth contactor (RFC), further improvements may be achieved. For example, a pulsed absorption contactor system with RFC may produce mass transfer enhancement (e.g., greater than 6.5×) beyond traditional counter-current absorber systems. Further, advantageously, even with such increased mass transfer (transfer of target compound into liquid solvent), such systems as disclosed herein may not incur a penalty of high-pressure-drop screen packing elements.

Advantageously, embodiments of the present disclosure may provide benefits relative to turndown operations of facilities that employ the pulsed absorption contactors of the present disclosure. For example, in conventional systems, extraction and capture of target compounds, chemicals, or components may be achieved at operation envelops of 100% down to about 75% (e.g., reduced power, pressure etc.). However, operating at below 75% envelop may result in too low of a pressure within the system, and thus the system may not properly function. In contrast, by implementing embodiments of the present disclosure, the operating envelop may be increased to 100% down to about 40%. Accordingly, the systems described herein provide for a significantly larger operational range than systems that do not include the features described herein.

Embodiments of the present disclosure may be used in various applications and/or industries. For example, and without limitation, the pulsed absorption contactors of the present disclosure may be used post-combustion CO2capture for industrial processing plants, refineries, power plants, chilled ammonia process (CAP), mixed salt process (MSP), and liquid solvent capture processes. Depending on the specific application, the liquid solvent may be selected to achieve absorption of a specific target compound, chemical, or component. For example, and without limitation, various liquid solvents that may be used with the pulsed absorption contactors of the present disclosure may include monoethanolamine (MEA) solvents, ammonia, enhanced solvents, glycol, and the like, which may be selected to absorb or capture a specific desired target compound, chemical, or component. The target compounds, chemicals, or components may include, for example and without limitation, carbon dioxide, potassium carbonate, ammonia, or others. Furthermore, the pulsed absorption contactors of the present disclosure may be used as a dryer for dehydration of a fluid. It will be appreciated that the above are merely examples, and the pulsed absorption contactors of the present disclosure may be used in various other industries, applications, and/or with other gas streams and/or solvents.

Embodiment 1: A pulsed absorption contactor system comprising: a vessel having an inlet end and an outlet end, the vessel comprising: at least one gas inlet arranged at the inlet end of the vessel and configured to direct an input gas stream into the vessel; at least one gas outlet arranged at the outlet end of the vessel and configured to receive an output gas stream and direct the output gas stream out of the vessel; at least one liquid inlet arranged at the inlet end of the vessel and configured to direct an input liquid stream into the vessel; and at least one liquid outlet arranged at the outlet end of the vessel and configured to receive an output liquid stream and direct the output liquid stream out of the vessel; and a pulse generator system configured to induce a fluctuation in at least one of the input gas stream, the input liquid stream, or a combination of the input gas stream and the input liquid stream.

Embodiment 2: The pulsed absorption contactor system of any preceding embodiment, wherein the pulse generator system comprises a gas pulser arranged along the input gas stream and configured to impart a pressure pulse into the input gas stream.

Embodiment 3: The pulsed absorption contactor system of any preceding embodiment, wherein the pulse generator system comprises a liquid pulser arranged along the liquid input stream and configured to impart a pressure pulse into the input liquid stream.

Embodiment 4: The pulsed absorption contactor system of any preceding embodiment, wherein the pulse generator system comprises: a gas pulser arranged along the input gas stream and configured to impart a pressure pulse into the input gas stream; and a liquid pulser arranged along the input liquid stream and configured to impart a pressure pulse into the input liquid stream.

Embodiment 5: The pulsed absorption contactor system of any preceding embodiment, wherein the pressure pulse imparted to the input gas stream is a harmonic of the pressure pulse imparted to the input liquid stream.

Embodiment 6: The pulsed absorption contactor system of any preceding embodiment, wherein the pulse generator system comprises at least one pulse generator configured to control at least one pulser to impart a pulse into at least one of the gas stream and the liquid steam.

Embodiment 7: The pulsed absorption contactor system of any preceding embodiment, further comprising at least one packing element arranged within the vessel.

Embodiment 8: The pulsed absorption contactor system of any preceding embodiment, wherein the at least one packing element comprises corrugated screen packing.

Embodiment 9: The pulsed absorption contactor system of any preceding embodiment, wherein the pulse generator system comprises a vibration generator configured to impart vibrations into at least one of the input gas stream, the input liquid stream, or a mixture of gas and liquid from the input gas stream and the input liquid stream.

Embodiment 10: The pulsed absorption contactor system of any preceding embodiment, wherein the vibration generator is an acoustic wave generator.

Embodiment 11: The pulsed absorption contactor system of any preceding embodiment, wherein the vibration generator comprises at least one pulser arranged on an exterior of the vessel.

Embodiment 12: The pulsed absorption contactor system of any preceding embodiment, wherein the vibration generator comprises at least one pulser arranged within an interior of the vessel.

Embodiment 13: The pulsed absorption contactor system of any preceding embodiment, wherein the input gas stream comprises a target compound and the input liquid stream comprises a solvent selected to capture the target compound.

Embodiment 14: A method for capturing a target component from a gas within a liquid using a pulsed absorption contactor system comprising a vessel having an inlet end and an outlet end and a pulse generator system, the method comprising: supplying an input gas into the vessel through a gas inlet at the inlet end of the vessel; supplying an input liquid into the vessel through a liquid inlet at the inlet end of the vessel; and inducing a pressure wave within the vessel using the pulse generator system configured to induce a pulse in at least one of the input gas, the input liquid, and a mixture of the input gas and the input liquid, wherein an induced pulse from the pulse generator system creates a compression wave of a mixture of the input gas and the input liquid within the vessel.

Embodiment 15: The method of any preceding embodiment, wherein the pulse generator system comprises a gas pulser arranged to impart a pressure pulse into the input gas.

Embodiment 16: The method of any preceding embodiment, wherein the pulse generator system comprises a liquid pulser arranged to impart a pressure pulse into the input liquid.

Embodiment 17: The method of any preceding embodiment, wherein the pulse generator system comprises at least one pulse generator configured to control at least one pulser to impart a pulse into at least one of the input gas, the input liquid, and the mixture of the input gas and the input liquid.

Embodiment 18: The method of any preceding embodiment, further comprising at least one packing element arranged within the vessel.

Embodiment 19: The method of any preceding embodiment, wherein inducing of the pressure wave comprises generating vibrations and inducing the pressure wave into the at least one of the input gas, the input liquid, and the mixture of the input gas and the input liquid.

Embodiment 20: The method of any preceding embodiment, wherein the input gas comprises a target compound and the input liquid comprises a solvent selected to capture the target compound.

The teachings of the present disclosure may be used in a variety of well operations. These operations may involve using one or more treatment agents to treat a formation, the fluids resident in a formation, a borehole, and/or equipment in the borehole, such as production tubing. The treatment agents may be in the form of liquids, gases, solids, semi-solids, and mixtures thereof. Illustrative treatment agents include, but are not limited to, fracturing fluids, acids, steam, water, brine, anti-corrosion agents, cement, permeability modifiers, drilling muds, emulsifiers, demulsifiers, tracers, flow improvers etc. Illustrative well operations include, but are not limited to, hydraulic fracturing, stimulation, tracer injection, cleaning, acidizing, steam injection, water flooding, cementing, etc.