Energy-efficient solvent regeneration

Abstract

A method for regenerating a CO2-rich solvent includes producing a low-frequency ultrasound proximate the CO2-rich solvent, inducing convective mixing of the CO2-rich solvent, reducing a viscosity of the CO2-rich solvent, and releasing CO2 gas from the CO2-rich solvent. Additionally, a system for solvent regeneration includes at least one regeneration intensification unit, including an ultrasonic processor designed to apply sonication to the solvent, a transducer physically coupled to the ultrasonic processor, a horn physically coupled to the transducer, and a sonication reaction chamber physically coupled to the horn and fluidly coupled to a flask retaining the solvent, where the solvent is cycled between the flask and the sonication reaction chamber. Furthermore, a system for solvent regeneration includes a reboiler, a regenerator, a heat exchanger, an absorber, and at least one ultrasonic processor designed to apply sonication to the solvent.

Description

Attorney Docket No. IS24.1786-WOENERGY-EFFICIENT SOLVENT REGENERATIONCROSS REFERENCE PARAGRAPH

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 761,654, entitled 'ENERGY-EFFICIENT SOLVENT REGENERATION," filed February 21, 2025, the disclosure of which is hereby incorporated herein by reference.FIELD

[0002] The present disclosure relates generally to gas treatment and separation processes and, more particularly, to regeneration of carbon dioxide (CO2)-rich solvents used in solvent-based CO2 capture and / or acid gas removal operations in hydrocarbon production, processing, refining, and related industrial facilities.BACKGROUND

[0003] Solvent-based CO2 capture and acid gas removal are widely practiced for treating process streams such as natural gas, synthesis gas, and combustion-derived flue gas. In a typical arrangement, a CO2-lean solvent contacts a CO2-containing gas in an absorber where CO2 is transferred from the gas phase into the solvent to form a CO2-rich solvent. The CO2-rich solvent is then conveyed to a regeneration section (e.g., a regenerator / stripper) where absorbed CO2 is released to produce a CCh-lean solvent that can be returned to the absorber. Amines and amine-containing formulations (including aqueous amines such as monoethanolamine (MEA), blended amines, and related chemistries) are commonly employed because they can provide high CO2 capacity and favorable absorption kinetics under many operating conditions.

[0004] Despite widespread adoption, solvent regeneration can be a primary driver of energy consumption, operating cost, and overall process efficiency in solvent-based CO2 capture. In many commercial systems, regeneration is achieved by heating the CCh-rich solvent in a reboiler to elevate temperature and provide stripping vapor, thereby shifting equilibrium and / or facilitating reaction reversal to release CO2 in the regenerator. The associated thermal duty may be substantial, particularly when high solvent circulation rates are required to meet CO2 removal targets. Heat integration (e.g., lean / rich heat exchange) may reduce some of this burden, but significant external heat input is often still required. In addition to energy expense, elevated regeneration temperaturesAttorney Docket No. IS24.1786-WOmay contribute to solvent degradation and corrosion and may increase solvent losses and maintenance requirements in certain systems.

[0005] A variety of approaches have been proposed to reduce regeneration energy demand and / or intensify CO2 desorption. Examples include alternative solvent chemistries, process modifications advanced contacting configurations, and the use of supplementary driving forces intended to accelerate desorption kinetics or enhance mass transfer. However, many such approaches can introduce practical challenges, such as increased equipment complexity, retrofit difficulty, greater capital cost, operational constraints, or sensitivity to solvent properties (e.g., viscosity and foaming tendency) and plant-specific operating conditions.

[0006] Accordingly, there remains a need for solvent regeneration techniques that can reduce thermal energy demand and / or improve CO2 desorption performance while maintaining or improving operability and enabling practical deployment in commercial absorber-regenerator flow schemes. In particular, there is a need for systems and methods that can be incorporated into solvent circulation flow paths in a controllable manner, including in configurations that avoid or mitigate the complexity of installing intensification hardware inside large regeneration columns, and that can be applied to a range of solvent types and process conditions.SUMMARY

[0007] In one aspect, provided herein is a method for solvent regeneration comprising inducing convective mixing of a CCh-rich solvent via a plurality of regeneration intensification unit; inducing localized heating of the C Ch-rich solvent via the plurality of regeneration intensification unit; reducing viscosity of the CCh-rich solvent via the plurality of regeneration intensification unit; releasing CO2 gas from the reduced viscosity CCh-rich solvent; and pre-heating the solvent via the plurality of regeneration intensification unit before introducing a CCh-depleted solvent into a regenerator.

[0008] In another aspect, provided herein is a method for capturing carbon dioxide (CO2) comprising absorbing CCh-rich solvent; reducing viscosity of the CCh-rich solvent via a plurality of regeneration intensification unit by inducing microstreaming and heating; and releasing CO2 gas from the reduced viscosity CCh-rich solvent.

[0009] In another aspect, provided herein is a system for solvent regeneration comprising a plurality of regeneration intensification unit, wherein the system induces convective mixing of aAttorney Docket No. IS24.1786-WOCCh-rich solvent the plurality of regeneration intensification unit; induces localized heating of the CO2-rich solvent via the plurality of regeneration intensification unit; reduces viscosity of the CO2-rich solvent via the plurality of regeneration intensification unit; releases CO2 gas from the reduced viscosity CCh-rich solvent; and pre-heats the solvent via the plurality of regeneration intensification unit before introducing a C Ch-depleted solvent into a regenerator.

[0010] In another aspect, provided herein is a system for capturing carbon dioxide (CO2) comprising a plurality of regeneration intensification unit further comprising, wherein the system absorbs CCh-rich solvent; reduces viscosity of the CCh-rich solvent via a plurality of regeneration intensification unit by inducing microstreaming and heating; and releases CO2 gas from the reduced viscosity CCh-rich solvent.

[0011] In another aspect, provided herein is a method for regenerating a CCh-rich solvent in a solvent-based CO2 capture process, the method comprising directing at least a portion of the CO2-rich solvent through a regeneration intensification unit that is in fluid communication with a solvent circulation flow path, the regeneration intensification unit comprising a flow-through treatment region; while the portion flows through the flow-through treatment region, applying ultrasound to the portion in a pulsed mode to induce cavitation and convective mixing in the portion; and releasing CO2 from the portion to provide a CCh-lean solvent.

[0012] In another aspect, provided herein is a regeneration intensification unit for solvent regeneration, comprising a housing defining a flow-through chamber configured to receive a flowing CCh-rich solvent; at least one ultrasonic transducer coupled to the housing and configured to deliver acoustic energy into the flowing CCh-rich solvent within the flow-through chamber; and an ultrasonic processor coupled to the at least one ultrasonic transducer and configured to drive the at least one ultrasonic transducer to apply low-frequency ultrasound in a pulsed mode to the flowing CCh-rich solvent.

[0013] In a further aspect, provided herein is a system for solvent-based CO2 capture, comprising an absorber configured to contact a CCh-containing gas with a CCh-lean solvent to provide a CCh-rich solvent; a regenerator configured to release CO2 from the CCh-rich solvent to provide the CCh-lean solvent; a reboiler in fluid communication with the regenerator; a heat exchanger in a solvent circulation loop between the absorber and the regenerator; and at least one regeneration intensification unit positioned in the solvent circulation loop outside of the regenerator, the at leastAttorney Docket No. IS24.1786-WOone regeneration intensification unit configured to apply low-frequency ultrasound in a pulsed mode to a flowing portion of the CCh-rich solvent in a flow-through treatment region.BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present disclosure is best understood from the following detailed description when read with the accompanying Figures. It is emphasized that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.

[0015] FIG. 1 is a schematic diagram of a solvent-based CO2 capture process in a conventional tower system containing one or more regeneration intensification units in accordance with the present disclosure.

[0016] FIG. 2 is a schematic representation of an example solvent regeneration intensification unit used for CO2 desorption from solvents in accordance with the present disclosure.

[0017] FIG. 3 is a graph illustrating CO2 loading in 30 wt.% ethanolamine (MEA) at different desorption temperatures during CO2 desorption using only a heat source.

[0018] FIG. 4 is a graph illustrating CO2 loading in 30 wt.% MEA during CO2 desorption using only continuous sonication.

[0019] FIG. 5 is a graph illustrating CO2 loading in 30 wt.% MEA during CO2 desorption using pulsed-mode sonication.DETAILED DESCRIPTION

[0020] Illustrative examples of the subject matter claimed below will now be disclosed. In the interest of clarity, not all features of an actual implementation are described in this specification. It will be appreciated that in the development of any such actual implementation, numerous implementation-specific decisions may be made to achieve the developers’ specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort, even if complex and time-consuming, would be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.Attorney Docket No. IS24.1786-WO

[0021] Further, as used herein, the article “a” is intended to have its ordinary meaning in the patent arts, namely “one or more.” Herein, the term “about” when applied to a value generally means within the tolerance range of the equipment used to produce the value, or in some examples, means plus or minus 10%, or plus or minus 5%, or plus or minus 1%, unless otherwise expressly specified. Further, herein the term “substantially” as used herein means a majority, or almost all, or all, or an amount with a range of about 51% to about 100%, for example. Moreover, examples herein are intended to be illustrative only and are presented for discussion purposes and not by way of limitation.

[0022] The present disclosure relates to methods and systems for reducing the thermal energy demand for the regeneration of solvents in solvent-based CO2 capture processes. The regeneration intensification units disclosed herein may use ultrasound-induced cavitation as an additional driving force to initiate CO2 release at temperatures that are lower than that required in conventional solvent-based desorption process. The units may be installed in a flow-through system that resembles the flow of solvents in a conventional absorber-regenerator tower configuration.

[0023] The solvent may comprise an amine-containing solvent, such as an aqueous amine solution, a blended amine formulation, and / or a promoted amine formulation. For example, the solvent may comprise one or more sterically hindered amines, one or more diamines, and / or one or more amino alcohols. Non-limiting examples of such solvents include monoethanolamine (MEA), DEA, MDEA, AMP, piperazine (PZ), AEP, and combinations thereof. For example, the solvent may comprise MEA. In some instances, the solvent comprises an aqueous solution comprising total amine in a concentration of, for example, from about 0.1 wt.% to about 40 wt.% (e.g., a concentration of at least about 0.1 wt.%, at least about 1 wt.%, at least about 5 wt.%, at least about 10 wt.%, or at least about 20 wt.%, and / or a concentration of at most about 40 wt.%, at most about 30 wt.%, at most about 20 wt.%, or at most about 10 wt.%, and / or a concentration falling within a range bounded by any two of the preceding values), with a balance being water and / or other optional components, various cases, the solvent comprises water in a concentration of, for example, from about 60 wt.% to about 99.9 wt.% (e.g., a concentration of at least about 60 wt.%, at least about 70 wt.%, at least about 80 wt.%, or at least about 90 wt.%, and / or a concentration of at most about 99.9 wt.%, at most about 99 wt.%, at most about 95 wt.%, or at most about 90 wt.%, and / or a concentration falling within a range bounded by any two of the preceding values). The solventAttorney Docket No. IS24.1786-WOmay further comprise one or more additional components, including, for example, one or more corrosion inhibitors, antifoaming agents, oxidation inhibitors, degradation inhibitors, surfactants, heat-stable salt management additives, and / or reclamation additives.

[0024] The “CO2-rich” solvent may be characterized by an initial CO2 loading (sometimes referred to as a “rich” loading) of, for example, from about 0.1 mol CCh / mol alkalinity to about 0.5 mol CCh / mol alkalinity (e.g., a loading of at least about 0.1 mol CCh / mol alkalinity, at least about 0.2 mol CCh / mol alkalinity, or at least about 0.3 mol CCh / mol alkalinity, and / or a loading of at most about 0.5 mol CCh / mol alkalinity, at most about 0.4 mol CCh / mol alkalinity, or at most about 0.3 mol COz / mol alkalinity, and / or a loading falling within a range bounded by any two of the preceding values). The “CCh-lean” solvent may be characterized by a target lean loading of, for example, from about 0.1 mol CCh / mol alkalinity to about 0.2 mol CO2 / mol alkalinity (e.g., a loading of at least about 0.1 mol CCh / mol alkalinity, at least about 0.12 mol CCh / mol alkalinity, or at least about 0.15 mol CCh / mol alkalinity, and / or a loading of at most about 0.2 mol CCh / mol alkalinity, at most about 0.18 mol CCh / mol alkalinity, or at most about 0.15 mol CCh / mol alkalinity, and / or a loading falling within a range bounded by any two of the preceding values). In some instances, the solvent temperature at an inlet to a regeneration intensification unit is, for example, from about 25 °C to about 200 °C (e.g., a temperature of at least about 25 °C, at least about 50 °C, or at least about 100 °C, and / or a temperature of at most about 200 °C, at most about 150 °C, or at most about 100 °C, and / or a temperature falling within a range bounded by any two of the preceding values), and a pressure at the unit is, for example, from about 101 kPa to about 7000 kPa (absolute) (e.g., a pressure of at least about 101 kPa, at least about 500 kPa, or at least about 2000 kPa, and / or a pressure of at most about 7000 kPa, at most about 5000 kPa, or at most about 2000 kPa, and / or a pressure falling within a range bounded by any two of the preceding values).

[0025] In various instances, the systems and methods disclosed herein are applicable to removal of CO2 and / or other acid gases from a feed gas stream. Non-limiting examples of acid gases include CO2, H2S, COS, SO2, and combinations thereof.

[0026] For example, the methods and systems disclosed herein may be implemented in connection with a solvent circulation loop that includes, for example, an absorber configured to provide a CO2-rich solvent, a regenerator configured to provide a CO2-lean solvent, and one or more heat-transfer devices (e.g., one or more heat exchangers and / or a reboiler) configured to add and / or recover heatAttorney Docket No. IS24.1786-WOwithin the loop. In such instances, the CCh-rich solvent may be conveyed through one or more conduits and / or flowlines between these components, and the regeneration intensification units disclosed herein may be positioned to treat the solvent as the solvent flows through the conduits and / or flowlines.

[0027] As used herein, a “regeneration intensification unit” generally refers to equipment configured to apply energy and / or agitation to a solvent in a localized manner to promote CO2 desorption and / or to condition the solvent for subsequent desorption. In some instances, a regeneration intensification unit includes one or more ultrasonic components configured to generate an acoustic field within the solvent, thereby producing one or more of cavitation, acoustic streaming, microstreaming, and associated mixing effects. In other instances, a regeneration intensification unit includes one or more hydrodynamic cavitation components (e.g., a restriction, nozzle, venturi, rotor-stator device, or other flow-induced cavitation structure), optionally used alone or in combination with ultrasonic components.

[0028] In various instances, the regeneration intensification unit is configured to apply ultrasound to the solvent at a frequency selected to promote one or more of cavitation, acoustic streaming, microstreaming, and / or agitation. In some instances, the ultrasound comprises low-frequency ultrasound having a frequency of, for example, from about 1 kHz to about 50 kHz (e.g., a frequency of at least about 1 kHz, at least about 10 kHz, at least about 20 kHz, or at least about 30 kHz, and / or a frequency of at most about 50 kHz, at most about 40 kHz, at most about 30 kHz, or at most about 20 kHz, and / or a frequency falling within a range bounded by any two of the preceding values), such as about 20 kHz to about 40 kHz. In some instances, the ultrasound comprises higher-frequency ultrasound having a frequency of, for example, from about 100 kHz to about 5 MHz (e.g., a frequency of at least about 100 kHz, at least about 500 kHz, at least about 1 MHz, or at least about 2 MHz, and / or a frequency of at most about 5 MHz, at most about 2 MHz, at most about 1 MHz, or at most about 500 kHz, and / or a frequency falling within a range bounded by any two of the preceding values), such as about 1 MHz to about 2 MHz.

[0029] In some instances, ultrasound is applied at an acoustic power of, for example, from about 10 W to about 1000 W (e.g., an acoustic power of at least about 10 W, at least about 25 W, at least about 50 W, at least about 100 W, at least about 250 W, or at least about 500 W, and / or an acoustic power of at most about 1000 W, at most about 750 W, at most about 500 W, at most about 250 W, at most about 100 W, or at most about 50 W, and / or an acoustic power falling within a rangeAttorney Docket No. IS24.1786-WObounded by any two of the preceding values), and / or at an acoustic power density of, for example, from about 1 W / L to about 10000 W / L (e.g., an acoustic power density of at least about 1 W / L, at least about 5 W / L, at least about 10 W / L, at least about 50 W / L, at least about 100 W / L, at least about 500 W / L, or at least about 1000 W / L, and / or an acoustic power density of at most about 10000 W / L, at most about 5000 W / L, at most about 1000 W / L, at most about 500 W / L, at most about 100 W / L, at most about 50 W / L, or at most about 10 W / L, and / or an acoustic power density falling within a range bounded by any two of the preceding values). In various cases, the regeneration intensification unit is configured to provide a solvent residence time (or treatment time) of, for example, from about 10 seconds to about 6000 seconds (e.g., a residence time of at least about 10 seconds, at least about 30 seconds, at least about 60 seconds, at least about 300 seconds, at least about 600 seconds, or at least about 1800 seconds, and / or a residence time of at most about 6000 seconds, at most about 3600 seconds, at most about 1800 seconds, at most about 600 seconds, at most about 300 seconds, or at most about 60 seconds, and / or a residence time falling within a range bounded by any two of the preceding values) for a treated portion of the solvent stream.

[0030] In some instances, ultrasound is applied while the solvent is maintained at a bulk temperature of, for example, from about 20 °C to about 200 °C (e.g., a bulk temperature of at least about 20 °C, at least about 40 °C, at least about 60 °C, at least about 80 °C, at least about 100 °C, or at least about 150 °C, and / or a bulk temperature of at most about 200 °C, at most about 180 °C, at most about 150 °C, at most about 120 °C, at most about 100 °C, or at most about 80 °C, and / or a bulk temperature falling within a range bounded by any two of the preceding values). In some instances, ultrasound is applied while the solvent is flowing at a volumetric flow rate of, for example, from about 0.1 L / min to about 1000 L / min through a treatment region (e.g., a volumetric flow rate of at least about 0.1 L / min, at least about 0.5 L / min, at least about 1 L / min, at least about 5 L / min, at least about 10 L / min, at least about 50 L / min, or at least about 100 L / min, and / or a volumetric flow rate of at most about 1000 L / min, at most about 500 L / min, at most about 200 L / min, at most about 100 L / min, at most about 50 L / min, at most about 10 L / min, or at most about 5 L / min, and / or a volumetric flow rate falling within a range bounded by any two of the preceding values). In various cases, the regeneration intensification unit is configured to operate at a pressure drop across the unit of no greater than about 7000 kPa (e.g., no greater than about 7000 kPa, no greater than about 5000 kPa, no greater than about 2000 kPa, no greater than about 1000 kPa, no greater than about 500 kPa, no greater than about 200 kPa, or no greater than about 100 kPa).Attorney Docket No. IS24.1786-WO

[0031] Without being limited to any particular mechanism, the application of ultrasound may promote CO2 desorption by producing localized pressure oscillations, localized heating, formation and collapse of cavitation bubbles, and / or enhanced convective transport within the solvent.

[0032] The regeneration intensification units may be operated in a continuous mode, a pulsed mode, or a combination thereof. In some instances, pulsed operation includes alternating between “on” intervals in which ultrasound is applied and “off’ intervals in which ultrasound is reduced or halted, thereby establishing localized gradients and / or transient conditions within the solvent. In various cases, pulsed operation may be selected to maintain a desired CO2 desorption rate and / or to respond to changes in solvent properties and / or process conditions.

[0033]

[0023] In various instances, the regeneration intensification unit is operated in a pulsed mode in which ultrasound is applied during “on” intervals and reduced or halted during “off’ intervals. In some instances, an “on” interval (pulse width) is, for example, from about 1 millisecond to about 3600 seconds (e.g., a pulse width of at least about 1 ms, at least about 10 ms, at least about 100 ms, at least about 1 s, at least about 10 s, at least about 60 s, or at least about 600 s, and / or a pulse width of at most about 3600 s, at most about 1800 s, at most about 600 s, at most about 60 s, at most about 10 s, at most about 1 s, at most about 100 ms, or at most about 10 ms, and / or a pulse width falling within a range bounded by any two of the preceding values). In some instances, an “off’ interval is, for example, from about 1 millisecond to about 3600 seconds (e.g., an off interval of at least about 1 ms, at least about 10 ms, at least about 100 ms, at least about 1 s, at least about 10 s, at least about 60 s, or at least about 600 s, and / or an off interval of at most about 3600 s, at most about 1800 s, at most about 600 s, at most about 60 s, at most about 10 s, at most about 1 s, at most about 100 ms, or at most about 10 ms, and / or an off interval falling within a range bounded by any two of the preceding values). In various cases, the pulsed mode is characterized by a duty cycle of, for example, from about 1% to about 100% (e.g., a duty cycle of at least about 1%, at least about 5%, at least about 10%, at least about 20%, or at least about 50%, and / or a duty cycle of at most about 100%, at most about 80%, at most about 50%, at most about 20%, or at most about 10%, and / or a duty cycle falling within a range bounded by any two of the preceding values).

[0034] In some instances, the pulsed mode comprises repeating pulse trains. In some instances, the pulsed mode comprises applying a first pulsing scheme during a first portion of regeneration andAttorney Docket No. IS24.1786-WOapplying a second pulsing scheme during a second portion of regeneration. For example, the duty cycle may be reduced as solvent viscosity decreases and / or as CO2 desorption rate changes.

[0035] In various instances, the system includes one or more sensors configured to monitor one or more process parameters associated with the solvent and / or a vent stream. Non-limiting examples of monitored parameters include solvent temperature, solvent pressure, solvent flow rate, solvent density, solvent viscosity, CO2 concentration in a vent stream, total vent flow rate, and combinations thereof. In some instances, the system includes at least one CO2 analyzer and at least one flow meter fluidly coupled to an outlet stream of a regeneration intensification unit.

[0036] In some instances, an ultrasonic processor and / or controller is configured to adjust one or more ultrasound operating parameters based on the monitored parameter(s). Non-limiting examples of adjustable operating parameters include acoustic power, frequency, pulse width, off-time, duty cycle, pulse repetition frequency, solvent residence time in the unit, and combinations thereof.

[0037] In one non-limiting example control scheme, the controller:

[0038] (i) receives a measured CO2 concentration and a measured vent flow rate,

[0039] (ii) determines a CO2 desorption rate based on the measured CO2 concentration and the measured vent flow rate,

[0040] (iii) compares the CO2 desorption rate to a target desorption rate of, for example, from about 0.01 L / min to about 1000 L / min (e.g., a target desorption rate of at least about 0.01 L / min, at least about 0.1 L / min, at least about 1 L / min, at least about 10 L / min, or at least about 100 L / min, and / or a target desorption rate of at most about 1000 L / min, at most about 500 L / min, at most about 100 L / min, at most about 10 L / min, or at most about 1 L / min, and / or a target desorption rate falling within a range bounded by any two of the preceding values), and

[0041] (iv) adjusts at least one of pulse width, off-time, and duty cycle to maintain the CO2 desorption rate at or above the target desorption rate.

[0042] In another non-limiting example control scheme, the controller monitors a viscosity proxy and adjusts pulsing accordingly. For example, the ultrasonic processor may be configured to maintain a substantially constant ultrasound frequency, and a measured change in electrical power draw and / or acoustic coupling may be used as an indirect indicator of changing solvent viscosity. As a non-limiting example and for purposes of illustration, when the measured change in electricalAttorney Docket No. IS24.1786-WOpower draw and / or acoustic coupling indicates that viscosity has decreased to below a threshold of, for example, from about 1% to about 5% of an initial viscosity state (e.g., below at least about 5% of the initial viscosity state, below at least about 4% of the initial viscosity state, below at least about 3% of the initial viscosity state, below at least about 2% of the initial viscosity state, or below at least about 1% of the initial viscosity state, and / or below at most about 5% of the initial viscosity state, below at most about 4% of the initial viscosity state, below at most about 3% of the initial viscosity state, below at most about 2% of the initial viscosity state, or below at most about 1% of the initial viscosity state, and / or below a threshold bounded by any two of the preceding values), the controller may reduce acoustic power and / or duty cycle to, for example, from about 1% to about 5% (e.g., to about 1%, about 2%, about 3%, about 4%, or about 5%, and / or to a value bounded by any two of the preceding values).

[0043] In some instances, the controller is configured to switch between continuous mode and pulsed mode based on a trigger condition. Non-limiting examples of trigger conditions include: the solvent temperature reaching a steady-state condition; the CO2 desorption rate decreasing below a threshold; the solvent viscosity exceeding a threshold; and combinations thereof.

[0044] In various cases, the regeneration intensification units are configured for flow-through operation such that at least a portion of the solvent stream passes through (or is diverted through) a treatment region of the unit. For example, a regeneration intensification unit may be installed inline with a solvent flow path. Additionally or alternatively, a regeneration intensification unit may be installed in a bypass configuration such that the unit treats a diverted portion of the solvent stream that is returned to a main flow path downstream of the unit. In some such cases, one or more valves, manifolds, and / or flow control devices are used to selectively route solvent through one or more regeneration intensification units to provide operational flexibility.

[0045] For example, in various instances, the regeneration intensification unit comprises a flow-through chamber configured to receive a flowing solvent stream and to expose the flowing solvent stream to ultrasound within the flow-through chamber. In some such instances, the regeneration intensification unit may comprise a housing defining the flow-through chamber and one or more transducers coupled to the housing to deliver acoustic energy into the solvent.

[0046] In some instances, the regeneration intensification unit comprises a horn-based reactor, including one or more horns coupled to a reactor chamber. In some such instances, the regeneration intensification unit comprises a multi-stage unit comprising at least two horns and / or at least twoAttorney Docket No. IS24.1786-WOreactor chambers arranged in series such that the solvent is treated sequentially by the stages. In some instances, stages may operate at different frequencies and / or different duty cycles.

[0047] In various instances, the regeneration intensification unit comprises a plurality of transducers arranged circumferentially about a flow-through chamber, and / or arranged axially along a flow path, to provide more uniform acoustic exposure. In some instances, the regeneration intensification unit comprises a ring transducer, a plate transducer, a clamp-on transducer, and / or a sonotrode.

[0048] In some instances, the regeneration intensification unit comprises a hydrodynamic cavitation device configured to produce cavitation via flow-induced pressure reduction. Nonlimiting examples of hydrodynamic cavitation devices include a venturi, an orifice plate, a nozzle, a multi-hole restriction, a rotor-stator device, and combinations thereof. In some instances, the hydrodynamic cavitation device is used alone. In other instances, the hydrodynamic cavitation device is used in combination with ultrasound (e.g., upstream or downstream of an ultrasonic treatment region) to provide hybrid intensification.

[0049] In some instances, the regeneration intensification unit comprises a bypass loop module that includes (i) a bypass conduit coupled between an upstream location and a downstream location of a main solvent flowline, (ii) at least one intensification device within the bypass conduit, and (iii) one or more valves configured to control a bypass fraction of, for example, from about 0% to about 100% of a total solvent flow (e.g., a bypass fraction of at least about 0%, at least about 5%, at least about 10%, at least about 25%, at least about 50%, at least about 75%, or at least about 90%, and / or a bypass fraction of at most about 100%, at most about 95%, at most about 90%, at most about 75%, at most about 50%, at most about 25%, at most about 10%, or at most about 5%, and / or a bypass fraction falling within a range bounded by any two of the preceding values).

[0050] In various instances, the regeneration intensification unit comprises one or more ancillary components, including, for example, a heat jacket, an external heat exchanger, an insulation layer, a noise-reduction enclosure, a degassing separator, and / or a vent arrangement.

[0051] In various instances, a plurality of regeneration intensification units may be provided at different locations within the solvent circulation loop. For example, one or more regeneration intensification units may be positioned upstream of a reboiler to provide preheating and / or convective mixing of a CCh-rich solvent prior to entry into the reboiler. Additionally orAttorney Docket No. IS24.1786-WOalternatively, one or more regeneration intensification units may be positioned proximate a regenerator inlet to reduce viscosity and / or to condition the CCh-rich solvent for improved desorption performance within the regenerator. Additionally or alternatively, one or more regeneration intensification units may be positioned downstream of an absorber to reduce viscosity and / or pressure drop in flowlines and / or to promote CO2 release from the CCh-rich solvent.

[0052] In various instances, the regeneration intensification unit is positioned proximate a reboiler such that ultrasound is applied to the CCh-rich solvent upstream of the reboiler to provide preheating and / or convective mixing. In some instances, ultrasound is applied to reduce an external heat duty required from the reboiler by, for example, from about 1% to about 100% (e.g., a reduction of at least about 1%, at least about 5%, at least about 10%, at least about 20%, at least about 30%, at least about 50%, or at least about 75%, and / or a reduction of at most about 100%, at most about 75%, at most about 50%, at most about 30%, at most about 20%, at most about 10%, or at most about 5%, and / or a reduction falling within a range bounded by any two of the preceding values).

[0053] In some instances, ultrasound is applied under a reduced pressure condition to promote CO2 release.

[0054] In some instances, the system is configured to reduce solvent degradation by operating at a bulk regeneration temperature that is lower than a temperature used in a baseline process absent ultrasound treatment, while maintaining a target lean loading.

[0055] The foregoing overview is provided solely for the purpose of introducing certain example implementations and is not intended to limit the scope of the present disclosure. The example embodiments described below with reference to the Figures provide non-limiting illustrations of systems and methods consistent with the general concepts introduced above.

[0056] Referring now to FIG. 1, a conventional tower system 100 for CCh-capture is displayed containing one or more regeneration intensification units 102 in accordance with the present disclosure. The one or more regeneration intensification units 102 containing ultrasonic reactors may replace steam supplies conventionally included in such tower systems 100 with cavitation-induced heating for solvent regeneration. Advantageously, agitation caused by cavitation-induced bubble formation within the regeneration intensification units 102 may provide a powerful tool toAttorney Docket No. IS24.1786-WOincrease CO2 desorption rate during the regeneration process. The tower system 100 may further include a reboiler 104, a heat exchanger 106, a regenerator 108, and an absorber 110.

[0057] In some instances, the one or more regeneration intensification units 102 may operate with ultrasound-induced cavitation. In other instances, the one or more regeneration intensification units 102 may operate with hydrodynamic cavitation. In some such instances, the one or more regeneration intensification units 102 may operate in conjunction with heating in the reboiler 104 to reduce the need for large amount of steam to heat up the solvent.

[0058] During operation, a solvent stream may approach the reboiler 104. The one or more regeneration intensification units 102 proximate the reboiler 104 may be operated with low frequency ultrasound (e.g., 20-40 kHz) to preheat the solvent stream before entering the reboiler 104. Specifically, acoustic vibration (e.g., 30-40 kHz) by a regeneration intensification unit 102a may induce convective mixing, leading to an increase in temperature of the solvent stream. Ultrasonic cavitation (e.g., 20 kHz) by a regeneration intensification unit 102b may further induce localized heating, reducing a required heat duty of the reboiler 104. Advantageously, the CO2 desorption rate may also be increased significantly through ultrasound treatment under low pressure.

[0059] After passing through the reboiler 104, the solvent may flow (following the directions indicated by the arrows) past the heat exchanger 106 to the regenerator 108. A regeneration intensification unit 102c proximate the regenerator 108 may be operated with low frequency ultrasound (e.g., 20-40 kHz), resulting in a temperature-induced reduction in viscosity and preheating of the rich solvent before entry into the regenerator 108.

[0060] After exiting the absorber 110, the rich solvent may undergo a reduction in viscosity by a regeneration intensification unit 102d operating with low frequency ultrasound (e.g., 30-40 kHz). The regeneration intensification unit 102d may additionally induce microstreaming and heating to reduce a pressure drop in flowlines for high viscosity solvents, thus saving pump energy. In addition, a regeneration intensification unit 102e at the bottom of the absorber 110 may apply high-frequency ultrasonication irradiation (e g., 1-2 MHz), leading to an increase in effective interfacial areas between a gas and liquid phase of the solvent due to acoustic streaming, ensuring proper mixing and improving mass transfer. Advantageously, the acoustic fountain and dynamic convection flow generated under high-frequency ultrasound irritation may also improve the gas absorption process.Attorney Docket No. IS24.1786-WO

[0061] Ultrasound application in solvent-based CO2 capture within localized regeneration intensification units 102 may thus serve to circumvent the complexities arising from the design and implementation of intensification units inside of the regeneration tower 108 and may partially or significantly reduce CapEx and OpEx costs. By applying localized cavitation-induced heating and agitation to the solvent flowing through the flowlines, the regeneration intensification units 102 may be installed in-line to facilitate a flow-through operation rather than a bulk or batch operation. In various instances, the sonicators and cavitators within the localized regeneration intensification units 102 may be installed with a bypass mode to provide more control and flexibility in the intensification process.

[0062] Referring now to FIG. 2, a regeneration intensification unit 200 used for CO2 desorption and solvent regeneration may be provided in the form of at least a solvent system 202, a sonication setup 204, and a vent line 206. The regeneration intensification unit 200 may be designed to measure an effect of ultrasound cavitation on CO2 desorption kinetics as well as thermodynamic and rheological properties of the one or more solvents used in the desorption process.

[0063] The solvent system 202 may include a flask 208, a dry pipe 210, an acid trap 212, a condenser 214, and a chiller 216. A sample may be placed in the flask 208 for recycling through the sonication setup 204. In some instances, the flask 208 is an Erlenmeyer flask. The dry pipe 210 and the acid trap 212 may be designed to prevent solvent evaporation during the regeneration process and ensure adequate and reliable removal of moisture and amine content in an outlet stream from the sonication setup 204. In some cases, a temperature of the condenser 214 may be controlled by the chiller 216.

[0064] The sonication setup 204 may be provided in the form of an ultrasonic processor 218, an air-cooled transducer 220, a horn 222, and a sonication reactor chamber 224. The ultrasonic processor 218 may be physically coupled to the air-cooled transducer 220, which may be disposed above or adjacent to the horn 222. The horn 222 may be physically coupled to the sonication reactor chamber 224. The sonication reactor chamber 224 may be fluidly coupled to an oil heater / chiller 226 for temperature control. In some instances, the horn 222 is a full-wave horn. In some such instances, the horn 222 is a full-wave Barbell horn. In other instances, the sonication reactor chamber 224 includes a heat jacket 228. In various cases, the sonication setup 204 is installed within a noise-reduction box 230 in order to contain any noise or vibrations generated from the sonication setup 204 during operation.Attorney Docket No. IS24.1786-WO

[0065] The sonication setup 204 may be designed to receive carbon dioxide via the CCh-loaded solvent sample within the flask 208 and recycle the sample between the flask 208 and the sonication reactor chamber 224 via one or more conduits 232 and / or pumps 234. In some instances, the one or more conduits 232 may be composed of chemical-compatible tubing. In some such instances, the one or more conduits 232 are thermally insulated to prevent heat loss. In other instances, the one or more pumps 234 may be peristaltic pumps. In various cases, the one or more conduits 232 and / or pumps 234 are additionally coupled to one or more pressure gauges installed to prevent pressure build up in the system.

[0066] During operation, the CCh-loaded solvent sample may be provided to the sonication setup 204, where sonication and / or heating of the sample may lead to an increase of solvent temperature and a decrease in solvent viscosity, accompanied by a significant release of CO2 gas. In some instances, the ultrasonic processor 218 may contain an internal sensor or controller to measure sonication power. In some such instances, the ultrasonic processor 218 is self-adapted so as to maintain a constant level of sonication frequency applied to the solvent. As a result, reduction of sonication intensity during the desorption process may indicate a graduate decrease in the solvent viscosity as solvent regeneration progresses. In other such instances, the ultrasonic processor 218 is configured to apply ultrasound in a pulsation mode for greater efficacy.

[0067] The vent line 206 may be designed for removal of CO2 degassed during solvent regeneration. In various instances, the carbon dioxide is removed from the recycle loop at or near ambient pressure. The vent line 206 may include a vent 236 through which carbon dioxide may safely be released into the atmosphere.

[0068] In some instances, the unit 200 may include one or more sensors for measuring and / or monitoring a status of one or more parameters associated with the sonication setup 204. By way of one example, one or more thermostats 238 may be fluidly coupled to the sonication reactor chamber 224 and the oil heater / chiller 226 to supply both heating and cooling functions. By way of another example, a thermocouple 240 may be fluidly coupled to the flask 208 for constant temperature measurement. By way of yet another example, a mass flow meter 242 and a carbon dioxide analyzer 244 may be fluidly coupled to outlet streams from the sonication reactor chamber 224 to measure total gas flow rate and CO2 concentration. By way of an additional example, an amine detection tube 246 and a humidity sensor 248 may measure a concentration of water andAttorney Docket No. IS24.1786-WOethanolamine (MEA) in the gasified carbon dioxide. In some instances, one or more of the sensors may be physically coupled to the vent line 206.

[0069] In various instances, the unit 200 may further include a plurality of gas tanks 250 for purging the unit 200 before and / or after solvent regeneration cycles. In some instances, the one or more gas tanks 250 may store and dispense one or more of carbon dioxide and / or nitrogen.

[0070] FIGs. 3-5 display several examples of results of CO2 desorption for proof-of-concept heating and sonicating cases. Tests were conducted on a small-scale research apparatus (such as the tower 100) dedicated to CO2 capture. Substantial and measurable effects of ultrasonic oscillations on the desorption processes of CO2 in both aqueous and non-aqueous solutions were identified and quantified through experimentation. Additionally, the impact of pressure oscillations on the thermodynamic and rheological properties of liquids was investigated. Basic principles governing the influence of these oscillations on those processes were established.

[0071] FIG. 3 is a graph 300 illustrating CO2 loading 302 in 30 wt.% MEA at different desorption temperatures during CO2 desorption using only a heat source, where temperature is indicated by the curve 304. Line 306 indicates the equilibrium CO2 loading in 30 wt.% measured at the same temperature and pressure.

[0072] FIG. 4 is a graph 400 illustrating CO2 loading 402 in 30 wt.% MEA during CO2 desorption using only sonication, where temperature is indicated by the curve 404. Lines 406 indicate the equilibrium CO2 loading in 30 wt.% measured at the same temperature and pressure. As shown, CO2 desorption 402 slowed down and reached a flat level when the solvent temperature 404 reached steady-state and ultrasound-induced cavitation was applied in a continuous mode.

[0073] FIG. 5 is a graph 500 illustrating CO2 loading 502 in 30 wt.% MEA during CO2 desorption using pulsed-mode sonication, where temperature is indicated by the curve 504. Line 506 lines indicate the equilibrium CO2 loading in 30 wt.% measured at the same temperature and pressure. As shown, a high CO2 desorption rate 502 was maintained when ultrasound-induced cavitation was applied in a pulsed “on and off’-mode and large temperature gradients were established locally.EMBODIMENTS

[0074] Embodiment 1. A method for regenerating a carbon dioxide-rich solvent in a solvent-based carbon dioxide capture process, the method comprising: directing at least a portion of the carbonAttorney Docket No. IS24.1786-WOdioxide-rich solvent through a regeneration intensification unit arranged in fluid communication with a solvent circulation flow path, the regeneration intensification unit comprising a flow-through treatment region; and while the portion flows through the flow-through treatment region, applying ultrasound to the portion in a pulsed mode to induce cavitation and convective mixing in the portion, thereby promoting release of carbon dioxide from the portion to provide a carbon dioxide-lean solvent.

[0075] Embodiment 2. The method of Embodiment 1, wherein applying the ultrasound comprises applying low-frequency ultrasound having a frequency of from about 1 kHz to about 50 kHz.

[0076] Embodiment 3. The method of Embodiment 2, wherein the frequency is from about 20 kHz to about 40 kHz.

[0077] Embodiment 4. The method of any of Embodiments 1-3, wherein applying the ultrasound in the pulsed mode comprises alternating between (i) an on-interval during which ultrasound is applied and (ii) an off-interval during which ultrasound is reduced or halted.

[0078] Embodiment 5. The method of Embodiment 4, wherein the pulsed mode is characterized by at least one of: a pulse width of from about 1 millisecond to about 3600 seconds; an off-interval of from about 1 millisecond to about 3600 seconds; or a duty cycle of from about 1% to about 100%.

[0079] Embodiment 6. The method of any of Embodiments 1-5, wherein the regeneration intensification unit is installed in-line with the solvent circulation flow path.

[0080] Embodiment 7. The method of any of Embodiments 1-5, wherein the regeneration intensification unit is installed in a bypass configuration such that the portion comprises a diverted portion of a main solvent flow that is returned to the main solvent flow downstream of the regeneration intensification unit.

[0081] Embodiment 8. The method of any of Embodiments 1-7, further comprising controlling at least one of pulse width, off-time, or duty cycle of the pulsed mode based on at least one monitored parameter associated with the solvent and / or a vent stream.

[0082] Embodiment 9. The method of Embodiment 8, wherein the at least one monitored parameter comprises at least one of solvent temperature, solvent pressure, solvent flow rate, solvent viscosity, carbon dioxide concentration in the vent stream, or total vent flow rate.Attorney Docket No. IS24.1786-WO

[0083] Embodiment 10. A system for solvent-based carbon dioxide capture, comprising: an absorber configured to contact a carbon dioxide-containing gas with a carbon dioxide-lean solvent to provide a carbon dioxide-rich solvent; a regenerator configured to release carbon dioxide from the carbon dioxide-rich solvent to provide the carbon dioxide-lean solvent; a reboiler in fluid communication with the regenerator; a heat exchanger in a solvent circulation loop between the absorber and the regenerator; and a regeneration intensification unit positioned in the solvent circulation loop outside of the regenerator, the regeneration intensification unit comprising (i) a housing defining a flow-through chamber configured to receive a flowing portion of the carbon dioxide-rich solvent, and (ii) at least one ultrasonic transducer coupled to the housing and configured to deliver acoustic energy into the flowing portion within the flow-through chamber; wherein the regeneration intensification unit is configured to apply ultrasound in a pulsed mode to the flowing portion in a flow-through treatment region to induce cavitation and convective mixing.

[0084] Embodiment 11. The system of Embodiment 10, further comprising an ultrasonic processor coupled to the at least one ultrasonic transducer and configured to drive the at least one ultrasonic transducer to apply low-frequency ultrasound in the pulsed mode.

[0085] Embodiment 12. The system of Embodiment 10 or Embodiment 11, wherein the regeneration intensification unit further comprises a horn coupled between the at least one ultrasonic transducer and the flow-through chamber.

[0086] Embodiment 13. The system of any of Embodiments 10-12, wherein the regeneration intensification unit comprises a plurality of ultrasonic transducers arranged circumferentially about the flow-through chamber and / or arranged axially along a flow path to provide more uniform acoustic exposure.

[0087] Embodiment 14. The system of any of Embodiments 10-13, wherein the regeneration intensification unit further comprises a hydrodynamic cavitation device positioned upstream or downstream of the flow-through chamber.

[0088] Embodiment 15. The system of any of Embodiments 10-14, wherein the regeneration intensification unit comprises a bypass loop module including (i) a bypass conduit coupled between an upstream location and a downstream location of a main solvent flowline, (ii) at least one intensification device within the bypass conduit, and (iii) one or more valves configured to control a bypass fraction of from about 0% to about 100% of a total solvent flow.Attorney Docket No. IS24.1786-WO

[0089] The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the disclosure. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the systems and methods described herein. The foregoing descriptions of specific examples are presented for purposes of illustration and description. They are not intended to be exhaustive of or to limit this disclosure to the precise forms described. Obviously, many modifications and variations are possible in view of the above teachings. The examples are shown and described in order to best explain the principles of this disclosure and practical applications, to thereby enable others skilled in the art to best utilize this disclosure and various examples with various modifications as are suited to the particular use contemplated. It is intended that the scope of this disclosure be defined by the claims and their equivalents below.

[0090] When introducing elements of the present disclosure or the preferred embodiment(s) thereof, the articles “a”, “an”, “the”, and “said” are intended to mean that there are one or more of the elements. Additionally, references to “one embodiment” or “an embodiment” of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features.

[0091] The terms “comprising”, “including”, and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. The term “consisting of’ is intended to be exclusive and to encompass only the listed elements. It will be understood that if an embodiment is described as “comprising” one or more elements, an embodiment “consisting of’ the same elements is also within the scope of the present disclosure as if expressly described herein.

[0092] The phrases, unless otherwise specified, “consists essentially of’ and “consisting essentially of’ do not exclude the presence of other steps, elements, or materials, whether or not, specifically mentioned in this specification, so long as such steps, elements, or materials, do not affect the basic and novel characteristics of the present disclosure, additionally, they do not exclude impurities and variances normally associated with the elements and materials used.

[0093] Numerical ranges used herein include the numbers recited in the range. For example, the numerical range “from 1 weight percent to 10 weight percent” includes 1 weight percent and 10 weight percent within the recited range.

[0094] For the sake of brevity, only some ranges are explicitly disclosed herein. However, ranges from any lower limit may be combined with any upper limit to recite a range not explicitly recited, as well as, ranges from any lower limit may be combined with any other lower limit to recite aAttorney Docket No. IS24.1786-WOrange not explicitly recited, in the same way, ranges from any upper limit may be combined with any other upper limit to recite a range not explicitly recited. Additionally, within a range includes every point or individual value between its end points even though not explicitly recited. Thus, every point or individual value may serve as its own lower or upper limit combined with any other point or individual value or any other lower or upper limit, to recite a range not explicitly recited.

[0095] All numerical values within the detailed description herein are modified by “about” the indicated value, and take into account experimental error and variations that would be expected by a person having ordinary skill in the art.

[0096] The specific embodiments described herein have been illustrated by way of example, and it should be understood that these embodiments may be susceptible to various modifications and alternative forms. It should be further understood that the claims are not intended to be limited to the particular forms disclosed, but rather to cover all modifications, equivalents, and alternatives falling within the spirit and scope of this disclosure.

[0097] The techniques presented and claimed herein are referenced and applied to material objects and concrete examples of a practical nature that demonstrably improve the present technical field and, as such, are not abstract, intangible or purely theoretical. Further, if any claims appended to the end of this specification contain one or more elements designated as “means for (perform )ing (a function)...” or “step for (perform)ing (a function).. it is intended that such elements are to be interpreted under 35 U.S.C. § 112(f). However, for any claims containing elements designated in any other manner, it is intended that such elements are not to be interpreted under 35 U.S.C. § H2(f).

[0098] While the present disclosure has been described with respect to a number of embodiments and examples, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope and spirit of the present disclosure.

Claims

Attorney Docket No. IS24.1786-WOCLAIMSWhat is claimed is:

1. A method for regenerating a CCL-rich solvent in a solvent-based CO2 capture process, the method comprising:directing at least a portion of the CCh-rich solvent through a regeneration intensification unit that is in fluid communication with a solvent circulation flow path, the regeneration intensification unit comprising a flow-through treatment region;while the portion flows through the flow-through treatment region, applying low-frequency ultrasound to the portion in a pulsed mode to induce cavitation and convective mixing in the portion; andreleasing CO2 from the portion to provide a CCh-lean solvent.

2. The method of claim 1, wherein the regeneration intensification unit is installed in-line with the solvent circulation flow path.

3. The method of claim 1, wherein the regeneration intensification unit is installed in a bypass configuration such that the portion comprises a diverted portion of a main solvent flow that is returned to the main solvent flow downstream of the regeneration intensification unit.

4. The method of claim 1, further comprising pre-heating the portion via the regeneration intensification unit prior to introducing the portion into a reboiler.

5. The method of claim 1, further comprising reducing a viscosity of the portion via the pulsed mode low-frequency ultrasound.

6. The method of claim 1, wherein a frequency of the low-frequency ultrasound is between 20 kHz and 40 kHz.

7. The method of claim 1, wherein applying the low-frequency ultrasound in the pulsed mode comprises alternating between (i) an on-interval during which ultrasound is applied and (ii) an off-interval during which ultrasound is reduced or halted.Attorney Docket No. IS24.1786-WO8. The method of claim 7, further comprising controlling at least one of a pulse width, an off-time, or a duty cycle of the pulsed mode based on a monitored parameter associated with the solvent and / or a vent stream.

9. The method of claim 8, wherein the monitored parameter comprises at least one of solvent temperature, solvent pressure, solvent flow rate, solvent viscosity, CO2 concentration in the vent stream, or total vent flow rate.

10. The method of claim 1, wherein the solvent comprises an amine-containing solvent.

11. A regeneration intensification unit for solvent regeneration, comprising:a housing defining a flow-through chamber configured to receive a flowing CCh-rich solvent;at least one ultrasonic transducer coupled to the housing and configured to deliver acoustic energy into the flowing C Ch-rich solvent within the flow-through chamber; andan ultrasonic processor coupled to the at least one ultrasonic transducer and configured to drive the at least one ultrasonic transducer to apply low-frequency ultrasound in a pulsed mode to the flowing CCh-rich solvent.

12. The regeneration intensification unit of claim 11, further comprising a horn coupled between the at least one ultrasonic transducer and the flow-through chamber.

13. The regeneration intensification unit of claim 11, wherein the housing is configured for in-line installation in a solvent flowline.

14. The regeneration intensification unit of claim 11, wherein the regeneration intensification unit comprises a plurality of ultrasonic transducers arranged circumferentially about the flowthrough chamber and / or arranged axially along a flow path to provide more uniform acoustic exposure.

15. The regeneration intensification unit of claim 11, wherein the ultrasonic processor isAttorney Docket No. IS24.1786-WOconfigured to adjust at least one of acoustic power, frequency, pulse width, off-time, or duty cycle based on at least one sensor signal.

16. The regeneration intensification unit of claim 11, wherein the regeneration intensification unit further comprises a hydrodynamic cavitation device positioned upstream or downstream of the flow-through chamber.

17. A system for solvent-based CO2 capture, comprising:an absorber configured to contact a CCh-containing gas with a CCh-lean solvent to provide a CCh-rich solvent;a regenerator configured to release CO2 from the CO2-rich solvent to provide the CC -lean solvent;a reboiler in fluid communication with the regenerator;a heat exchanger in a solvent circulation loop between the absorber and the regenerator; andat least one regeneration intensification unit positioned in the solvent circulation loop outside of the regenerator, the at least one regeneration intensification unit configured to apply low-frequency ultrasound in a pulsed mode to a flowing portion of the CCh-rich solvent in a flow-through treatment region.

18. The system of claim 17, wherein the at least one regeneration intensification unit is positioned upstream of the reboiler.

19. The system of claim 17, wherein the at least one regeneration intensification unit is positioned upstream of an inlet of the regenerator.

20. The system of claim 17, wherein the solvent comprises monoethanolamine (MEA).

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