Horizontal system for co2 adsorption and conversion to bicarbonate for marine vessels

Abstract

An energy-and cost-efficient system and method for CO2 capture from a moving marine vessel's emissions and storage thereof as bicarbonate ions in ambient waters are described. The system comprises a two-stage AWL-type reactor, wherein horizontally oriented reactor components are positioned below the waterline of the marine vessel. The positioning and orientation of the reactor components, as well as a number of other advantageous implements, allow to use the motion of the marine vessel across water for pumping the ambient water into and through the system, thus eliminating the need for additional water pumps, and affording significant energy and operation costs savings.

Description

HORIZONTAL SYSTEM FOR CO2 ADSORPTION AND CONVERSION TO BICARBONATE FOR MARINE VESSELSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The current application claims the benefit of and priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application No. 63 / 744,727, entitled “Horizontal System for CO2 Adsorption and Conversion to Bicarbonate for Marine Vessels”, filed January 13, 2025, the disclosure of which is incorporated herein by reference in its entirety for all purposes.FIELD OF THE INVENTION

[0002] The invention is generally directed to a system and method for CO2 capture from a moving marine vessel’s emissions and permanent storage of the captured CO2 as bicarbonate ions in ambient waters.BACKGROUND OF THE INVENTION

[0003] Carbon dioxide (CO2) constitutes about 0.04% (400 parts per million) of the atmosphere, however, despite its relatively small overall concentration, CO2 is a potent greenhouse gas that plays an important role in regulating the Earth's surface temperature. Presently, anthropogenic CO2 generation is taking place at a rate greater than it is being consumed and / or stored, leading to increasing concentrations of CO2 in the atmosphere. As such, there exists a growing concern that rising levels of CO2 in the Earth’s atmosphere may present a substantial environmental challenge. Accordingly, there is an increased interest in developing methods for removing CO2 from emission streams and the atmosphere and storing it in a manner that prevents its future release into the atmosphere. This capture and storage of CO2 carbon are collectively known as CO2 sequestration, or Carbon Capture and Storage (CCS).

[0004] In particular, the marine shipping industry is important for worldwide trade and economic health, yet marine vessels, such as container ships and bulk carriers,significantly contribute to carbon output. Therefore, there exists a great and urgent need for decarbonizing exhaust of marine vessels, among other polluters.SUMMARY OF THE INVENTION

[0005] Various embodiments are directed to a system for energy efficient CO2 sequestration from a marine vessel and conversion of the sequestered CO2 to bicarbonate ions for permanent and safe storage in a body of water, wherein the system is installed aboard the marine vessel moving across the body of water with a speed, generating an exhaust gas stream including the CO2, and having a waterline relative to the body of water, and wherein the system includes:a bubble reactor characterized by a bubble reactor length, a bubble reactor width smaller than the bubble reactor length, and a bubble reactor depth smaller than the bubble reactor length; wherein the bubble reactor includes a plurality of interconnected pipes distributed throughout the bubble reactor, and wherein each pipe of the plurality of interconnected pipes further includes a plurality of small holes distributed throughout each pipe;a packed beds reactor including a plurality of packed beds connected in parallel, wherein each packed bed of the plurality of packed beds includes a reaction medium capable of converting CO2 to HCO3; and wherein each packed bed is characterized by a vertical dimension smaller than the bubble reactor length, and each packed bed is set up for a throughout and upward water flow along the vertical dimension;a connector chamber including a gas-water separator vented to the atmosphere and providing a fluid communication between the bubble reactor and the packed beds reactor; wherein the gas-water separator includes a plurality of separator pipes extending from below the waterline to above the waterline; a water inlet including at least one inlet water scoop further including a plurality of scoop holes, characterized by a scoop hole size and a scoop hole number, for delivering an ambient water from the body of water into the bubble reactor;an effluent outlet for returning a processed effluent water exiting the packed beds reactor to the body of water;a blower for pressurizing the exhaust gas stream and delivering the exhaust gas stream to the bubble reactor viaa gas inlet; andany number of primer pumps, additional valves, inlets, and outlets, as needed to supply and efficiently, as well as safely, operate the system; and wherein the bubble reactor is positioned within the marine vessel below the waterline, such that the bubble reactor length is parallel to the waterline;the packed beds reactor is positioned within the marine vessel below the waterline; and the water inlet and the effluent outlet are positioned on the marine vessel at the same level below the waterline.

[0006] In various such embodiments, the body of water is sea or ocean, and the ambient water is seawater.

[0007] In still various such embodiments, the ambient water is freshwater.

[0008] In still yet various embodiments, the exhaust gas stream is delivered into the bubble reactor with a venturi effect.

[0009] In yet still various such embodiments, the packed beds reactor is positioned within the marine vessel below the bubble reactor.

[0010] In yet various such embodiments, the reaction medium is limestone.

[0011] Various other embodiments are directed to a method for energy efficient CO2 sequestration from a marine vessel and conversion of the sequestered CO2 to bicarbonate ions for permanent and safe storage in a body of water, wherein method is employed aboard the marine vessel moving across the body of water with a speed, generating an exhaust gas stream including the CO2, and having a waterline relative to the body of water, wherein the method includes:installing a system below the waterline, wherein the system includes:a bubble reactor characterized by a bubble reactor length, a bubble reactor width smaller than the bubble reactor length, and a bubble reactor depth smaller than the bubble reactor length; wherein the bubble reactorincludes a plurality of interconnected pipes distributed throughout the bubble reactor, and wherein each pipe of the plurality of interconnected pipes further includes a plurality of small holes distributed throughout each pipe;a packed beds reactor including a plurality of packed beds connected in parallel, wherein each packed bed of the plurality of packed beds includes a reaction medium capable of converting CO2 to HCO3 and wherein each packed bed is characterized by a vertical dimension smaller than the bubble reactor length, and each packed bed is set up for a throughout and upward water flow along the vertical dimension; a connector chamber including a gas-water separator vented to the atmosphere and providing a fluid communication between the bubble reactor and the packed beds reactor; wherein the gas-water separator includes a plurality of separator pipes extending from below the waterline to above the waterline;a water inlet including at least one inlet water scoop including a plurality of scoop holes, characterized by a scoop hole size and a scoop hole number, for delivering an ambient water from the body of water into the bubble reactor;an effluent outlet for returning a processed effluent water exiting the packed beds reactor to the body of water;a blower for pressurizing the exhaust gas stream and delivering the exhaust gas stream to the bubble reactor viaa gas inlet; andany number of primer pumps, additional valves, inlets, and outlets, as needed to supply and efficiently, as well as safely, operate the system; and whereinthe bubble reactor is positioned within the marine vessel below the waterline, such that the bubble reactor length is parallel to the waterline;the packed beds reactor is positioned within the marine vessel below the waterline; andthe water inlet and the effluent outlet are positioned on the marine vessel at the same level below the waterline;starting a motion of the marine vessel;optionally using one or more priming pump to start a flow of the ambient water from the body of water into and through the system, and to expunge any air gaps or air bubbles in the system;activating the at least one inlet water scoop to bring the ambient water into the bubble reactor through the water inlet, such that the plurality of interconnected pipes becomes submerged in the ambient water within the bubble reactor; directing the exhaust gas stream to the blower, pressurizing the exhaust gas stream in the blower, and further directing thus pressurized exhaust gas stream to the bubble reactor; andallowing the ambient water promoted by the motion of the marine vessel to flow through the bubble reactor, the connector chamber, the packed beds reactor, and out of the system and the marine vessel through the effluent outlet, to capture CO2 from the exhaust gas stream, return the CO2-depleted exhaust gas stream to the atmosphere, convert the captured CO2 to bicarbonate ions, and safely and permanently store the bicarbonate ions in the body of water.

[0012] In various such embodiments, the body of water is sea or ocean, and the ambient water is seawater.

[0013] In still various such embodiments, the ambient water is freshwater.

[0014] In still yet various embodiments, the exhaust gas stream is delivered into the bubble reactor with a venturi effect.

[0015] In yet still various such embodiments, the packed beds reactor is positioned within the marine vessel below the bubble reactor.

[0016] In yet various such embodiments, the reaction medium is limestone.

[0017] Additional embodiments and features are set forth in part in the description that follows, and in part will become apparent to those skilled in the art upon examination ofthe specification or may be learned by the practice of the disclosed subject matter. A further understanding of the nature and advantages of the present disclosure may be realized by reference to the remaining portions of the specification and the drawings, which form a part of this disclosure.BRIEF DESCRIPTION OF THE DRAWINGS

[0018] These and other features and advantages of the present invention will be better understood by reference to the following detailed description when considered in conjunction with the accompanying data and figures, wherein:

[0019] FIG. 1 provides illustrative energy use diagrams for typical gas adsorber systems aboard marine vessels of similar size, wherein the gas adsorber systems rely on spray towers for scrubbing the marine vessels’ exhaust gas, and wherein each marine vessel burns 32.7 tons of heavy fuel oil (HFO) / day, but has different amounts of water flowing through the gas adsorber systems (12,000 m3 / hr and 36,000 m3 / hr, left and right diagrams, respectively), according to prior art.

[0020] FIG. 2 provides a schematic of the system and method for CO2 capture from a moving marine vessel’s emissions and permanent storage of the captured CO2 as bicarbonate ions in ambient water, in accordance with embodiments of the application.

[0021] FIG. 3 provides a flow chart of the method’s process utilizing the system in accordance with embodiments of the application.

[0022] FIG. 4 provides data illustrating the relationship between a hole size of the water onboarding inlet water scoop or scoops, a marine vessel’s speed, and the resulting water flux through the system, wherein the plot lines show the size of a single scoop hole needed as a function of the water flux required by the system for a Discharge Coefficient of 0.8, in accordance with embodiments of the application.DETAILED DISCLOSURE

[0023] Turning now to the schemes, images, and data, a system for energy efficient CO2 sequestration aboard a marine vessel moving across a body of water and permanent storage of the sequestered CO2 as bicarbonate in the body of water is described, as wellas a method of use thereof. In particular, in many embodiments, CO2 emitted by the marine vessel is sequestered, converted to bicarbonate, and stored in the body of water by the system, wherein the system is installed on the marine vessel having a waterline relative to the body of water and moving across the body of water with a speed, while generating an exhaust gas stream comprising CO2 to be sequestered. In many embodiments, the system comprises: a bubble reactor, wherein the bubble reactor is a gas / water contactor; and a packed beds reactor comprising one or more beds packed with a medium for converting CO2 to HCOs-; wherein the bubble reactor and the packed beds reactor are in fluid communication with each other via a connector chamber comprising a gas-water separator vented to the atmosphere. Furthermore, in many embodiments, the system is in fluid communication with the body of water via a water inlet equipped with at least one inlet water scoop for delivering an ambient water from the body of water into the bubble reactor; and an effluent outlet for returning a processed water to the body of water from the packed beds reactor. In many such embodiments, each inlet water scoop comprises a plurality of scoop holes characterized by a scoop hole size. In many embodiments, the water inlet comprises at least one inlet water scoop on each side of the waterline near the front of the marine vessel. In many embodiments, the effluent outlet comprises a “back flow” protection. In some such embodiments, the back flow protection is an effluent outlet scoop. In many embodiments, the system further comprises a blower for pressurizing the exhaust gas stream and delivering the pressurized exhaust gas stream to the bubble reactor via a gas inlet; and any number of primer pumps, additional valves, inlets, and outlets as needed to supply and safely and efficiently operate the system. In many embodiments, the body of water is ocean or sea, and the ambient water is seawater (SW). However, in some embodiments, the body of water is a lake or a river, and the ambient water is freshwater (FW). In some other embodiments, the ambient water is a mixture of SW and FW.

[0024] In many embodiments, the bubble reactor, characterized by a bubble reactor length, a bubble reactor width smaller than the bubble reactor length, and a bubble reactor depth smaller than the bubble reactor length, is positioned below the waterline, such that the bubble reactor length is parallel to the waterline. In many embodiments, the bubblereactor comprises the ambient water and a plurality of interconnected pipes distributed throughout the bubble reactor and submerged in the ambient water within the bubble reactor, wherein each pipe of the plurality of interconnected pipes further comprises a plurality of small holes distributed throughout each pipe to entrain a gas into a liquid. In many such embodiments, the exhaust gas stream entering the bubble reactor is delivered via the plurality of pipes and, as it exits the plurality of pipes through the plurality of small holes, the exhaust gas stream forms gas bubbles in the ambient water of the bubble reactor. In many embodiments, the bubble reactor further comprises a plurality of baffles and turbulence generating protrusions, such as to keep the gas bubbles small and continuously present in the ambient water, and to prevent separation of gas and water within the bubble reactor into separate layers.

[0025] In many embodiments, the gas-water separator of the connector chamber comprises a plurality of separator pipes extending from below the waterline to above the waterline.

[0026] In many embodiments, the packed beds reactor is positioned below the waterline and horizontally relative to the waterline. In some embodiments, the packed beds reactor is positioned below the bubble reactor. In many embodiments, the packed beds reactor comprises a plurality of packed beds, wherein each packed bed comprises a reaction medium capable of converting CO2 to HCOs’.

[0027] In many embodiments, the water inlet and the effluent outlet are positioned at the same level below the waterline.

[0028] Accordingly, in many embodiments, once the marine vessel is underway and moving across the body of water, one or more priming pumps are first, optionally, utilized to start the ambient water flow into and through the system, and or to expunge any air gaps or air bubbles in the system. Furthermore, in many embodiments, the at least one inlet water scoop is activated to bring the ambient water into the bubble reactor through the water inlet. In many such embodiments, the exhaust gas stream is simultaneously directed to the blower, wherein the exhaust gas stream is pressurized and further directed to the bubble reactor, wherein the pressurized exhaust gas stream joins with the ambient water flow, in some embodiments, utilizing a venturi effect. In many embodiments, theambient water is then promoted by the motion of the marine vessel to sequentially flow through the bubble reactor, the connector chamber, the packed beds reactor, and out of the marine vessel through the effluent outlet, such as to capture CO2 from the exhaust gas stream, return the CO2-depleted exhaust gas stream to the atmosphere, convert the captured CO2 to bicarbonate ions, and, accordingly, to safely and permanently store the bicarbonate ions in the ambient water.

[0029] It will be understood that the embodiments of the invention described herein are not intended to be exhaustive or to limit the invention to precise forms disclosed. Rather, the embodiments selected for description have been chosen to enable one skilled in the art to practice the invention.

[0030] Carbon capture and storage (CCS) efforts have long been centered on Earth’s atmosphere, wherein various approaches have been employed to “scrub” carbon dioxide from air, or directly from polluters’ exhaust, and store it underground or in the ocean. For example, in the marine shipping industry, many marine vessels are equipped with onboard carbon capture systems that capture the emitted CO2 and concentrate it for later removal from the ship (e.g., when in port). However, such systems and approaches are capture only systems and, thus, they require further treatment of the captured CO2 to complete its permanent storage and / or utilization.

[0031] On the other hand, a number of promising systems and methods for sequestration and permanent storage of CO2 in the ocean as bicarbonate, such as, for example, the Accelerated Weathering of Limestone (AWL) systems and methods, have been reported. Such systems, when installed on an individual ship, both capture the CO2 from the ship’s emissions and safely and permanently store the captured CO2 as bicarbonate ions in the ocean - all while the ship is underway, without the need to offload the captured carbon product in a destination port.

[0032] However, many CCS systems / processes that capture and store CO2 directly from a ship’s exhaust stream, such as, for example, AWL systems, suffer from poor efficiency of CO2 removal and high energy intensity of the removal process - two key metrics of CCS processes. For example, in contrast to sulfur scrubbers, wherein spraytowers are effectively and efficiently employed to absorb sulfur oxide gas from a marine vessel’s exhaust, implementation of analogous CO2 scrubbers requires large fluxes of water to achieve reasonable CO2 removal efficiencies (tens of percent), due to poor solubility of CO2 in water, especially as compared to SOx compounds. In addition, CO2 typically represents a much larger fraction of a marine vessel’s total exhaust volume (~5%) than SOx compounds.

[0033] Accordingly, CO2 capture methods relying on adsorption of CO2 gas into water, such as AWL-type methods, typically require larger water flows through a sequestration system than similar SOx capture systems. As such, flowing larger amounts of water through CO2 capture systems results in increased back pressure, when the water flow is forced though a spray tower for spraying droplets into the adsorber medium (i.e., water), which, in turn, requires a significant amount of energy to overcome, as illustrated, for example, in FIG. 1. More specifically, the energy usage diagrams provided in FIG. 1 illustrate that, while a typical gas adsorber system aboard a ship burning 32.7 tons of HFO / day requires the same amount of energy (340 kilowatts in this example) to pressurize the ship’s exhaust gas stream fed into the system, regardless of the amount of seawater flown through, the energy demand for pressurizing the water flow grows significantly (from 145 to 830 kilowatts), and comes to dominate the overall energy requirement for the system, with larger water flow (36,000 m3 / hr instead of 12,000 m3 / hr, respectively). Therefore, conventional CO2 scrubbers are, typically, less effective and less energy efficient, especially as compared to their SOx scrubber analogs.

[0034] In addition, the spraying towers / features conventionally employed in the sequestration systems that rely on contacting gas and liquid phases break the continuous flow / flux of water through such systems, and, therefore, any power used to raise and pressurize the large fluxes of water to the top of the scrubber tower are lost from the system. In other words, wherever the water flow continuity is broken, the embodied energy from raising the water stream above the waterline can no longer be recovered by letting the water flow downhill. As such, only once the water flow continuity is reestablished, can a primed system have a water flow through it due to the ship’s motion alone.

[0035] This application is directed to embodiments of a system and method for energy efficient and effective CO2 capture from a marine vessel’s emissions and permanent storage of the captured CO2 as bicarbonate ions in ambient water, while the marine vessel is underway. In many such embodiments, the system installed on a marine vessel having a waterline comprises a two-stage / two component reactor, wherein both components are positioned below the waterline of the marine vessel and oriented horizontally relative to the waterline of the marine vessel, i.e. , along the waterline and the direction of the marine vessel’s movement. In many embodiments, the system is an AWL system, and the two- stage reactor is an AWL reactor. In many embodiments, the two-stage reactor comprises a bubble reactor for contacting gas and liquid phases of the method (the first stage), and a packed beds reactor for converting the captured CO2 to bicarbonate (the second stage), wherein the bubble reactor and the packed beds reactor are in fluid communication with each other via a connector chamber serving as a degasser of the liquid phase of the system and method. Furthermore, in many embodiments, the system is in fluid communication with the ambient water of the marine vessel via a water inlet for supplying the ambient water to the bubble reactor with help of at least one inlet water scoop, and an effluent outlet for returning the water carrying the bicarbonate product of the system and method from the packed beds reactor to the ambient water. In many embodiments, the water inlet and the effluent outlet are positioned at the same level of the marine vessel’s frame below the waterline. In addition, in many embodiments, the system also comprises: a blower for pressurizing the emissions stream of the marine vessel; a gas inlet for directing the pressurized emissions stream to the bubble reactor; a gas outlet in fluid communication with the atmosphere for releasing the CO2-depleted emissions stream from the system into the atmosphere; and any number of additional valves, inlets, outlets, and primer pumps, as needed, for safe and efficient operation of the system. In many embodiments, the packed beds reactor comprises a plurality of packed beds connected in parallel, wherein each packed bed of the plurality of packed beds further comprises a reaction medium for converting aqueous CO2 to bicarbonate ions. In many embodiments, the reaction medium is limestone grains for reacting the acid in theaqueous CO2 with the base in the limestone to afford bicarbonate. In many embodiments, the forward motion of the marine vessel provides the power needed to push ambient water into, through, and out of the two-stage reactor of the system. In addition, in some embodiments, the water / effluent flow through the system is further aided by judicious use of gravity forces. Accordingly, in many such embodiments, wherein the components of the system are oriented horizontally (i.e., along the direction of the marine vessel’s movement across water), the ambient water is promoted into, through, and out of the system, without the need for water pumps, other than optional primer pumps that start the flow.

[0036] More specifically, in many embodiments, an exhaust gas stream comprising CO2 that is emitted by the marine vessel is directed to the bubble reactor via the blower and the gas inlet, wherein the CO2 from the exhaust gas steam is contacted with and captured into the ambient water flown into and through the bubble reactor from the marine vessel’s environment via the water inlet. In many embodiments, the marine vessel’s environment (i.e., the ambient water) is ocean or sea, and, thus, the ambient water is seawater. However, in some other embodiments, the environment is a lake or a river, and, in such embodiments, the ambient water is freshwater. In yet some other embodiments, the ambient water is a mixture of seawater and freshwater. In many embodiments, any excess gas accumulating in the bubble reactor (the first stage of the two-stage reactor) is vented to the atmosphere.

[0037] In many embodiments, next, the CO2-charged aqueous effluent flows (as promoted by the marine vessel’s movement and water flow continuity) from the bubble reactor, through the degassing connector chamber, and into the packed beds reactor (the second stage of the two-stage reactor), where it is converted to bicarbonate with help of the reaction medium.

[0038] Next, in many embodiments, the effluent water carrying the bicarbonate leaves the packed beds reactor via the effluent outlet and flows back into the marine vessel’s environment, e.g., the ocean. In many embodiments, the effluent water leaves the marine vessel at the same height below the waterline as the ambient water enters the system. In other words, in many embodiments, the water inlet and the effluent outlet are positionedon the marine vessel’s frame at the same height below the waterline. Therefore, in many embodiments, the motion of the marine vessel provides the pumping power that propels the ambient water into and through the horizontally oriented system of the instant disclosure, without having to pump water at any point of the system and method. In addition, since, according to many embodiments, the gas bubbles formed in the CO2 sequestration process described herein are bled off / released (within the connector chamber) between the gas adsorption stage conducted in the bubble reactor and the CO2 to bicarbonate conversion stage conducted in the packed beds reactor, a continuous flow of water is maintained throughout the entire system. In other words, in many embodiments, the gas / water separating / effluent degassing connector chamber allows to maintain continuity of the water flow throughout the entire system, while venting the CO2- depleted exhaust gas stream to the atmosphere. As such, in many embodiments, by eliminating the gas bubbles from the aqueous effluent prior to it entering the packed beds reactor, the highest level of contact between water and the reaction medium is maintained in the packed beds reactor, and the greatest conversion of CO2 to bicarbonate ions is ensured.

[0039] Accordingly, in many embodiments, the system and method for CO2 capture from emissions of a marine vessel and permanent storage of the captured CO2 in the ocean afford many energy and other efficiencies and advantages. More specifically, as one example, in many embodiments, once the system is (optionally) primed to start the flow of the ambient water into the system and purged of extraneous air, the flow of the ambient water through the system is only driven by the forward motion of the marine vessel (e.g., a ship), without the need for high energy water pumps. As another example, in many embodiments, the system and method allow to avoid the considerable costs of CO2 purification and compression associated with conventional CCS systems and methods by:1) utilizing the bubble reactor to solubilize the marine vessel’s exhaust gas stream in water directly, without pre-concentrating the CO2 steam fed into the system; and 2) safely and permanently storing CO2 as stable bicarbonate ions directly in the ambient water (e.g., ocean), thus eliminating the need for concentrating, carrying,and offloading carbon products to another permanent storage solution upon landing.

[0040] More specifically, FIG. 2 schematically illustrates the system and method of many embodiments for installation on a marine vessel to effectively and efficiently capture and store the CO2 emitted by the marine vessel, while FIG. 3 provides a flow chart summarizing the same. As shown in FIG. 2 and indicated in FIG. 3, and according to many embodiments, first, the exhaust gas stream emitted by the marine vessel is slightly concentrated / pressurized (Step 1) and bubbled directly into the ambient water, which, in turn, is delivered into the horizontally oriented bubble reactor (“Gas / Seawater contactor” in FIG. 2) located below the waterline (“WL” in FIG. 2) from the marine vessel’s aqueous environment by means of the marine vessel’s movement (Step 2).

[0041] To this end, in many embodiments, the exhaust gas stream is first pressurized to ~0.3 bar in the blower (FIG. 2, Step 1 ), so that the exhaust gas stream can be moved around the marine vessel, and then delivered to the bubble reactor via the gas inlet. In some embodiments, the pressurized exhaust gas stream is delivered into the bubble reactor with a venturi effect.

[0042] In many embodiments, the ambient to the marine vessel water is brought onboard the marine vessel and into the bubble reactor via the water inlet with help of at least one inlet water scoop (FIG. 2, Step 2 and “Inlet SW scoop”). In many such embodiments, the at least one inlet water scoop comprises a plurality of scoop holes sized to bring the required water flux as a function of the marine vessel’s speed, as explained and illustrated in FIG. 4. More specifically, FIG. 4 provides data illustrating the dependency of the water flux through the system of many embodiments on the marine vessel’s speed and the size of the scoop holes of the at least one inlet water scoop. Even more specifically, the plot lines in FIG. 4 show the size of a single scoop hole needed as a function of water flux required by the system for a Discharge Coefficient of 0.8. Here, the Discharge Coefficient accounts for the wall losses and extra energy needed over and above the pressure drop theoretically needed to bring water onboard from ambient pressure to essentially zero pressure. In many embodiments, the number of scoop holes in the plurality of scoop holes is also adjusted such as to optimize the water flux deliveredto the system. In many embodiments, the marine vessel’s environment is the ocean, and the ambient water is seawater, however, in other embodiments, the environment is a lake or a river, and the ambient water is freshwater. In yet other embodiments, the ambient water is a mixture of seawater and freshwater.

[0043] Furthermore, in many embodiments, the bubble reactor comprises a plurality of interconnected pipes running throughout the bubble reactor, wherein each pipe of the plurality of interconnected pipes further comprises a plurality of small holes distributed throughout each pipe. As such, in many embodiments, forcing the pressurized exhaust gas stream through the plurality of pipes of the bubble reactor and out of the plurality of small holes into the ambient water within the bubble reactor creates a plurality of gas bubbles (FIG. 2, Step 3), which, in turn, improves efficiency of CO2 adsorption into water. (Notably, in many embodiments, the water in the bubble reactor used to adsorb CO2 is, in turn, energy-efficiently delivered to the bubble reactor by means of marine vessel’s forward motion.) More specifically, in many embodiments, the efficiency of CO2 adsorption into the water within the bubble reactor is a function of the bubble size distribution and the length of time the bubbles spend in the water. To this end, marine vessels are typically very long (commonly > 100 meters long), allowing to accommodate long, horizontally oriented bubble reactors of many embodiments (wherein the bubble reactor is characterized by the bubble reactor length, the bubble reactor width smaller than the bubble reactor length, and the bubble reactor depth smaller than the bubble reactor length). In addition, in many embodiments, roughness is added to the bubble reactor’s chamber (FIG. 2, Step 3) such as to maintain a turbulent mixture of bubbles and water, and to keep the bubbles small. In some such embodiments, the roughness is achieved by the addition of protrusions into the flow of water to disrupt the flow and to cause the gas bubbles to break up and stay in contact with the water flowing through the bubble reactor. Accordingly, in many embodiments, the instant horizontally oriented bubble reactor is capable of adsorbing much more CO2 at a much lower cost / energy than any conventional vertically oriented bubble / sprayer tower. Moreover, it should be noted here, that the instant approach to CO2 solubilization is in contrast to conventional CCS systems and methods, wherein, typically, a CO2 containing gas stream is pushed throughvertically oriented columns of water for absorption, and wherein taller columns afford higher CO2 removal efficiencies, but require more energy to overcome the hydrostatic head.

[0044] Next, in many embodiments, once the desired level of CO2 adsorption is reached in the bubble reactor, the water saturated with CO2 leaves the bubble reactor and travels, being promoted by the marine vessel’s movement, towards the packed beds reactor via the connector chamber (“Gas / SW separator” in FIG. 2). In many such embodiments, as the water saturated with CO2 passes through the connector chamber, bubbles of the exhaust gas depleted of CO2 are encouraged to rise upwards and separate from the aqueous medium carrying the dissolved CO2 (FIG. 2, Step 4). More specifically, in many embodiments, the connector chamber comprises an upper part connected to an exhaust gas return system and / or opened to the atmosphere, further comprising a plurality of connector chamber pipes running from below to above the waterline of the marine vessel. As such, in many embodiments, the exhaust gas stream depleted of CO2 is allowed to escape from the system, while maintaining continuity of the water flow through the system. In addition, in many embodiments, opening the upper portion of the connector chamber to the atmosphere allows for variability of the waterline of the marine vessel with the changes in the marine vessel’s ballast condition, while maintaining the uninterrupted release of the CO2-depleted exhaust gas stream.

[0045] Furthermore, it should be noted here that, when the formation of air gaps in the system is prevented with the help of the implements and according to the methods described herein, the forward motion of the marine vessel affords water flow through the system without any need for extra pumps. Nevertheless, in some embodiments, the instant system places an extra drag on the main engine of the marine vessel, leading to a parasitic load that must be accounted for in the final evaluation of the net CO2 removed from the marine vessel’s exhaust. Still, in general, the efficiency of a ship’s main engine is larger than the auxiliary generators used on board to power extra equipment such as water pumps. Accordingly, in many embodiments, although priming pumps might be used initially to start the water flowing through the system and to fill any air gaps in thesystem, any such priming pumps are turned off once the marine vessel is moving and the at least one inlet water scoop is open to incoming ambient water.

[0046] Next, in many embodiments, the CCh-charged water enters the packed beds reactor (FIG. 2, Step 5). In many such embodiments, the CO2-charged water enters the packed beds reactor (“limestone beds” in FIG. 2) at its base as shown in FIG. 2. In many embodiments, the packed beds reactor comprises a plurality of packed beds linked in parallel, each packed with the reaction medium. In many embodiments, the reaction medium is limestone grains. In many such embodiments, the acid of the aqueous CO2 is neutralized by the base in the reaction medium via the AWL reaction (wherein, for example, the reaction medium is limestone):>However, in many embodiments, the reaction medium comprises any material or reagent selected from the group comprising: CaO; a carbonate, including CaCOs (limestone), further including its aragonite, calcite and vaterite forms, dolomite, and Na2COs; NaHCCh; a silicate, including MgSiOs, olivine, pyroxene, mafic rock; another material capable of sequestering CO2, and any combination thereof. As such, in many embodiments, the CO2 from the marine vessel’s exhaust is converted within the packed beds reactor to bicarbonate ions, which, in turn, are carried out of the system with the aqueous effluent, and delivered / deposited into the ambient water of the marine vessel, such as, for example, the surrounding ocean, sea, lake, or river, for safe and permanent storage.

[0047] It should be noted here that, in general, in an AWL system, the efficiency of CO2 gas absorption by an aqueous medium (e.g., in the bubble reactor of the system) is increased by increasing the water flux; however, the efficiency of CO2 reaction with a reaction medium, such as, for example, limestone (e.g., in the packed beds reactor of the system), to from bicarbonate is increased by slowing the water flow and increasing the residence time within the reaction medium. Accordingly, in many embodiments, the water flow entering the packed beds reactor is split into a plurality of streams fed into the plurality of packed beds, such as to maximize the residence time of aqueous CO2 in the packed beds reactor and, thus, the overall efficiency of CCh.conversion to bicarbonate, without reducing the water flow though the bubble reactor, i.e., without reducing efficiency of CO2dissolution in water. More specifically, in many embodiments, each stream of the plurality of streams enters its corresponding packed bed of the plurality of packed beds of the packed bed reactor at the base of the packed bed, and, as such, the water flow’s water entering the packed beds reactor is spread evenly throughout the packed beds to minimize channeling of the reaction medium’s grains. In addition, in many embodiments, a head of water is maintained at the top of each packed bed to allow gravity to trap smaller grains of the reaction medium before they are carried away by the flowing water. In some embodiments, the packed beds are “disk” shaped. In some such embodiments, each such “disk” is several meters in radius and about one meter high. In many embodiments, each packed bed is characterized by a vertical dimension smaller than any of its horizontal dimensions. In many embodiments, the vertical dimension of each packed bed is many times smaller than the bubble reactor length.

[0048] Next, in many embodiments, the aqueous effluent comprising bicarbonate formed in the packed beds reactor exits the packed beds reactor, the system, and the marine vessel through the effluent outlet (FIG. 2, Step 6) and is released into the marine vessel’s environment for safe and permanent storage. In many embodiments, the effluent outlet is positioned on the marine vessel’s frame at the same level as the water inlet. As such, in many embodiments, the proper positioning of the water inlet and effluent outlet at the same or approximately the same level below the waterline further eliminates the need for additional energy of water pumping and, thus, affords additional energy savings.

[0049] Accordingly, in many embodiments, implementation of the instant system and method for CO2 sequestration and storage directly from a moving marine vessel offers a number of energy and cost saving benefits, especially as compared to conventional AWL systems and methods aboard ships. More specifically, in many embodiments, the system and method rely on the forward movement of the marine vessel for pumping ambient water into the system and promoting the ambient water through the system, thus eliminating the need for high energy water pumps. In addition, in many embodiments, the judicious positioning and arrangement of the system’s various elements and components, as well as the utilization of the marine vessel’s advantageous capabilities and circumstances, further enhance the efficiency of the CO2 capture, conversion, andstorage process. As such, the system and method of many embodiments efficiently capture CO2 into ambient water and convert it into stable bicarbonate ions for further release and permanent, as well as safe, storage directly in the marine vessel’s aqueous environment, thus eliminating the need for temporary storage and handling of carbon products for offloading upon landing.DOCTRINE OF EQUIVALENTS

[0050] This description of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form described, and many modifications and variations are possible in light of the teaching above. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications. This description will enable others skilled in the art to best utilize and practice the invention in various embodiments and with various modifications as are suited to a particular use. The scope of the invention is defined by the following claims.

Claims

CLAIMS:

1. A system for energy efficient CO2 sequestration from a marine vessel and conversion of the sequestered CO2 to bicarbonate ions for permanent and safe storage in a body of water, wherein the system is installed aboard the marine vessel moving across the body of water with a speed, generating an exhaust gas stream comprising the CO2, and having a waterline relative to the body of water, and wherein the system comprises:a bubble reactor characterized by a bubble reactor length, a bubble reactor width smaller than the bubble reactor length, and a bubble reactor depth smaller than the bubble reactor length; wherein the bubble reactor comprises a plurality of interconnected pipes distributed throughout the bubble reactor, and wherein each pipe of the plurality of interconnected pipes further comprises a plurality of small holes distributed throughout each pipe;a packed beds reactor comprising a plurality of packed beds connected in parallel, wherein each packed bed of the plurality of packed beds comprises a reaction medium capable of converting CO2 to HCO3; and wherein each packed bed is characterized by a vertical dimension smaller than the bubble reactor length, and each packed bed is set up for a throughout and upward water flow along the vertical dimension;a connector chamber comprising a gas-water separator vented to the atmosphere and providing a fluid communication between the bubble reactor and the packed beds reactor; wherein the gas-water separator comprises a plurality of separator pipes extending from below the waterline to above the waterline;a water inlet comprising at least one inlet water scoop further comprising a plurality of scoop holes, characterized by a scoop hole size and a scoop hole number, for delivering an ambient water from the body of water into the bubble reactor;an effluent outlet for returning a processed effluent water exiting the packed beds reactor to the body of water;a blower for pressurizing the exhaust gas stream and delivering the exhaust gas stream to the bubble reactor viaa gas inlet; andany number of primer pumps, additional valves, inlets, and outlets, as needed to supply and efficiently, as well as safely, operate the system; and wherein the bubble reactor is positioned within the marine vessel below the waterline, such that the bubble reactor length is parallel to the waterline;the packed beds reactor is positioned within the marine vessel below the waterline;andthe water inlet and the effluent outlet are positioned on the marine vessel at the same level below the waterline.

2. The system of claim 1 , wherein the body of water is sea or ocean, and the ambient water is seawater.

3. The system of claim 1 , wherein the ambient water is freshwater.

4. The system of claim 1 , wherein the exhaust gas stream is delivered into the bubble reactor with a venturi effect.

5. The system of claim 1, wherein the packed beds reactor is positioned within the marine vessel below the bubble reactor.

6. The system of claim 1, wherein the reaction medium is limestone.

7. A method for energy efficient CO2 sequestration from a marine vessel and conversion of the sequestered CO2 to bicarbonate ions for permanent and safe storage in a body of water, wherein method is employed aboard the marine vesselmoving across the body of water with a speed, generating an exhaust gas stream comprising the CO2, and having a waterline relative to the body of water, wherein the method comprises:installing a system below the waterline, wherein the system comprises:a bubble reactor characterized by a bubble reactor length, a bubble reactor width smaller than the bubble reactor length, and a bubble reactor depth smaller than the bubble reactor length; wherein the bubble reactor comprises a plurality of interconnected pipes distributed throughout the bubble reactor, and wherein each pipe of the plurality of interconnected pipes further comprises a plurality of small holes distributed throughout each pipe;a packed beds reactor comprising a plurality of packed beds connected in parallel, wherein each packed bed of the plurality of packed beds comprises a reaction medium capable of converting CO2 to HCO3; and wherein each packed bed is characterized by a vertical dimension smaller than the bubble reactor length, and each packed bed is set up for a throughout and upward water flow along the vertical dimension; a connector chamber comprising a gas-water separator vented to the atmosphere and providing a fluid communication between the bubble reactor and the packed beds reactor; wherein the gas-water separator comprises a plurality of separator pipes extending from below the waterline to above the waterline;a water inlet comprising at least one inlet water scoop comprising a plurality of scoop holes, characterized by a scoop hole size and a scoop hole number, for delivering an ambient water from the body of water into the bubble reactor;an effluent outlet for returning a processed effluent water exiting the packed beds reactor to the body of water;a blower for pressurizing the exhaust gas stream and delivering the exhaust gas stream to the bubble reactor viaa gas inlet; andany number of primer pumps, additional valves, inlets, and outlets, as needed to supply and efficiently, as well as safely, operate the system; and whereinthe bubble reactor is positioned within the marine vessel below the waterline, such that the bubble reactor length is parallel to the waterline; the packed beds reactor is positioned within the marine vessel below the waterline; andthe water inlet and the effluent outlet are positioned on the marine vessel at the same level below the waterline;starting a motion of the marine vessel;optionally using one or more priming pump to start a flow of the ambient water from the body of water into and through the system, and to expunge any air gaps or air bubbles in the system;activating the at least one inlet water scoop to bring the ambient water into the bubble reactor through the water inlet, such that the plurality of interconnected pipes becomes submerged in the ambient water within the bubble reactor; directing the exhaust gas stream to the blower, pressurizing the exhaust gas stream in the blower, and further directing thus pressurized exhaust gas stream to the bubble reactor; andallowing the ambient water promoted by the motion of the marine vessel to flow through the bubble reactor, the connector chamber, the packed beds reactor, and out of the system and the marine vessel through the effluent outlet, to capture CO2 from the exhaust gas stream, return the CO2-depleted exhaust gas stream to the atmosphere, convert the captured CO2 to bicarbonate ions, and safely and permanently store the bicarbonate ions in the body of water.

8. The method of claim 7, wherein the body of water is sea or ocean, and the ambient water is seawater.

9. The method of claim 7, wherein the ambient water is freshwater.

10. The method of claim 7, wherein the exhaust gas stream is delivered into the bubble reactor with a venturi effect.

11. The method of claim 7, wherein the packed beds reactor is positioned within the marine vessel below the bubble reactor.

12. The method of claim 7, wherein the reaction medium is limestone.

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