Systems and methods for CO2 sequestration in marine vessels

Abstract

Provided are systems and methods for sealing emissions from marine vessels. Emissions (flue gases from exhaust, or CO2 under pressure in cylinders carried on board, or CO2 obtained via capture during ship navigation) are mixed with seawater in a reactor (e.g., via gas exchange balanced by headspace or bubbling by a diffuser) until a pH of 5.5-6.5 is obtained. The system and reactor pump seawater through a reactor vessel comprising a reaction medium (e.g., carbonate and silicate). The reactor produces an effluent that can be discharged into the ocean. The effluent produced by the reaction according to an embodiment has approximately twice the alkalinity (Alk) and dissolved inorganic carbon (DIC) of the seawater introduced and has a higher CaCl2 than the improved CaCl2 of seawater. +2 concentration.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application No. 62 / 852,236, filed May 23, 2019, by Adkins et al., entitled “Systems and Methods for CO2 Sequestration in Marine Vessels,” which is hereby incorporated by reference in its entirety. Technical Field

[0003] The present invention generally relates to systems and methods for sequestering emissions from marine vessels. Background Art

[0004] Carbon dioxide (CO2) makes up about 0.04% (400 parts per million) of the atmosphere. Although the total concentration of CO2 is relatively small, it is a potent greenhouse gas that plays an important role in regulating the temperature of the Earth's surface. Currently, the artificial generation of CO2 occurs at a rate greater than that at which CO2 is consumed and / or stored, resulting in an increase in the concentration of CO2 in the atmosphere. There is a growing concern that the rising content of CO2 in the Earth's atmosphere may pose significant environmental challenges. Therefore, there is a growing interest in developing methods for removing CO2 from emission streams and the atmosphere and storing it in a manner that prevents future releases of CO2 into the atmosphere. This capture and storage is collectively referred to as CO2 sequestration. Summary of the Invention

[0005] Many embodiments of the present invention relate to systems and methods for sequestering emissions from marine vessels.

[0006] In one embodiment, an emissions sequestration reactor for a marine vessel comprises: a reaction vessel having at least a gas inlet connected to an emissions output flow fluid from the marine vessel, a seawater inlet connected to a seawater source fluid, and a fluid outlet, the reaction vessel further having at least a mixing zone adjacent to the seawater and gas inlets, and a reaction zone disposed between the mixing zone and the outlet; a reaction medium disposed within the reaction zone and configured to sequester at least one of carbon and sulfur from the output emissions; and a diffusion barrier having a porous reaction medium disposed thereon, located between the mixing zone and the reaction zone, and configured to allow the fluid to prevent the porous reaction medium from passing into the mixing zone while allowing seawater to pass from the mixing zone into the reaction zone.

[0007] In a further embodiment, the seawater inlet is connected to a structural access point on the hull of the marine vessel.

[0008] In another embodiment, the fluid outlet directs water to a location proximate to a propeller of a marine vessel.

[0009] In yet further embodiments, the effluent sequestration reactor further comprises an inflow pump in fluid communication with the seawater inlet for pumping seawater into the reaction vessel at a desired flow rate.

[0010] In yet another embodiment, the effluent sequestration reactor further comprises an outflow pump in fluid communication with the seawater outlet for pumping the seawater out of the reaction vessel at a desired flow rate.

[0011] In yet further embodiments, the emissions sequestration reactor further comprises a sensor for monitoring reaction parameters within the emissions sequestration reactor.

[0012] In yet another embodiment, the sensor measures a parameter selected from the group consisting of temperature, pH, pressure, pCO2, alkalinity, ion concentration, turbidity, optical depth, spectral data, and flow rate.

[0013] In yet further embodiments, the sensor is in communication with a controller configured to control the kinetics of the reaction.

[0014] In yet another embodiment, the controller controls the reaction kinetics via at least one of: introducing additional reaction medium; increasing water inlet; increasing water outlet; decreasing water inlet; decreasing water outlet; releasing pressure; increasing pressure; increasing temperature; and decreasing temperature.

[0015] In still other embodiments, the emissions sequestration reactor further comprises a reaction medium inlet coupled to the reaction vessel to provide additional reaction medium to the reaction zone.

[0016] In yet other embodiments, the emissions sequestration reactor further comprises a gravity feed system or conveyor system for providing the reaction medium to the reactor vessel.

[0017] In still yet further embodiments, the reactor vessel is a closed system.

[0018] In yet another embodiment, the reactor vessel includes an overpressure vent for maintaining pressure in the reactor vessel.

[0019] In yet a further embodiment, the reaction medium is selected from at least one of carbonates and silicates.

[0020] In yet another embodiment, the emissions sequestration reactor further comprises a system for controlling the flow of exhaust gas into the reaction vessel.

[0021] In still further embodiments, the emissions sequestration reactor further comprises a system for controlling the temperature of the reactor vessel using the heat of the exhaust gas.

[0022] In yet other embodiments, the reaction medium comprises particles having a diameter of about 500-700 μm.

[0023] In yet a further embodiment, the reaction medium comprises particles having a diameter of about 70-100 μm.

[0024] In yet another embodiment, the emissions sequestration reactor further comprises a system for increasing contact between the gas phase and the liquid phase.

[0025] In yet further other embodiments, a system for sequestering emissions from marine vessels comprises: a first reaction vessel having at least a gas inlet connected to an emission output flow fluid from the marine vessel, and a seawater inlet connected to a seawater source fluid; a second reaction vessel having at least a fluid outlet; and a reaction medium disposed in the second reaction vessel and configured to sequester at least one of carbon and sulfur from the output emissions, wherein the first reaction vessel and the second reaction vessel are connected via a conduit fluid.

[0026] In a further embodiment, the seawater inlet is connected to a structural access point on the hull of the marine vessel.

[0027] In another embodiment, the fluid outlet directs water to a location proximate to a marine vessel propeller.

[0028] In yet further embodiments, the effluent sequestration reactor further comprises an inflow pump in fluid communication with the seawater inlet for pumping seawater into the reaction vessel at a desired flow rate.

[0029] In yet another embodiment, the effluent sequestration reactor further comprises an outflow pump in fluid communication with the seawater outlet for pumping seawater out of the reaction vessel at a desired flow rate.

[0030] In yet further embodiments, the emissions sequestration reactor further comprises a sensor for monitoring reaction parameters within the emissions sequestration reactor.

[0031] In yet another embodiment, the sensor measures a parameter selected from the group consisting of temperature, pH, pressure, pCO2, alkalinity, ion concentration, turbidity, optical depth, spectral data, and flow rate.

[0032] In yet further embodiments, the sensor is in communication with a controller configured to control the reaction kinetics.

[0033] In yet another embodiment, the controller controls the reaction kinetics via at least one of: introducing additional reaction medium; increasing water inlet; increasing water outlet; decreasing water inlet; decreasing water outlet; releasing pressure; increasing pressure; increasing temperature; and decreasing temperature.

[0034] In still other embodiments, the emissions sequestration reactor further comprises a reaction medium inlet coupled to the reaction vessel to provide additional reaction medium to the reaction zone.

[0035] In yet other embodiments, the emissions sequestration reactor further comprises a gravity feed system or conveyor system for providing the reaction medium to the reactor vessel.

[0036] In still yet further embodiments, the reactor vessel is a closed system.

[0037] In yet another embodiment, the reactor vessel includes an overpressure vent for maintaining pressure in the reactor vessel.

[0038] In yet a further embodiment, the reaction medium is selected from at least one of carbonates and silicates.

[0039] In yet another embodiment, the emissions sequestration reactor further comprises a system for controlling the flow of exhaust gas into the reaction vessel.

[0040] In still further embodiments, the emissions sequestration reactor further comprises a system that utilizes heat from the exhaust gas to control the temperature of the reactor vessel.

[0041] In yet other embodiments, the reaction medium comprises particles having a diameter of about 500-700 μm.

[0042] In yet a further embodiment, the reaction medium comprises particles having a diameter of about 70-100 μm.

[0043] In yet another embodiment, the emissions sequestration reactor further comprises a system for increasing contact between the gas phase and the liquid phase.

[0044] In yet another embodiment, a method for sequestering carbon from a marine vessel includes providing a reaction medium disposed within a reaction zone of a reaction vessel, the reaction medium configured to sequester pollutants from an emission source, wherein the pollutants include at least one of carbon and sulfur; mixing seawater with the emission from the marine vessel; and flowing the seawater and emission mixture through a porous medium to sequester the pollutants from the mixture.

[0045] In still further other embodiments, the reaction medium is selected from at least one of carbonates and silicates.

[0046] In yet other embodiments, the reaction medium comprises particles having a diameter of about 500-700 μm.

[0047] In yet a still further embodiment, the reaction medium comprises particles having a diameter of about 70-100 μm.

[0048] In yet still another embodiment, seawater is obtained from a structural access point on the hull of the marine vessel that is in fluid communication with the reaction vessel.

[0049] In still yet another embodiment, the reaction vessel comprises a fluid outlet.

[0050] Other embodiments and features are set forth in part in the following description and, in part, will become apparent to those skilled in the art upon examination of this specification, or may be learned by practice of the disclosed subject matter. A further understanding of the nature and advantages of the present disclosure may be achieved by reference to the remainder of the specification and drawings, which form a part of this disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] These and other features and advantages of the present apparatus and method will be better understood by reference to the following detailed description when considered in conjunction with the accompanying data and drawings, which are presented as exemplary embodiments of the present disclosure and are not to be construed as exhaustive of the scope of the present method, wherein:

[0052] Figures 1A-1B A schematic diagram of a reactor system according to an embodiment is provided.

[0053] Figure 2 A method for sequestering emissions according to an embodiment is provided.

[0054] Figure 3 Data is provided regarding a steady-state calculation method for a reactor system according to an embodiment.

[0055] Figure 4 Data is provided regarding the effects of seawater mixing on reactor systems according to embodiments.

[0056] Figure 5 Data is provided regarding the effects of volume and flow rate on reactor systems according to embodiments.

[0057] Figure 6 Data is provided regarding the effects of volume and flow rate on DIC flux from a reactor system, according to embodiments.

[0058] Figure 7 Data is provided regarding the effects of volume and flow rate on pCO2 output from a reactor system according to embodiments.

[0059] Figure 8 Data is provided regarding the effects of mixing ratios on reactor systems according to embodiments. DETAILED DESCRIPTION

[0060] With reference now to the accompanying drawings, a system and method for sequestering emissions (e.g., CO2) is provided. In various embodiments, carbon emissions are obtained from sources such as ambient capture (e.g., direct air capture), from ships or other launch devices (emitters), or from contained or compressed CO2 exhaust. In certain embodiments, emissions (flue gas from a ship's exhaust, or CO2 under pressure in a cylinder carried on board, or CO2 obtained via capture during the ship's voyage) are mixed with seawater in a reactor (e.g., via gas exchange balanced by the headspace or bubbling through a diffuser) until the seawater is acidified (e.g., with a pH of 5.5-6.5). Various embodiments of the system and reactor pump seawater through a reactor vessel containing reaction medium particles. The reaction medium according to various embodiments includes one or more of carbonates (e.g., CaCO3, aragonite, calcite, sodium bicarbonate, etc.) and / or silicates (e.g., MgSiO3, olivine, pyroxene, mafic rock, etc.). Many embodiments utilize CaCO3 having an average particle size of 100 μm (e.g., the size of fine sand). Certain embodiments have a particle size finer than 100 μm. In some embodiments, the reactor produces an effluent that can be discharged into the ocean. Exemplary reactions using a CaCO3 medium include CO2 + seawater + CaCO3, where the effluent includes dissolved CaCO3. +2 and HCO3 - ions, so that the water leaving the reactor vessel has about twice or more the dissolved inorganic carbon (DIC) concentration and alkalinity (Alk) as the incoming seawater and has an elevated Ca above seawater values. +2 concentration (e.g., about at least 10% higher than seawater values).

[0061] Similar to the above, further embodiments also remove sulfur emissions from sources including exhaust, ambient capture, or storage, where sulfur dioxide (SO2) or other sulfur oxides (SO x ) is mixed with seawater and reacted with a carbonate or silicate reaction medium. In such an embodiment, SO2 + seawater + CaCO3 produces SO4 in the effluent.

[0062] Implementation Methods of Reactor Systems

[0063] With reference to the accompanying figures, embodiments of a system for treating emissions from a marine vessel are provided. Figures 1A-1B Emissions treatment reactors according to various embodiments are described. In particular, Figure 1A A single stage reactor 100 is illustrated, while Figure 1B A dual stage reactor 150 is illustrated.

[0064] exist Figure 1A In many embodiments, a reactor vessel 102 is provided in fluid communication with an inlet 104 for effluent (e.g., gaseous carbon, sulfur, etc.). Additional embodiments include a water inlet 106 for seawater in fluid communication with the reactor vessel 102. In many embodiments, the inlet 106 is connected to a structural access point (e.g., a hole, orifice, or drain) in the hull of the vessel so that incoming water can flow directly into the reactor vessel 102. Some embodiments include an inlet pump 108 in fluid communication with the inlet 106 to help move seawater into the reactor vessel 102. Further embodiments include a water outlet 110 for seawater, some of which include an outflow pump 112 in fluid communication with the outlet 110 to help water leave the reactor vessel 102. In many embodiments, a large amount of reaction medium 114 is disposed within the reactor vessel 102, wherein the reaction medium 114 is configured to sequester carbon from the output effluent. In various embodiments, the reaction medium 114 includes one or more of carbonates and silicates. In various embodiments, reaction medium 114 is separated from inlet 104 by diffusion barrier 116. Although some embodiments are configured to operate at ambient pressure, other embodiments are configured to operate under specific pressure or pressure range. Certain embodiments include overpressure vent 118 for maintaining the pressure of reaction vessel and / or serving as pressure relief (unloading) vent by discharging excess fluid (e.g., gas or water) when the pressure in reaction vessel 102 exceeds an appropriate limit. Further, some embodiments include a reaction medium inlet 120 connected to reaction vessel 102 for providing additional reaction medium 114 in reaction zone 115. Certain embodiments further include a system 119 for improving the contact between the gas phase rising from inlet 104 and the liquid phase rising from inlet 106. In certain embodiments, the system 119 for improving the contact between the gas phase and the liquid phase is a bubbler.

[0065] During operation of such a system embodiment, exhaust gases are piped into the reaction system 100 via the inlet 104. In some such embodiments, the ship's exhaust gases are emitted from the main engine via a manifold through a chimney (typically) located near the rear (stern) of the ship or vessel. In certain embodiments, the inlet 104 includes valves, nozzles, connectors, special geometric shapes (e.g., U-shaped bodies), blowers, and / or other fixtures for improving the flow into the reaction vessel 102 and / or for preventing any material within the reaction vessel 102 from flowing back into the inlet 104. Any method or system for capturing ship exhaust gases can be used to guide the exhaust gases through the seawater reaction system according to the embodiment. It will be understood that the reactor system according to the embodiment can be combined with other emission systems typically associated with ship exhaust systems (including, for example, "scrubbers" configured to remove particulate waste or standard pollutants (e.g., NOx, SOx, PM, VOCs, etc.)). The embodiment can also use an exhaust system that mixes the exhaust gases with seawater (also known as a "wet exhaust" system), which is used on many inboard motor boats. In this process, the water is heated and the gas is cooled. Heating the seawater increases its kinetic "power (energy)", causing dissolution to occur faster than described below with respect to baseline measurements (for seawater at T = 21°C). Various calculations and / or measurements have shown that the carbonate dissolution rate as a function of temperature in seawater at unsaturated levels, such as those expected for the application, increases by a factor of 3-4 for an increase in temperature from 5°C to 37°C.

[0066] When flue gas is introduced into the system through gas inlet 104, a water inlet 106 moves seawater into the reaction vessel 102 with or without a pump 108, and the seawater leaves the reaction vessel 102 via outlet 110 with or without a second pump 112. The combination of inlet 106 and outlet 110 circulates water through the system at a desired rate (e.g., 1000-2000 liters / second). The specific configuration of the inflow pump 108 and outflow pump 112 varies with the specific reactor 100 location. For example, if the reactor is located below the waterline of a ship, the inlet 106 can be provided via a gravity feed so that water is pushed into the reaction chamber 102 without the assistance of the pump 108. However, an outflow pump 112 may be required to move water out of the reaction vessel 102. As a corollary, if the reactor 100 is above the waterline of a vessel, an inflow pump 108 may be required to introduce water into the reaction vessel 102, while the outlet 110 may be configured to be gravity fed. The pumping strength of the inflow pump 108 or the outflow pump 112 depends on the specific location of the reactor 100, such that a greater distance from the vessel's waterline to the reactor 100 may necessitate a more powerful pump.

[0067] In various embodiments, the incoming water is pumped into the reactor system from a sea chest located below the vessel, which screens out large debris (trash). Although the figures show a configuration in which the water mixes with the flue gas as it enters the bottom of the reactor vessel 102, it should be understood that the water can be mixed with the flue gas in any configuration (e.g., from the top or side of the reactor vessel). In some embodiments, the incoming seawater at surface ocean temperature (0-30° C.) can be heated by the flue gas (as previously described) or by waste heat from an engine using a heat exchanger.

[0068] In many embodiments, the outflow pump 112 can be configured to remove water from the reaction vessel at the same rate as water enters. In various embodiments, the removal of finely divided media (e.g., CaCO3) from the outlet pump can be minimized by allowing the water column above the sediment-water slurry to act as a sediment barrier. In various embodiments, the return pump can be omitted when the configuration allows the seawater to be returned to the ocean by overflow or gravity feed.

[0069] In various embodiments, the seawater / gas is mixed in a mixing zone 122 of the reactor vessel 100. This mixing zone may be separated from the main reactor vessel 102 by a diffusion barrier 116. A large volume of reaction medium (e.g., an approximately 6" layer of limestone approximately 1.3 cm in diameter) is disposed above the screen. This layer of reaction medium serves as a permeable horizon for the water and gas mixture to move through before encountering the fine sand-sized limestone. Above this permeable horizon, another large volume of reaction medium (e.g., CaCO3 (limestone) having a diameter of 100 μm) is disposed so that it can react with the seawater + CO2 during the water residence time (e.g., approximately 8 minutes) within the reactor. In embodiments, turbulent flow within the reaction vessel can cause the calcium carbonate to mix thoroughly, thereby allowing the gas / seawater mixture to permeate the reaction medium. It is understood that, in some embodiments, the volume of the reaction vessel in which the gas and seawater mix can be adjusted by moving the position of the screen. Furthermore, while specific examples of particle sizes for the reaction medium are provided, particles of other sizes can also be positioned directly on top of the screen 116, such as a layer of pebble-cobble sized limestone particles can be provided to aid in mixing the water-gas mixture as it permeates through a pack of fine sand-sized limestone particles.

[0070] During the process, the tiny reaction medium (e.g., limestone sand) is converted into ion products (e.g., Ca and HCO 3 ) and therefore must be continuously replenished. Therefore, in many embodiments, access components can be provided to ensure that a continuous supply of medium is achieved in the reaction vessel (e.g., via gravity feed, conveyor system, or other loading devices). For example, in various embodiments, the reaction medium can be provided via a transmission mechanism comprising a slurry with surface seawater. In such a configuration, water is carried by the input device (e.g., water and flue gas can enter via inlet 104 and inlet 106). Such limestone slurry can be arranged in a shipping container (e.g., in a removable bladder) so that the slurry can flow to its mixed destination by gravity. The embodiment of such a bladder can be removable so that they can be folded at the destination and returned to the port of departure so as to free up a container for cargo when returning. In various other embodiments, a dedicated shipping container can be used to accommodate the slurry mixture. In some such embodiments, the container can be made foldable so that they can be transported back when not displaced like many cargo containers.

[0071] However, a standard shipping container or twenty-foot equivalent unit (TEU) may not be able to bear the weight of the medium. For example, a TEU filled with carbonate medium may exceed the loading limit of the TEU. Therefore, certain embodiments use various alternative methods to hold and / or store the medium. Some embodiments may use towed slurry bags so that the reaction medium does not take up cargo space. Such bag embodiments may have one or more mechanisms for bringing the slurry to the ship, including, for example, an internal bladder that is arranged to pump the slurry to the ship via a towline, an electric power source, an internal bladder that expands to squeeze out the slurry via the water (fresh or seawater) being pumped in, and a mechanical device for squeezing out or vacuuming the slurry. The slurry system in various embodiments may also be integrated into the ship's ballast mechanism. In such an embodiment, the slurry is loaded and then, as the slurry is consumed, it is replaced by seawater. In such an embodiment, the bladder and / or other mechanisms may remain separate. It is understood that any and all of the aforementioned may be provided with monitoring, control, and safety mechanisms. Other embodiments use hoppers or other storage systems that are constructed and configured to accommodate large amounts of medium.

[0072] In some embodiments, the reaction medium of the present invention is a mixture of CaCO and 2. Although the above discussion provides CaCO as a possible reaction medium, it will be understood that it is also possible to use any reaction medium that can seal up CO . Exemplary materials include, for example, calcite, aragonite, sodium carbonate, sodium bicarbonate, magnesium silicate etc. Some embodiments introduce the combination of carbonate and silicate medium for reaction. Various embodiments use 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, 20:1 or higher carbonate / silicate ratio to optimize reaction conditions and / or kinetics. Some embodiments can change the carbonate / silicate ratio to optimize reaction conditions and / or reaction kinetics.

[0073] In addition, reaction medium does not need to be pure, so that some mediums can include other components, as long as reaction medium can react in reactor to sequester carbon, sulphur or other emissions.When reaction material is CaCO 3 , it can be ground high-purity limestone or can be the CaCO 3 obtained by digging (dredge) carbonate-rich sediment (comprising the sediment rich in calcium carbonate). CaCO 3 composition (whether it is pure calcite or pure aragonite or other materials) will affect the speed of dissolution and CO 2 and / or the neutralization rate of sulphur. For example, in various embodiments, if aragonite is used to replace calcite, the dissolution rate of reaction can be improved. Reaction rate can also be changed by changing the particle size of reactant material (for example, carbonate, silicate etc.). For example, the dissolution of the particle of about 500-700 μm of diameter is slower than 30 times of the particle of about 70-100 μm. Therefore, in many embodiments, finer granulated medium (for example, carbonate and / or silicate) can be used to improve reaction rate. Furthermore, the particle size can be adjusted to control the bubble size, which can increase the interaction between the gas and liquid phases.

[0074] In a further embodiment, pressure, temperature, and / or other relevant reaction parameters are changed to control reaction kinetics. By using a circulation line configured to capture the heat generated from one or more engines, some embodiments regulate temperature via using engine heat. Other embodiments are configured to utilize the heat from exhaust gases to raise the temperature for reaction. Some embodiments include a system for cooling a reactor or reactor vessel. In some such embodiments, reactor cooling is achieved by passing through a circulation line of a water body. Other embodiments can control temperature by using auxiliary heating or cooling elements (such as heaters and coolers).

[0075] Some embodiment is the open system that allows reaction to be carried out in a specific place under ambient pressure.Other embodiment is closed system, and it allows pressure to increase gradually and / or regulate in reaction vessel.Reaction pressure can increase gradually by water and gas being introduced in reactor.In some embodiments, reaction pressure is regulated using valve (such as overpressure exhaust port 118), and described valve can be opened to discharge or maintain pressure, and pressure raises by introducing waste gas simultaneously.

[0076] Some embodiment has one or more sensors 124 to monitor reaction parameters, such as temperature, pH, pressure, pCO , alkalinity, ion concentration, turbidity, optical depth, spectral data, flow velocity, and / or any other relevant parameter.In many of these embodiments, sensor 124 communicates (such as wired or wireless) with monitor or controller 126, to provide reading, alarm and / or to record the state of ongoing reaction.In a further embodiment, monitor or controller 126 is configured to control reaction kinetics by introducing other reaction medium, raising or lowering water inlet or water outlet, releasing or raising pressure, raising or lowering temperature, and / or any other relevant parameter for controlling reaction kinetics. The advantage of monitoring and controlling reaction parameters is to keep reactor efficiency and keep the chemical composition of effluent water. For example, the introduction of too much alkali in effluent can cause the precipitation of carbonate, causes CO 2 release, thereby makes part or all of capture efficiency invalid.

[0077] In the reaction vessel of many embodiments, CO2 is balanced with seawater and dissolved in water; However, other gases (e.g., N2 and / or Ar) and unreacted CO2 can be directed to an overpressure exhaust port 118 (e.g., via a suitable ventilation chimney). Similarly, an outflow 110 with or without an outflow pump 112 guides water to leave the container from the reaction vessel via a suitable pipeline and return to the ocean. In many embodiments, the water can leave the ship through a (conical and perforated) diffuser located in any suitable position. Effluent water is allowed to pass through the discharge pipe along the perforations in a smaller amount to enhance mixing and dilution of the effluent with the surrounding seawater. In various embodiments, the outlet can be located near the ship propeller. In such an embodiment, the instant dilution (50x) of the reaction vessel effluent is achieved. Subsequently, the water is further mixed with the surface seawater by the action of the propeller blades and the turbulence in the wake of the ship.

[0078] Figure 1BA dual-stage reaction reactor 150 according to many embodiments is described. In many embodiments of the dual-stage reactor 150, a first reaction vessel 152 is used to mix a gas feed entering via inlet 104 with water entering via inlet 106 to produce acidified water, wherein both inlets 104, 106 are in fluid communication with the first reaction vessel 152. Additionally, a second reaction vessel 154 allows for a reaction between the acidified water produced in the first reaction vessel 152 and the reaction medium 114. Neutralized effluent from the second reaction vessel 154 is discharged through an outlet 110 in fluid communication with the second reaction vessel 154. As described elsewhere herein, the inflow and outflow of water can be assisted by the use of one or more pumps 108, 112 in fluid communication with the water inlet 106 or outlet 110. In certain embodiments, the first reaction vessel 152 is in fluid communication with the second reaction vessel 154 via a conduit 156 to allow the acidified water from the first reaction vessel 152 to travel to the second reaction vessel 154. In many embodiments, the flow through conduit 156 is supported by a pump 158 that is in fluid communication with conduit 156. However, certain embodiments use gravity-assisted delivery by placing first reaction vessel 152 above second reaction vessel 154. The overpressure in either reaction chamber 152, 154 can be exhausted by overpressure vent 118, and additional reaction medium can be input to second reaction vessel 154 via reaction medium inlet 120. One or more sensors 124 can be added to one or both of reaction vessels 152, 154 to monitor reaction conditions. As described elsewhere herein, sensor 124 can communicate with monitor or controller 126 to monitor or control the reaction conditions in reaction vessels 152, 154.

[0079] It will be appreciated that the reaction vessels 102, 152, 154 may be of any suitable size or volume. For example, the increased size of ships or other marine vessels is accompanied by increased power plant sources, which generate more emissions. Larger reaction vessels 102, 152, 154 will compensate for the increased CO₂ production resulting from such increased size. Furthermore, the increased speed of ships or other marine vessels increases CO₂ emissions due to the increased propulsion force, thus, additional reaction vessel size will compensate for faster ocean transportation.

[0080] In various embodiments, the reaction vessel may be a multiple of a standard container (or twenty-foot equivalent unit or TEU). For example, in some embodiments, the reaction vessel may be 10 m x 10 m x 10 m, and therefore approximately 1000 m 3 (=35,000 feet 3), which is equivalent to 27 TEUs or a stack of 20' containers with a 3×3×3 configuration. It is understood that such a reaction vessel will be configured to accommodate corrosive (pH 6) seawater that can weigh up to 48,000 pounds. In some embodiments, such a reaction vessel can be made of, for example, stainless steel, titanium, or any other suitable metal. Although a particular volume of reaction vessel is described, such a vessel can be provided in a variety of volumes so that CO2 neutralization can be implemented at different rates and volumes depending on the desired operating conditions.

[0081] It will be appreciated that the reactors 100, 150 may be included on any number of vessels or uses including cargo ships, ferries, tankers, cruise ships, ocean liners, and other marine vessels. It will also be appreciated that the reactors 100, 150 as described herein are suitable for capturing or sequestering many types of emissions and are not limited to ships or other marine vessels. Certain embodiments are configured to be static and capture atmospheric carbon, sulfur, or other emissions such that the reactor is combined with a direct air capture system. Further, when implemented on marine vessels, various embodiments are configured as stand-alone systems that can be installed during the conversion of existing marine vessels, while other embodiments are constructed as a single unit during the construction of new vessels.

[0082] refer to Figure 2 , additional embodiments relate to methods of sequestering carbon using a carbon sequestration reactor, such as described herein. Specifically, Figure 2 A method 200 for sequestering carbon using reactor embodiments is illustrated. At 202, many embodiments provide a reaction medium in a reaction vessel, such as described elsewhere herein, disposed within the reaction vessel. At 204, various embodiments mix seawater and effluents from a source within the reaction vessel. As described elsewhere herein, one or more reaction vessels may be used, depending on whether a single or dual stage reactor is used. Likewise, some embodiments may provide reaction medium 202 and mix seawater and effluents 204 in a single reaction vessel, or may provide reaction medium 202 to a first reaction vessel and mix seawater and effluents 204 in a second reaction vessel. At 206, many embodiments flow the mixture of seawater and effluents through the reaction medium such that carbon is sequestered from the mixture. It should be noted that various embodiments will simultaneously and / or in different stages than the reactor. Figure 2 The features of method 200 are performed in the order described and illustrated in FIG.

[0083] Certain embodiments include more than one reactor 100, 150 in a larger system for sequestering carbon, sulfur, or other emissions. In such embodiments, multiple reactors 100, 150 are placed in series or in parallel. For example, in a series connection, the effluent from one reactor can be fed into a second reactor to allow for additional reactions and neutralization of the acidity in the water. When a two-stage reactor 150 is used, some systems use only the second reaction chamber 154 to allow continued neutralization of the water via the reaction medium 114. In embodiments using a parallel system, a gas inlet 104 can be fed to multiple reactors 110, 150 to increase the amount of carbon, sulfur, or other emissions that dissolve in the water and acidify the water.

[0084] Exemplary embodiments

[0085] Although specific embodiments of reaction systems, reaction system functionality, and reaction system applications are discussed in the following sections, it should be understood that these embodiments are provided by way of example and are not intended to be limiting.

[0086] Example settings

[0087] In an illustrative example, 1.25×10 9 A g supply of CaCO3 will titrate the CO2 produced by a ship burning 175 tons of diesel fuel per day (a 10,000 TEU ship traveling at 21 knots). Assuming a porosity of 50%, this mass (and therefore volume) of granular CaCO3 can be packed into a space with a volume equivalent to 24.3 three standard 20' shipping containers (TEUs). A shipping container (one TEU) is 8' x 8.5' x 20'. It is 38.14m 3 Therefore, approximately 24 shipping containers of CaCO3 (50% porosity) per day must be used to neutralize a ship >10,000 TEU traveling at 20 knots. This is based on 175 tons of fuel per day and a conversion factor to carbon of 0.855. This is approximately 15×10 7 grams of CaCO3 (514,890 moles of carbon).

[0088] In the following example simulation, the following assumptions are made:

[0089] 5% CO2 in flue gas,

[0090] Volume 10×10×10m 3 The reactor,

[0091] 250 L / s seawater flow rate through a volume of 50% rock and 50% pre-bubbled CO2 / seawater,

[0092] Starting alkalinity (Alk) of 2200 μmol / L, starting dissolved inorganic carbon (DIC) of 2000 μmol / L, and starting [Ca] of 10.3 mmol / L

[0093] Limestone reaction medium ground to 100 μm diameter,

[0094] • Experimentally determined dissolution rate data at 21°C (uncatalyzed).

[0095] In these embodiments, the calculation is performed in 3 steps:

[0096] 1. Bubble flue gas into seawater and assume complete equilibrium.

[0097] 2. Calculate the time course (evolution time) of the dissolution reaction in the reactor.

[0098] 3. The output of the steady-state reactor was taken and mixed with varying amounts of ambient seawater.

[0099] Based on these parameters and the average transit time across the Atlantic (9 days) and Pacific (16 days), the ship would need to carry a volume equivalent to 219 to 389 shipping containers (TEUs) filled with CaCO. However, the mass of a TEU filled with CaCO may exceed the TEU weight specification, and therefore, the TEU may not be completely filled with reaction medium. Similarly, additional TEUs may be required to accommodate all of the reaction medium and / or a hopper may be installed to accommodate the reaction medium.

[0100] As will be discussed in more detail below, to achieve this CO2 neutrality, seawater must be pumped from the surface ocean into the gas equilibration chamber and through the reaction chamber (containing CaCO3) at a rate of 36,000-72,000 liters / second (571,000-1,141,000 grams / minute), depending on the rates determined via kinetic analysis. Assuming a ship speed of 20 knots (approximately 10 meters / second), this maximum water flux requires 7.25 m 2 (approximately 9′ x 9′) of hull opening to achieve the required 72,000 L / s.

[0101] Example 1: Study of the time course of the reactor reaching steady state

[0102] Methods: In a first study, the time course of various parameters of a reactor according to an embodiment in the steady-state direction is provided: pH, pCO2, [CO3], alkalinity (Alk), dissolved inorganic carbon (DIC)), and saturation (Ω, which is a measure of the thermodynamic potential for formation or dissolution of a mineral according to the following: ).

[0103] Results: The data were summarized in Figure 3In this study, the ambient seawater had 2000 μmol / L DIC and 2200 μeq / L Alk. The reactor input (after mixing between seawater and flue gas) had 3768 μmol / L DIC, 2200 μeq / L Alk, and 5000 ppm pCO2. The output after the reaction was calculated to be: 4880 μmol / L DIC, 4425 μeq / L Alk, and 1562 ppm pCO2. This shows that the reaction does dissolve a significant fraction of the carbon introduced into the reactor. Specifically, the reaction dissolves 1.05×10 5 moles of C, which is equivalent to one TEU of carbonate every 4 days. As discussed, based on estimates, this will not be enough to capture all CO2 emissions. However, as also shown, the Ω or saturation level within the reactor is only 0.73 (where 1 represents saturation).

[0104] Conclusion: This means that the reactor conditions (e.g., volume, flow, etc.) can be further designed to increase the reaction rate. In the following section, further discussion of how to control the reaction rate within the reactor (according to embodiments) will be provided.

[0105] Example 2: Study of mixing of pCO2 outputs

[0106] Method: As described above, the pCO2 output at steady state in the reactor is approximately 1562 ppm. This pCO2 output is high and can result in outgassing of the reactor effluent, which would reduce net carbon sequestration. According to some embodiments, the effluent can be mixed with seawater at the output to reduce the pCO2.

[0107] Results: As Figure 4 As shown in the data graph, mixing the output effluent with seawater significantly reduces the output pCO2. Specifically, at a 5-fold mixing ratio, the pCO2 drops to about 1350 ppm, at 10-fold, to about 889 ppm, and at 30-fold, to about 641 ppm.

[0108] Example 3: Effect of reactor volume and flow rate on reactor efficiency

[0109] Methods: In the third study, e.g. Figure 5-7 As summarized in , the effects of reactor volume and flow rate on multiple reactor parameters were investigated.

[0110] Results: Specifically, Figure 5As shown in , lower flow rates and larger volumes allow the reaction to proceed further to completion, e.g., increasing DIC, alkalinity, etc. in the reactor effluent. However, a more important parameter is the DIC flux through the system (e.g., the product of [DIC] and flow rate). Data from this DIC flux study is provided in Figure 6 As shown, the DIC flux does not depend on the volume of the reactor, however, the changes in flow rate are large compared to the changes in DIC.

[0111] Conclusion: Based on these studies, a flow rate of approximately 2000 l / s would provide a residence time of 0.66 TEU / day, meaning that using four or five such systems would potentially achieve the target storage rate of 3 TEU / day. Figure 7 As shown in , the output of pCO2 is affected by both flow rate and volume. At a given flow rate, a larger reactor volume results in a smaller pCO2 value. This effect will be further discussed in the following section.

[0112] Example 4: Effect of Volume on Post-mixing

[0113] Methods: As previously discussed, it has been shown that by engineering flow rates and post-reaction mixing, it is possible to improve the efficiency of reactor embodiments in capturing carbon. Figure 8 As shown in , at the same time, the volume of the reactor does have an influence on the pCO2 after mixing with seawater.

[0114] Conclusion: Therefore, the volume of the reactor can be designed (as allowed by the footprint of the vessel) to further improve the efficiency of the reactor embodiment.

[0115] DOCTRINE OF EQUIVALENTS

[0116] While several alternative configurations for the system have been described, it should be apparent that any of the various system configurations may be implemented in accordance with many embodiments of the present invention.

[0117] More generally, as can be inferred from the above discussion, the above concepts can be implemented in various arrangements according to embodiments of the present invention. Thus, although the present invention has been described in certain specific aspects, many additional modifications and variations will be apparent to those skilled in the art. Therefore, it should be understood that the present invention can be practiced in ways other than those specifically described. Therefore, the embodiments of the present invention should be considered in all respects as illustrative and not restrictive.

Claims

1. An emission sequestration reactor for a marine vessel having a hull and a waterline, wherein the marine vessel produces an emission stream, the emission sequestration reactor comprising: a reaction vessel comprising at least a gas inlet in fluid communication with the effluent stream, a seawater inlet in fluid communication with a source of seawater, and a fluid outlet; the reaction vessel further comprising at least a mixing zone adjacent to the seawater and gas inlets, and a reaction zone disposed between the mixing zone and the fluid outlet; a reaction medium disposed within the reaction zone and configured to sequester at least one of carbon dioxide and sulfur dioxide from the effluent stream; and A diffusion barrier, on which the reaction medium is disposed, is located between the mixing zone and the reaction zone and is configured to prevent the reaction medium from passing into the mixing zone while allowing seawater to pass from the mixing zone into the reaction zone.

2. The emission storage reactor according to claim 1, wherein: The seawater inlet is connected to a structure access point located on the hull of the marine vessel.

3. The emission storage reactor according to claim 1, wherein: The fluid outlet directs the water to the location of the propeller of the marine vessel.

4. The effluent sequestration reactor of claim 1 , further comprising an inflow pump in fluid communication with the seawater inlet for pumping seawater into the reaction vessel at a desired flow rate.

5. The effluent sequestration reactor of claim 1, further comprising an outflow pump in fluid communication with the fluid outlet for pumping seawater out of the reaction vessel at a desired flow rate.

6. The emissions sequestration reactor of claim 1, further comprising a sensor for monitoring reaction parameters within the emissions sequestration reactor.

7. The emission sequestration reactor according to claim 6, wherein: The sensor measures a parameter selected from the group consisting of: temperature, pH, pressure, ion concentration, optical depth, spectral data, and flow rate.

8. The emission sequestration reactor according to claim 6, wherein: The sensor measures a parameter selected from the group consisting of: pCO2, alkalinity and turbidity.

9. The emission sequestration reactor according to claim 6, wherein: The sensor communicates with a controller configured to control the reaction kinetics.

10. The emission sequestration reactor according to claim 9, wherein: The controller controls the reaction kinetics via at least one of: introducing additional reaction medium; increasing water inlet; increasing water outlet; decreasing water inlet; decreasing water outlet; releasing pressure; increasing pressure; increasing temperature; and decreasing temperature.

11. The emissions sequestration reactor of claim 1 , further comprising a reaction medium inlet connected to the reaction vessel to provide additional reaction medium to the reaction zone.

12. The emissions sequestration reactor of claim 11, further comprising a gravity feed system or a conveyor system for providing the reaction medium to the reaction vessel.

13. The emission sequestration reactor according to claim 1, wherein: The reaction vessel is a closed system.

14. The emission sequestration reactor according to claim 13, wherein: The reaction vessel includes an overpressure vent for maintaining the pressure of the reaction vessel.

15. The emissions sequestration reactor of claim 1, wherein: The reaction medium is selected from at least one of carbonates and silicates.

16. The emissions sequestration reactor of claim 1, further comprising a flow system for controlling and directing the flow of emissions into the reaction vessel.

17. The emissions sequestration reactor of claim 16, further comprising a thermal system that utilizes heat from the emissions stream to control the temperature of the reaction vessel.

18. The emissions sequestration reactor of claim 1, wherein: The reaction medium contains particles with a diameter of 500-700 μm.

19. The emissions sequestration reactor of claim 1, wherein: The reaction medium contained particles with a diameter of 70-100 μm.

20. The emissions sequestration reactor of claim 1, further comprising a system for increasing contact between the gas phase and the liquid phase.

21. A method of sequestering carbon dioxide from a marine vessel having a hull and a waterline and producing an emissions stream, wherein the method is performed using an emissions sequestration reactor as claimed in any one of claims 1 to 20, the method comprising: providing a reaction medium configured to sequester pollutants from an emissions output stream of a marine vessel, wherein the pollutants comprise at least one of carbon dioxide and sulfur dioxide; providing and mixing seawater with effluent from the effluent stream within the effluent sequestration reactor; and A mixture of seawater and effluent is flowed through a reaction medium within an effluent sequestration reactor such that pollutants are sequestered from the mixture.

22. The method of claim 21, wherein: The reaction medium is selected from at least one of carbonates and silicates.

23. The method of claim 21, wherein: The reaction medium contains particles with a diameter of 500-700 μm.

24. The method of claim 21, wherein: The reaction medium contained particles with a diameter of 70-100 μm.

25. The method of claim 21, wherein Seawater is obtained from a structural access point on the hull of the marine vessel that is in fluid communication with the emissions sequestration reactor.

26. The method of claim 21, wherein: The emissions storage reactor is located below the waterline of the ocean vessel.

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