Marine carbon capture and storage methods and equipment

Abstract

Provided are methods and equipment for marine carbon capture and storage (marine CCS) and direct air capture (DAC) that can be used to perform carbon capture and storage of flue gas emitted from marine facilities that use fossil energy, such as coastal power plants and ships. This invention employs a natural engineering method, using natural seawater to scrub and dissolve CO2 gas for carbon capture. The carbonate neutralization of natural seawater and the resulting bicarbonate are used for ocean storage in the water column. Low head and high water flow are used to conserve energy. Discharge meets environmental regulations. This invention provides an affordable, environmentally friendly, and effective means of using marine ecosystems for carbon absorption and storage to address climate change.

Description

[Technical field]

[0001] The present invention relates to a method and equipment for marine carbon capture and storage (marine CCS) and / or direct air capture (DAC), which is applicable to carbon dioxide capture and storage for coastal power plants, marine vessels, and other marine facilities that burn fossil fuels.The present invention belongs to the technical fields of clean energy and geo-engineering. [Background technology]

[0002] Carbon dioxide capture and storage, or CCS, is a necessary technological solution to reduce greenhouse gases in the atmosphere. However, all existing CCS technologies are costly geological storage solutions and are far from economically and affordably viable, making large-scale emission reductions difficult to achieve.

[0003] According to geoscience theory, the absorption of excess carbon dioxide in the atmosphere will ultimately depend on the deep ocean water column. In this regard, large-scale studies by international organizations further show that the oceans already naturally absorb CO2 from the atmosphere at a rate of about 6 Gt / year, and that CO2 naturally flows to the deep oceans. International studies also show that carbon dioxide is a naturally occurring product, and that due to the large size of the ocean carbon reservoir (many times larger than those on land), its overall impact on the marine environment should be very small (IEA OCEAN STORAGE OF CO2). The conclusion of these studies is that marine carbon storage is the most cost-effective and promising measure to address climate change, and it is also the safest and most effective. For this reason, further tests of marine carbon storage were carried out in 2001. They consist of injecting liquid carbon dioxide into two waters, Hawaii and Norway. However, although funds and materials (including 60 tons of liquid carbon dioxide) were prepared, the test was ultimately banned because the Environmental Protection Agency pointed out that the injection of CO2 into the ocean in the form of liquid, dense gas or solid would lead to the immediate death of the ocean, which would severely damage the ecological environment of the injected sea area. Therefore, this test belongs to the "ocean dumping" act prohibited by the London Convention and the OSPAR Convention. Since then, international experimental research on marine carbon storage has been stagnant for more than 10 years. Therefore, if the storage method of high-concentration carbon dioxide in geological storage continues to be used, marine storage tests cannot be carried out in the ocean. Therefore, the benefits of the "most cost-effective measure" cannot be demonstrated and applied, and marine storage cannot become a practical measure for carbon reduction. Ultimately, the long-held desire to effectively respond to climate change using marine resources cannot be achieved. Summary of the Invention [Problem to be solved by the invention]

[0004] The objective of the marine carbon capture and storage method and system of the present invention is to overcome the shortcomings of the prior art of marine carbon storage and provide the most cost-effective approach to marine carbon storage that also complies with environmental regulations, so that marine carbon storage can be a practical solution to address climate change, and at the same time, the solution is economically and environmentally viable. [Means for solving the problem]

[0005] The present invention first provides a method for producing a 1) a carbon capture step including scrubbing a gas containing carbon dioxide with pumped seawater to provide scrubbed seawater as a product of carbon capture that has absorbed the carbon dioxide from the gas; 2) a carbon storage step, comprising discharging the products of carbon capture into the ocean water column for ocean storage; The present invention provides a method for marine carbon capture and storage, comprising:

[0006] In a preferred embodiment, in step 2), the products of carbon capture are discharged under atmospheric pressure through a pipe into the ocean water column.

[0007] In a preferred embodiment, the method further comprises adjusting the ratio of the volume of seawater to the volume of carbon dioxide in the carbon capture product to adjust the pH value of the carbon capture product discharged to the ocean.

[0008] In a preferred embodiment, the gas containing carbon dioxide in step 1) is atmospheric air and the seawater for washing is a mixture of air and water, which is influenced by wind and / or ocean currents. Power obtained by The water is pumped using electricity generated by solar panels and / or solar panels.

[0009] In a preferred embodiment, the carbon dioxide containing gas is flue gas emitted from the combustion of fossil fuels.

[0010] In a preferred embodiment, the method further comprises the step of absorbing at least 10%, or at least 20%, or at least 50%, or at least 70%, or at least 80%, or at least 90% of the carbon dioxide in the flue gas into seawater and then discharging into the ocean water column, the volume of seawater configured to be sufficient to absorb at least 10%, or at least 20%, or at least 50%, or at least 70%, or at least 80%, or at least 90% of the carbon dioxide of the flue gas.

[0011] In a preferred embodiment, the method further comprises the step of seawater being pumped to a head of 50m or less, or 40m or less, or 30m or less, or 20m or less, or 19m or less, or 15m or less, or 12m or less, or 10m or less, or 9m or less, or 8m or less, or 6m or less, or 5m or less, or 4m or less, or 2m or less, or 1m or less, for scrubbing the carbon dioxide containing flue gas, where a head of 0m is the sea level at the location where the scrubbing seawater is pumped.

[0012] In a preferred embodiment, the method further comprises providing a packing, performing washing in the packing, and configuring the head of the pumped washing seawater such that the energy consumption of the carbon capture is 1000MJ / t or less, 500MJ / t or less, or 400MJ / t or less, or 350MJ / t or less, or 300MJ / t or less, or 250MJ / t or less, or 200MJ / t or less, or 150MJ / t or less, or 100MJ / t or less, or 60MJ / t or less, or 50MJ / t or less, or 40MJ / t or less, or 30MJ / t or less, or 20MJ / t or less, or 10MJ / t or less, or 5MJ / t or less.

[0013] In a preferred embodiment, the entire process from carbon capture to carbon storage is a continuous reaction.

[0014] In a preferred embodiment, the method further comprises discharging the products of the carbon capture into the surface and / or intermediate and / or deep layers of the ocean water column.

[0015] In a preferred embodiment, the method further comprises discharging the washed seawater into a current in the ocean's water column that does not pass through the location where the washing seawater is pumped.

[0016] In a preferred embodiment, washing with the packing is accomplished by large area contact between the washing seawater and the flue gas.

[0017] The present invention secondly provides a method for marine carbon capture and storage, the method comprising: a. continuously introducing carbon dioxide-containing flue gas discharged from a combustor for burning fossil fuels into a carbon capture device; b. continuously introducing seawater into a carbon capture device; c. providing a filler in the carbon capture device to increase the contact area between the flue gas in step a and the seawater in step b, so as to scrub the flue gas and absorb the carbon dioxide in the flue gas; d. continuously discharging the scrubbed flue gas into the atmosphere, wherein the amount of carbon dioxide in the scrubbed flue gas is reduced; e. continuously discharging the seawater containing the carbon dioxide produced in step c from the carbon capture device; f. continuously discharging the seawater containing carbon dioxide produced in step e to an ocean carbon storage site for carbon storage; wherein the fossil fuel is selected from the group consisting of coal, oil and gas, the combustor is selected from the group consisting of a steam turbine boiler, an internal combustion engine and a gas turbine used in a coastal power plant or a marine vessel, the flue gas is generated by the combustion of the fossil fuel, and the seawater in step b is seawater pumped from the ocean to be used directly for scrubbing and / or seawater pumped from the ocean to first cool the combustor before being used for scrubbing.

[0018] In preferred embodiments, at least 10%, or at least 20%, or at least 50%, or at least 70%, or at least 80%, or at least 90% of the carbon dioxide in the flue gas in step a is removed compared to the scrubbed flue gas in step d.

[0019] In a preferred embodiment, at least 20% of the carbon dioxide in the flue gas in step a is removed compared to the scrubbed flue gas in step d.

[0020] In a preferred embodiment, the difference between the elevated temperature of the seawater containing carbon dioxide that is continuously discharged in step e and the temperature of the seawater introduced into the carbon capture unit in step b is less than 50°C.

[0021] In a preferred embodiment, the difference between the elevated temperature of the carbon dioxide-containing seawater continuously discharged in step e and the temperature of the seawater introduced into the carbon capture unit in step b is less than 20°C.

[0022] In a preferred embodiment, the difference between the elevated temperature of the seawater containing carbon dioxide that is continuously discharged in step e and the temperature of the seawater introduced into the carbon capture unit in step b is less than 2°C.

[0023] In a preferred embodiment, the difference between the reduced pH value of the seawater containing carbon dioxide continuously exhausted in step e and the pH value of the seawater at the carbon storage location is no more than 2 pH units.

[0024] The present invention thirdly provides a system for marine carbon capture and storage, the system comprising: A combustor that generates smoke by burning a fossil fuel; a carbon capture device connected to the combustor for scrubbing the flue gas and capturing carbon dioxide; a seawater pumping device for introducing seawater into the carbon capture device; a stack for delivering the cleaned flue gas out of the carbon capture device; Seawater discharge pipe and The carbon capture device includes a water supply and a packed bed, the seawater outlet of the carbon capture device is connected to a seawater discharge pipe, the outlet of the discharge pipe being disposed in the ocean water column.

[0025] In a preferred embodiment, the elevation of the water supply unit of the carbon capture unit is configured to be 50m or less, or 40m or less, or 30m or less, or 20m or less, or 19m or less, or 15m or less, or 12m or less, or 10m or less, or 9m or less, 8m or less, 6m or less, 5m or less, 4m or less, 2m or less, or 1m or less, where the elevation of the water supply unit is defined by the distance between the horizontal centerline of the water supply unit and the sea surface where the wash seawater is pumped by the seawater pumping unit.

[0026] In a preferred embodiment, the seawater pumping unit for the carbon capture unit is a seawater cooling system for the combustor and / or a seawater intake pump.

[0027] In a preferred embodiment, the installation further comprises a seawater adjustment pump connected to the water regulator for adjusting the pH value of the washing seawater discharged into the ocean.

[0028] In a preferred embodiment, the packing bed of the carbon recovery unit consists of industrial bulk packing, and / or conventional packing, and / or packing of perforated plates, and / or grids.

[0029] In a preferred embodiment, the dry packing factor of the packing is 5 to 2000 / m, where the definition of the dry packing factor is in accordance with the manual of conventional packing industry products.

[0030] In a preferred embodiment, the seawater outlet pipe is a pipe made of a membrane.

[0031] In a preferred embodiment, the carbon capture unit is located on an offshore platform that has an elevation that is adjustable according to tides.

[0032] The present invention fourthly provides a marine carbon capture and storage facility for carrying out the method of the present invention, the facility comprising: A carbon capture device; a seawater pumping device for introducing seawater into the carbon capture device; For seawater pumping equipment power To supply power Facilities and a water supply device on top of the carbon capture device; a water collector located below the carbon capture device; A seawater discharge pipe connected to a water collector; Includes.

[0033] In a preferred embodiment, power The facility is wind power Device , and / or ocean current wave conversion devices, and / or solar power generation devices.

[0034] In a preferred embodiment, power The facilities include: A wind-driven device; a power transmission device connected to the seawater pump device for transmitting the power obtained by the wind-driven device to the seawater pump device; The power transmission includes a mechanical transmission and / or an electromechanical transmission consisting of a wind generator and an electric motor.

[0035] In a preferred embodiment, power The facilities include: A water-driven device; a power transmission device connected to the seawater pump device for transmitting power obtained by the water-driven device to the seawater pump device; The power transmission includes a mechanical transmission and / or an electromechanical transmission consisting of a hydro-generator and an electric motor.

[0036] In a preferred embodiment, the two above-mentioned installations for carrying out the method of the invention are fixed to the seabed and / or to an offshore platform.

[0037] The following description is intended to explain the technical principles and effects of the present invention.

[0038] The principle used in the present invention is that carbon dioxide is a natural substance that is soluble and abundant in seawater, and the storage of carbon dioxide in the ocean can be large-scale, long-term, and environmentally friendly. In the present invention, flue gas emitted from fossil fuels is washed with seawater, or the atmosphere (i.e., air in its natural state) is directly collected and washed to dissolve the carbon dioxide in the flue gas and / or atmosphere, thereby achieving the purpose of carbon capture. Then, the seawater in which the flue gas and / or carbon dioxide in the atmosphere are dissolved is discharged to the surface layer, and / or intermediate layer, and / or deep layer of the ocean water column to achieve the purpose of carbon storage under conditions in which related indicators such as pH value comply with environmental regulations. In addition, the diffusion of ocean currents can further reduce the harmful effects on the marine environment and further enhance the effect of ocean storage. The seawater in which carbon dioxide is dissolved can be discharged to the surface layer, intermediate layer, or deep layer of the sea or ocean water column. Some other studies have shown that CO2 can be stored for 1000 years if it is discharged to a depth of 1000m in the ocean.

[0039] CO2 dissolves in seawater according to the following reaction (from left to right): CO2+H2O⇔H2CO3(carbonic acid) H2CO3⇔H + +HCO3 - (Bicarbonate ion) HCO3 - ⇔H + +CO3 2- (carbonate ion) Bicarbonate ions are the predominant form of carbon dioxide in seawater. Carbonic acid, bicarbonate ions, and carbonate ions are collectively referred to as dissolved inorganic carbon (DIC).

[0040] Usually, the solubility of carbon dioxide in water is very low, so the seawater washing results in the washed seawater containing low concentrations of CO2, i.e. low concentrations of DIC. The term "low concentration" should be understood in comparison with the prior art, where the product of carbon capture is in the form of pure liquid carbon dioxide, dense gas or solid, in which the concentration of carbon dioxide is several orders of magnitude higher than that in the present invention. Those skilled in the art may consider that the energy consumption is huge in the present invention, since a large amount of washing seawater is required due to the "low concentration". However, in the present invention, the total energy consumption can be reduced by reducing the pumping head of the seawater, so that the cost of carbon capture and storage is at least one order of magnitude lower than that of conventional CCS technology. In coastal thermal power plants, the cost can be further reduced by reusing the cooling water.

[0041] At the same time, sulfur dioxide is also a natural substance that is soluble in seawater and exists abundantly, and the amount of sulfur dioxide in flue gas is less than that of carbon dioxide, and sulfur dioxide is more soluble in water than carbon dioxide, so the present invention has the effect of flue gas desulfurization. Therefore, the present invention also has the effect of flue gas desulfurization.

[0042] Clearly, application of the present invention can expand the commercial application of carbon capture and storage in coastal regions with a high concentration of large carbon emission sources. In such situations, the benefits of scale are significant.

[0043] If this invention is applied to maritime transportation, it can achieve twofold effects. First, it can utilize the ocean's surface carbon sink resources so that carbon emissions that were previously uncaptured and released can now be captured and stored, reducing carbon dioxide emissions from ships at a very low cost. Second, it can avoid the use of low-sulfur fuels and indirectly reduce carbon emissions from the oil refining industry. Thus, the shipping industry can be relieved from the dual pressures of international carbon and sulfur reduction laws. The economic and environmental benefits can be continuously maintained.

[0044] When the carbon capture and storage of the present invention is used on natural air, there are particularly important advantages. The first reason is that the atmospheric circulation can be used to capture all kinds of carbon emissions without transportation costs, including emitted carbon emissions that cannot be captured otherwise. The second reason is that carbon capture and storage with zero energy consumption can be achieved by using wind, ocean currents, solar, and other renewable energies. The third reason is that there is no limit to the sea area and no support of peripheral equipment is required, so a large number of installations can be installed in any sea area. Effect of the Invention

[0045] Clearly, the present invention, based on the principles of geoscience, achieves good technical results by adopting the methods of natural engineering. The present invention provides an affordable, practical and effective technical approach to achieve the long-standing desire to use marine resources to respond to climate change. [Brief description of the drawings]

[0046] [Figure 1] FIG. 1 is a schematic diagram showing an example of steps for carrying out the seawater carbon capture and storage method of the present invention. [Diagram 2] FIG. 2 is a schematic diagram showing another embodiment of the steps of carrying out the seawater carbon capture and storage method of the present invention. [Diagram 3] FIG. 1 is a schematic diagram showing an example of the present invention used in an onshore gas-steam combined cycle power plant. [Figure 4] FIG. 1 is a schematic diagram illustrating another embodiment of the present invention for use in a coastal coal-fired power plant. [Diagram 5] 1 is a schematic diagram showing an example of a marine vessel of the present invention. [Figure 6] FIG. 1 is a schematic diagram illustrating an example of hydro-powered marine atmospheric carbon capture and storage of the present invention. [Figure 7] FIG. 1 is a schematic diagram showing an example of wind-powered marine atmospheric carbon capture and storage of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0047] The names of components or structures corresponding to the reference numbers in the drawings are as follows:

[0048] The present invention relates to 1) a carbon capture step including scrubbing a gas containing carbon dioxide with pumped seawater to provide scrubbed seawater as a product of carbon capture that has absorbed the carbon dioxide from the gas; 2) a carbon sequestration step, comprising discharging the products of the carbon capture into the ocean water column; The present invention provides a method for marine carbon capture and storage, comprising:

[0049] The term "seawater" as used herein refers to natural seawater obtained from a sea or ocean, including natural seawater for cooling industrial facilities. The objectives of the present invention can be achieved by using seawater without the addition of other substances (e.g., adding alkali). Of course, other additives can be added to achieve special purposes, such as to absorb some special components in flue gas, depending on the application.

[0050] The term "scrubbing" as used herein refers to the step of contacting seawater with gas for the purpose of carbon dioxide capture. Contacting can be carried out in equipment including, but not limited to, spray injectors, bubblers, venturi towers, atomizers, filters, rotary atomizers, grates, tray columns, or packed columns.

[0051] The term "carbon capture" as used herein refers to the step of capturing CO2 from the carbon dioxide-containing gas during the scrubbing process. During the scrubbing process, some of the CO2 dissolves in the seawater and becomes dissolved inorganic carbon (DIC) in the scrubbed seawater.

[0052] The term "carbon sequestration" as used herein refers to the step of discharging the washed seawater containing the CO2 in the flue gas through a pipe directly into the ocean water column under normal pressure. In the carbon sequestration process, concentrated CO2 is not required prior to discharge. If necessary, the CO2 can be further diluted by adding additional seawater to adjust the pH value of the discharged seawater to comply with environmental regulations. Different regions of the ocean, including different ocean depths, may have different requirements regarding the pH value of the discharged seawater.

[0053] The term "ocean water column" as used herein refers to the surface (tens of meters deep), mesophase (less than a few hundred meters deep), or deep (more than a few hundred meters deep) ocean waters. International studies by the IPCC and IEA have shown that the physical and chemical systems of the ocean water column, and marine ecosystems, are capable of environmentally sound absorption and storage of carbon dioxide.

[0054] Flowing water, or currents, can enhance the effectiveness of ocean carbon storage: if carbon capture products are discharged into currents in the ocean's water column where no washwater can be pumped through the inlet, discharged water can be prevented from returning to the inlet.

[0055] It is common knowledge that CO2 dissolves in water, and seawater can absorb more CO2. However, so far, there have been no reports on technical approaches where seawater is used for carbon capture and storage. The reason is that those skilled in the art are accustomed to thinking that the only available way to reduce costs is to purify the captured CO2 to high concentrations in liquid, dense gas or solid form in order to reduce the material volume and thus the cost of transportation and storage. They cannot think of low concentration approaches, since the cost of high concentration solutions is far from a practical technology with affordable cost.

[0056] The inventor has been working on research into desulfurization by seawater washing for many years. The inventor accidentally discovered that a low-concentration solution of seawater washing can not only desulfurize but also capture and store carbon. Furthermore, the inventor has also discovered a method to significantly reduce the cost, making it affordable and practical.

[0057] The inventor of the present invention first found that in the prior art of seawater washing desulfurization (FGD, EGC), less than 10% of the carbon dioxide in the flue gas was usually dissolved in the washing water, which was released into the atmosphere during the process of drainage and aeration. Therefore, the inventor conducted tests on FGD at coastal power plants and EGC on marine tankers for many years. The tests showed that if the seawater washing desulfurization technology is appropriately modified, carbon dioxide dissolved in seawater will not be released outside the seawater, or a small amount of carbon dioxide dissolved in seawater can be released outside the seawater, under the condition that the discharged seawater complies with environmental regulations.

[0058] The inventors of the present invention have also found in further testing that increasing the amount of washing seawater can result in the capture and storage of 10% or more of the carbon dioxide in the flue gas. The inventors have also found that the increased energy consumption and cost in the process of increasing the amount of washing seawater can be reduced by reducing the lift of the washing seawater pumped. In this case, the cost for capture and storage of at least 20% of the carbon dioxide in the flue gas is usually affordable for various applications such as power plants and ships. The following part of this application provides a detailed description of several examples in which the cost of removing more carbon dioxide is affordable in some typical applications. In these examples, the goal of capturing and storing 30% or more, or 40% or more, or 50% or more, or 60% or more, or 70% or more, or 80% or more, or 90% or more of the carbon dioxide in the flue gas is ultimately achieved. In an example of a coastal power plant, as much as 99% of the CO2 in the flue gas is captured and stored, and the increased cost is affordable.

[0059] A given amount of water can dissolve a limited amount of CO2 (typically 1m 3 At room temperature and pressure, fresh water is approximately 0.8m 3 100% of CO2 can be absorbed by seawater, and seawater can absorb a little more than fresh water), so if a large amount of CO2 needs to be captured from the flue gas, a large amount of wash water is required. For example, in one example power plant, if all of the original cooling seawater is used to wash the flue gas, only about 30% of CO2 can be captured. If more than 90% of CO2 needs to be captured, additional wash seawater, about twice the amount of the original cooling seawater, needs to be added. Generally speaking, it is a very huge amount. For an affordable cost, two technical measures need to be adopted. One is to reduce the energy consumption of pumping seawater, and the other is to increase the absorption efficiency of seawater for CO2 to minimize the amount of wash seawater required. First, the head of the seawater pumped up, i.e., the altitude of the carbon capture device, should be lowered to reduce the energy consumption of pumping seawater. In one example large power plant, a carbon capture device with an altitude of 50m, where the wash seawater is pumped up, can meet the requirement. Of course, in another embodiment, 40m or 30m can also meet the requirement. For some typical applications such as power plants and marine vessels, the following embodiments of this application provide detailed explanations. In these embodiments, the carbon capture device into which the washing seawater is pumped is configured with an elevation of 20m or less, or 19m or less, or 15m or less, or 12m or less, or 10m or less, or 9m or less, or 8m or less, or 6m or less, or 5m or less, or 4m or less, or 2m or less, or 1m or less. In another embodiment, since the average tide level in a local area at different times varies greatly, the carbon capture device is installed on a platform or floating dock, which has an adjustable elevation according to the tide level. In such a case, the energy consumption for pumping seawater is reduced to a minimum level due to the principle that the boat rises with the water level.

[0060] Meanwhile, the inventors have also found in tests that among all kinds of washing equipment, the filling washing device or absorption tower as the carbon recovery device is the best one for reducing the amount of washing seawater and the lift of the seawater pumped up by the pump. As a result, the energy consumption for pumping up the seawater is the smallest and the operation is the most stable. Based on many years of experience engaged in the desulfurization and carbon dioxide absorption tests of seawater washing, the inventors of the present invention have also found that the preferred dry packing factor of the packing is 5 to 2000 / m (the definition of the dry packing factor is written in the manual of the conventional packing industrial product). Such a packing provides the best effect of carbon recovery by seawater washing. For example, a packing with a dry packing factor of 5 / m can meet the requirements. In the following examples, packings with dry packing factors of 10 / m, or 15 / m, or 35 / m, or 55 / m, or 65 / m, or 95 / m, or 150 / m, or 250 / m, or 350 / m, or 450 / m, or 650 / m, or 850 / m, or 1000 / m, or 1200 / m, or 1500 / m, or 1800 / m, or 2000 / m may also meet the requirements. Packing washing refers to washing achieved by large area contact between the washing seawater and the discharged flue gas in the packing.

[0061] According to the above description, the inventors of the present invention have found that by measures including reducing the lift of the seawater pumped up and packing washing, the energy consumption of carbon capture is ultimately reduced, and the total cost of CCS technology is reduced to a practical level. For example, in one example, the energy consumption of carbon dioxide capture is 1000 MJ / t (million joules / ton) or less, which is practical. For power plant and marine vessel applications, the examples below show that carbon capture energy consumption of 500MJ / t or less, or 400MJ / t or less, or 350MJ / t or less, or 300MJ / t or less, or 250MJ / t or less, or 200MJ / t or less, or 150MJ / t or less, or 100MJ / t or less, or 60MJ / t or less, or 50MJ / t or less, or 40MJ / t or less, or 30MJ / t or less, or 20MJ / t or less, or 10MJ / t or less, or 5MJ / t or less is also practical.

[0062] Furthermore, the inventor has found that according to the present invention, carbon capture and storage can be used for natural air on the sea (DAC), which has a good effect on reducing carbon content in the atmosphere. In the following examples, only mechanical energy and / or electrical energy obtained from wind on the sea, and / or waves of ocean currents, and / or sunlight and other natural energy are used, which are all renewable energy. That means that the energy consumption is zero. Therefore, the operating cost is very low, and only construction costs and depreciation costs are required, and no power generation and transportation and peripheral equipment support are required. Furthermore, the construction cost is also very low. On the other hand, the purpose of building many wind and wave power generation facilities is to replace fossil energy offshore to eventually reduce carbon emissions in the atmosphere. However, according to the present invention, carbon dioxide in the atmosphere can be directly captured and stored. In this case, the efficiency of reducing carbon is higher.

[0063] A further detailed explanation of the invention is given in the following examples with reference to the drawings.

[0064] Example 1 This is a basic embodiment of the marine carbon capture and storage method of the present invention. As shown in Figure 1, the method includes 1) a carbon capture step including scrubbing a gas containing carbon dioxide with pumped seawater to provide scrubbed seawater as a carbon capture product that has absorbed the carbon dioxide from the gas, and 2) a carbon storage step including discharging the carbon capture product into the ocean water column for ocean storage.

[0065] In a variation based on this embodiment, in step 2), the products of carbon capture are discharged through a pipe into the ocean water column under normal pressure. The entire process from carbon capture to carbon storage is a continuous reaction.

[0066] In another variation based on this embodiment, the method further includes adjusting the ratio of the volume of seawater to the volume of carbon dioxide in the carbon capture product to adjust the pH value of the carbon capture product discharged to the ocean.

[0067] In another variation on this embodiment, the method further includes discharging the carbon capture products into a current in the ocean's water column that does not pass through where the wash water is pumped.

[0068] In the following variations on this embodiment, the method further includes discharging the products of the carbon capture into the surface and / or intermediate and / or deep layers of the ocean water column.

[0069] Example 2 This is another basic embodiment of the marine carbon capture and storage method of the present invention. As shown in Figure 2, the gas containing carbon dioxide is flue gas discharged by burning fossil fuel, and the method includes the steps of: a. continuously introducing flue gas containing carbon dioxide discharged from a combustor for burning fossil fuel into a carbon capture device; b. continuously introducing seawater into the carbon capture device; c. providing a filler in the carbon capture device to increase the contact area between the flue gas in step a and the seawater in step b to enhance the absorption of carbon dioxide by the seawater; d. continuously discharging the scrubbed flue gas into the atmosphere; e. continuously discharging the seawater containing carbon dioxide generated in step c from the carbon capture device; and f. continuously discharging the seawater containing carbon dioxide generated in step e into a carbon storage location in the ocean water column for carbon storage. Here, the fossil fuel is selected from the group consisting of coal, oil, and gas. The combustor is selected from the group consisting of a steam turbine boiler, an internal combustion engine, and a gas turbine used in a coastal power plant or a marine vessel. The flue gas is generated by the combustion of fossil fuels. The seawater in step b is seawater pumped from the ocean and used directly for washing and / or seawater pumped from the ocean to first cool the combustor before being used for washing.

[0070] Example 3 This is an example based on Example 2 above. As shown in Figure 2, at least 10% of the carbon dioxide in the flue gas in step a is removed compared to the scrubbed flue gas in step d.

[0071] In a variation on this embodiment, at least 20% of the carbon dioxide in the flue gas in step a is removed compared to the scrubbed flue gas in step d.

[0072] In further variations on this embodiment, at least 30%, or at least 40%, or at least 50%, or at least 60%, or at least 70%, or at least 80%, or at least 90% of the carbon dioxide in the flue gas in step a is removed compared to the scrubbed flue gas in step d.

[0073] Example 4 This is an embodiment based on embodiment 2. The difference between the reduced pH value of the seawater containing carbon dioxide continuously discharged in step e and the pH value of the seawater at the discharge location is less than 2 pH units. This pH value is achieved by configuring the amount of flue gas introduced into the carbon capture device, the amount of washing seawater, and the gas-liquid ratio. The purpose is to comply with the relevant regulations and technical standards regarding ocean discharge.

[0074] Example 5 This is a basic example of an ocean recovery and storage facility for carrying out the method of the present invention. As shown in FIG. A combustor 1 that generates smoke by burning a fossil fuel; a carbon capture unit 2 connected to the combustor for scrubbing the flue gas and capturing carbon dioxide; a seawater pumping device 3 for introducing seawater into the carbon capture device 2; a chimney 6 for delivering the cleaned flue gas out of the carbon capture device 2; Seawater discharge pipe 7 and The carbon recovery device 2 includes a water supply device 2.1. The carbon recovery device 2 is equipped with a packed bed. The seawater outlet 5 of the carbon capture device 2 is connected to an exhaust pipe 7, and the outlet of the exhaust pipe 7 is disposed in the ocean water column.

[0075] Example 6 This is an example based on Example 5. The carbon capture device 2 includes a water supply device 2.1. The water supply device has an altitude 2.2 of 20 m or less. The altitude 2.2 of the water supply device is determined by the distance between the horizontal centerline of the water supply device 2.1 and the sea surface 3.2 where the washing seawater is pumped by the seawater pumping device 3.

[0076] In further variations based on this embodiment, the height 2.2 of the water supply device is 19m or less, 15m or less, 12m or less, 10m or less, 9m or less, 8m or less, 6m or less, 5m or less, 4m or less, 2m or less, 1m or less.

[0077] The purpose of lowering the altitude 2.2 of the water supply system is to reduce the energy consumption in seawater supply, which is the major energy consumption of the CCS technology in the present invention.

[0078] The carbon recovery device 2 is equipped with a packed bed. The packed bed is made of industrial bulk packing, and the packing has a dry packing factor of 5 / m.

[0079] In one variation based on this embodiment, the packing has a dry packing factor of 30 / m.

[0080] In some other variations on this embodiment, the packing has a dry packing factor of 60 / m, 120 / m, 200 / m, 300 / m, 400 / m, 500 / m, 600 / m, 700 / m, 800 / m, 900 / m, 1000 / m, 1200 / m, 1400 / m, 1600 / m, 1800 / m, or 2000 / m, respectively.

[0081] In a variation on this embodiment, the packed bed consists of standard packing. In another variation on this embodiment, the packed bed consists of a packing of perforated plates.

[0082] In variations on this embodiment, the packed bed may comprise a combination of different packing materials.

[0083] Example 7 This is an embodiment based on Example 5. As shown in FIG. 4, a seawater pumping device 3 connected to a carbon capture device 2 is a seawater cooling system for a combustor 1.

[0084] In a variant based on this embodiment, the seawater pumping device 3 is a seawater booster pump 3.1.

[0085] In another variation based on this embodiment, the seawater pumping arrangement 3 is a seawater cooling system and a seawater booster pump 3.1 for the combustor 1. The purpose of such an arrangement is to provide a larger amount of water to reduce carbon dioxide emissions.

[0086] Example 8 This is an example of a coastal gas-steam combined cycle power plant. As shown in Figure 3, there are three sets of gas-steam combined cycle generating units in the power plant. The power of each generating unit is 400MW, and the total power is 1200MW. In this example, there are two implementation stages.

[0087] In the first phase of implementation, carbon dioxide will be captured in the flue gas from one power generation unit. At least 90% of the carbon dioxide in the flue gas will be dissolved and captured in seawater washes and emitted into the ocean water column. Around one million tonnes of carbon dioxide will be captured and stored per year.

[0088] A high-concentration carbon capture and storage project has been carried out at this power plant before. In this project, carbon dioxide in the flue gas of one power generation unit is captured. Approximately one million tons of carbon dioxide per year is captured and stored. The project method includes the steps of carbon dioxide absorption, desorption, purification, compression and transportation. The captured high-concentration carbon dioxide is injected into an offshore oil field for enhanced oil recovery (EOR). A special platform is provided in the ocean. This project belongs to the geological storage on the seabed. After the project is completed, enhanced oil recovery can bring a certain income and the total cost of the project is lower than that of other non-EOR CCS, but the total cost is still not affordable. Therefore, the project was finally terminated.

[0089] The carbon capture device of this embodiment is installed in the vacant space reserved for the previous CCS project. The area required by the carbon capture device is only one-fifth of the area of ​​the previous space. The altitude of the water supply device of the carbon capture device is about 10m. The existing seawater cooling system is directly used as the seawater introduction equipment. The existing inlet and outlet for cooling water at the power plant are also directly used, and the depth of the outlet in the water column is more than 150m. In the coastal power plant, for cooling efficiency, the cooling water outlet is originally located in the ocean water column where the ocean current does not pass through the cooling water inlet. In this case, after the captured carbon dioxide is discharged by washing, the carbon dioxide is rapidly diffused and diluted by the ocean current, which further reduces the originally small impact on the marine environment. The energy consumption for capturing carbon dioxide is less than 100MJ / t, and the cost for manufacturing and operating the CCS device is 1 / 10 of the original cost of the high-concentration project.

[0090] The second phase of implementation will build on the first phase of implementation by adding more carbon capture devices and seawater pumps to capture seawater wash carbon and store carbon in the ocean water column for the other two power units. After the second phase of implementation is completed, approximately 3 million tonnes of carbon dioxide at the plant will be captured and stored.

[0091] In one variation on this embodiment, the carbon capture device is mounted on a platform with an adjustable height depending on the tides. In another variation on this embodiment, the carbon capture device is mounted on a floating dock. Thus, energy consumption for pumping seawater can be minimized regardless of the tides.

[0092] Example 9 This is an example of a coastal coal power plant. The combustor is a 600 MW coal fired power unit, as shown in Figure 4. There are two implementation phases in this example.

[0093] In the first phase of implementation, at least 25% of the carbon dioxide in the flue gas from the power generation units will be dissolved and captured in seawater scrubbing. 70,000 tonnes / hour of cooling water from the power plant will be used directly as seawater scrubbing. Approximately 800,000 tonnes of carbon dioxide will be captured and stored per year.

[0094] In the second phase of implementation, about 95% of the carbon dioxide in the flue gas from the power generation units will be dissolved and captured in the wash seawater. An additional 210,000 tonnes / hour of wash seawater will be added, which will be supplied by an additional seawater introduction pump. After the second phase of implementation is completed, about 3 million tonnes of carbon dioxide will be captured and stored for the power generation units.

[0095] A packed tower is used in the carbon capture unit to reduce the altitude, and the altitude of the water supply unit is about 9 m. To perform marine carbon storage, a mesh organic membrane water pipe is used to discharge seawater into the mid-layer of the ocean water column at a depth of about 300 m.

[0096] In this embodiment, the CO2 emissions in the power plant flue gas are reduced by 80%. The energy consumption for carbon dioxide capture is less than 200MJ / t.

[0097] Example 10 This embodiment is shown in Figure 4. The seawater conditioning pump 4 is connected to a water regulator to adjust the pH value of the cleaning seawater discharged into the ocean. This is a better way to control the pH value of the discharged seawater and the energy consumption is minimal.

[0098] The washed water, containing carbon dioxide, is discharged into the midzone, an 800m deep layer of the ocean's water column, between the surface and the seafloor.

[0099] In a variation on this embodiment, the washed seawater containing carbon dioxide is pumped to a depth of 1500 m in the ocean water column. Research shows that if the carbon dioxide is pumped to a depth of more than 1000 meters in the ocean, it can be stored for more than 1000 years.

[0100] Example 11 This is an example of a marine vessel. As shown in FIG. 5, the combustor 1 includes a 130 MW two-stroke marine diesel engine. Heavy fuel oil with 3.5% v / v sulfur is used as fuel. The amount of CO2 generated is about 8100 Nm 3 / h. The carbon capture device is configured to replace the original silencer. The height of the water supply device is 6 m based on the fill water line. The amount of washing seawater for carbon capture and storage is about 5800 tonnes / h. The seawater booster pump 3.1 can be adjusted to control the pH value of the discharged seawater. In this embodiment, the CO2 emissions of the ship's flue gas are reduced by 50-70% (the specific values ​​are related to the quality and temperature of the seawater in which the ship sails) and the SO2 emissions are reduced by 98%. The effect is equivalent to the use of fuel with 0.5% sulfur. Thus, low-cost existing oil can still be used after 2020, when the sulfur limit in international shipping will be implemented by the United Nations. The energy consumption for carbon dioxide capture is less than 20 MJ / t. The cost of the whole method corresponds to 0.6% of the engine's fuel consumption at maximum power. The discharge of seawater complies with the MEPC regulations of MARPOL Annex VI. The washed seawater is discharged into the surface layer of the ocean's water column.

[0101] In this embodiment, the pH value of the inlet and outlet seawater is detected and controlled in compliance with MEPC regulations of MARPOL Annex VI. The engine exhaust gases are washed with seawater on board the ship at sea, without adding any chemicals. The difference in pH value between the discharged washing seawater and the inlet seawater is less than 2 pH units. Therefore, the washing seawater can be discharged directly into the ocean, i.e. into the surface layer of the ocean water column.

[0102] In a variation of this embodiment in the construction of a new ship, the ship's fuel is LNG, which, although producing less carbon emissions than those from coal and oil, is still a type of fossil energy whose carbon emissions need to be reduced and controlled.

[0103] Example 12 This is an example of an offshore carbon direct air capture (DAC) and storage installation. As shown in Figure 6, the installation: A carbon capture device 2; a seawater pumping device 3 for introducing seawater into the carbon capture device 2; Seawater pump unit 3 power To supply power Facility 14; a water supply device 2.1 on top of the carbon capture device 2; a water collector 2.3 at the bottom of the carbon capture device 2; A drain pipe 7 connected to the water collector 2.3; Includes. The installation is fixed to a floating platform in the ocean, which is in turn fixed to the seabed.

[0104] In a variation on this embodiment, the installation is fixed on an offshore platform that is rigidly connected to the ocean floor. In another variation on this embodiment, the installation is fixed on a mobile offshore platform.

[0105] Example 13 This is an example based on Example 12. As shown in FIG. power Facility 14 is 14.2 water-driven device; a power transmission device 14.3 connected to the seawater pump device 3 for transmitting the power obtained by the water-driven device 14.2 to the seawater pump device 3; The power transmission device 14.3 is a mechanical transmission device.

[0106] In a variant of this embodiment, the drive train 14.3 is an electromechanical transmission consisting of a hydro-generator and an electric motor.

[0107] Example 14 This is another embodiment based on the embodiment 12. As shown in FIG. power Facility 14 is 14.1 A wind-driven device; a power transmission device 14.3 connected to the seawater pump device 3 for transmitting the power obtained by the wind-driven device 14.1 to the seawater pump device 3; The power transmission device 14.3 is a mechanical transmission device.

[0108] In this embodiment, a drain pipe 7 is connected to the water collector 2.3 under the carbon capture device 2. The outlet of this drain pipe 7 is placed in the water column of the ocean to discharge the cleaning seawater containing carbon dioxide into the ocean. A vertical axis rotor is used in the wind-driven device. Alternatively, a horizontal axis rotor can be used. The wind-driven device converts the obtained wind energy into rotational mechanical energy to directly drive the seawater pumping device to pump the seawater. The effect of cleaning and capturing the carbon dioxide is better if the seawater of a deeper layer of the ocean is pumped up. If the water level in the water collector under the carbon capture device sends the cleaning seawater to a deeper ocean layer, the effect of carbon sequestration is better. The power transmission device 14.3 has a mechanical speed adjustment function. The carbon capture device 2 is designed to open vertically to help catch the wind. A filling consisting of a lattice plate and a lattice is provided to increase the cleaning efficiency.

[0109] In a variation of this embodiment, a hollow spray tower is used as the carbon capture device. In another variation of this embodiment, a conventional scrubbing tower is used as the carbon capture device. In another variation of this embodiment, the scrubbing seawater is sprayed directly onto the sea surface rather than being collected by a collector.

[0110] In another variation on this embodiment, a blower is used to blow air through the carbon capture device, the power for the blower also being provided by a wind driven device.

[0111] The equipment of the above embodiment is a kind of carbon-reducing wind turbine equipment. The manufacturing and maintenance costs of the equipment are much lower than those of a wind turbine with the same rotor diameter. The effect of reducing the carbon content in the atmosphere of the equipment is many times that of a wind turbine because multi-stage energy conversion is not required.

[0112] Example 15 This is another example based on Example 12. power Facility 14 is 14.1 A wind-driven device; 14.3 Power transmission device and where the drive train 14.3 is an electromechanical transmission consisting of a wind-driven generator and an electric motor. power As the installation 14, an offshore wind turbine is directly used.

[0113] In a modification based on this embodiment, power A solar power generation facility is directly used as the facility 14 .

[0114] The scope of protection of the claims of the present invention is not limited to the above embodiments. [Explanation of symbols]

[0115] 1 Combustor 2 Carbon capture equipment 2.1 Water supply equipment 2.2 Altitude of water supply system 2.3 Water collector 3 Seawater pumping equipment 3.1 Seawater booster pump 3.2 Sea level 4 Seawater adjustment pump 5 Seawater outlet 6. Chimney 7 Seawater discharge pipe 8 Water regulator 9. Sea Chest 10. Ship's main seawater duct 11 Rooms 12 Coast 13 Ocean Currents 14 power equipment 14.1 Wind-powered devices 14.2 Water-powered devices 14.3 Power Transmission 15. Wind

Claims

1. 1. A method for seawater carbon capture and storage, the method comprising: 1) a carbon recovery step including pumping seawater, introducing the seawater into a carbon recovery device (2), scrubbing a gas containing carbon dioxide with the seawater pumped by the pump, and providing scrubbed seawater as a carbon recovery product that absorbs the carbon dioxide from the gas, and adjusting the ratio of the volume of seawater to the volume of carbon dioxide in the carbon recovery product in order to adjust the pH value of the carbon recovery product discharged into the ocean; 2) a carbon storage step including discharging the product of the carbon capture into the ocean water column for ocean storage; wherein the product of the carbon capture is discharged under atmospheric pressure through a pipe into the ocean water column.

2. 2. The method according to claim 1, wherein the carbon dioxide containing gas in step 1) is atmospheric air and the seawater for washing is pumped using wind and / or ocean current power and / or solar power.

3. 2. The method of claim 1, wherein the carbon dioxide containing gas is flue gas emitted by the combustion of fossil fuels.

4. 4. The method of claim 3, further comprising absorbing at least 10%, or at least 20%, or at least 50%, or at least 70%, or at least 80%, or at least 90% of the carbon dioxide in the flue gas into washing seawater which is then discharged into the ocean water column, wherein a volume of the washing seawater is configured to be sufficient to absorb at least 10%, or at least 20%, or at least 50%, or at least 70%, or at least 80%, or at least 90% of the carbon dioxide in the flue gas.

5. The method of claim 1, further comprising the step of pumping the seawater to a head of 50m or less, or 40m or less, or 30m or less, or 20m or less, or 19m or less, or 15m or less, or 12m or less, or 10m or less, or 9m or less, or 8m or less, or 6m or less, or 5m or less, or 4m or less, or 2m or less, or 1m or less to scrub flue gas containing carbon dioxide, wherein a head of 0m is the sea level at the location where the scrubbing seawater is pumped.

6. 4. A seawater carbon capture and storage facility for carrying out the method of claim 3, comprising: a combustor (1) for generating said flue gas by burning said fossil fuel; a carbon capture unit (2) connected to the combustor for scrubbing the flue gas and capturing carbon dioxide; a seawater pumping device (3) for introducing seawater into the carbon capture device (2); a chimney (6) for delivering the cleaned flue gas out of the carbon recovery device (2); A seawater discharge pipe (7); a seawater adjustment pump (4) connected to a water regulator (8) for adjusting the pH value of the seawater after cleaning that is discharged into the ocean; the carbon capture device (2) comprises a water supply device (2.1) and a packed bed, a seawater outlet (5) of the carbon capture device (2) is connected to the seawater discharge pipe (7), and an outlet of the seawater discharge pipe (7) is disposed in the ocean water column.

7. 7. An installation according to claim 6, wherein the packed bed of the carbon recovery unit (2) consists of industrial bulk packing, and / or conventional packing, and / or packing of perforated plates, and / or grids.

8. 3. A seawater carbon capture and storage facility for carrying out the method of claim 2, comprising: A carbon capture device (2); a seawater pumping device (3) for introducing seawater into the carbon capture device (2); a power plant (14) for supplying power to the seawater pump device (3); a water supply device (2.1) located above the carbon recovery device (2); a water collector (2.3) located at the bottom of the carbon recovery device (2); a seawater discharge pipe (7) connected to said water collector (2.3); a seawater adjustment pump (4) connected to a water regulator (8) for adjusting the pH value of the seawater after cleaning that is discharged into the ocean; Facilities including.

9. The power equipment (14) includes: A wind-driven device (14.1), a power transmission device (14.3) connected to the seawater pump device (3) for transmitting the power obtained by the wind-driven device (14.1) to the seawater pump device (3); 9. The installation according to claim 8, comprising: a power transmission (14.3) comprising a mechanical transmission and / or an electromechanical transmission consisting of a wind generator and an electric motor.

10. The power equipment (14) includes: A water-driven device (14.2), a power transmission device (14.3) connected to the seawater pump device (3) for transmitting the power obtained by the water-driven device (14.2) to the seawater pump device (3); 9. The installation according to claim 8, comprising: a power transmission device (14.3) comprising a mechanical transmission device and / or an electromechanical transmission device consisting of a hydro-generator and an electric motor.

11. A power plant comprising a seawater carbon capture and storage facility according to claim 6 or 7.

12. A marine vessel comprising a seawater carbon capture and storage installation according to claim 6 or 7.

13. A system for atmospheric carbon capture and storage, comprising equipment for seawater carbon capture and storage as described in any one of claims 8 to 10.

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