Seawater type air direct carbon capture and storage method and device

Abstract

The invention relates to a seawater type air direct carbon capture and storage method and device (Ocean DACCS). According to the scheme, direct carbon capture and ocean storage are carried out on air only through natural seawater, and natural energy sources such as wind energy, light energy and wave energy are used for driving; a low-cost large-scale clean negative emission climate retarding solution with zero carbon footprint, zero artificial chemical footprint and zero land physical footprint is formed.

Description

[0001] The original application of this divisional invention application (hereinafter referred to as the present invention) is: application number 201710426783.3, application date 2017.06.08, priority data 201610408323.3 2016.06.11CN and 201710137942.82017.03.09CN; the original application invention name is "Seawater Carbon Capture and Storage Method and Device", which is used for capturing and storing carbon dioxide emitted by fossil energy marine facilities such as coastal power plants and marine ships and / or contained in the atmosphere, and belongs to the field of clean energy and marine engineering technology. Technical Field

[0002] The seawater direct air carbon capture and storage method and device (Ocean DACCS) of the present invention is used to capture and store carbon dioxide contained in the atmosphere, and belongs to the field of climate mitigation carbon negative emission technology and marine engineering technology. Background Art

[0003] In the past 30 years of international climate mitigation action, the capture and storage of CO2 from fossil fuel flue gas, namely the CCS (Carbon Capture and Storage) solution, has been regarded as a key pillar of climate mitigation, but it has always faced challenges in cost and scale and has failed to play a role. In the past 10 years, the direct capture and storage of CO2 in the air, namely DACCS (Direct Air Carbon Capture and Storage), also known as the negative emissions (NET) technology solution, has been unprecedentedly expected to be the key and core technology for achieving climate goals, and even the ultimate technical means.

[0004] However, the existing DACCS technology routes are mainly biological and chemical, and their cost and scale challenges are far more serious than CCS. For example, the biological DACCS technology solution uses carbon sinks in coastal and marine biological systems (mangroves, seaweed, etc.), but its overall available scale is far smaller than the necessary scale for climate mitigation, so it cannot become an important technology for climate mitigation; another type of chemical DAC (Direct Air Carbon Capture) solution, its material and energy consumption includes: air contactor energy consumption, strong alkaline chemical absorption, sub-strong alkaline chemical replacement, two sets of chemical regeneration systems, and a high-power oxygen production plant for the regeneration system, and a thermal power plant specially built to provide heat and electricity for the entire DAC system. Some studies have estimated that the full deployment of this type of DAC process will consume more than half of the world's existing electricity generation.

[0005] Therefore, the American Physical Society (APS) research report "Direct Air Capture of CO2 with Chemicals 2011" believes that the existing chemical DAC technology route is not economically viable for climate mitigation, and its technological improvements are not sufficient to reduce costs to a feasible level; unless a new technology route with fundamental changes is introduced. Summary of the invention

[0006] The purpose of the present invention is to overcome the fundamental defects of existing negative emission technologies, namely, unaffordable costs and lack of the necessary scale for climate mitigation, and to provide a net negative emission technology solution that is cost-effective and has the scale for climate mitigation.

[0007] The first aspect of the present invention is to provide a seawater carbon capture and storage method, the method comprising the following steps:

[0008] 1) Carbon capture: extracting seawater to wash the gas containing carbon dioxide, and generating washed seawater containing carbon dioxide dissolved in the gas as a carbon capture product;

[0009] 2) Carbon sequestration: injecting the carbon capture integrated product into the sea water to store seawater carbon.

[0010] The further technical solution is:

[0011] The carbon capture integrated product described in step 2) is injected into the ocean water body by using a normal pressure pipeline.

[0012] The amount of seawater and the amount of carbon dioxide in the carbon capture product are proportionally controlled to control the pH value of the carbon capture product when it is injected into the sea.

[0013] The carbon dioxide-containing gas in step 1) refers to the atmosphere; the seawater washing is to use wind, and / or ocean currents and waves, and / or sunlight to provide power to extract seawater for washing.

[0014] The gas containing carbon dioxide is waste gas emitted from the combustion of fossil fuels.

[0015] At least 10%, or 20%, or 50%, or 70%, or 80%, or 90% of the carbon dioxide in the exhaust gas is dissolved in washed seawater and then injected into the sea water. The amount of washed seawater is configured to be sufficient to absorb at least 10%, or 20%, or 50%, or 70%, or 80%, or 90% of the carbon dioxide in the exhaust gas.

[0016] The extracted seawater is lifted to an altitude not more than 50m, or 40m, or 30m, or 20m, or 19m, or 15m, or 12m, or 10m, or 9m, or 8m, or 6m, or 5m, or 4m, or 2m, or 1m to wash the exhaust gas containing carbon dioxide, and the zero meter (0m) reference of the altitude is the sea level where the seawater is extracted.

[0017] Provide fillers, and wash the fillers and control the lifting height of the washed seawater so that the energy consumption for capturing carbon dioxide is no more than 1000MJ / t, or 500MJ / t, or 400MJ / t, or 350MJ / t, or 300MJ / t, or 250MJ / t, or 200MJ / t, or 150MJ / t, or 100MJ / t, or 60MJ / t, or 50MJ / t, or 40MJ / t, or 30MJ / t, or 20MJ / t, or 10MJ / t, or 5MJ / t.

[0018] The carbon capture to the carbon sequestration is a continuous reaction process.

[0019] The carbon capture products are injected into the ocean water, that is, injected into the surface layer, and / or the middle layer, and / or the deep layer of the ocean.

[0020] The carbon capture integrated product is injected into the sea water body by injecting the washed sea water into the ocean current, which does not pass through the ocean current where the sea water is extracted.

[0021] The packing washing is to make the washing seawater and the discharged waste gas contact with each other over a large area through the packing to wash;

[0022] The second aspect of the present invention is to provide a seawater carbon capture and storage method, the steps comprising:

[0023] a. continuously introduce the exhaust gas containing carbon dioxide generated by the combustion of the fossil fuel burner into the carbon capture device;

[0024] b. Continuously introduce seawater into the carbon capture device;

[0025] c. In the carbon collector, the contact area between the exhaust gas introduced in step a and the seawater introduced in step b is increased by fillers to wash and dissolve the carbon dioxide in the exhaust gas;

[0026] d. Continuously discharge the purified waste gas with reduced carbon dioxide gas after seawater washing into the atmosphere;

[0027] e. The seawater containing the exhaust carbon dioxide in step c is continuously output from the carbon capture device;

[0028] f. continuously discharging the seawater containing waste gas carbon dioxide continuously outputted in step e into the ocean carbon sequestration area to achieve ocean carbon sequestration;

[0029] The fossil fuels include coal, oil, and natural gas; the burners are burners used in coastal thermal power plants or marine vessels; the burners include boilers and steam turbines, internal combustion engines, and gas turbines; the exhaust gas is flue gas generated by the combustion of fossil fuels; the seawater in step b is seawater directly extracted from the ocean, or / and seawater directly extracted from the ocean and reused after being used for burner cooling.

[0030] The further technical solution is:

[0031] In the seawater carbon capture and storage method, the mass of carbon dioxide gas in the waste gas purified in step d is reduced by at least 10%, or 20%, or 50%, or 70%, or 80%, or 90% of the mass of carbon dioxide gas in the waste gas in step a.

[0032] In the seawater carbon capture and storage method, the mass of carbon dioxide gas in the waste gas purified in step d is reduced by at least 20% of the mass of carbon dioxide gas in the waste gas in step a.

[0033] In the seawater carbon capture and storage method, the temperature of the seawater containing waste gas carbon dioxide continuously output in step e is less than 50° C. higher than the temperature of the seawater introduced into the carbon capture device in step b.

[0034] In the seawater carbon capture and storage method, the temperature of the seawater containing waste gas carbon dioxide continuously output in step e is less than 20° C. higher than the temperature of the seawater introduced into the carbon capture device in step b.

[0035] In the seawater carbon capture and storage method, the temperature of the seawater containing waste gas carbon dioxide continuously output in step e is less than 2°C higher than the temperature of the seawater introduced into the carbon capture device in step b.

[0036] In the seawater carbon capture and storage method, the pH value of the seawater containing waste gas carbon dioxide continuously output in step e is no lower than the background pH value of the seawater in the carbon storage area by no more than 2 pH units.

[0037] The third aspect of the present invention is to provide a seawater carbon capture and storage device for the method of the present invention, which includes a burner that generates fossil fuel combustion exhaust gas, and a carbon capturer connected to the burner for washing the exhaust gas to capture carbon dioxide, seawater extraction equipment for introducing seawater into the carbon capturer, and an exhaust pipe for outputting purified exhaust gas from the carbon capturer, as well as a seawater drain pipe; the carbon capturer has a filler layer inside and includes a water distributor, the seawater output port of the carbon capturer is connected to the seawater drain pipe, and the outlet of the seawater drain pipe is connected to the ocean water body.

[0038] The further technical solution is:

[0039] The seawater carbon capture and storage device has a water distributor height of less than or equal to 50m, or 40m, or 30m, or 20m, or 19m, or 15m, or 12m, or 10m, or 9m, or 8m, or 6m, or 5m, or 4m, or 2m, or 1m; the water distributor height is the height of the horizontal center line of the water distributor relative to the sea level at the water intake point of the seawater extraction equipment.

[0040] The seawater carbon capture and storage device described herein has a seawater extraction device which is a seawater cooling system of the burner and / or a seawater extraction pump.

[0041] The seawater carbon capture and storage device has a seawater control pump connected to a regulator for controlling the pH value of the washed seawater when it is injected into the sea.

[0042] The filler layer in the carbon collector of the seawater carbon capture and storage device is composed of industrial bulk fillers, and / or structured fillers, and / or perforated plate fillers, and / or grids.

[0043] The dry packing factor of the filler is 5-2000 / m, and the definition of the dry packing factor is determined according to the conventional filler industry product manual.

[0044] The seawater type carbon capture and storage device has a seawater discharge pipe which is a membrane water pipe.

[0045] The carbon capture device is installed on an ocean platform whose height can be adjusted according to the tide level.

[0046] The fourth aspect of the present invention is to provide a seawater carbon capture and storage device for use in the method of the present invention, which includes a carbon capturer, a seawater extraction device for transporting seawater to the carbon capturer, a power device for providing power to the seawater extraction device, a water distributor located above the carbon capturer, a water collector below the carbon capturer, and a seawater drainage pipe connected to the water collector.

[0047] The further technical solution is:

[0048] The power equipment includes wind power equipment, and / or ocean current wave energy conversion equipment, and / or solar power generation equipment.

[0049] The power equipment includes a pneumatic device and a power connection device. The power connection device is connected to the seawater extraction equipment to transfer the kinetic energy generated by the pneumatic device to the seawater extraction equipment. The power connection device is a mechanical connection device and / or an electromechanical connection device composed of a wind turbine and an electric motor.

[0050] The power equipment includes a hydraulic device and a power connection device. The power connection device is connected to the seawater extraction equipment to transfer the kinetic energy generated by the hydraulic device to the seawater extraction equipment. The power connection device is a mechanical connection device and / or an electromechanical connection device composed of a hydraulic generator and an electric motor.

[0051] The above two devices used in the method of the present invention are fixed on the seabed and / or the marine platform.

[0052] Technical principles and effects of the present invention:

[0053] The present invention utilizes the principle that carbon dioxide is a natural substance that is soluble in seawater and exists in large quantities in seawater, and can be stored in the ocean in a friendly manner for a long time and in large quantities. Seawater is used to wash fossil fuel waste gas, or directly wash the collected atmosphere, that is, the air in its natural state, to dissolve the carbon dioxide in the waste gas and / or the atmosphere for carbon capture, and then the seawater containing the carbon dioxide in the waste gas and / or the atmosphere is injected into the surface layer, and / or the middle layer, and / or the deep water body of the ocean under the condition of controlling the pH value and other indicators to comply with environmental regulations, to implement marine carbon sequestration; the use of ocean current diffusion can further reduce the impact on the marine environment and enhance the sequestration effect. The depth of injection into the ocean water body can be the surface layer, the middle layer or the deep layer. Some studies have shown that CO2 injected into the ocean 1000m deep can be sealed for 1000 years.

[0054] CO2 dissolves in seawater and reacts from left to right according to the following equilibrium equation:

[0055]

[0056] Among them, bicarbonate ions are the main form of carbon dioxide in seawater, and together with carbonic acid and carbonate ions, they are collectively referred to as dissolved inorganic carbon (DIC).

[0057] Generally, the solubility of carbon dioxide in water is very low, so seawater washing produces washed seawater containing low concentration of CO2, that is, low concentration of DIC. The low concentration is relative to the prior art: the carbon capture products of the prior art are pure carbon dioxide liquid, dense phase gas or solid, and the carbon content per unit volume of the medium is several orders of magnitude higher than that of the present invention. People may think that low concentrations require a larger amount of seawater for washing, which will result in a huge total energy consumption. However, the present invention uses methods such as controlling the seawater lifting height to control the total energy consumption, which can reduce the cost of capturing and storing carbon dioxide by at least one order of magnitude compared to the existing CCS scheme. The reuse of cooling wastewater from coastal thermal power plants can further reduce costs.

[0058] At the same time, since sulfur dioxide is also a natural substance that is soluble in seawater and exists in large quantities in seawater, and the sulfur dioxide content in flue gas is less than that of carbon dioxide and is more soluble in water, the present invention has the technical effect of flue gas desulfurization.

[0059] Obviously, coastal areas often have densely populated large-scale carbon emission sources and prominent economies of scale. The application of the present invention is conducive to achieving commercial-scale carbon capture and storage.

[0060] The application of this invention in the marine shipping industry can produce dual technical effects: first, it can utilize the carbon sink resources in the ocean surface to achieve carbon capture and storage of fugitive carbon emissions that could not be captured before, thereby reducing carbon emissions from ships at an ultra-low cost; second, it can avoid switching to low-sulfur fuel, indirectly reducing carbon emissions from the oil refining industry. Therefore, the shipping industry can effectively resolve the dual pressures of international carbon reduction and sulfur reduction laws and continue to maintain the dual advantages of economy and greenness.

[0061] The application of the present invention to capture and store carbon in the air in its natural state is also of special significance. First, it is equivalent to utilizing the atmospheric circulation to transport and capture various types of carbon emissions at no cost, including fugitive carbon emissions that cannot be captured by other means. Second, it utilizes renewable energy sources such as wind, ocean currents, and sunlight for zero-energy carbon capture and storage. Third, it is not limited to sea areas and does not require surrounding support. It can be installed in large quantities in various sea areas.

[0062] Obviously, the present invention has achieved good technical results based on the principles of geoengineering and the use of natural engineering methods, adding an affordable and feasible effective technical solution to realize people's long-term desire to use marine resources to cope with climate change. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 It is a schematic diagram of the implementation steps of the seawater carbon capture and storage method of the present invention.

[0064] Figure 2 It is another schematic diagram of the implementation steps of the seawater carbon capture and storage method of the present invention.

[0065] Figure 3 It is a schematic diagram of an embodiment of the present invention applied to a coastal gas-steam combined cycle power plant.

[0066] Figure 4 It is a schematic diagram of another embodiment of the present invention used in a coastal coal-fired power plant.

[0067] Figure 5 It is a schematic diagram of an embodiment of the present invention applied to marine vessels.

[0068] Figure 6 It is a schematic diagram of an embodiment of the hydraulic offshore atmospheric carbon capture and storage of the present invention.

[0069] Figure 7It is a schematic diagram of an embodiment of the wind power offshore atmospheric carbon capture and storage according to the present invention.

[0070] The names of the objects marked with figure numbers in the accompanying drawings are:

[0071] 1—burner, 2—carbon collector, 2.1—water distributor, 2.2—height of water distributor, 2.3—water collector, 3—seawater extraction equipment, 3.1—seawater increment pump, 3.2—sea level, 4—seawater regulating pump, 5—wash seawater output port, 6—exhaust pipe, 7—drain pipe, 8—regulator, 9—ship’s seabed door, 10—ship’s seawater main, 11—cabin, 12—coast, 13—ocean current, 14—power equipment, 14.1—pneumatic device, 14.2—hydraulic device, 14.3—power connection device, 15—wind. DETAILED DESCRIPTION

[0072] The present invention provides a seawater carbon capture and storage method, comprising the following steps:

[0073] 1) Carbon capture: extracting seawater to wash the gas containing carbon dioxide, and generating washed seawater containing carbon dioxide dissolved in the gas as a carbon capture product;

[0074] 2) Carbon sequestration: injecting the carbon capture integrated product into the sea water to store seawater carbon.

[0075] The seawater mentioned here refers to natural seawater extracted from the ocean, including natural seawater extracted from the ocean for cooling industrial facilities. In the present invention, the seawater can achieve the purpose of the present invention without adding any other substances (e.g., adding alkali). Of course, in some applications, some other additives can also be added to achieve specific purposes, for example, in order to absorb a certain specific component in the exhaust gas.

[0076] The scrubbing mentioned here refers to the capture of carbon dioxide by contacting seawater with a gas containing carbon dioxide. The contacting methods include, but are not limited to, reactors such as jet injectors, bubblers, venturi towers, sprinklers, filters, rotary atomizers, grid towers, perforated plate towers or packed towers.

[0077] Carbon capture here means that the scrubbing process captures CO2 in the gas containing carbon dioxide. This is because part of the CO2 in the scrubbing process dissolves into the scrubbing seawater and becomes dissolved inorganic carbon (DIC) in the scrubbing seawater.

[0078] Carbon sequestration here means that washed seawater containing CO2 dissolved in exhaust gas is directly injected into the ocean water using normal pressure pipelines. The dissolved CO2 is not concentrated before injection, but it can be further diluted if necessary by adding additional seawater to control the pH value of the discharge water to the range required by environmental regulations, because different sea areas, including sea areas at different depths, may have different requirements for specific environmental indicators such as the pH value of the discharge water.

[0079] The ocean water mentioned here refers to the ocean surface (tens of meters deep), middle layer (hundreds of meters deep) or deep layer (hundreds of meters deep). International research organized by IPCC and IEA shows that the physical and chemical systems of the ocean water itself, as well as the marine ecosystem within it, can absorb and store carbon dioxide in a friendly manner.

[0080] Utilizing the diffusion of flowing ocean water, i.e. ocean currents, can make marine carbon sequestration more effective, especially by discharging carbon capture products into ocean currents in sea water that do not pass through water intakes, thus avoiding the backflow of drainage to water intakes.

[0081] It is common knowledge that CO2 is soluble in water and the ocean can absorb a lot of CO2. However, there is still a lack of technical solutions for using seawater to capture and store carbon. This is because technicians in this field have always been accustomed to believing that only by purifying the captured CO2 into a high-concentration method of liquid, dense gas or solid to reduce the volume of materials in the transportation and storage links can the cost be affordable; since the cost of the high-concentration method is far from being reduced to an affordable level, any low-concentration solution is even more unimaginable.

[0082] However, during their long-term research on seawater washing and desulfurization, the inventors of this application unexpectedly discovered that the low-concentration method of seawater washing can not only desulfurize, but also achieve carbon capture and storage, and they have found a way to significantly reduce costs to an affordable and practical level.

[0083] The inventor of the present application first discovered that in the existing seawater scrubbing and desulfurization processes (FGD, EGC), usually less than 10% of the carbon dioxide in the exhaust gas is dissolved into the scrubbing seawater, but then is driven into the atmosphere during the aeration of the wastewater. Therefore, the inventor of the present application conducted many years of experiments on a coastal thermal power plant FGD and an ocean tanker EGC embodiment and confirmed that the appropriate seawater scrubbing and desulfurization process design can make the scrubbing wastewater expel less or even no carbon dioxide without affecting environmental protection regulations.

[0084] The inventor of the present application has found through further embodiments that increasing the amount of scrubbing seawater can capture and seal more than 10% of the carbon dioxide in the exhaust gas, and further taking process measures to control the seawater lifting height can control the increased energy consumption and cost of increasing the amount of scrubbing seawater. In this way, in various applications, such as power plants and ship embodiments, the increased cost of capturing and sealing at least 20% of the carbon dioxide in the exhaust gas is generally acceptable. If more carbon dioxide is to be removed and the cost is acceptable, the following embodiments are described in detail in several typical applications, and the goal of capturing and sealing no less than 30%, or 40%, or 50%, or 60%, or 70%, or 80%, or 90% of the carbon dioxide in the exhaust gas can be achieved; in the coastal thermal power plant embodiment, even if 99% of the CO2 in the exhaust gas is captured and sealed, the increased cost is acceptable.

[0085] The reason for increasing the amount of seawater for washing is that the amount of CO2 that can be dissolved in a certain amount of seawater is limited. Generally, at normal temperature and pressure, 1m 3 Fresh water can dissolve about 0.8m 3 The amount of CO2 gas that can be dissolved in seawater is slightly higher. To capture a large amount of CO2 from the exhaust gas, a large amount of washing seawater is needed. For example, in an embodiment of a power plant, using all the original cooling seawater to wash the flue gas can only achieve a carbon dioxide capture rate of about 30%. To increase the capture rate to more than 90%, the amount of washing seawater that needs to be increased is about twice the amount of the original cooling seawater. Generally speaking, this is a very large amount. To make the cost acceptable, two process measures need to be taken. One is to control the energy consumption of extracting seawater, and the other is to control the absorption efficiency of washing seawater for CO2 to minimize the amount of seawater. In order to control the energy consumption of extracting seawater, it is necessary to control the lifting height of the washing seawater, that is, to lift it to the height required by the carbon capturer. For an embodiment of a large power plant, the seawater required for the carbon capturer to be lifted to an altitude of 50m can meet the needs. Of course, in other embodiments, 40m or 30m can also meet the needs. In several typical applications, such as power plants and marine vessels, the following embodiments provide specific details, and the seawater lifting height required for the carbon capturer is no more than 20m, or 19m, or 15m, or 12m, or 10m, or 9m, or 8m, or 6m, or 5m, or 4m, or 2m, or 1m. In another embodiment, due to the large average tidal drop in the local sea area, the carbon capturer is set on a platform whose height can be adjusted with the tide level, or on a floating dock, and the principle of rising water lifts the boat can be used to keep the energy consumption of seawater lifting to the lowest level.

[0086] On the other hand, the inventors of the present application have also found through examples that among the many washing methods, using a packed scrubber or an absorption tower as a carbon capture device is more conducive to reducing the amount of seawater and reducing the height of the washing seawater lifting, so the energy consumption of extracting seawater is the least and the operation is the most stable. Based on the long-term experience in seawater washing and desulfurization, as well as the test for absorbing carbon dioxide, the inventors of the present application have also found that the dry packing factor of the packing used is preferably 5 to 2000 / m (the definition of the dry packing factor is given by the conventional packing industry product manual), which can make the seawater washing carbon capture effect better. For example, the embodiment with a dry packing factor of 5 / m can meet the requirements. In the following embodiments, the dry packing factor 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 can also meet the requirements. The packing washing is to wash by making the washing seawater contact with the discharged exhaust gas through a large area of ​​the packing.

[0087] Thus, the inventors of the present application have found that by adopting measures such as packing washing and controlling the lifting height of washing seawater, the energy consumption of carbon capture can be controlled, and the overall cost of CCS process can be reduced to a practical level. For example, in one embodiment, the energy consumption of carbon dioxide capture is controlled to no more than 1000MJ / t (megajoules / ton), which meets practical needs; in power plant and ship applications, the following embodiments further show that the energy consumption of carbon capture is controlled to no more than 500MJ / t, or 400MJ / t, or 350MJ / t, or 300MJ / t, or 250MJ / t, or 200MJ / t, or 150MJ / t, or 100MJ / t, or 60MJ / t, or 50MJ / t, or 40MJ / t, or 30MJ / t, or 20MJ / t, or 10MJ / t, or 5MJ / t, which can also meet practical needs.

[0088] The inventors of the present application further discovered that the present invention can be used to capture and store carbon in the air in a natural state at sea, and the effect of reducing the carbon content in the atmosphere is very good. The following embodiments only use mechanical energy and / or electrical energy converted from natural energy such as offshore wind power, and / or ocean currents and waves, and / or sunlight, that is, renewable energy, which is equal to zero energy consumption and has extremely low operating costs. Only the construction cost is depreciated, and since there is no need to generate electricity and transmit it to the shore and no surrounding support is required, its construction cost is also very low. On the other hand, the purpose of building a large number of offshore wind power and wave power is nothing more than to replace onshore fossil energy to ultimately reduce carbon emissions to the atmosphere. The present invention directly captures and stores carbon dioxide in the atmosphere, and has a higher carbon reduction effect.

[0089] The present invention is further described below with reference to the accompanying drawings and embodiments.

[0090] Example 1: This is a basic example of the seawater carbon capture and storage method of the present invention. Figure 1 As shown, the implementation steps include: 1) carbon capture: extracting seawater to wash the gas containing carbon dioxide, and generating washed seawater with carbon dioxide dissolved in the gas as a carbon capture product; 2) carbon sequestration: injecting the carbon capture product into the sea water to store seawater carbon.

[0091] A further embodiment is that the carbon capture integrated product in step 2) is injected into the ocean water body by using a normal pressure pipeline. The carbon capture to the carbon storage is a continuous reaction process.

[0092] Another embodiment is to control the ratio of the amount of seawater to the amount of carbon dioxide in the carbon capture product to control the pH value of the carbon capture product when it is injected into the sea.

[0093] Another embodiment is to discharge the carbon capture product into the sea water, that is, to inject the washed sea water into the ocean current, which does not pass through the ocean current where the sea water is extracted.

[0094] The carbon capture integrated products of the following embodiments are injected into the sea water, that is, injected into the surface layer, and / or the middle layer, and / or the deep layer of the sea.

[0095] Embodiment 2: is another basic embodiment of the seawater carbon capture and storage method of the present invention, as shown in the attached Figure 2 As shown, the gas containing carbon dioxide is the waste gas emitted by the combustion of fossil fuels, and the implementation steps include: a. continuously introducing the waste gas containing carbon dioxide generated by the combustion discharged from the burner into the carbon capture device; b. continuously introducing seawater into the carbon capture device; c. in the carbon capture device, the contact area between the waste gas introduced in step a and the seawater introduced in step b is increased by fillers so that the seawater can wash and dissolve the carbon dioxide in the waste gas; d. continuously discharging the purified waste gas with reduced carbon dioxide gas after washing with seawater into the atmosphere; e. discharging the seawater containing the waste gas carbon dioxide dissolved in step c from the carbon capture device; f. continuously outputting the seawater containing exhaust gas carbon dioxide continuously outputted in step e into the sea water body to realize ocean carbon sequestration; the fossil fuels include coal, oil and natural gas; the burners are burners used in coastal thermal power plants or marine vessels; the burners include boiler turbine devices, internal combustion engines, gas turbines and gas-steam combined power devices; the exhaust gas or flue gas is exhaust gas generated by the combustion of fossil fuels; the seawater in step b is seawater directly extracted from the ocean and / or seawater directly extracted from the ocean and reused after being used for burner cooling.

[0096] Embodiment 3: is an embodiment based on embodiment 2, as shown in the attached Figure 2The mass of carbon dioxide gas reduced in the waste gas purified in step d is at least 10% of the mass of carbon dioxide gas in the waste gas described in step a.

[0097] In another embodiment, the mass of carbon dioxide gas in the waste gas purified in step d is reduced by at least 20% of the mass of carbon dioxide gas in the waste gas in step a.

[0098] In the following embodiments, the mass of carbon dioxide gas in the waste gas purified in step d is reduced by at least 30%, 40%, 50%, 60%, 70%, 80%, and 90% of the mass of carbon dioxide gas in the waste gas described in step a.

[0099] Example 4: This is an example based on Example 2. The pH value of the seawater containing waste gas carbon dioxide continuously output in step e is no lower than the background pH value of the seawater in the injection area by no more than 2 pH units. This is controlled by designing the amount of waste gas, the amount of seawater introduced into the carbon capture device, and the ratio of gas to liquid, in order to comply with the regulations and technical standards for marine drainage.

[0100] Example 5: is a basic example of a seawater carbon capture and storage device for use in the method of the present invention, as shown in the attached Figure 3 As shown, it includes a burner 1 for generating exhaust gas from the combustion of fossil fuels, and a carbon collector 2 connected to the burner for washing the exhaust gas to capture carbon dioxide, a seawater extraction device 3 for introducing seawater into the carbon collector, and an exhaust pipe 6 for extracting purified exhaust gas from the carbon collector, as well as a seawater drain pipe 7; the carbon collector has a packing layer inside and includes a water distributor 2.1, the seawater outlet 5 of the carbon collector is connected to the seawater drain pipe 7, and the outlet of the seawater drain pipe is connected to the ocean water body.

[0101] Embodiment 6 is an embodiment based on Embodiment 5. The carbon collector 2 includes a water distributor 2.1, and the height 2.2 of the water distributor is less than or equal to 20m; the height 2.2 of the water distributor is the height value of the horizontal center line of the water distributor 2.1 relative to the sea level 3.2 of the water intake point of the seawater extraction device 3.

[0102] There are also the following embodiments in which the heights of the water distributors are less than or equal to 19m, 15m, 12m, 10m, 9m, 8m, 6m, 5m, 4m, 2m, and 1m respectively.

[0103] The purpose of lowering the water distributor height 2.2 is to reduce the energy consumption of extracting seawater, which is the main energy consumption of the process of the present invention.

[0104] A packing layer is arranged inside the carbon collector 2 and is composed of industrial bulk packing, and the dry packing factor of the packing is 5 / m.

[0105] In another embodiment, the dry packing factor of the filler is 30 / m.

[0106] In the following embodiments, the dry filling factors of the fillers are 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 and 2000 / m respectively.

[0107] Another embodiment is that the packing layer is composed of structured packing. Still another embodiment is that the packing layer is composed of orifice packing.

[0108] Another embodiment is that the filler layer is composed of a mixture of various fillers.

[0109] Embodiment 7: is an embodiment based on embodiment 5. Figure 4 As shown, the seawater extraction device 3 connected to the carbon capture device 2 is a seawater cooling system of the burner 1 .

[0110] The seawater extraction device 3 of another embodiment is a seawater increment pump 3.1.

[0111] In another embodiment, the seawater extraction equipment 3 is a seawater cooling system and a seawater increment pump 3.1 of the burner 1. This is to reduce the emission of a larger amount of carbon dioxide and provide a larger amount of seawater.

[0112] Example 8: Example of a coastal gas-steam combined cycle power plant, such as Figure 3 The plant has three gas-steam combined cycle generator sets, each with 400MW, for a total of 1200MW installed capacity. This embodiment is implemented in two phases.

[0113] The first phase of implementation will capture carbon dioxide from the exhaust gas of one of the generating units. At least 90% of the carbon dioxide in the flue gas of this unit will be captured, dissolved in scrubbing seawater, and then injected into the sea water, capturing and storing about 1 million tons of carbon dioxide annually.

[0114] The plant had previously designed a high-concentration carbon capture and storage project, which also captured carbon dioxide from the exhaust gas emitted by one of the power generating units. It captures and stores about 1 million tons of carbon dioxide annually, and is designed with processes such as carbon dioxide absorption, desorption, purification, compression, and transportation. The captured high-concentration carbon dioxide is injected into the submarine oil field for oil recovery (EOR) to increase production, and is equipped with a dedicated offshore platform, which is a submarine geological storage solution. After the project design was completed, it was found that although oil recovery and increased production could bring certain income, making the total cost lower than other non-EOR CCS projects, it was still not low enough for people to bear, so the project was eventually terminated.

[0115] The carbon capture device of this embodiment is installed in the empty site prepared for the original CCS project, and only one-fifth of the area is required; the height of the carbon capture water distributor is about 10m; the seawater introduction equipment directly uses the existing seawater cooling system of the power plant, so it also uses the existing cooling water intake and outlet of the power plant, and the drainage depth is greater than 150 meters; because the cooling outlet of the coastal power plant is originally in the ocean current that does not flow through the water intake in order to ensure cooling efficiency, the washed and captured carbon dioxide will also be rapidly diffused and diluted with the ocean current after being discharged, making the already small impact on the marine environment even smaller. The energy consumption of capturing carbon dioxide in this embodiment is no more than 100MJ / t, and the cost and operating cost of the CCS device are both one-tenth of the original high-concentration project.

[0116] The second phase will expand the first phase and add carbon capture devices and seawater inlet pumps, and carry out seawater washing carbon capture and ocean water carbon storage for the remaining two generating units. After the completion of the second phase, the plant will capture and store about 3 million tons of carbon dioxide annually.

[0117] Another embodiment is to place the carbon collector on a platform whose height can be adjusted according to the tide level. Another embodiment is to place the carbon collector on a floating ocean platform. In this way, the energy consumption of lifting seawater can be minimized regardless of high or low tide.

[0118] Example 9: Coastal coal-fired power plant example, such as Figure 4 The burner is a 600MW coal-fired power generation unit, which will be implemented in two phases.

[0119] In the first phase of implementation, at least 25% of the carbon dioxide in the flue gas emitted by the generator sets will be captured and dissolved in scrubbing seawater. The scrubbing seawater will directly utilize the power plant's existing 70,000t / h cooling seawater, capturing and storing approximately 800,000 tons of carbon dioxide annually.

[0120] In the second phase, about 95% of the carbon dioxide in the flue gas emitted by the generator set is captured and dissolved in the scrubbing seawater. The amount of scrubbing seawater required for this configuration needs to be increased by 210,000t / h, which comes from the expanded seawater inlet pump. After the completion of the second phase, the generator set will capture and store about 3 million tons of carbon dioxide annually.

[0121] The carbon capture device uses a packed tower to reduce its height, and its water distributor is about 9m high. It uses an organic woven film water pipe to transport water to the middle layer of the ocean about 300m below sea level to implement marine carbon storage.

[0122] This embodiment reduces CO2 emissions from flue gas in power plants by 80%, and the energy consumption for capturing carbon dioxide is no more than 200 MJ / t.

[0123] Embodiment 10: This embodiment is as follows Figure 4, which has a seawater control pump connected to the regulator to control the pH value of the washed seawater when it is injected into the sea. This implementation can better control the pH value of the discharged seawater while minimizing energy consumption.

[0124] The seawater containing carbon dioxide after washing is discharged into the ocean water body between the sea level and the seabed, specifically the middle ocean water body 800m below the sea surface.

[0125] Another embodiment is to inject the washed seawater containing carbon dioxide into the deep ocean water body 1500m below the sea level. Some studies have shown that injecting carbon dioxide thousands of meters into the ocean can seal carbon dioxide for thousands of years.

[0126] Embodiment 11: is an embodiment of a marine vessel, such as Figure 5 Burner 1 includes a 30MW marine two-stroke diesel engine, fueled by heavy oil with a sulfur content of 3.5% vv, and CO2 production of about 8100Nm 3 / h, the carbon capture device and the original silencer are combined to design and build, and the water distributor height is 6m, which is considered according to the heavy load waterline of the ship; the carbon capture and storage water volume is about 5800t / h, and the seawater increment pump 3.1 flow rate is adjustable to control the pH value of the drainage; the ship exhaust gas treated by this embodiment: CO2 is reduced by 50-70% (the specific value is related to the seawater quality and water temperature where the ship is sailing), SO2 is reduced by 98%, equivalent to 0.5% S fuel, and the existing low-cost fuel can continue to be used after the United Nations implements the global shipping sulfur limit in 2020. The energy consumption of capturing carbon dioxide is not more than 20MJ / t, and the full-process operation cost is equivalent to 0.6% of the full-power fuel consumption of the main engine. The drainage complies with the MEPC rules under Annex VI of the MARPOL Convention and is discharged into the surface water of the ocean.

[0127] This embodiment is provided with pH detection and control at the water inlet and the outlet, which complies with the MEPC rules under Annex VI of the MARPOL Convention: for a moving ship, the engine exhaust gas is washed with seawater without adding chemical agents, and the pH change of the washing wastewater produced does not exceed 2 pH units of the inlet seawater, and direct discharge into the sea, that is, injection into the surface water of the ocean, is permitted.

[0128] Another example of a new ship fuel is LNG, which produces less carbon emissions than coal and fuel oil, but is still a fossil energy source that needs to reduce and control carbon emissions.

[0129] Embodiment 12 is an embodiment of an atmospheric carbon capture and storage device on the ocean, such as Figure 6It comprises a carbon capturer 2, a seawater extraction device 3 for conveying seawater to the carbon capturer, a power device 14 for providing power to the seawater extraction device, a water distributor 2.1 located above the carbon capturer 2, a water collector 2.3 located below the carbon capturer 2, and a seawater drainage pipe 7 connected to the water collector. The device is installed on a platform floating on the sea surface, and the platform is anchored to the seabed.

[0130] Another embodiment of the device is mounted on an offshore platform rigidly connected to the seabed. In another embodiment, the device is mounted on a mobile offshore platform.

[0131] Embodiment 13: is a further embodiment based on embodiment 12, such as Figure 6 The power device 14 includes a hydraulic device 14.2 and a power connection device 14.3. The power connection device 14.3 is connected to the seawater extraction device 3 to transfer the kinetic energy generated by the hydraulic device 14.2 to the seawater extraction device 3. The power connection device 14.3 is a mechanical connection device.

[0132] The power connection device 14.3 described in another embodiment is an electromechanical connection device composed of a hydroelectric generator and an electric motor.

[0133] Embodiment 14: is a further embodiment based on embodiment 12, such as Figure 7 The power device 14 includes a pneumatic device 14.1 and a power connection device 14.3. The power connection device 14.3 is connected to the seawater extraction device 3 to transfer the kinetic energy generated by the pneumatic device 14.1 to the seawater extraction device 3. The power connection device 14.3 is a mechanical connection device.

[0134] The water collector 2.3 below the carbon capture device 2 of this embodiment is connected to a seawater drainage pipe 7, the outlet of which is connected to the ocean water body so as to inject the washed seawater containing dissolved carbon dioxide into the sea. The wind turbine is a vertical axis wind wheel. A horizontal axis wind wheel can also be used. The wind turbine converts the captured offshore wind energy into rotational mechanical energy, which directly drives the seawater extraction equipment to lift the seawater. The seawater extracted from deeper depths has a better effect in washing and capturing carbon dioxide; the liquid level of the water collector below the carbon capture device is such that the deeper the washed seawater is injected into the sea, the better the carbon dioxide sealing effect. The power connection device 14.3 has a mechanical speed regulation function. The carbon capture device 2 adopts a vertical open design to facilitate wind capture; a filler composed of a grid plate and a grid mesh is provided therein to improve the washing efficiency.

[0135] It is also an embodiment that the carbon collector is a hollow spray tower. It is also an embodiment that the carbon collector is a conventional scrubber. It is another embodiment that the scrubber seawater is directly spread on the ocean surface without being collected by a water collector.

[0136] In another embodiment, the carbon collector uses a blower to force air to blow, and the power of the blower also comes from a pneumatic device.

[0137] The device in the above embodiment is also a carbon reduction windmill device, and its manufacturing and maintenance costs are much lower than those of a wind turbine with the same wind rotor diameter. Since it does not require multi-stage energy conversion, its effectiveness in reducing atmospheric carbon content is several times greater than that of the latter.

[0138] Embodiment 15 is another embodiment based on embodiment 12, wherein the power equipment 14 comprises a wind turbine 14.1 and a power connection device 14.3, wherein the power connection device 14.3 is an electromechanical connection device composed of a wind turbine and an electric motor. In this case, the power equipment 14 directly adopts an existing offshore wind turbine.

[0139] In another embodiment, the power device 14 directly adopts existing solar power generation equipment.

[0140] The protection scope of the claims of the present invention is not limited to the above-mentioned embodiments.

Claims

1. A seawater-based direct carbon capture and storage method, characterized in that: The method comprises the following steps: 1) Carbon capture: extracting seawater to wash the gas containing carbon dioxide, and generating washed seawater containing carbon dioxide dissolved in the gas as a carbon capture product; the gas containing carbon dioxide is air in a natural state; 2) Carbon sequestration: injecting the carbon capture integrated product into the ocean water for marine carbon sequestration; the injection into the ocean water is performed by injecting into the ocean water using a normal pressure pipeline.

2. The method according to claim 1, characterized in that: The extraction of seawater is to extract seawater from the deeper part of the ocean.

3. The method according to claim 1, characterized in that: The power for extracting seawater for washing comes from natural energy such as wind power, and / or ocean current waves, and / or sunlight.

4. A seawater air direct carbon capture and storage device for the method according to claim 1, characterized in that: It comprises a carbon capturer (2), a seawater extraction device (3) for conveying seawater to the carbon capturer (2), a power device (14) for providing power to the seawater extraction device (3), and a water distributor (2.1) at the top and a water collector (2.3) at the bottom of the carbon capturer (2), as well as a seawater drainage pipe (2.2).

5. The device according to claim 4, characterized in that The power equipment (14) comprises a wind-driven device (1.1) and a power connection device (1.3). The power connection device (1.3) is connected to the seawater extraction device (3) to transfer the kinetic energy generated by the wind-driven device (1.1) to the seawater extraction device (3). The power connection device (1.3) is a mechanical connection device and / or an electromechanical connection device composed of a wind turbine and an electric motor.

6. The device according to claim 4, characterized in that The power equipment (14) comprises a hydraulic device (1.2) and a power connection device (1.3). The power connection device (1.3) is connected to the seawater extraction device (3) to transfer the kinetic energy generated by the hydraulic device (1.2) to the seawater extraction device (3). The power connection device (1.3) is a mechanical connection device and / or an electromechanical connection device composed of a hydraulic generator and an electric motor.

7. The device according to claim 4, characterized in that The carbon collector (2) adopts a vertical open design that is conducive to natural wind capture.

8. The device according to claim 4, characterized in that The carbon collector (2) uses a blower to force air to blow.

9. The device according to claim 4, characterized in that The power equipment (14) adopts existing wind power generators, and / or existing solar power generation equipment, and / or existing ocean current wave power generation equipment.

10. An air direct carbon capture system device, characterized in that: The invention comprises the technical features as described in any one of claims 1 to 9.

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