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 provides a seawater-based direct carbon capture and storage method for air, 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 product into the sea water to perform marine carbon sequestration;

[0010] The gas containing carbon dioxide is air in its natural state.

[0011] The further technical solution is:

[0012] The carbon capture integrated product is injected into the ocean water body by using a normal pressure pipeline.

[0013] The seawater is extracted from the deeper part of the ocean.

[0014] The power for extracting seawater for washing comes from natural energy such as wind power, and / or ocean current waves, and / or sunlight.

[0015] The second aspect of the present invention is to provide a seawater-based air direct carbon capture and storage method, the steps comprising:

[0016] a. Continuously introduce air into the carbon collector;

[0017] b. Continuously introduce seawater into the carbon capture device;

[0018] c. In the carbon capture device, the contact area between the air introduced in step a and the seawater introduced in step b is increased by fillers to wash and dissolve the carbon dioxide in the air;

[0019] d. Continuously discharge the air with reduced carbon dioxide gas after seawater washing into the atmosphere;

[0020] e. continuously outputting the seawater containing carbon dioxide dissolved in the air from the carbon capture device in step c;

[0021] f. continuously discharging the seawater containing carbon dioxide dissolved in the air outputted continuously in step e into the sea to achieve marine carbon sequestration;

[0022] The seawater in step b is seawater directly extracted from the ocean.

[0023] The third aspect of the present invention is to provide a technical solution of a seawater type air direct carbon capture and storage device for the method of the present invention:

[0024] It comprises a carbon capturer (2), a seawater extraction device (3) for conveying seawater to the carbon capturer (2), a power device (1) 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).

[0025] The further technical solution is:

[0026] The power equipment (1) 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.

[0027] The power equipment (1) 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.

[0028] The carbon collector (2) adopts a vertical open design that is conducive to natural wind capture.

[0029] The carbon collector (2) uses a blower to force air. The blower is powered by a power device (1).

[0030] The power equipment (1) includes existing wind power generation equipment, and / or existing solar power generation equipment, and / or existing ocean current wave power generation equipment.

[0031] Technical principles and effects of the present invention:

[0032] The present invention uses the principle that carbon dioxide is a natural substance that is soluble in seawater and stored in large quantities in the ocean in the form of bicarbonate (bicarbonate) ions. Seawater is used to wash the air to dissolve the carbon dioxide in the air for direct carbon capture, and then the seawater containing the carbon dioxide in the air is injected into the ocean water body to implement permanent ocean carbon sequestration in the bicarbonate ion (hydrogen ion) mode.

[0033] CO2 dissolves in seawater and reacts from left to right according to the following equilibrium equation:

[0034] CO2+H2O﹤=﹥H2CO3(carbonic acid)

[0035] H2CO3﹤=﹥H + +HCO3 - (Bicarbonate ion, also called bicarbonate ion)

[0036] HCO3 - ﹤=﹥H + +CO3 2- (Carbonate ion)

[0037] 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).

[0038] In particular, seawater drawn from deeper below the ocean surface is cooler and more effective at capturing carbon dioxide by scrubbing the air.

[0039] The effects of applying the ocean negative emission technology of the present invention are: first, the cost of achieving negative emissions is affordable and therefore feasible; second, it directly utilizes the natural carbon sink of the ocean and thus has the scale of climate mitigation. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic diagram of the implementation steps of the seawater-type air direct carbon capture and storage method of the present invention.

[0041] Figure 2 It is another schematic diagram of the implementation steps of the seawater-type air direct carbon capture and storage method of the present invention.

[0042] Figure 3 It is a schematic diagram of an embodiment of the wind-driven seawater-type air direct carbon capture and storage device of the present invention.

[0043] Figure 4 It is a schematic diagram of an embodiment of the hydraulically driven seawater-type air direct carbon capture and storage device of the present invention.

[0044] The names of the objects marked with figure numbers in the accompanying drawings are:

[0045] 1—power equipment, 1.1—pneumatic device, 1.2—hydraulic device, 1.3—power connection device, 1.4—wind, 2—air direct carbon capture device, 2.1—water distributor, 2.2—drain pipe, 2.3—water collector, 3—seawater extraction equipment. DETAILED DESCRIPTION

[0046] The present invention provides a seawater-based air direct carbon capture and storage method, comprising the following steps:

[0047] 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;

[0048] 2) Carbon sequestration: injecting the carbon capture product into the sea water to perform marine carbon sequestration;

[0049] The carbon dioxide-containing gas mentioned here is air in its natural state.

[0050] The extracted seawater mentioned here refers to natural seawater extracted from the ocean. In the present invention, the purpose of the present invention can be achieved by using only natural seawater without adding any other substances (for example, adding alkali). Moreover, the seawater extracted from a deeper depth has a better effect of washing and capturing carbon dioxide.

[0051] The scrubbing mentioned here refers to contacting seawater with air to capture carbon dioxide in the air. The contacting methods include but are not limited to: jet injectors, bubblers, venturi towers, sprinklers, filters, rotary atomizers, grid towers, perforated plate towers or packed towers and other reactors.

[0052] The carbon capture mentioned here refers to the capture of CO2 in the air during the scrubbing process. This is because scrubbing causes the CO2 in the air to dissolve into the scrubbing seawater and become dissolved inorganic carbon (DIC) in the scrubbing seawater.

[0053] Carbon sequestration here refers to the use of normal pressure pipelines to inject washed seawater containing CO2 dissolved in the air directly into the ocean. Since the carbon dioxide content in the air is only about 0.04%, it will hardly change the pH value of the washed wastewater.

[0054] The ocean water mentioned here includes the ocean surface (within tens of meters of water depth), middle layer (within hundreds of meters of water depth) and deep layer (within hundreds of meters of water depth). International research organized by IPCC and IEA shows that the carbon sink of the marine ecosystem (biological and non-biological factors) system accounts for more than 93% of the earth's natural carbon sink. As the main carrier of the marine ecosystem, the ocean water absorbs and stores a huge amount of carbon dioxide.

[0055] 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, no one is interested in the low-concentration solution.

[0056] 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.

[0057] 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.

[0058] Through further examples, it was found that increasing the amount of scrubbing seawater can capture and store more than 90% of the carbon dioxide in the exhaust gas, and can also control energy consumption and costs.

[0059] Further implementation also found that the application of the present invention can 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 extremely low operating costs. Only the construction cost is depreciated, and because there is no need to generate electricity and transmit electricity to the shore, and no surrounding support is required, the construction cost is also very low; on the other hand, the purpose of people 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, and the present invention directly captures and stores carbon dioxide in the atmosphere to achieve better carbon reduction effects.

[0060] The present invention is further described below with reference to the accompanying drawings and embodiments.

[0061] Example 1: This is a basic example of the seawater-based direct carbon capture and storage method of the present invention. Figure 1As 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 for marine carbon sequestration; the gas containing carbon dioxide is air in a natural state.

[0062] 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.

[0063] The pH value of seawater after air scrubbing remains almost unchanged.

[0064] 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.

[0065] Embodiment 2: is another basic embodiment of the seawater air direct carbon capture and storage method of the present invention, as shown in the attached Figure 2 As shown, the gas containing carbon dioxide is air in a natural state, and the implementation steps include: a. continuously introducing air 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 air introduced in step a and the seawater introduced in step b is increased by fillers to allow the seawater to wash and dissolve the carbon dioxide in the air; d. continuously discharging the purified air with reduced carbon dioxide gas after washing with seawater into the atmosphere; e. continuously outputting the seawater containing carbon dioxide in the air in step c from the carbon capture device; f. continuously discharging the seawater containing carbon dioxide in the air continuously output in step e into the sea water body to achieve marine carbon sequestration; the seawater in step b is seawater directly extracted from the deeper part of the ocean.

[0066] Example 3: is an example of an atmospheric carbon capture and storage device on the ocean, such as Figure 1 , 2 , 3, 4, it includes a carbon capturer 2, a seawater extraction device 3 for conveying seawater to the carbon capturer 2, a power device 1 for providing power to the seawater extraction device 3, a water distributor 2.1 located above the carbon capturer 2, a water collector 2.3 located below, and a seawater drainage pipe 2.2 connected to the water collector 2.3. The device is installed on a platform floating on the sea surface, and the platform is anchored to the seabed.

[0067] 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.

[0068] Embodiment 4: is a further embodiment based on embodiment 3, such as Figure 3The power device 1 includes a pneumatic 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 pneumatic device 1.1 to the seawater extraction device 3. The power connection device 1.3 is a mechanical connection device.

[0069] The water collector 2.3 below the carbon capture device 2 of this embodiment is connected to a seawater drainage pipe 2.2, and the outlet of the seawater drainage pipe 2.2 is connected to the ocean water body 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 power connection device 1.3 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 to improve the washing efficiency.

[0070] 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.

[0071] 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.

[0072] 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 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.

[0073] Embodiment 5: is a further embodiment based on embodiment 3, such as Figure 4 The power device 1 includes 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.

[0074] The power connection device 1.3 described in another embodiment is an electromechanical connection device composed of a hydroelectric generator and an electric motor.

[0075] Embodiment 6: The power device 1 comprises a wind turbine 1.1 and a power connection device 1.3. The power connection device 1.3 is an electromechanical connection device composed of a wind turbine and an electric motor. In this case, the power device 1 directly adopts an existing offshore wind turbine.

[0076] In another embodiment, the power device 1 directly adopts the existing solar power generation equipment.

[0077] In another embodiment, the power device 1 directly adopts the existing wave energy power generation equipment.

[0078] 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; 2) Carbon sequestration: injecting the carbon capture product into the sea water to perform marine carbon sequestration; The gas containing carbon dioxide is air in its natural state.

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 (1) 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 (1) 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 (1) 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 (1) adopts existing wind power generators, and / or existing solar power generation equipment, and / or existing ocean current wave power generation equipment.

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