阅读说明：本技术 一种船载二氧化碳捕集与封存装置及方法 (Shipborne carbon dioxide capturing and sealing device and method ) 是由 唐晓佳 朱益民 田悦 樊铭鹏 闯恒超 于 2021-09-29 设计创作，主要内容包括：本发明公开了一种船载二氧化碳捕集与封存的装置及方法,用于解决船舶运输中的温室气体排放问题,包括船端系统和岸端系统,其中船端系统包括：脱碳塔、循环池、固液分离器、喷雾干燥器、储罐；岸端系统包括：煅烧炉、压缩机、水化反应器。船舶废气进入脱碳塔,被氨基酸盐和氢氧化镁组成的混合吸收液捕集,吸收液经固液分离得到氨基酸盐溶液回用至循环池中,分离得到的产物为碳酸镁固体,经喷雾干燥后储存在储罐中,待船舶靠岸时转移至岸端系统的煅烧炉分解为氧化镁和高浓度CO-(2),氧化镁通过水化制得氢氧化镁浆料回用至船上。本发明利用氨基酸盐与氢氧化镁的混合吸收液,通过船岸的有效结合,实现了船舶碳减排的国际战略目标。(The invention discloses a device and a method for capturing and storing shipborne carbon dioxide, which are used for solving the problem of greenhouse gas emission in ship transportation and comprise a ship end system and a shore end system, wherein the ship end system comprises: a decarbonizing tower, a circulating pool, a solid-liquid separator, a spray dryer and a storage tank; the bank end system comprises: a calciner, a compressor and a hydration reactor. The ship waste gas enters a decarbonization tower and is captured by mixed absorption liquid consisting of amino acid salt and magnesium hydroxide, the absorption liquid is subjected to solid-liquid separation to obtain amino acid salt solution which is recycled to a circulating pool, the separated product is magnesium carbonate solid, the magnesium carbonate solid is stored in a storage tank after being spray dried, and the magnesium carbonate solid is transferred to a calcining furnace of a shore end system to be decomposed into magnesium oxide and high-concentration CO when a ship is in shore 2 And the magnesium oxide is hydrated to prepare magnesium hydroxide slurry for recycling to the ship. The invention utilizes ammoniaThe mixed absorption liquid of the base acid salt and the magnesium hydroxide effectively combines the ship shore to realize the international strategic target of the carbon emission reduction of the ship.)

1. A shipborne carbon dioxide capturing and sealing device is characterized by comprising a ship end system and a shore end system;

the ship end system comprises: a decarbonization tower (2), a circulation tank (3), a solid-liquid separator (5), a spray dryer (6), a storage tank I (7), a storage tank II (8) and a storage tank III (9);

wherein a spray absorption area (2.4) and a demister (2.5) are sequentially arranged between the gas inlet at the lower part of the decarburization tower (2) and the gas outlet at the top part;

the absorption liquid outlet at the bottom of the decarbonizing tower (2) is connected with a circulating pool (3), and the outlet of the circulating pool (3) is connected with two paths after passing through a circulating pump (4): the first path is connected with an inlet of the spraying absorption area (2.4), and the second path is connected with an inlet of the solid-liquid separator (5) through a regulating valve (14);

a solid phase outlet of the solid-liquid separator (5) is connected with a feed inlet of the spray dryer (6), and a discharge outlet of the spray dryer (6) is connected with a storage tank III (9);

the storage tank I (7) and the storage tank II (8) are connected with the circulating pool (3);

the shore end system comprises: a calciner (10), a compressor (11), a storage tank IV (12) and a hydration reactor (13);

an exhaust port of the calcining furnace (10) is sequentially connected with a compressor (11) and a storage tank IV (12);

the outlet of the calcining furnace (10) is connected with the inlet of the hydration reactor (13);

after the ship is landed, the calcining furnace (10) is connected with a storage tank III (9);

the outlet of the hydration reactor (13) is connected with the storage tank II (8).

2. The on-board carbon dioxide capture and sequestration plant according to claim 1, characterized in that it further comprises an associated exhaust gas cooling system comprising a spray cooling pipe (2.1), a cooling spray pump (2.2); the spray cooling pipe (2.1) is connected with the air inlet at the lower part of the decarburization tower (2), the bottom of the spray cooling pipe (2.1) is provided with a cooling liquid discharge port (2.3), and the spray cooling pipe (2.1) is connected with a cooling spray pump (2.2).

3. The on-board carbon dioxide capture and sequestration plant according to claim 1, characterized in that it further comprises a gas-gas heat exchanger (6.1), said gas-gas heat exchanger (6.1) being connected to the air inlet of the spray dryer (6).

4. The on-board carbon dioxide capture and sequestration plant according to claim 1, characterized in that the demister (2.5) is provided with a demister washing nozzle (2.6), said demister washing nozzle (2.6) being connected to the liquid phase outlet of the solid-liquid separator (5).

5. An on-board carbon dioxide capture and sequestration process, characterized in that it uses the device of any one of claims 1-4, comprising the following steps:

s1, enabling the desulfurized, denitrated and dedusted ship waste gas to enter from an air inlet at the lower part of the decarbonizing tower (2) through the exhaust pipe (1) of the marine internal combustion engine, carrying out contact reaction with a spray absorption liquid consisting of amino acid salt and magnesium hydroxide to remove carbon dioxide, removing entrained liquid drops through a demister, and exhausting the entrained liquid drops into the atmosphere from an exhaust port at the top of the decarbonizing tower (2);

s2, enabling the spray absorption liquid absorbing carbon dioxide to enter a circulating pool (3) through an absorption liquid outlet at the bottom of a decarbonizing tower (2), lifting the spray absorption liquid by a circulating pump (4), enabling one path of the spray absorption liquid to enter a spray absorption area (2.4) of the decarbonizing tower for circulating spray, enabling the other path of the spray absorption liquid to enter a solid-liquid separator (5) for separation, enabling clear liquid obtained by separation to be an amino acid salt solution, recycling the amino acid salt solution to the decarbonizing tower, washing a demister and maintaining the liquid level balance in the tower, enabling magnesium carbonate obtained by separation to enter a spray dryer (6), drying the magnesium carbonate and storing the magnesium carbonate in a storage tank III (9);

s3, shipWhen the device is in shore, the storage tank III (9) is connected with the calcining furnace (10), the magnesium carbonate in the storage tank III (9) is transferred to the calcining furnace (10), and the magnesium carbonate is decomposed into magnesium oxide and high-purity CO after being calcined₂And the obtained magnesium oxide is made into magnesium hydroxide slurry through a hydration reactor (13), and the magnesium hydroxide slurry is stored in a storage tank II (8) and is used as spraying absorption liquid for recycling.

6. The capture and sequestration process according to claim 5, characterized in that it further comprises: the ship exhaust gas subjected to desulfurization, denitration and dust removal in the step S1 enters an exhaust gas cooling system to be cooled, the cooling liquid is seawater, the seawater is pumped to a spray cooling pipe (2.1) by a cooling liquid spray pump (2.2) to cool the high-temperature exhaust gas, and then the seawater is directly discharged into the sea through a cooling liquid discharge port (2.3).

7. The capture and sequestration process according to claim 5, characterized in that, in step S3, the obtained high purity CO is obtained₂Cooled, compressed, liquefied and stored in a storage tank IV (12).

8. The capturing and sequestering method according to claim 5, wherein the spray absorption liquid contains magnesium hydroxide in a solid content of 5 to 15 wt% and an amino acid salt in a concentration of 0.5 to 1 mol/L.

9. The method of trapping and sequestering according to claim 5, wherein said amino acid salt is one or more of the potassium, sodium or lithium salts of glycine, arginine, alanine, proline, sarcosine, lysine.

Technical Field

The invention relates to the technical field of ship waste gas treatment, in particular to a device and a method for capturing and sealing ship-borne carbon dioxide.

Background

90% of global trade is done by marine, and environmental problems associated with shipping are also of high interest to international society. Since 2016 effective Paris protocol, shipping industry has been on increasing demand for decarbonization sounds. The International Maritime Organization (IMO) fourth greenhouse gas research (GHG4) report on day 4/8 in 2020 shows that the carbon emissions from the shipping industry account for 2.89% of the total global emissions in 2018. If the current growth situation is kept, the global ship carbon emission is predicted to increase by 90% -130% in 2050, and the reduction of greenhouse gas emission becomes an urgent problem in international shipping. For this reason, IMO enacted a preliminary strategy for the abatement of greenhouse gases in the shipping industry in the MEPC 72 resolution.

The carbon dioxide capture and sequestration technology (CCS) plays an important role as a high-efficiency greenhouse gas emission reduction means in the field of land-source carbon emission reduction, but is limited by the special application environment of ships, and the research on the shipborne CCS technology is still in the starting stage. In recent years, traditional ship-borne CCS technical schemes are proposed in competition in traditional ship-reinforced countries such as England, Sweden, Finland, Norway, Japan and the like, and the technical route mostly takes a land-based mature alcohol amine method (represented by monoethanolamine MEA) as a technical blueprint: such as the project of the European Star (Eurostat) of Norway, the project of CC-Ocean of Mitsubishi, the project of CCShip of Norway's institute of science and technology, the project of DecrisCO2 of the applied science research organization of the Netherlands, etc., the company of Wailan, Finland, and the company of African Afavalava also show that by modifying their vessel exhaust gas scrubbing desulfurizing towers, the replacement of alcohol amine solvent can be used for decarburization treatment, and has been verified by a real vessel. The carbon trapping scheme by the alcohol amine method has the advantages of mature technology and high trapping efficiency, but the absorption liquid needs to be heated and regenerated, the energy consumption is extremely high, and the device has the defects of large volume, serious corrosion and easy volatilization of the absorption liquidThe problems of degradation and the like seriously restrict the application of the ship. Other research and development institutions have attempted to use cryogenic freezing for carbon capture of marine exhaust: such as the project A3C of PMW corporation in the uk, the project decarbonocei dominated by japanese mail carriers. However, the conventional cryogenic freezing method is mainly used for CO₂High concentration (more than 90%) and CO in ship exhaust gas₂Concentrations generally below 6% and the presence of other condensable gases, such as water vapor, which cause plugging of the tubes during cryogenic cooling of the exhaust gas, are major bottlenecks limiting the technology. China has relatively late research on the aspect of shipborne CCS, and only a few related patents are disclosed in recent years, for example, CN201410621722.9 discloses that ethanolamine is used for capturing and recycling CO in ship exhaust gas₂CN201910217968.2 discloses that sodium hydroxide is used for absorbing CO in waste gas₂And regenerating sodium hydroxide by adopting calcium hydroxide. CN201710589328.5 discloses the absorption of CO with sodium hydroxide₂Regenerating the absorption liquid by electrolysis and collecting the precipitated high-concentration CO₂. CN202010712441.X discloses a method for absorbing and trapping CO in ship exhaust gas by PTFE high-pressure membrane separation and GLY-PZ₂The technical scheme of (1). CN201710281609.4 discloses a method for capturing CO in desulfurized ship exhaust gas by using a membrane separator₂The method of (1). The proposed solution is either similar to foreign research or based on an immature membrane separation system. The situation of carbon emission reduction in the shipping industry is urgent, the key window period for forming available technologies is 2020 to 2030, the efficient and available shipborne CCS technical scheme is urgently needed to be developed and matured, and technical support is provided for China to deal with IMO strategic implementation and fulfill the international commitment of carbon emission.

Disclosure of Invention

The invention aims to provide an efficient and feasible method for using CO in ship exhaust gas₂The device and the method for trapping and sealing aim at solving the problem of greenhouse gas emission generated in the process of ship transportation.

In order to achieve the aim, the invention provides a shipborne carbon dioxide capturing and sealing device, which comprises a ship end system and a shore end system;

the ship end system comprises: the system comprises a decarbonization tower, a circulation tank, a solid-liquid separator, a spray dryer, a storage tank I, a storage tank II and a storage tank III;

wherein a spray absorption area and a demister are sequentially arranged between the gas inlet at the lower part of the decarburization tower and the gas outlet at the top part of the decarburization tower;

the absorption liquid outlet at the bottom of the decarburization tower is connected with a circulating tank, and the outlet of the circulating tank is connected with two paths after passing through a circulating pump: the first path is connected with an inlet of the spraying absorption area, and the second path is connected with an inlet of the solid-liquid separator through a regulating valve;

a solid phase outlet of the solid-liquid separator is connected with a feed inlet of the spray dryer, and a discharge outlet of the spray dryer is connected with a storage tank III;

the storage tank I and the storage tank II are connected with a circulating pool;

the shore end system comprises: the device comprises a calcining furnace, a compressor, a storage tank IV and a hydration reactor;

the exhaust port of the calcining furnace is sequentially connected with a compressor and a storage tank IV;

the outlet of the calcining furnace is connected with the inlet of the hydration reactor;

after the ship is landed, the calcining furnace is connected with a storage tank III;

the outlet of the hydration reactor is connected with the storage tank II.

In the technical scheme, the device further comprises an exhaust gas cooling system connected with the air inlet of the decarbonizing tower, wherein the exhaust gas cooling system comprises a spray cooling pipe and a cooling spray pump; the exhaust pipe of the marine internal combustion engine is connected with the air inlet of the decarbonizing tower through a spray cooling pipe, the bottom of the spray cooling pipe is provided with a cooling liquid discharge port, and the spray cooling pipe is connected with a cooling spray pump.

In the technical scheme, the device further comprises a gas-gas type heat exchanger, the gas-gas type heat exchanger is connected with a gas inlet of the spray dryer, a heat source of the gas-gas type heat exchanger is from an exhaust pipe of the internal combustion engine for taking off the ship, and a heat source is provided for the drying sprayer by using the waste heat of the ship exhaust gas.

In the above technical scheme, further, a demister cleaning nozzle is arranged on the demister, and the demister cleaning nozzle is connected with a liquid phase outlet of the solid-liquid separator.

The invention also provides a method for capturing and sealing off the shipborne carbon dioxide, which comprises the following steps:

(1) the ship waste gas after desulfurization, denitration and dust removal enters from an air inlet of a decarbonizing tower through a marine internal combustion engine exhaust pipe, contacts and reacts with a spraying absorption liquid consisting of amino acid salt and magnesium hydroxide to remove carbon dioxide, and then is removed with entrained liquid drops through a demister and is exhausted into the atmosphere from an exhaust port at the top of the decarbonizing tower;

(2) the spray absorption liquid absorbing the carbon dioxide enters a circulating pool through an absorption liquid outlet at the bottom of the decarbonizing tower, is lifted by a circulating pump and then is divided into two paths, wherein one path enters a spray absorption layer of the decarbonizing tower and then enters the circulating pool again to realize circulating spray, the other path enters a solid-liquid separator to be separated, the separated clear liquid is an amino acid salt solution and is recycled to a demister cleaning nozzle to be used for washing a demister and maintaining the liquid level balance in the tower, and the separated magnesium carbonate enters a spray dryer to be dried and then stored in a storage tank III; periodically supplementing small amounts of amino acid salt and magnesium hydroxide slurry into the circulating pool by a storage tank I and a storage tank II respectively;

(3) when ships are in port, the magnesium carbonate in the storage tank III is transferred to a shore end system, enters a calcining furnace, and is decomposed into magnesium oxide and high-purity CO after being calcined₂And preparing magnesium hydroxide slurry from the obtained magnesium oxide through a hydration reactor, storing the magnesium hydroxide slurry in a storage tank II, and recycling the magnesium hydroxide slurry as spraying absorption liquid.

CO-generation in the column₂Absorption, magnesium hydroxide dissolution, CO₂The reaction of cure-blocking and amino acid salt regeneration is as follows:

(1)CO₂absorption:

2H₂NRCOO^-+CO₂→^-OOCRNHCOO^-+⁺H₃NRCOO^-

^-OOCRNHCOO^-+H₂O→H₂NRCOO^-+HCO₃ ^-

HCO₃ ^-→H⁺+CO₃ ^2-

(2) dissolving magnesium hydroxide:

Mg(OH)₂→Mg²⁺+2OH^-

(3)CO₂curing and sealing:

CO₃ ^2-+Mg²⁺→MgCO₃

(4) amino acid salt regeneration:

⁺H₃NRCOO^-+OH^-→H₂NRCOO^-+H₂O

in the above technical scheme, further, the ship exhaust gas after desulfurization, denitration and dust removal in step (1) enters an exhaust gas cooling system to be cooled, the cooling liquid is seawater, the seawater is pumped to a spray cooling pipe by a cooling liquid spray pump 2.2 to cool the high-temperature exhaust gas, and then the seawater is directly discharged into the sea through a cooling liquid discharge port.

In the above technical solution, further, the high purity CO obtained in the step (3)₂And cooling, compressing and liquefying the mixture and storing the mixture in a storage tank IV.

In the technical scheme, furthermore, the solid content of magnesium hydroxide in the spray absorption liquid is 5-15 wt%, and the concentration of amino acid salt is 0.5-1 mol/L.

In the above technical solution, further, the amino acid salt is one or more of potassium salt, sodium salt or lithium salt of glycine, arginine, alanine, proline, sarcosine or lysine.

In the technical scheme, the energy of the calcining furnace is wind power, photoelectricity or biomass fuel, and the reaction heat of hydration of the magnesium oxide is used for providing a heat source for the calcining furnace.

The invention takes magnesium hydroxide and amino acid salt as mixed absorption liquid, and the amino acid salt has CO equivalent to the alcohol amine method₂Capture efficiency of absorbing CO₂The formed intermediate reacts with magnesium hydroxide to regenerate amino acid salt in situ, and the circulation of the amino acid salt is realized. CO2₂Safely storing in the form of magnesium carbonate, transferring the magnesium carbonate to the shore after the ship arrives at the port, calcining and decomposingIs magnesium oxide and high purity CO₂(can be directly compressed and utilized) to realize magnesium circulation.

The technical scheme of the invention has the following beneficial effects:

1. the whole system of the invention is divided into a ship end system and a shore end system, and CO in the ship exhaust gas₂Through trapping, the magnesium carbonate is safely stored in the form of magnesium carbonate, and after the ship is berthed, the magnesium carbonate is transferred to the shore end and is calcined and decomposed into magnesium oxide and high-purity CO₂Realizing magnesium circulation and recycling of ship exhaust gas;

2. the invention takes magnesium hydroxide and amino acid salt as mixed absorption liquid to absorb CO₂The formed intermediate reacts with magnesium hydroxide to regenerate amino acid salt in situ, so that the cyclic utilization of the amino acid salt is realized, and the chemical regeneration method replaces the traditional thermal regeneration method, so that the energy consumption is greatly reduced;

3. the amino acid salt is a novel green carbon dioxide absorbent, has ionic property, overcomes the problems of corrosion, volatilization, degradation and the like of an alcohol amine method, and simultaneously avoids the problems of corrosion, volatilization, degradation and the like of an alcohol amine method system; CO absorption with amino acid salts₂Accelerate CO₂The dissolution in water overcomes the defect that magnesium hydroxide lye absorbs CO₂The problem of low efficiency; magnesium hydroxide is known to be useful for mineralizing sequestered CO₂Storage of CO per unit mass in minerals of₂The substance with the largest capacity can reach 76w/w percent (the storage efficiency of calcium hydroxide is 59w/w percent)); the magnesium hydroxide is used as a desulfurizer which is always provided for ships, and has advantageous application conditions when being used for decarbonization treatment of ship waste gas;

4. the heat absorption of the decomposition of magnesium carbonate is 117.8kJ/mol, the heat release of the hydration of magnesium oxide is 81.2kJ/mol, and the calcining furnace is arranged on a docking shore, so that extra energy required by calcining can be zero-carbon energy such as wind power, photoelectric energy and the like which are difficult to directly use on a ship and can be conveniently obtained on the land.

5. The combination mode of the ship end trapping safety sealing and the shore end decomposing by utilizing the renewable energy is equivalent to the mode of taking the technology of the invention as a bridge, and indirectly finishes the application of the renewable energy in ships.

Drawings

FIG. 1 is a schematic structural view of a shipborne carbon dioxide capturing and sealing device according to the present invention;

wherein: 1. marine internal combustion engine exhaust pipes; 2. 2.1 parts of a decarburization tower, 2.2 parts of a spray cooling pipe, 2.2 parts of a cooling spray pump, 2.3 parts of a cooling liquid discharge port, 2.4 parts of a spray absorption zone, 2.5 parts of a demister, and 2.6 parts of a demister cleaning nozzle; 3. a circulation tank; 4. a circulation pump; 5. a solid-liquid separator; 6. spray dryer, 6.1, gas-gas type heat exchanger; 7. a storage tank I; 8. a storage tank II; 9. a storage tank III; 10. a calciner; 11. a compressor; 12. a storage tank IV; 13. a hydration reactor; 14. and adjusting the valve.

Detailed Description

The following examples are presented to enable one of ordinary skill in the art to more fully understand the present invention and are not intended to limit the invention in any way.

The following non-limiting examples are presented to enable those of ordinary skill in the art to more fully understand the present invention and are not intended to limit the invention in any way.

An onboard carbon dioxide capturing and sealing device is shown in figure 1 and comprises a ship end system arranged in a ship body and a shore end system arranged in a wharf berth;

wherein ship end system includes: decarbonization tower 2, circulation pond 3, circulating pump 4, solid-liquid separator 5, spray dryer 6, storage tank I7, storage tank II8, storage tank III9, bank end system includes: the calcining furnace 10, the compressor 11, the storage tank IV12 and the hydration reactor 13;

a spray absorption area 2.4 and a demister 2.5 are sequentially arranged between the gas inlet at the lower part of the decarburization tower 2 and the gas outlet at the top part;

the absorption liquid outlet at the bottom of the decarbonizing tower 2 is connected with a circulating pool 3, and the outlet of the circulating pool 3 is connected with two paths after passing through a circulating pump 4: the first path is connected with an inlet of a solid-liquid separator 5, and the second path is connected with an inlet of a spraying absorption area 2.4 through a regulating valve 14;

a solid phase outlet of the solid-liquid separator 5 is connected with a feed inlet of the spray dryer 6, and a discharge outlet of the spray dryer 6 is connected with a storage tank III 9;

the storage tank I7 and the storage tank II8 are connected with the circulating tank 3;

the exhaust port of the calcining furnace 10 is sequentially connected with a compressor 11 and a storage tank IV 12;

the outlet of the calcining furnace 10 is connected with the inlet of the hydration reactor 13;

after the ship is landed, the calcining furnace 10 is connected with a storage tank III 9;

the outlet of the hydration reactor 13 is connected to a reservoir II 8.

The storage tank I is an amino acid salt solution storage tank, the storage tank II is a magnesium hydroxide slurry storage tank, the storage tank III is a magnesium carbonate storage tank, and the storage tank IV is liquid CO₂And (4) storage tank.

In one embodiment of the invention, the system further comprises an exhaust gas cooling system connected with the air inlet of the decarbonization tower 2, wherein the exhaust gas cooling system comprises a spray cooling pipe 2.1 and a cooling spray pump 2.2; the exhaust pipe 1 of the marine internal combustion engine is connected with the air inlet of the decarburization tower through a spray cooling pipe 2.1, the bottom of the spray cooling pipe 2.1 is provided with a cooling liquid discharge port 2.3, and the spray cooling pipe 2.1 is connected with a cooling spray pump 2.2.

In one embodiment of the invention, the drying sprayer further comprises a gas-gas type heat exchanger 6.1, the gas-gas type heat exchanger 6.1 is connected with the gas inlet of the spray dryer 6, and the heat source of the gas-gas type heat exchanger 6.1 is from the exhaust pipe 1 of the internal combustion engine for the ship to take off, so that the heat source is provided for the drying sprayer by using the waste heat of the exhaust gas of the ship, and the energy is saved.

In one embodiment of the invention, the demister 2.5 is provided with a demister cleaning nozzle 2.6, and the demister cleaning nozzle 2.6 is connected with a liquid phase outlet of the solid-liquid separator 5.

The method for collecting and storing the shipborne carbon dioxide by using the device comprises the following steps:

(1) the desulfurized, denitrated and dedusted ship waste gas enters a spray cooling pipe 2.1 through a marine internal combustion engine exhaust pipe 1, cooling liquid is seawater, the seawater is pumped to the spray cooling pipe 2.1 by a cooling liquid spray pump 2.2 to cool high-temperature waste gas, then the seawater is directly discharged into the sea through a cooling liquid discharge port 2.3, the ship waste gas enters from an air inlet at the lower part of a decarbonization tower, amino acid salt and magnesium hydroxide respectively enter a circulation tank 3 from a storage tank I7 and a storage tank II8, spray absorption liquid consisting of the amino acid salt and the magnesium hydroxide enters a spray absorption area 2.4 through a circulation pump 4 to be subjected to contact reaction to remove carbon dioxide, entrained liquid drops are removed by a demister 2.5, and the entrained liquid drops are discharged into the atmosphere from an exhaust port at the top of the decarbonization tower 2;

(2) the spray absorption liquid absorbing carbon dioxide enters a circulation pool 3 through an absorption liquid outlet at the bottom of a decarbonizing tower 2, one path of the spray absorption liquid enters a spray absorption layer 2.4 of the decarbonizing tower again for circular spraying after being lifted by a circulation pump 4, the other part of the spray absorption liquid enters a solid-liquid separator 5 through an adjusting valve 14 for separation, the separated clear liquid is an amino acid salt solution and is recycled to a demister cleaning nozzle 2.6 in the decarbonizing tower for washing the demister and maintaining the liquid level balance in the tower, the separated magnesium carbonate enters a spray dryer 6, a drying heat source is derived from the waste heat of the ship waste gas, the magnesium carbonate is temporarily stored in a storage tank III9 after being dried, and a small amount of amino acid salt and magnesium hydroxide slurry are periodically supplemented into the circulation pool 3 by a storage tank I7 and a storage tank II8 respectively;

(3) when a ship is landed, the storage tank III9 is connected with the calcining furnace 10, the magnesium carbonate in the storage tank III9 is transferred to the calcining furnace 10, and the magnesium carbonate is decomposed into magnesium oxide and high-purity CO after being calcined₂The obtained high-purity CO₂Cooling, compressing, liquefying and storing in a storage tank IV12, reacting the obtained magnesium oxide by a hydration reactor 13 to prepare magnesium hydroxide slurry, storing in a storage tank II8 as spray absorption liquid for recycling, wherein the energy source of the calcining furnace 10 is wind power, photoelectric or biomass fuel, and simultaneously, the heat of hydration reaction of the magnesium oxide is utilized to provide a heat source for the calcining furnace 10.

It should be noted that the CO is absorbed in the circulating tank 3₂The concentration of the amino acid salt in the sprayed absorption liquid is reduced, and the concentration requirement of the sprayed absorption liquid in the decarbonizing tower 2 cannot be met, so that the amino acid salt is introduced into a solid-liquid separator 5 for separation.

The specific spraying absorption liquid is a mixed solution prepared from magnesium hydroxide and amino acid salt according to the proportion of 5-15 wt% of solid content of magnesium hydroxide and 0.5-1 mol/L of concentration of amino acid salt; wherein the amino acid salt is one or more of potassium salt, sodium salt or lithium salt of glycine, arginine, alanine, proline, sarcosine and lysine.

The above examples are merely preferred embodiments of the present invention, and are not intended to limit the embodiments. The protection scope of the present invention shall be subject to the scope defined by the claims. Other variations and modifications may be made on the basis of the above description. Obvious variations or modifications of this invention are within the scope of the invention.