Synthesis method and system of green fuel

Abstract

The invention relates to a synthetic method and system of green fuel. The disclosed synthesis system comprises a carbon dioxide trapping device, a water electrolysis device and a fuel synthesis device, the carbon dioxide trapping device comprises an absorber, a causticizer, a digester, a calcinator and a regeneration electrolytic cell which are interconnected; an inlet of the causticizer, an inlet of the regeneration electrolytic bath and an inlet of the absorber are respectively connected with an outlet of the absorber; an outlet of the causticizer is connected with an inlet of the calcinator; an outlet of the regeneration electrolytic bath is connected with an inlet of the absorber; the gas outlet of the regeneration electrolytic bath is further connected with an inlet of the calcinator, an outlet of the calcinator is connected with an inlet of the digester, an outlet of the digester is further connected with an inlet of the causticizer, and an outlet of the causticizer is further connected with an inlet of the absorber; an inlet of the reactor is connected with an outlet of the calcinator; the outlet of the water electrolyser is also connected with the inlet of the reactor; circulating water is also introduced into the inlet of the water electrolyser. Heat waste is avoided, and energy consumption is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of green fuel synthesis, and in particular relates to a green fuel synthesis method and a system thereof. Background Art

[0002] To address global climate change, we should avoid further greenhouse gas emissions or promote the use of green electricity and green fuels. For example, by using green energy to combine carbon dioxide captured from the air with hydrogen produced by water electrolysis, we can produce green fuels such as green methanol and green aviation fuel.

[0003] Currently, there are methods for capturing carbon dioxide from the air, such as alkaline solution absorption combined with calcination or adsorption and temperature-swing desorption. The alkaline solution absorption combined with calcination has the advantage of mature equipment, but this method requires high-temperature combustion heat, and the whole process will release a large amount of waste heat. The alkaline solution absorption combined with electrolysis has advantages, but it produces a mixture of carbon dioxide and oxygen, which requires further purification of the carbon dioxide. As for the adsorption and temperature-swing desorption method, it has the advantage of requiring lower heat quality, but the heat demand is large, and the cost of directly using high-grade energy to drive it is too high.

[0004] The existing method of capturing carbon dioxide from the air and synthesizing green organic fuel has problems such as low carbon dioxide purity, requiring secondary purification, and releasing a large amount of waste heat, resulting in high energy consumption. Summary of the Invention

[0005] In view of this, the present invention aims to solve at least one of the technical problems in the related art to a certain extent. To this end, the present invention provides a green fuel synthesis method and system, which can efficiently capture carbon dioxide from the air using an alkaline absorbent under the drive of green electricity to generate carbonates. The hydrogen obtained after electrolytic regeneration can be burned in the system to generate heat, and pure carbon dioxide is generated by calcination. At the same time, carbon dioxide is captured from the air by adsorption under the drive of the waste heat output by the system, and organic fuel is synthesized by carbon dioxide and hydrogen; thereby, a large amount of high-temperature heat can be avoided from the outside, and low-grade heat will not be wasted. At the same time, there is no need to further purify the carbon dioxide generated by electrolysis, which simplifies the process and reduces energy consumption.

[0006] In order to solve the above-mentioned technical problems, the present invention is achieved as follows:

[0007] According to a first aspect of the present invention, the present invention provides a green fuel synthesis system, comprising:

[0008] a carbon dioxide capture plant comprising an interconnected absorber, causticizer, digester, calciner and regenerative electrolyzer;

[0009] The absorber is provided with a product solution outlet, an absorbent inlet and a product solution inlet, wherein the product solution outlet is connected to the inlet of the causticizer, the solution inlet of the regeneration electrolyzer and the product solution inlet respectively;

[0010] The carbonate precipitate outlet and the absorbent outlet of the causticizer are connected to the raw material inlet of the calciner and the absorbent inlet of the absorber respectively;

[0011] The inlet of the digester is connected to the alkaline oxide outlet of the calciner, and the hydroxide outlet of the digester is connected to the hydroxide inlet of the causticizer;

[0012] The regeneration electrolytic cell is further provided with a gas outlet, which is connected to the gas inlet of the calciner;

[0013] A water electrolysis device, comprising a water electrolysis tank having a hydrogen outlet;

[0014] The fuel synthesis device comprises a reactor, wherein the raw gas inlet of the reactor is respectively connected with the hydrogen outlet and the outlet of the calciner.

[0015] In some of the embodiments, the carbon dioxide capture device further comprises a preheater;

[0016] The alkaline oxide inlet of the preheater is connected to the alkaline oxide outlet of the calciner, and the alkaline oxide outlet of the preheater is connected to the inlet of the digester. The carbonate precipitate outlet of the preheater is also connected to the inlet of the calciner, and the gas outlet of the preheater is connected to the raw gas inlet of the reactor. The carbonate precipitate inlet of the preheater is connected to the carbonate precipitate inlet of the causticizer, and the gas inlet of the preheater is connected to the gas outlet of the calciner.

[0017] In some of the embodiments, the carbon dioxide capture device further comprises a dryer;

[0018] The carbonate precipitate inlet of the dryer is connected to the carbonate precipitate outlet of the causticizer and the steam outlet of the digester respectively; the steam inlet of the dryer is connected to the carbonate precipitate outlet of the causticizer and the steam outlet of the digester respectively; the carbonate precipitate outlet of the dryer is also connected to the carbonate precipitate inlet of the preheater.

[0019] In some of the embodiments, the carbon dioxide capture device further comprises an adsorber;

[0020] The dryer is further provided with a first steam outlet, and the steam inlet of the adsorber is connected to the first steam outlet; the gas outlet of the preheater and the gas outlet of the adsorber are respectively connected to the inlet of the CO2 tank, and the outlet of the CO2 tank is connected to the raw gas inlet of the reactor;

[0021] A compressor and a condenser are respectively provided between the outlet of the preheater and the inlet of the CO2 tank, and between the gas outlet of the adsorber and the gas inlet of the CO2 tank.

[0022] In some of the embodiments, the water electrolysis device further comprises a heat pump;

[0023] The heat pump is connected to the regeneration electrolytic cell and the water electrolytic cell respectively, and circulating water is introduced into the inlet of the heat pump, and the heat pump delivers circulating water to the regeneration electrolytic cell and the water electrolytic cell respectively;

[0024] The heat pump is further provided with a second steam outlet, the second steam outlet being in communication with the steam inlet of the adsorber;

[0025] The hydrogen outlet of the water electrolyzer is connected to the inlet of the H2 tank, the outlet of the H2 tank is connected to the raw gas inlet of the reactor, and a compressor is also connected between the hydrogen outlet of the water electrolyzer and the inlet of the H2 tank.

[0026] In some of the embodiments, the fuel synthesis device further comprises a first heat exchanger;

[0027] The product inlet of the first heat exchanger is communicated with the product outlet of the reactor. The first heat exchanger is further provided with a third steam outlet, which is communicated with the steam inlet of the adsorber.

[0028] In some of the embodiments, the fuel synthesis device further comprises a second heat exchanger;

[0029] The raw gas inlet of the second heat exchanger is connected to the outlet of the H2 tank and the outlet of the CO2 tank respectively, and the product inlet of the second heat exchanger is connected to the product outlet of the first heat exchanger; the raw gas outlet of the second heat exchanger is connected to the inlet of the reactor.

[0030] In some of the embodiments, the fuel synthesis device further comprises a third heat exchanger;

[0031] The product inlet of the third heat exchanger is connected to the product outlet of the second heat exchanger, and the water inlet of the third heat exchanger is also connected to circulating water;

[0032] The water outlet of the third heat exchanger is communicated with the water inlet of the first heat exchanger.

[0033] In some of the embodiments, the fuel synthesis device further comprises a separator;

[0034] The product inlet of the separator is connected to the product outlet of the third heat exchanger, and a condenser is further connected between the product inlet of the separator and the product outlet of the third heat exchanger;

[0035] The gas outlet of the separator is also connected to the raw gas inlet of the second heat exchanger, and a compressor is also connected between the gas outlet of the separator and the raw gas inlet of the second heat exchanger. The product outlet of the separator outputs green organic fuel.

[0036] According to a second aspect of the present invention, the present invention provides a method for synthesizing green fuel, using the green fuel synthesis system of any one embodiment of the first aspect of the present invention, comprising:

[0037] Air is transported to the absorber to react with the absorbent in the absorber to generate a product solution. After the pH value of the product solution drops to a specified value, part of the solution is transported to the causticizer to generate carbonate precipitates, and part of the solution is transported to the regeneration electrolytic cell. Before the pH value drops to the specified value, the solution is circulated to the absorber to capture carbon dioxide in the air. New absorbent is replenished to the absorber through the causticizer and the regeneration electrolytic cell.

[0038] The carbonate precipitate is transported to the calciner, the product solution is electrolyzed in the regeneration electrolytic cell, and the generated hydrogen and mixed gas are transported to the calciner to burn and calcine the carbonate to generate oxides and carbon dioxide;

[0039] The oxide is transported to a digester to generate hydroxide, the hydroxide is transported to a causticizer to generate absorbent, and the absorbent is input into the absorber together with the absorbent generated in the regeneration electrolyzer, and the absorbent is then input into the absorber;

[0040] At the same time, the water electrolyzer generates hydrogen by electrolyzing water, which is transported to the reactor. The reaction obtains carbon dioxide from the calciner, and the carbon dioxide and the hydrogen are synthesized into green organic fuel.

[0041] The implementation of the technical solution of the present invention has at least the following beneficial effects:

[0042] The green fuel synthesis system of the present invention is provided with an interconnected absorber, causticizer, digester, calciner and regeneration electrolyzer through a carbon dioxide capture device; the inlet of the causticizer, the inlet of the regeneration electrolyzer and the inlet of the absorber are respectively connected to the outlet of the absorber; the outlet of the causticizer is connected to the inlet of the calciner, and the outlet of the regeneration electrolyzer is connected to the inlet of the absorber; the regeneration electrolyzer is also provided with a gas outlet, which is also connected to the inlet of the calciner, the outlet of the calciner is connected to the inlet of the digester, the outlet of the digester is also connected to the inlet of the causticizer, and the outlet of the causticizer is also connected to the inlet of the absorber; a fuel synthesis device is also provided, including a reactor, the inlet of the reactor is connected to the outlet of the calciner; and a water electrolysis device is provided, including a water electrolyzer, the outlet of the water electrolyzer is also connected to the inlet of the reactor, and the inlet of the water electrolyzer is also fed with circulating water. Driven by green electricity, the present invention uses an alkaline absorbent to efficiently capture carbon dioxide from the air and generate carbonates. The hydrogen obtained after electrolytic regeneration can be burned in the system to generate heat, and pure carbon dioxide is generated by calcination. At the same time, driven by the waste heat output by the system, carbon dioxide is captured from the air by adsorption, and organic fuel is synthesized from carbon dioxide and hydrogen. This avoids obtaining a large amount of high-temperature heat from the outside and does not cause waste of low-grade heat. At the same time, there is no need to further purify the carbon dioxide generated by the electrolysis method, which simplifies the process procedure and reduces energy consumption.

[0043] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0045] Figure 1 The structure of the green fuel synthesis system provided by the present invention is shown as follows Figure 1 ;

[0046] Figure 2 The structure of the green fuel synthesis system provided by the present invention is shown as follows Figure 2 ;

[0047] Figure 3 The figure shows a flow chart of the synthesis method of the green fuel provided by the present invention.

[0048] Description of reference numerals:

[0049] 100 – CO2 capture plant;

[0050] 110 - causticizer; 120 - dryer; 130 - digester; 140 - preheater; 150 - calciner; 160 - adsorber; 170 - regeneration electrolyzer; 180 - absorber;

[0051] 200——Electrolysis water device;

[0052] 210——water electrolyzer; 220——heat pump;

[0053] 300 – Fuel synthesis unit;

[0054] 310 - reactor; 320 - first heat exchanger; 330 - second heat exchanger; 340 - third heat exchanger; 350 - separator;

[0055] 400——Compressor; 500——CO2 tank; 600——H2 tank; 700——Condenser.

[0056] The above drawings illustrate specific embodiments of the present invention, which will be described in more detail below. These drawings and the accompanying description are not intended to limit the scope of the present invention in any way, but rather to illustrate the concept of the present invention to those skilled in the art by reference to specific embodiments. DETAILED DESCRIPTION

[0057] The present invention will be further described below with reference to specific examples. It should be understood that these examples are only intended to illustrate the present invention and are not intended to limit the scope of the present invention.

[0058] The endpoints of the ranges and any values ​​disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range or the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0059] Unless otherwise specified, all embodiments and optional embodiments of the present invention can be combined with each other to form new technical solutions.

[0060] Unless otherwise specified, all technical features and optional technical features of the present invention can be combined with each other to form a new technical solution.

[0061] Unless otherwise specified, all steps of the present invention may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), which means that step (c) may be added to the method in any order, for example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0062] Unless otherwise specified, the terms "include" and "comprising" used in the present invention may be open-ended or closed-ended. For example, "include" and "comprising" may mean that other components not listed may also be included or that only the listed components are included.

[0063] By capturing carbon dioxide from the air and then using it to synthesize methanol, aviation fuel, etc., carbon dioxide can be reused and greenhouse gases can be effectively reduced. Existing methods for capturing carbon dioxide include alkali solution absorption combined with calcination or adsorption and temperature-variable desorption. Among them, the alkali solution absorption combined with calcination method is to capture carbon dioxide through an alkaline solution such as sodium hydroxide and then obtain alkaline carbon oxide through high-temperature calcination to generate carbon dioxide; since this method requires high-temperature calcination, a considerable part of the released waste heat is wasted, which has problems such as high energy consumption and poor energy-saving effect. The mixed gas of carbon dioxide captured by alkali solution absorption combined with electrolysis and oxidation needs to be further purified to obtain carbon dioxide, which makes the procedure complicated and the purification energy consumption high.

[0064] In view of this, the present invention provides a green fuel synthesis system that can effectively capture carbon dioxide from the air, and the hydrogen generated by the regenerative electrolyzer in the system can be used for calcination to generate higher-purity carbon dioxide, and the waste heat of the system is used to generate steam to provide it to the adsorption method for air carbon capture, and then the carbon dioxide is further used to synthesize green fuel.

[0065] The specific technical solutions of the present invention are as follows:

[0066] In some embodiments of the present invention, a green fuel synthesis system is provided, comprising: a carbon dioxide capture device 100, a water electrolysis device 200, and a fuel synthesis device 300; wherein the carbon dioxide capture device 100 includes an absorber 180, a causticizer 110, a digester 130, a calciner 150, and a regeneration electrolyzer 170 that are interconnected; the absorber 180 is provided with a product solution outlet, an absorbent inlet, and a product solution inlet, and the product solution outlet is respectively connected to the inlet of the causticizer 110, the solution inlet of the regeneration electrolyzer 170, and the product solution inlet; the outlet of the causticizer 110 is respectively connected to the inlet of the calciner 150 and the absorbent inlet; the inlet of the digester 130 is connected to the outlet of the calciner 150, and the inlet of the digester 130 is connected to the inlet of the causticizer 110; the regeneration electrolyzer 170 is further provided with a gas outlet, and the gas outlet is connected to the inlet of the calciner 150.

[0067] refer to Figure 1 The carbon dioxide capture device 100 includes, but is not limited to, one or more of a coupled hydrogen production and carbon dioxide capture module driven by electrical energy, a carbon dioxide capture module driven by high-temperature thermal energy, or a carbon dioxide capture module driven by waste heat within the system. In a preferred embodiment, the carbon dioxide capture device 100 may include a coupled hydrogen production and carbon dioxide capture module driven by electrical energy, a carbon dioxide capture module driven by high-temperature thermal energy, or a carbon dioxide capture module driven by waste heat within the system; through the functional complementarity and coordinated operation of the various modules within the carbon dioxide capture device 100, green electricity is efficiently utilized, the advantages of each module are fully utilized, the disadvantages are offset, and the energy of the carbon dioxide capture device 100 is efficiently coupled, thereby effectively reducing the energy consumption of capturing carbon dioxide and synthesizing organic fuel from carbon dioxide, and further effectively reducing the energy consumption cost of green fuel production.

[0068] An absorbent, such as sodium hydroxide solution, potassium hydroxide solution or calcium hydroxide solution, may be added to the carbon dioxide capture device 100. When air passes through the carbon dioxide capture device 100, the absorbent may absorb carbon dioxide in the air and react to generate a product solution, thereby capturing carbon dioxide.

[0069] Continue to refer Figure 1The carbon dioxide capture device 100 includes an interconnected absorber 180, a causticizer 110, a digester 130, a calciner 150, and a regeneration electrolytic cell 170. The inlet of the causticizer 110, the inlet of the regeneration electrolytic cell 170, and the product solution inlet of the absorber 180 are respectively connected to the product solution outlet of the absorber 180. An absorbent is added to the absorber 180. The absorber 180 can capture carbon dioxide in the air and react with the absorbent to generate a product solution. The product solution may contain products after the carbon dioxide and the absorbent are completely reacted, as well as products after the carbon dioxide and the absorbent are not completely reacted. The product solution after sufficient absorption of carbon dioxide can be divided into two parts, wherein the causticizer 110 will use the obtained part of the product solution to generate carbonate precipitates and transport them to the calciner 150; the regeneration electrolytic cell 170 will electrolyze the other part of the product solution to generate a mixed gas of carbon dioxide and oxygen and hydrogen, and transport them to the calciner 150; the absorber 180 will use the obtained product solution that has not fully absorbed carbon dioxide to continue to adsorb carbon dioxide in the air.

[0070] In this way, the product solution transported to the causticizer 110 generates a carbonate precipitate after reaction, and the product solution transported to the regeneration electrolytic cell 170 generates a mixture of carbon dioxide and oxygen and hydrogen after electrolysis. The carbonate precipitate, the mixed gas and the hydrogen are then transported to the calciner 150, where the carbonate is calcined to generate carbon dioxide by burning the hydrogen to generate heat. In this way, higher-purity carbon dioxide can be obtained after dehumidification for use as a raw material for synthesizing green organic fuels, avoiding the high energy consumption and cost of further purification of the mixture of carbon dioxide and oxygen produced by the regeneration electrolytic cell 170. At the same time, the combustion of hydrogen generates water, calcining carbonates does not damage the air environment, and the generated mixed gas can be more conveniently purified and stored for subsequent use. The product solution circulated to the absorber 180 can also further absorb carbon dioxide, allowing the absorbent to fully react and improve the efficiency of the absorbent.

[0071] In a preferred embodiment, a spraying member may be provided in the absorber 180. The spraying member is provided at the top of the absorber 180. The spraying member includes a plurality of nozzles with spray holes. The absorbent and the product solution may be sprayed through the spraying member, thereby increasing the contact area between the absorbent and the air and allowing the absorbent and the carbon dioxide to react more fully.

[0072] The water electrolysis device 200 and the fuel synthesis device 300 are respectively connected to the carbon dioxide capture device 100. The water electrolysis device 200 and the fuel synthesis device 300 are connected. The fuel synthesis device 300 obtains raw gas hydrogen from the water electrolysis device 200 and obtains carbon dioxide from the carbon dioxide capture device 100, and then synthesizes green organic fuel.

[0073] Continue to refer Figure 1 The alkaline oxide outlet of calciner 150 is also connected to the inlet of digester 130. Calciner 150 burns hydrogen obtained from regeneration electrolyzer 170 to generate heat, which calcines the carbonate obtained from causticizer 110, converting the carbonate into oxide. This oxide is then transported to digester 130, which then converts the oxide into hydroxide. The hydroxide inlet of causticizer 110 is also connected to the hydroxide outlet of digester 130. Causticizer 110 also obtains hydroxide from digester 130, which reacts with the product solution obtained from absorber 180 to produce absorbent. This absorbent is then transported to absorber 180 to absorb carbon dioxide from the air.

[0074] In some embodiments, the system further includes a water electrolysis device 200 and a fuel synthesis device 300, wherein the water electrolysis device 200 includes a water electrolyzer 210 having a hydrogen outlet; the fuel synthesis device 300 includes a reactor 310, and the raw gas inlet of the reactor 310 is respectively connected to the hydrogen outlet and the outlet of the calciner 150.

[0075] refer to Figure 1 The water electrolysis module 200 can be connected to the regeneration electrolyzer 170, and the water electrolyzer 210 in the water electrolysis module 200 can produce hydrogen and oxygen by electrolyzing water. Part of the hydrogen can be used to burn to generate heat to supply calcined carbonate to produce carbon dioxide. Another part of the hydrogen in the water electrolyzer 210 or all of the hydrogen can be transported to the reactor 310. The reactor 310 is connected to the water electrolyzer 210 and the calciner 150 respectively. The reactor 310 obtains carbon dioxide from the calciner 150 and hydrogen from the water electrolyzer 210, and then the reactor 310 synthesizes CO2 and H2 into green organic fuels, such as methanol. In this way, the energy in the system can be efficiently utilized to calcine carbonates, and it can also serve as a heat source for synthesizing green fuels, allowing the system to generate heat by itself and apply the heat to every location in the system, achieving maximum and efficient heat application, avoiding obtaining high-temperature heat from the outside or wasting low-grade heat, effectively reducing energy consumption and saving costs.

[0076] The present invention provides a green fuel synthesis system. The system comprises a carbon dioxide capture device, an interconnected absorber, a causticizer, a digester, a calciner and a regeneration electrolyzer. The inlet of the causticizer, the inlet of the regeneration electrolyzer and the inlet of the absorber are respectively connected to the outlet of the absorber. The outlet of the causticizer is connected to the inlet of the calciner, and the outlet of the regeneration electrolyzer is connected to the inlet of the absorber. The regeneration electrolyzer is further provided with a gas outlet, which is further connected to the inlet of the calciner, the outlet of the calciner is connected to the inlet of the digester, the outlet of the digester is further connected to the inlet of the causticizer, and the outlet of the causticizer is further connected to the inlet of the absorber. A fuel synthesis device is further provided, comprising a reactor, the inlet of the reactor is connected to the outlet of the calciner. A water electrolysis device is also provided, comprising a water electrolyzer, the outlet of the water electrolyzer is further connected to the inlet of the reactor, and circulating water is also introduced into the inlet of the water electrolyzer. Driven by green electricity, the present invention can efficiently capture carbon dioxide from the air using an alkaline absorbent to generate carbonates. Heat can be generated in the system by burning hydrogen regenerated by electrolysis, and pure carbon dioxide is generated by calcination. Carbon dioxide and hydrogen are then combined to form organic fuel. This avoids obtaining a large amount of high-temperature heat from the outside world and does not cause waste of low-grade heat. At the same time, there is no need to further purify the carbon dioxide generated by electrolysis, thus simplifying the process and reducing energy consumption.

[0077] In some embodiments, the carbon dioxide capture device further comprises a preheater; the alkaline oxide inlet of the preheater 140 is connected to the alkaline oxide outlet of the calciner 150, and the alkaline oxide outlet of the preheater 140 is connected to the inlet of the digester 130; the carbonate precipitate outlet of the preheater 140 is connected to the carbonate precipitate inlet of the calciner, and the gas outlet of the preheater 140 is connected to the feed gas inlet of the reactor 310. The carbonate precipitate inlet of the preheater 140 is connected to the carbonate precipitate outlet of the causticizer 110, and the gas inlet of the preheater 140 is connected to the gas outlet of the calciner.

[0078] refer to Figure 1The preheater 140 is primarily used to preheat the carbonate precipitate obtained from the causticizer 110 before feeding it into the calciner 150. It also recovers waste heat from the mixture of carbon dioxide and water vapor output from the calciner 150. Furthermore, the preheater 140 is also used to recover waste heat from the oxide obtained from the calciner 150 before feeding it into the digester 130. The digester 130 reacts the oxide obtained from the preheater 140 with water input from the digester 130's water inlet to produce hydroxides, which are then transported to the causticizer 110 to react with the product solution to produce carbonate precipitates and an absorbent solution. The preheater 140 can preheat the carbonate precipitate and recover waste heat from the product output from the calciner, thereby saving energy. It can also cool the oxide, allowing it to react more efficiently in the digester 130, improving the reaction efficiency of the system.

[0079] In some embodiments, the carbon dioxide capture device 100 further includes a dryer 120; the carbonate precipitate inlet of the dryer 120 is connected to the carbonate precipitate outlet of the causticizer 110, and the steam inlet of the dryer 120 is connected to the steam outlet of the digester 130; the carbonate precipitate outlet of the dryer 120 is also connected to the carbonate precipitate inlet of the preheater 140.

[0080] refer to Figure 1 The dryer 120 is connected between the causticizer 110 and the preheater 140. The dryer 120 can first dry the carbonate precipitate obtained from the causticizer 110 to remove moisture from the carbonate, and then output the dried carbonate to the preheater 140 for preheating. The preheated carbonate is then input into the calciner 150 for calcination, thereby providing high-temperature heat and allowing the carbonate to be calcined more quickly to decompose and produce gases such as carbon dioxide. In addition, the dryer 120 can also utilize the heat of the steam obtained from the digester 130 to avoid heat waste.

[0081] In some embodiments, the carbon dioxide capture device 100 also includes an adsorber 160; the dryer 120 is also provided with a first steam outlet, and the inlet of the adsorber 160 is connected to the first steam outlet; the gas outlet of the preheater 140 and the gas outlet of the adsorber 160 are respectively connected to the inlet of the CO2 tank 500, and the outlet of the CO2 tank 500 is connected to the raw gas inlet of the reactor 310; a compressor 400 and a condenser 700 are respectively provided between the gas outlet of the preheater 140 and the inlet of the CO2 tank 500, and between the gas outlet of the adsorber 160 and the inlet of the CO2 tank 500.

[0082] refer to Figure 1, the dryer 120 is also provided with a first steam outlet, and the first steam outlet is connected to the inlet of the adsorber; the adsorber 160 is filled with an active adsorbent, such as zeolite, porous zinc oxide or metal organic framework material, and the active adsorbent adsorbs carbon dioxide in the air, and the steam input from the first steam outlet has a certain amount of heat, which can cause the active adsorbent to desorb and produce carbon dioxide. After the mixed gas output from the calciner 150 is dried, relatively pure carbon dioxide can be obtained, and the carbon dioxide can be further compressed by the compressor 400 and stored in the CO2 tank 500; a condenser 700 can also be provided between the gas outlet of the adsorber 160 and the inlet of the CO2 tank 500. Since the mixed gas after passing through the preheater 140 is carbon dioxide and water, it is dehumidified by the condenser 700 and then compressed to obtain high-pressure carbon dioxide.

[0083] In some embodiments, the water electrolysis device 200 further includes a heat pump 220; the heat pump 220 is respectively connected to the regeneration electrolyzer 170 and the water electrolyzer 210, and circulating water is introduced into the inlet of the heat pump 220, and the heat pump 220 transports circulating water to the regeneration electrolyzer 170 and the water electrolyzer 210 respectively; the heat pump 220 is also provided with a second steam outlet, and the second steam outlet is connected to the steam inlet of the adsorber 160; the hydrogen outlet of the water electrolyzer 210 is connected to the inlet of the H2 tank 600, and the outlet of the H2 tank 600 is connected to the raw gas inlet of the reactor 310, and a compressor is also connected between the hydrogen outlet of the water electrolyzer 210 and the inlet of the H2 tank 600.

[0084] refer to Figure 1 Circulating water is introduced into the inlet of heat pump 220, which then circulates the circulating water to regeneration electrolyzer 170 and water electrolyzer 210. Since regeneration electrolyzer 170 and water electrolyzer 210 generate heat when electrolyzing the product solution and water, this heat is further improved by heat pump 220 to generate steam, which is then output through a second steam outlet provided on heat pump 220 and then transported to adsorber 160. The heat of the steam can cause the active adsorbent in adsorber 160 to desorb and produce carbon dioxide. The outlet of water electrolyzer 210 is also connected to a compressor and H2 tank 600. The hydrogen produced by water electrolyzer 210 is compressed by the compressor and stored in H2 tank 600, while the generated oxygen can be directly discharged.

[0085] In some embodiments, the fuel synthesis device 300 also includes a first heat exchanger 320; the product inlet of the first heat exchanger 320 is connected to the product outlet of the reactor 310, and the first heat exchanger 320 is also provided with a third steam outlet, which is connected to the steam inlet of the adsorber 160.

[0086] refer to Figure 1 and Figure 2Water can also be introduced into the water inlet of the first heat exchanger 320. The first heat exchanger 320 is mainly used to heat the remaining H2 and CO2 output by the reactor 310 and the remaining heat in the green organic fuel to generate steam. The steam can be input into the adsorber 160 through the third steam outlet. The steam can desorb the active adsorbent in the adsorber 160 to produce carbon dioxide.

[0087] In some embodiments, the fuel synthesis device 300 also includes a second heat exchanger 330; the raw gas inlet of the second heat exchanger 330 is connected to the outlet of the H2 tank 600 and the outlet of the CO2 tank 500 respectively, and the product inlet of the second heat exchanger 330 is connected to the product outlet of the first heat exchanger 320; the raw gas outlet of the second heat exchanger 330 is connected to the inlet of the reactor.

[0088] refer to Figure 1 and Figure 2 The inlet of the second heat exchanger 330 is connected to the outlet of the H2 tank 600 and the outlet of the CO2 tank 500, and the product inlet of the second heat exchanger 330 is connected to the product outlet of the first heat exchanger 320. The remaining H2 and CO2 output by the first heat exchanger 320 and the remaining heat of the green organic fuel are preheated through the second heat exchanger 330 to preheat the H2 and CO2, so that the carbon dioxide and hydrogen in the reactor 310 can react more efficiently, save energy, generate green organic fuel, and improve the reaction rate and efficiency in the reactor 310.

[0089] In some embodiments, the fuel synthesis device 300 also includes a third heat exchanger 340; the product inlet of the third heat exchanger 340 is connected to the product outlet of the second heat exchanger 330, and the water inlet of the third heat exchanger 340 also flows into circulating water; the water outlet of the third heat exchanger 340 is connected to the water inlet of the first heat exchanger 320.

[0090] refer to Figure 1 and Figure 2 The water inlet of the third heat exchanger 340 is connected to circulating water. The third heat exchanger 340 preheats the circulating water and then transfers it to the first heat exchanger 320. The third heat exchanger 340 uses the remaining H2 and CO2 output from the second heat exchanger 330, as well as the residual heat of the green organic fuel, to heat the water entering the third heat exchanger 340. In this way, the energy and resources of the entire synthesis system can be recycled and efficiently utilized, thereby improving the synthesis efficiency of the entire synthesis system and reducing energy consumption.

[0091] In some embodiments, the fuel synthesis device 300 further includes a separator 350. The product inlet of the separator 350 is connected to the product outlet of the third heat exchanger 340, and a condenser is connected between the product inlet of the separator 350 and the product outlet of the third heat exchanger 340. The gas outlet of the separator 350 is also connected to the feed gas inlet of the second heat exchanger 330, and a compressor is further connected between the gas outlet of the separator 350 and the feed gas inlet of the second heat exchanger 330. The product outlet of the separator 350 outputs green organic fuel.

[0092] refer to Figure 1 and Figure 2 Since the reaction in the reactor 310 may not be complete, the products output by the reactor 310 include green organic fuel and the reaction raw materials carbon dioxide and hydrogen. The separator 350 is connected to the reactor 310, and is mainly used to separate the remaining raw gas and green organic fuel output from the reactor 310, thereby outputting the green organic fuel to the system, and the remaining raw gas is compressed by the compressor and then re-transported to the reactor 310 for reaction, thereby maximizing the system's utilization of the raw gas, effectively reducing waste, and not causing carbon dioxide to be discharged, thereby achieving zero carbon emissions for the synthesis system.

[0093] In some embodiments of the present invention, a method for synthesizing green fuel is further provided, using the green fuel synthesis system of any of the above embodiments of the present invention, comprising:

[0094] S101. Air is transported to the absorber 180 to react with the absorbent in the absorber 180 to generate a product solution. After the pH value of the product solution drops to a specified value, part of the solution is transported to the causticizer 110 to generate carbonate precipitates, and part of the solution is transported to the regeneration electrolytic cell 170. Before the pH value drops to a specified value, the solution is circulated to the absorber 180 to capture carbon dioxide in the air. New absorbent is replenished to the absorber 180 through the causticizer 110 and the regeneration electrolytic cell 170.

[0095] S102, transporting the carbonate precipitate to the calciner 150, regenerating the electrolysis product solution in the electrolytic cell 170, and transporting the generated hydrogen and mixed gas to the calciner 150, burning and calcining the carbonate to generate oxides and carbon dioxide.

[0096] S103: The oxide is transported to the digester 130 to generate hydroxide, the hydroxide is transported to the causticizer 110 to generate absorbent, and the absorbent is input into the absorber 180 together with the absorbent generated by the regeneration electrolytic cell 170, and the absorbent is then input into the absorber 180.

[0097] S104. At the same time, the water electrolyzer 210 generates hydrogen by electrolyzing water and transmits it to the reactor 310. The reactor 310 obtains carbon dioxide from the calciner 150 and synthesizes CO2 and H2 into green organic fuel.

[0098] In some preferred embodiments, while step S103 is being carried out, the adsorber 160 absorbs carbon dioxide in the air and uses steam generated by waste heat from the system to heat the adsorbent to desorb the adsorbent and obtain carbon dioxide; then in step 104, the reactor 310 obtains carbon dioxide from the calciner 150 and the adsorber 160, and synthesizes CO2 and H2 into green organic fuel.

[0099] Specifically, through the system in the above embodiment, as Figure 2 As shown, in this embodiment, potassium hydroxide is used as an absorbent and is added to the absorber 180 to absorb carbon dioxide and generate a potassium carbonate-rich solution. A portion of the solution is transported to the regeneration electrolytic cell 170 to be regenerated into a potassium hydroxide solution, and the other portion is transported to the causticizer 110 to generate a calcium carbonate precipitate. After passing through the dryer 120 and the preheater 140, it reaches the calciner 150 for calcination to generate a mixed gas. After passing through the preheater 140, pure carbon dioxide is obtained. The mixed gas is stored in the CO2 tank 500 through the compressor 400. The hydrogen obtained in the regeneration electrolytic cell 170 is transported to the calciner 150 for combustion. The heat generated is used to decompose the calcium carbonate to generate carbon dioxide and calcium oxide. The calcium oxide is then transported to the digester 130 to react with water to generate calcium hydroxide. The calcium hydroxide is transported from the digester 130 to the causticizer 110 and added to the potassium carbonate-rich solution in the causticizer 110 to generate potassium hydroxide. The potassium hydroxide solution generated by the causticizer 110 and the regeneration electrolytic cell 170 is transported to the absorber 180. The adsorber absorbs carbon dioxide in the air, and the adsorbent is regenerated by steam generated by the waste heat of the system. The carbon dioxide is input into the CO2 tank, and the water electrolyzer 210 generates hydrogen which is input into the H2 tank. The obtained H2 and CO2 are synthesized into organic fuel in the reactor 310.

[0100] Parts of the present invention that are not described in detail are well known to those skilled in the art.

[0101] The basic principles of the present invention have been described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, and effects mentioned in the present invention are merely illustrative and non-limiting, and should not be construed as necessarily possessed by each embodiment of the present invention. Furthermore, the specific details disclosed above are provided for illustrative purposes and to facilitate understanding, and are not intended to be limiting. These details do not necessarily limit the present invention to being implemented using these specific details.

[0102] It should be noted that the terms "and / or" or " / " used herein are merely a description of an association relationship between associated objects, indicating that three relationships may exist. For example, A and / or B may represent three situations: A exists alone, A and B exist at the same time, and B exists alone. The singular forms "a," "the," and "the" used in the embodiments of the present invention and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0103] In the detailed description and claims, a list of items connected by the terms "at least one of," "at least one of," "at least one of," or other similar terms may mean any combination of the listed items. For example, if items A and B are listed, the phrase "at least one of A and B" means only A; only B; or A and B. In another example, if items A, B, and C are listed, the phrase "at least one of A, B, and C" means only A; or only B; only C; A and B (excluding C); A and C (excluding B); B and C (excluding A); or all of A, B, and C. Item A may contain a single element or multiple elements. Item B may contain a single element or multiple elements. Item C may contain a single element or multiple elements.

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A green fuel synthesis system, characterized in that: include: a carbon dioxide capture plant comprising an interconnected absorber, causticizer, digester, calciner and regenerative electrolyzer; The absorber is provided with a product solution outlet, an absorbent inlet and a product solution inlet, wherein the product solution outlet is connected to the inlet of the causticizer, the solution inlet of the regeneration electrolyzer and the product solution inlet respectively; The carbonate precipitate outlet of the causticizer is connected to the raw material inlet and the absorbent inlet of the calciner respectively; the inlet of the digester is connected to the alkaline oxide outlet of the calciner, and the hydroxide outlet of the digester is connected to the hydroxide inlet of the causticizer; The regeneration electrolytic cell is further provided with a gas outlet, which is connected to the inlet of the calciner; A water electrolysis device, comprising a water electrolysis tank having a hydrogen outlet; The fuel synthesis device comprises a reactor, wherein the raw gas inlet of the reactor is respectively connected with the hydrogen outlet and the outlet of the calciner.

2. The green fuel synthesis system according to claim 1, characterized in that: The carbon dioxide capture device further comprises a preheater; The alkaline oxide inlet of the preheater is connected to the outlet of the calciner, and the alkaline oxide outlet of the preheater is connected to the inlet of the digester; the alkaline oxide outlet of the preheater is also connected to the inlet of the calciner and the inlet of the reactor respectively; The carbonate precipitate inlet of the preheater is connected to the carbonate precipitate inlet of the causticizer, and the gas inlet of the preheater is connected to the gas outlet of the calciner.

3. The green fuel synthesis system according to claim 2, characterized in that: The carbon dioxide capture device further comprises a dryer; The carbonate precipitate inlet of the dryer is connected to the carbonate precipitate outlet of the causticizer and the steam outlet of the digester respectively; the steam inlet of the dryer is connected to the carbonate precipitate outlet of the causticizer and the steam outlet of the digester respectively; the carbonate precipitate outlet of the dryer is also connected to the carbonate precipitate inlet of the preheater.

4. The green fuel synthesis system according to claim 3, characterized in that: The carbon dioxide capture device also includes an adsorber, a CO2 tank and an H2 tank; The dryer is further provided with a first steam outlet, and the steam inlet of the adsorber is connected to the first steam outlet; the gas outlet of the preheater and the gas outlet of the adsorber are respectively connected to the inlet of the CO2 tank, and the outlet of the CO2 tank is connected to the raw gas inlet of the reactor; A compressor and a condenser are respectively provided between the outlet of the preheater and the inlet of the CO2 tank, and between the gas outlet of the adsorber and the gas inlet of the CO2 tank.

5. The green fuel synthesis system according to claim 4, characterized in that: The water electrolysis device also includes a heat pump; The heat pump is connected to the regeneration electrolytic cell and the water electrolytic cell respectively, and circulating water is introduced into the inlet of the heat pump, and the heat pump delivers circulating water to the regeneration electrolytic cell and the water electrolytic cell respectively; The heat pump is further provided with a second steam outlet, the second steam outlet being in communication with the steam inlet of the adsorber; The hydrogen outlet of the water electrolyzer is connected to the inlet of the H2 tank, the outlet of the H2 tank is connected to the raw gas inlet of the reactor, and a compressor is also connected between the hydrogen outlet of the water electrolyzer and the inlet of the H2 tank.

6. The green fuel synthesis system according to any one of claims 1 to 5, characterized in that: The fuel synthesis device further includes a first heat exchanger; The product inlet of the first heat exchanger is communicated with the product outlet of the reactor. The first heat exchanger is further provided with a third steam outlet, which is communicated with the steam inlet of the adsorber.

7. The green fuel synthesis system according to claim 6, characterized in that: The fuel synthesis device further includes a second heat exchanger; The raw gas inlet of the second heat exchanger is connected to the outlet of the H2 tank and the outlet of the CO2 tank respectively, and the product inlet of the second heat exchanger is connected to the outlet of the first heat exchanger; the raw gas outlet of the second heat exchanger is connected to the inlet of the reactor.

8. The green fuel synthesis system according to claim 7, characterized in that: The fuel synthesis device further includes a third heat exchanger; The product inlet of the third heat exchanger is connected to the product outlet of the second heat exchanger, and the water inlet of the third heat exchanger is also connected to circulating water; The water outlet of the third heat exchanger is communicated with the water inlet of the first heat exchanger.

9. The green fuel synthesis system according to claim 8, characterized in that: The fuel synthesis device further includes a separator; The product inlet of the separator is connected to the product outlet of the third heat exchanger, and a condenser is further connected between the product inlet of the separator and the product outlet of the third heat exchanger; The gas outlet of the separator is also connected to the raw gas inlet of the second heat exchanger, and a compressor is also connected between the gas outlet of the separator and the raw gas inlet of the second heat exchanger; the product outlet of the separator outputs green organic fuel.

10. A method for synthesizing green fuel, characterized in that: A green fuel synthesis system according to any one of claims 1 to 9, comprising: Air is transported to an absorber to react with an absorbent in the absorber to generate a product solution. After the pH value of the product solution drops to a specified value, part of the solution is transported to a causticizer to generate carbonate precipitates, and part of the solution is transported to a regeneration electrolytic cell. Before the pH value drops to a specified value, the recycled part is transported to the absorber to mix with the absorbent and capture carbon dioxide in the air. The absorbent is replenished to the absorber through the causticizer and the regeneration electrolytic cell. The carbonate precipitate is transported to the calciner, the product solution is electrolyzed in the regeneration electrolytic cell, and the generated hydrogen and mixed gas are transported to the calciner to burn and calcine the carbonate to generate oxides and carbon dioxide; The oxide is transported to a digester to generate hydroxide, the hydroxide is transported to a causticizer to generate absorbent, the absorbent and the absorbent generated in the regeneration electrolytic cell are input into the absorber, and the absorbent is then input into the absorber; At the same time, the water electrolyzer generates hydrogen by electrolyzing water, which is transported to the reactor. The reaction obtains carbon dioxide from the calciner, and the carbon dioxide and the hydrogen are synthesized into green organic fuel.

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