Ship carbon dioxide exhaust gas treatment system

Abstract

The present application provides a ship carbon dioxide tail gas treatment system, the system captures high concentration carbon dioxide captured by traditional CCS capture device, realizes carbon dioxide tail gas utilization electric conversion through electro-catalytic reduction technology, stores or directly discharges liquid organic product mainly in formic acid / formate, replaces existing liquefied storage CCS scheme, reduces energy consumption and storage space, and the product has higher economic value than liquid carbon dioxide.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ship decarbonization, in particular to a ship carbon dioxide tail gas treatment device and system. BACKGROUND

[0002] The world today is facing the severe challenge of global climate change, which is driving the development of clean energy and carbon reduction technologies. Carbon peak and carbon neutrality have become the common task of governments and enterprises. The shipping industry is one of the important sources of greenhouse gases. Currently, shipping fuels are mainly low-sulfur fuel oil, high-sulfur fuel oil, diesel, and LNG, and shipping carbon dioxide emissions are mainly concentrated in the use of these fossil fuels. With the implementation of the International Maritime Organization's emission reduction strategy, carbon reduction will become an important direction for future ship emission control.

[0003] Currently, ship emission reduction mainly relies on the use of low-carbon clean fuels, reduction of ship energy consumption, and carbon capture and storage (CCS) technology. However, these methods still have limitations. Reducing ship energy consumption has limited effect on carbon reduction and cannot achieve large-scale carbon reduction for ships. Low-carbon clean fuel ships such as methanol ships, ammonia ships, and LNG ships are an important technical direction for future ship carbon reduction, but they have high construction costs, expensive clean fuels, and immature technology, making them difficult to be widely applied.

[0004] Currently, the mainstream of ships still uses fossil fuels for power, and for this type of stock ship, only CCS technology can be used to capture and store carbon dioxide tail gas to achieve carbon reduction. Although CCS technology can achieve large-scale carbon reduction for stock fossil fuel ships, it has high energy consumption, and the captured carbon dioxide can only be stored in storage tanks, which requires a large storage space and has low utilization value, making it difficult to meet the actual application requirements of ships.

[0005] The applicant has been committed to the development of technology and equipment in the field of CCUS for a long time, and has adjusted and optimized the structure and control of the equipment for different application scenarios, and thus provides a ship carbon dioxide tail gas utilization treatment device. The device can form a ship carbon dioxide tail gas treatment system with a CCS capture device, and by applying high-performance, high-selectivity, and long-life electrochemical catalysts to the tail gas utilization treatment device through electro-catalytic reduction technology, the carbon dioxide tail gas can be converted into liquid organic products mainly in the form of formic acid / formate for storage or direct emission, replacing the existing CCS scheme of liquefied storage, reducing energy consumption and storage space, and the products have higher economic value than liquid carbon dioxide. SUMMARY

[0007] TECHNICAL PROBLEM

[0008] The purpose of the present application is to overcome the problems of high energy consumption, large storage space and low utilization value after capture of the existing CCS carbon emission reduction technology in the ship industry, and to provide a brand new ship carbon dioxide tail gas treatment system.

[0009] Technical solution

[0010] To solve the above technical problems, the present application provides a ship carbon dioxide tail gas treatment system, which comprises a desulfurization tower, a carbon capture reaction tower and an electrocatalytic reaction integrated device, the desulfurization tower is connected with the carbon capture reaction tower through a pipeline, the emission tail gas after desulfurization and denitrification enters the carbon capture reaction tower through the pipeline for carbon dioxide capture, the carbon capture reaction tower is connected with the electrocatalytic reaction integrated device through a pipeline, and the products converted by the electrocatalytic reaction integrated device can be directly discharged into the sea or stored in the ship ballast tank through the pipeline.

[0011] Among them, the gas components captured by the carbon capture reaction tower have a carbon dioxide volume concentration of >65%, a sulfur dioxide of <100ppm, and an oxygen volume concentration of <10%.

[0012] Among them, the ship carbon dioxide tail gas treatment system can further comprise a carbon dioxide storage tank.

[0013] Among them, the electrocatalytic reaction integrated device specifically comprises a reactant material supply device, a plurality of carbon dioxide reactors, a reactant material collection device and a container shell, and the reactant material supply device, the carbon dioxide reactors and the reactant material collection device are arranged and fixed in the container shell.

[0014] Among them, the specific structure of the carbon dioxide reactor comprises: 2 end plates, 2 insulating plates, n cathode gas flow field plates, n cathode gas diffusion electrodes, n cathode electrolyte flow field plates, n ion exchange membranes, n anode gas diffusion electrodes, n anode electrolyte flow field plates and sealing washers, the 2 end plates are at the outermost side, the 2 insulating plates are respectively adjacent to one end plate, the cathode gas flow field plate and the anode electrolyte flow field plate are respectively adjacent to one insulating plate, the cathode gas diffusion electrode and the anode gas diffusion electrode are respectively adjacent to the cathode gas flow field plate and the anode electrolyte flow field plate, the cathode electrolyte flow field plate and the cathode gas diffusion electrode are adjacent, the ion exchange membrane is arranged between the cathode electrolyte flow field plate and the anode gas diffusion electrode, wherein, there is a sealing washer between every two plates, and n≤20.

[0015] The reactant material supply device comprises a carbon dioxide gas supply device, a cathode electrolyte supply device and an anode electrolyte supply device, the carbon dioxide gas supply device, the cathode electrolyte supply device and the anode electrolyte supply device are respectively connected to corresponding feeding ports of the carbon dioxide reactor through pipelines, the feeding flow and pressure of the carbon dioxide gas, the feeding flow and pressure of the anode electrolyte and the cathode electrolyte are controlled and monitored through the proportion valve, the pressure sensor and the flow sensor arranged on the pipelines, and then the electro-catalytic reaction efficiency and the electric energy utilization efficiency are controlled.

[0016] The carbon dioxide gas supply device comprises a gas buffer tank, a pressure reducing valve, a pressure sensor, a proportion valve, a pressure sensor, a flow sensor and a connecting pipeline.

[0017] The cathode electrolyte supply device comprises a cathode liquid storage tank, a delivery pump, a proportion valve, a flow sensor, a pressure sensor and a connecting pipeline.

[0018] The anode electrolyte supply device comprises an anode liquid storage tank, a delivery pump, a solenoid valve, a pressure sensor, a flow sensor and a connecting pipeline.

[0019] The cathode electrolyte is circulated for 3-7 days, and the anode electrolyte is circulated for 10-25 days.

[0020] Beneficial effects

[0021] The application provides a ship carbon dioxide tail gas treatment system, which realizes the utilization of carbon dioxide tail gas by electro-catalytic reduction technology, and the carbon dioxide tail gas captured by a traditional CCS capture device is converted into liquid organic products mainly in the form of formic acid / formate by electric conversion for storage or direct emission, so that the existing CCS scheme of liquid storage is replaced, energy consumption and storage space are reduced, and the products have higher economic value than liquid carbon dioxide. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a whole structure diagram of the ship carbon dioxide tail gas treatment system of the application;

[0023] Figure 2 is a top view of the electro-catalytic reaction integrated device of the application;

[0024] Figure 3 is a front view of the electro-catalytic reaction integrated device of the application;

[0025] Figure 4 is a whole structure diagram of the electro-catalytic reaction integrated device of the application.

[0026] Best mode of the application

[0027] The application provides a ship carbon dioxide tail gas treatment system, which comprises a desulfurization tower, a carbon capture reaction tower and an electrocatalytic reaction integrated device, the desulfurization tower is connected with the carbon capture reaction tower through a pipeline, the emission tail gas after desulfurization and denitrification enters the carbon capture reaction tower through the pipeline for carbon dioxide capture, the carbon capture reaction tower is connected with the electrocatalytic reaction integrated device through a pipeline, the product converted by the electrocatalytic reaction integrated device can be directly discharged into the sea or stored in the ship ballast tank through the pipeline, and is used for being converted into a higher value product on land, and can be used as a carbon source for a biological fermentation system to be converted into a multi-carbon product.

[0028] The gas component entering the carbon capture reaction tower through the desulfurization tower has a sulfur dioxide concentration of 10-100 ppm and a carbon dioxide volume concentration of 1.0%-5.5%.

[0029] The gas component after carbon capture by the carbon capture reaction tower has a carbon dioxide volume concentration of > 65%, a sulfur dioxide content of < 100 ppm and an oxygen volume concentration of < 10%.

[0030] Limited by the energy consumption and carbon dioxide emission reduction amount in the ship scene, the electrocatalytic reaction integrated device cannot realize 100% conversion of captured carbon dioxide into liquid organic products for large ships, therefore, the ship carbon dioxide tail gas treatment system can further comprise a carbon dioxide storage tank for storing part of the captured carbon dioxide.

[0031] The electrocatalytic reaction integrated device specifically comprises a reactant material supply device, a plurality of carbon dioxide reactors, a reactant material collection device and a container shell. The reactant material supply device, the carbon dioxide reactors and the reactant material collection device are arranged and fixed in the container shell respectively.

[0032] According to the processing scale of the electrocatalytic reaction integrated device, different numbers of carbon dioxide reactors are connected, the volume of a single carbon dioxide reactor is 0.1-0.3 m 3 , the daily processing capacity of a single carbon dioxide reactor is 180-500 kg, and the power is 8-30 kw, the carbon dioxide processing capacity and the power are related to multiple factors such as the number of reactor series connection, electrode area and catalyst performance.

[0033] Based on the power of the standby generator on the ship is usually 700kw, the power allocated to the capture reactor tower is 400kw, the demand of daily capture of <48t of carbon dioxide can be realized, the power allocated to the integrated device of electro-catalytic reaction is 300kw, according to the single carbon dioxide highest daily processing capacity of 500kg in the integrated device of electro-catalytic reaction provided by the application and the power of single reactor under the processing capacity of at least 8kw-30kw, the daily processing demand of <20t of carbon dioxide can be realized at present, and the design and matching of the integrated device of electrochemical reaction and the carbon dioxide storage tank are carried out according to the total power of the generator provided by the ship. The specific structure of the single carbon dioxide reactor comprises: two end plates, two insulating plates, n cathode gas flow field plates, n cathode gas diffusion electrodes, n cathode electrolyte flow field plates, n ion exchange membranes, n anode gas diffusion electrodes, n anode electrolyte flow field plates and sealing gaskets, the two end plates are at the outermost side, the two insulating plates are respectively adjacent to one of the end plates, the cathode gas flow field plate and the anode electrolyte flow field plate are respectively adjacent to one of the insulating plates, the cathode gas diffusion electrode and the anode gas diffusion electrode are respectively adjacent to the cathode gas flow field plate and the anode electrolyte flow field plate, the cathode electrolyte flow field plate is adjacent to the cathode gas diffusion electrode, and the ion exchange membrane is arranged between the cathode electrolyte flow field plate and the anode gas diffusion electrode. Wherein, there is a sealing gasket between every two plates, and n≤20.

[0034] Wherein, one insulating plate, one cathode gas flow field plate, one cathode gas diffusion electrode, one cathode electrolyte flow field plate, one ion exchange membrane, one anode gas diffusion electrode and a plurality of sealing gaskets form a single cell module; the single cell module can be amplified by series connection to form the required single carbon dioxide reactor.

[0035] Wherein, the electrolysis voltage can be applied to the entire amplified series-connected single carbon dioxide reactor or the single cell module of each series-connected carbon dioxide reactor.

[0036] The anode gas diffusion electrode is coated with an anode catalyst, which can be a commercially available iridium-based or ruthenium-based catalyst.

[0037] The cathode gas diffusion electrode is coated with a cathode catalyst, which can be a commercially available copper-based catalyst, bismuth-based catalyst or tin-based catalyst.

[0038] The carbon dioxide reactor can also adopt other types of electrolytic cell structures, such as MEA membrane electrode structure, specifically by removing the cathode electrolyte flow field plate, the cathode gas flow field plate is adjacent to the cathode gas diffusion electrode, and the cathode gas diffusion electrode is adjacent to the ion exchange membrane.

[0039] For the MEA membrane electrode structure, the anode catalyst and the cathode catalyst are directly coated on both sides of the ion exchange membrane.

[0040] The ion exchange membrane can be a cation exchange membrane or a proton exchange membrane.

[0041] The reactant supply device comprises a carbon dioxide gas supply device, a cathode electrolyte supply device and an anode electrolyte supply device, each of which is connected to a corresponding inlet of the carbon dioxide reactor through a pipeline, and the feeding flow rate and pressure of the carbon dioxide gas, the anode electrolyte and the cathode electrolyte are controlled and monitored through the proportioning valve, the pressure sensor and the flow sensor arranged on the pipeline, so as to control the electro-catalytic reaction efficiency and the electric energy utilization efficiency.

[0042] The carbon dioxide gas supply device comprises a gas buffer tank, a pressure reducing valve, a pressure sensor, a proportioning valve, a pressure sensor, a flow sensor and a connecting pipeline, the gas buffer tank is connected to the pressure reducing valve through the connecting pipeline, the pressure reducing valve is connected to the proportioning valve through the connecting pipeline, the proportioning valve is connected to the carbon dioxide reactor through the pipeline, and the pressure sensor and the flow sensor are arranged on the pipeline and can be interchanged.

[0043] The carbon dioxide gas supply device can further comprise a heater arranged between the pressure reducing valve and the proportioning valve, which can heat the temperature of the captured carbon dioxide gas source, so as to improve the electrochemical catalytic reaction efficiency.

[0044] The carbon dioxide gas supply device can further comprise a humidifier arranged between the pressure reducing valve and the proportioning valve, which can humidify the captured carbon dioxide gas source, so as to improve the subsequent electrochemical catalytic reaction efficiency.

[0045] The humidifier mainly comprises a gas inlet, a gas outlet, a water inlet and a water outlet, and an internal bundled hollow fiber. The working principle is as follows: the gas and water are countercurrently introduced into the humidifier, the dry gas enters the hollow fiber through the gas inlet of the humidifier, and the water enters the inside of the humidifier (outside the hollow fiber) through the water inlet of the humidifier. Based on the pressure difference between the inside and outside of the hollow fiber (the outside is greater than the inside), the water passes through the fiber to humidify the gas.

[0046] The cathode electrolyte supply device comprises a cathode liquid storage tank, a delivery pump, a proportioning valve, a flow sensor, a pressure sensor and a connecting pipeline, the cathode liquid storage tank is connected to the delivery pump through the connecting pipeline, the delivery pump is connected to the carbon dioxide reactor through the connecting pipeline, and the proportioning valve, the pressure sensor and the flow sensor are arranged on the connecting pipeline in sequence, wherein the pressure sensor and the flow sensor can be interchanged.

[0047] The anode electrolyte supply device comprises an anode liquid storage tank, a delivery pump, a solenoid valve, a pressure sensor, a flow sensor and a connecting pipeline, the anode liquid storage tank is connected to the delivery pump through the connecting pipeline, the delivery pump is connected to the carbon dioxide reactor through the connecting pipeline, and a proportional valve, a pressure sensor and a flow sensor are sequentially arranged on the connecting pipeline, wherein the positions of the pressure sensor and the flow sensor are interchangeable.

[0048] The carbon dioxide gas supply device, the cathode electrolyte supply device and the anode electrolyte supply device can further comprise a solenoid valve arranged before the proportional valve, which can control the use of the reaction path based on actual demand, thereby minimizing the use of materials and reducing the cost of ship decarbonization.

[0049] The carbon dioxide reactor has three feeding ports and three discharging ports, the feeding ports are specifically carbon dioxide gas inlets, cathode electrolyte inlets and anode electrolyte inlets, and the discharging ports are specifically carbon dioxide gas outlets, cathode electrolyte outlets and anode electrolyte outlets.

[0050] The reaction product collecting device comprises a carbon dioxide gas recycling device, a cathode outlet product recycling collecting device and an anode outlet product recycling collecting device.

[0051] The purpose of the recycling collecting device is firstly to reduce the loss of reaction materials, fully utilize the reaction materials and improve the utilization efficiency of the reaction materials. The utilization efficiency of the electrochemical reaction materials without recycling is low, which brings huge material loss and material cost. Secondly, the recycling device can also optimize the recycling times of the reaction materials to balance the utilization efficiency of the reaction materials and the energy conversion efficiency. For the ship industry, energy consumption is always a problem that cannot be avoided in ship decarbonization. The energy consumption on the ship is limited, and how to achieve carbon dioxide emission reduction while not affecting normal shipping within the limited energy consumption is the first problem to be solved in the industry. The applicant finds the most reasonable recycling time through research and testing to ensure that the ship decarbonization treatment work is maximized.

[0052] Specifically, the carbon dioxide gas can be recycled for a long time, preferably for 10-30 days, more preferably for 15-25 days, and after the recycling is terminated, the discharged gas is treated by alkali absorption.

[0053] Specifically, the recycling times of the cathode electrolyte are preferably 3-10 days, more preferably 3-7 days. If the recycling times are too many, the ion conductivity will be reduced, which will affect the performance of the electrocatalytic reaction. If the recycling times are too low, the electrolyte cannot be fully utilized, which will cause the cost to rise.

[0054] Specifically, the circulation times of the anode electrolyte are preferably 5-20 days, and more preferably 8-15 days. Compared with the cathode electrolyte, the anode electrolyte only has water involved in the reaction, and thus has less loss and longer circulation time, thereby reducing the cost. If the circulation times of the anode electrolyte are too many, the pH value of the electrolyte will decrease, and the ionic conductivity will decrease, thereby affecting the performance of the electrocatalytic reaction. In addition, the anode electrolyte discharged after circulation can also be used as an alkali solution for absorbing CO2.

[0055] The carbon dioxide gas circulation pipeline comprises a gas-liquid separator, a gas return pump, a proportional valve and a connecting pipeline, the gas-liquid separator comprises a gas-liquid mixed inlet, a gas outlet and a liquid outlet, the gas-liquid mixed inlet is connected with the carbon dioxide cathode gas outlet of the reactor through the connecting pipeline, the gas-liquid separator is used to separate the carbon dioxide gas and the cathode reaction liquid at the outlet of the reactor, the gas outlet is recycled to the connecting pipeline of the carbon dioxide gas supply device through the gas return pump, and is further introduced into the carbon dioxide reactor for circulation reaction, which is beneficial to improving the utilization efficiency of carbon dioxide, and the liquid outlet is recycled to the cathode liquid storage tank through the connecting pipeline.

[0056] The cathode outlet product circulation collection device comprises, in sequence, a proportional valve, a gas-liquid separator, a cathode buffer tank, a cathode byproduct gas storage tank and a three-way valve, and electromagnetic valves and connecting pipelines are arranged at two outlets of the three-way valve.

[0057] The proportional valve arranged in the cathode outlet product collection device can be used to adjust the back pressure and ensure the pressure balance in the reactor.

[0058] The gas-liquid separator is used to separate a small amount of carbon monoxide and hydrogen produced in the cathode reaction, the gas outlet of the gas-liquid separator is connected to the cathode byproduct gas storage tank, and the cathode byproduct gas storage tank is used to store the byproduct carbon monoxide and hydrogen.

[0059] The liquid outlet of the gas-liquid separator is connected to the three-way valve, one outlet of the three-way valve is recycled back to the cathode liquid storage tank for circulation use, and the other outlet is connected to the cathode buffer tank.

[0060] The reaction liquid in the cathode buffer tank can be directly discharged into the sea through the pipeline or stored in the ballast tank through the pipeline.

[0061] The electromagnetic valves arranged at the two outlet routes of the three-way valve can be used to control the circulation use time of the cathode electrolyte and improve the utilization efficiency of the reactants.

[0062] The anode outlet product circulation collecting device comprises a proportional valve, a gas-liquid separator and a connecting pipeline, and the reacted anode electrolyte is circulated and supplemented into the anode liquid storage tank through the connecting pipeline from the carbon dioxide reactor anode electrolyte outlet.

[0063] The proportional valve of the anode outlet product circulation collecting device can also be used to adjust the back pressure to ensure the pressure balance of the reactor.

[0064] The proportional valve of the anode outlet product circulation collecting device is provided with a gas-liquid separation device behind it, which is used to separate and discharge the oxygen generated by the anode reaction.

[0065] The reaction material supply device, the carbon dioxide reactor and the reaction material collecting device are fixed in the container module through optimized design and arrangement, the carbon dioxide gas, the cathode electrolyte and the anode electrolyte are respectively transported into the carbon dioxide reactor by the reaction material supply device, the carbon dioxide gas is reduced into liquid organic / organic salt products, mainly formic acid / formate, through catalytic reaction of high-efficiency catalyst under the driving of electric power, and then the reacted products are circulated or collected through the reaction product collecting device.

[0066] The application also provides a method for treating carbon dioxide tail gas by using the above-mentioned ship carbon dioxide tail gas treatment system, specifically comprising the following steps:

[0067] The high-concentration carbon dioxide tail gas obtained by sequentially passing through the desulfurization tower and the carbon capture reaction tower is introduced into the gas buffer tank in the electro-catalytic reaction integrated device, and is further introduced into the carbon dioxide reactor for electro-catalytic treatment.

[0068] In order to ensure the pressure of the reaction gas source, the pressure in the gas buffer tank is required to be greater than 0.5Mpa, and the flow and pressure of the gas, the cathode electrolyte and the anode electrolyte entering the single carbon dioxide reactor are controlled to optimize and improve the electrochemical performance and energy conversion efficiency of the reactor.

[0069] Based on the large-size reactor, the gas pressure entering the carbon dioxide reactor is preferably 20-200kpa, and further preferably 20-150kpa; the pressure of the cathode electrolyte and the anode electrolyte entering the carbon dioxide reactor is also preferably 20-200kpa, and more preferably 20-150kpa; wherein the carbon dioxide gas side pressure is 5-10kpa higher than the cathode electrolyte side pressure, which not only can improve the diffusion of the carbon dioxide gas to the cathode gas diffusion electrode, but also can effectively alleviate the reverse osmosis of the cathode electrolyte to the gas side through the gas diffusion electrode.

[0070] The gas flow into the carbon dioxide reactor is preferably 1200-4500 L / h, further preferably 1500-2300 L / h; the flow of the catholyte and the anolyte into the carbon dioxide reactor is kept consistent, specifically 0.1-1 times the carbon dioxide gas flow, more preferably 0.2-0.4 times the carbon dioxide gas flow;

[0071] In addition, the overall performance can also be improved by controlling the temperature and humidity of the carbon dioxide gas entering the reactor. Certain temperature can improve the kinetics of the reaction and promote the occurrence of the reaction. Suitable humidity is conducive to the formation of gas-liquid-solid three-phase interface and the progress of the reaction.

[0072] Specifically, the temperature of the carbon dioxide gas entering the reactor is preferably 25-60℃, more preferably 35-50℃;

[0073] Specifically, the humidity of the carbon dioxide gas entering the reactor is preferably 30%-100%, more preferably 50%-80%.

[0074] Embodiments of the present application

[0075] The embodiments of the present application are described in detail below with examples and drawings, so that the process of how the present application applies technical means to solve technical problems and achieve technical effects can be fully understood and implemented.

[0076] As shown in Figure 1 The present application provides a ship carbon dioxide tail gas treatment system, which comprises a desulfurization tower 2, a carbon capture reaction tower 3, an electro-catalytic reaction integrated device 1 and a carbon dioxide storage tank 4. The desulfurization tower 2 is connected to the carbon capture reaction tower 3 through a pipeline. The exhaust gas after desulfurization and denitrification enters the carbon capture reaction tower 3 through the pipeline for carbon dioxide capture. The carbon capture reaction tower 3 is connected to the electro-catalytic reaction integrated device 1 through a pipeline. The high-concentration CO2 gas obtained by capture is introduced into the electro-catalytic reaction integrated device 1. The products of electro-catalytic conversion can be directly discharged into the sea or stored in the ship ballast tank 5 through a pipeline. Another pipeline of the carbon capture reaction tower 3 is connected to the carbon dioxide storage tank 4 for storing part of the captured carbon dioxide.

[0077] As shown in Figures 2 to 4As shown, the integrated electro-catalytic reactor provided by the present application specifically comprises a reactant supply device 11, 32 carbon dioxide reactors 12, a reactant collection device 13 and a container shell 14. The reactant supply device 11, the carbon dioxide reactor 12 and the reactant collection device 13 are respectively arranged and fixed in the container shell 14. The total carbon dioxide treatment capacity of the integrated electro-catalytic reactor is 12.8 t / d, and the carbon dioxide treatment capacity of a single carbon dioxide reactor is 400 kg / d.

[0078] The cathode of the carbon dioxide reactor uses commercially available SnO2 (Aldrich) as the catalyst carrier, and the loading amount is 1 mg / cm 2 ; the anode uses commercially available IrO2 (Macklin) as the catalyst, and the loading amount is 0.5 mg / cm 2 ; the ion exchange membrane uses a nafion 115 membrane; 1M / L KHCO3 solution is used as the cathode electrolyte, 1M / L KOH solution is used as the anode electrolyte, and the power of a single reactor is 9.35 kw.

[0079] The reactant supply device 11 comprises a carbon dioxide gas supply device 111, a cathode electrolyte supply device 112 and an anode electrolyte supply device 113. The carbon dioxide gas supply device 111, the cathode electrolyte supply device 112 and the anode electrolyte supply device 113 are respectively connected to the corresponding feeding ports of the carbon dioxide reactors through pipelines. The feeding flow rate and pressure of the carbon dioxide gas, the feeding flow rate and pressure of the anode electrolyte and the cathode electrolyte are controlled and monitored by the proportioning valves, pressure sensors and flow sensors arranged on the pipelines, so as to control the electro-catalytic reaction efficiency and the electric energy utilization efficiency.

[0080] The carbon dioxide gas supply device 111 comprises a gas buffer tank, a pressure reducing valve, a pressure sensor, a proportioning valve, a pressure sensor, a flow sensor and connecting pipelines. The gas buffer tank is connected to the pressure reducing valve through the connecting pipelines, the pressure reducing valve is connected to the proportioning valve through the connecting pipelines, the proportioning valve is connected to the carbon dioxide reactors through the pipelines, and the pressure sensor and the flow sensor are arranged on the pipelines and can be interchanged.

[0081] The cathode electrolyte supply device 112 comprises a cathode liquid storage tank, a delivery pump, a proportioning valve, a flow sensor, a pressure sensor and connecting pipelines. The cathode liquid storage tank is connected to the delivery pump through the connecting pipelines, the delivery pump is connected to the carbon dioxide reactors through the connecting pipelines, and the proportioning valve, the pressure sensor and the flow sensor are arranged on the connecting pipelines in sequence, wherein the pressure sensor and the flow sensor can be interchanged.

[0082] The anode electrolyte supply device 113 includes an anode storage tank, a delivery pump, a solenoid valve, a pressure sensor, a flow sensor and a connecting pipeline, the anode storage tank is connected with the delivery pump through the connecting pipeline, the delivery pump is connected to the carbon dioxide reactor through the connecting pipeline, a proportional valve, a pressure sensor and a flow sensor are sequentially arranged on the connecting pipeline, wherein the positions of the pressure sensor and the flow sensor are interchangeable.

[0083] The reaction product collecting device 13 comprises a carbon dioxide gas circulating device 131, a cathode outlet product circulating collecting device 132 and an anode outlet product circulating collecting device 133.

[0084] The carbon dioxide gas input into the carbon dioxide reactor can be circulated for a long time of 15-25 days, after the circulation is terminated, the discharged gas is treated by alkali absorption.

[0085] The cathode electrolyte is circulated for 3-7 days, and the anode electrolyte is circulated for 10-25 days.

[0086] The carbon dioxide gas circulating pipeline 131 comprises a gas-liquid separator, a gas backflow pump, a proportional valve and a connecting pipeline, the gas-liquid separator comprises a gas-liquid mixed inlet, a gas outlet and a liquid outlet, the gas-liquid mixed inlet is connected with the carbon dioxide cathode gas outlet of the reactor through the connecting pipeline, the gas-liquid separator is used to separate the carbon dioxide gas and the cathode reaction liquid at the outlet of the reactor, the gas outlet is recycled to the connecting pipeline of the carbon dioxide gas supply device through the gas backflow pump, and is further input into the carbon dioxide reactor for circulating reaction, which is beneficial to improve the utilization efficiency of carbon dioxide, and the liquid outlet is recycled to the cathode storage tank through the connecting pipeline.

[0087] The cathode outlet product circulating collecting device 132 comprises a proportional valve, a gas-liquid separator, a cathode buffer tank 1321, a cathode byproduct gas storage tank 1322 and a three-way valve arranged in sequence, and a solenoid valve and a connecting pipeline are respectively arranged at two outlets of the three-way valve.

[0088] The anode outlet product circulating collecting device 133 comprises a proportional valve, a gas-liquid separator and a connecting pipeline, the reacted anode electrolyte is recycled to the anode storage tank through the connecting pipeline at the anode electrolyte outlet of the carbon dioxide reactor.

[0089] The application is specifically the optimized design and arrangement of the reactant supply device 11, the carbon dioxide reactor 12 and the reactant collection device 13 which are respectively fixed in the container module 14, the reactant supply device 11 respectively transports the carbon dioxide gas, the cathode electrolyte and the anode electrolyte into the carbon dioxide reactor 12, and the carbon dioxide gas is reduced into liquid organic / organic salt products mainly in the form of formic acid / formate through the catalytic reaction of the high-efficiency catalyst under the driving of electricity. Then, the products after the reaction are recycled or collected through the reaction product collection device 13.

[0090] Efficiency test of electrolyte recycling of carbon dioxide reactor

[0091] Taking a 2000cm 2 long cathode gas diffusion electrode as an example, the electrolyte recycling efficiency of a single carbon dioxide reactor is tested, wherein the single reactor is composed of 20 single-cell modules connected in series; specifically, the carbon dioxide reactor is composed of 2 end plates, 2 insulating plates, 20 cathode gas flow field plates, 20 cathode gas diffusion electrodes, 20 cathode electrolyte flow field plates, 20 ion exchange membranes, 20 anode gas diffusion electrodes and 20 anode electrolyte flow field plates; wherein the cathode uses commercially available SnO2 (Aldrich) as the catalyst carrier, and the loading amount is 1mg / cm 2 ; the anode uses commercially available IrO2 (Macklin) as the catalyst, and the loading amount is 0.5mg / cm 2 ; the ion exchange membrane selects a nafion 115 membrane; 1M / L KHCO3 solution is used as the cathode electrolyte, 1M / L KOH solution is used as the anode electrolyte, and the capacity of the cathode and anode electrolytes is 5000L; the captured CO2 after desulfurization and denitrification treatment has a purity of 80%.

[0092] The gas flow rate and pressure entering the reactor are 22560L / h and 100kpa respectively; the flow rate and pressure of the cathode electrolyte and the anode electrolyte are consistent, and are 4500L / h and 95kpa respectively; the temperature of the materials entering the reactor is room temperature, and the humidity of the CO2 gas is 50%; the fluctuation of all parameters does not exceed 1%. Then, the operation is carried out according to the conditions of different examples in Table 1, the recycling time of CO2, cathode electrolyte and anode electrolyte entering the carbon dioxide reactor is set, and then the influence of different recycling times on the formic acid product is explored.

[0093] The faraday efficiency refers to the percentage of the actual product and the theoretical product, and the theoretical product is the amount of reduction electrons generated by the catalytic electrode using electric energy. The number of electron transfer in the catalytic reaction is calculated, and the total amount of products that can be generated by all reduction CO2 in theory. The content of the product is obtained by liquid chromatography detection.

[0094] From the comparison of examples 1 to 4 and comparative examples 1 to 6 in table 1, it can be seen that, under the same conditions, the increase of the recycling time of different materials has no obvious effect on the performance of the overall electrochemical reaction and the Faraday efficiency of the target reaction product, so optimizing the recycling time of the reaction materials is beneficial to improving the utilization efficiency of the reaction materials.

[0095] Comparing comparative example 1, example 2, example 3 and example 4, it can be seen that, under a certain recycling time, the carbon dioxide gas, the cathode electrolyte and the anode electrolyte have little effect on the overall electrochemical reaction performance, which shows that the recycling time of the carbon dioxide gas, the cathode electrolyte and the anode electrolyte can be optimized to achieve the full utilization of the reaction materials.

[0096] Comparing comparative example 1, comparative example 1 and comparative example 2, it can be seen that the recycling time of carbon dioxide has little effect on the overall performance, which is mainly because the purity of carbon dioxide gas is relatively high and the supply of carbon dioxide is sufficient.

[0097] Comparing comparative example 3, comparative example 3 and comparative example 4, it can be seen that the recycling time of the cathode electrolyte greatly affects the performance and efficiency of the electrochemical reaction. The difference between the recycling time of 1 day and 5 days is very small, and when the recycling time reaches 10 days, the current density and Faraday efficiency decrease very obviously, which is mainly due to the long recycling time of the electrolyte, which leads to the precipitation of the solution, on the one hand, the ionic conductivity of the solution decreases; on the other hand, the precipitation of the salt crystal affects the diffusion of carbon dioxide gas, and thus the performance and efficiency of the electrochemical reaction are affected.

[0098] Comparing comparative example 4, comparative example 5 and comparative example 6, it can be seen that the recycling time of the anode electrolyte also affects the performance and efficiency of the electrochemical reaction to some extent. When the recycling time is not long, it has little effect on the overall electrochemistry. When the recycling time reaches a certain length, the decrease of the current density of the electrochemistry is very obvious, on the one hand, a large amount of carbon dioxide in the air is dissolved in the long recycling time, which reduces the PH value and ionic conductivity of the anode; on the other hand, the decrease of hydroxyl ion greatly affects the oxygen evolution reaction of the anode, resulting in the increase of overpotential.

[0099] Table 1 effect of different material recycling time on electrochemical performance and target product

[0100]

[0101] Industrial applicability

[0102] The present application provides a ship carbon dioxide tail gas treatment system, the system will capture high concentration carbon dioxide captured by traditional CCS capture device, through electrocatalytic reduction technology, realize carbon dioxide tail gas utilization electric conversion to liquid organic product mainly with formic acid / formate for storage or direct emission, to replace the existing liquefied storage CCS scheme, reduce energy consumption and storage space, the product has higher economic value than liquid carbon dioxide.

[0103] All the above primary implementation of this intellectual property, without setting restrictions on other forms of implementation of this new product and / or new method. Those skilled in the art will utilize this important information, the above content modification, to achieve similar execution. However, all modifications or improvements based on the new product of the present application are reserved.

[0104] The above description is only the preferred embodiment of the present application, not other forms of the present application, any skilled in the art may use the above disclosed technical content to change or modify the equivalent embodiment of equivalent changes. However, any simple modification, equivalent change and modification of the above embodiment without departing from the technical solution of the present application, according to the technical essence of the present application, still belongs to the protection scope of the technical solution of the present application.

Claims

1. A ship CO2 exhaust gas treatment system, characterized by: The carbon dioxide storage tank is connected with the carbon capture reaction tower through a pipeline. The carbon dioxide reaction device includes a reactant supply device, a plurality of carbon dioxide reactors, a reactant collection device, and a container shell. The single carbon dioxide reactor includes two end plates, two insulating plates, n cathode gas flow field plates, n cathode gas diffusion electrodes, n cathode electrolyte flow field plates, n ion exchange membranes, n anode gas diffusion electrodes, n anode electrolyte flow field plates, and a sealing gasket. The power of the electro-catalytic reaction integrated device is 300 kW.

2. A ship CO2 exhaust gas treatment system according to claim 1, characterised in that: The carbon dioxide volume concentration in the gas component captured by the carbon capture reaction tower is greater than 65%, the sulfur dioxide volume concentration is less than 100 ppm, and the oxygen volume concentration is less than 10%.

3. A ship CO2 exhaust gas treatment system according to claim 1 or 2, characterised in that: The carbon dioxide storage tank is further included.

4. A ship CO2 exhaust gas treatment system according to claim 1 or 2, characterised in that: The reactant supply device includes a carbon dioxide gas supply device, a cathode electrolyte supply device, and an anode electrolyte supply device.

5. A ship CO2 exhaust gas treatment system according to claim 4, characterised in that: The carbon dioxide gas supply device includes a gas buffer tank, a pressure reducing valve, a pressure sensor, a proportional valve, a pressure sensor, a flow sensor, and a connecting pipeline.

6. A ship CO2 exhaust gas treatment system according to claim 5, characterised in that: The cathode electrolyte supply device includes a cathode liquid storage tank, a delivery pump, a proportional valve, a flow sensor, a pressure sensor, and a connecting pipeline.

7. A ship CO2 exhaust gas treatment system according to claim 5, characterised in that: The anode electrolyte supply device includes an anode liquid storage tank, a delivery pump, a solenoid valve, a pressure sensor, a flow sensor, and a connecting pipeline.

8. A method for carbon dioxide treatment using the ship carbon dioxide tail gas treatment system according to any one of claims 1 to 7. The high-concentration carbon dioxide tail gas obtained by sequentially passing through the desulfurization tower and the carbon capture reaction tower is introduced into the gas buffer tank in the electro-catalytic reaction integrated device, and is further introduced into the carbon dioxide reactor for electro-catalytic treatment, in the carbon dioxide reactor, the cathode electrolyte is circulated for 3-7 days, and the anode electrolyte is circulated for 10-25 days; The gas pressure entering the carbon dioxide reactor is 20-200 kPa, the cathode electrolyte and the anode electrolyte entering the carbon dioxide reactor have a pressure of 20-200 kPa, and the carbon dioxide gas side pressure is higher than the cathode electrolyte side pressure by 5-10 kPa.

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