WO2024017053A1

WO2024017053A1 - Ship carbon dioxide tail gas treatment system

Info

Publication number: WO2024017053A1
Application number: PCT/CN2023/105557
Authority: WO
Inventors: 周明新; 张小明
Original assignee: 深圳中科翎碳生物科技有限公司
Priority date: 2022-07-20
Filing date: 2023-07-03
Publication date: 2024-01-25
Also published as: CN116732572A; CN115011980A

Abstract

The present invention provides a ship carbon dioxide tail gas treatment system. In the system, high-concentration carbon dioxide captured by a traditional CCS capturing device passes through an electrocatalytic reduction technology, so as to achieve the electrical conversion of carbon dioxide tail gas into a liquid organic product, which mainly comprises formic acid/formate, for storage or direct emission, which replaces an existing liquefaction-storage CCS scheme, and reduces the energy consumption and the storage space, such that the product has a higher economic value compared with liquid carbon dioxide.

Description

Ship carbon dioxide exhaust treatment system

Technical field

The invention relates to the technical field of ship decarbonization, and in particular to a ship carbon dioxide tail gas treatment device and system.

Background technique

Today's world is facing the severe challenge of global climate change, which is promoting the development of clean energy and carbon reduction and emission reduction technologies. Carbon peaking and carbon neutrality have become a common task for governments and enterprises around the world. 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. Shipping carbon dioxide emissions are mainly concentrated on the use of these fossil fuels. With the implementation of the International Maritime Organization's emission reduction strategy, carbon emission reduction will become an important direction for ship emission management in the future.

At present, ship emission reduction is mainly based on the use of low-carbon clean fuels, reducing ship energy consumption and ship carbon capture and storage (CCS) technology. But these methods still have major limitations. Reducing ship energy consumption has limited effect on carbon reduction and cannot achieve large-scale carbon emission reduction for ships. Although low-carbon clean fuel ships, such as methanol ships, ammonia ships, and LNG ships, are an important technical direction for future ship carbon emission reduction, the construction cost is high, clean fuel is expensive, and the current technology is not yet mature and cannot be promoted and applied on a large scale. .

At present, mainstream ships still use fossil fuels to provide power. For this type of existing ships, CCS technology can only be used to capture and store carbon dioxide tail gas to achieve carbon emission reduction. Although CCS technology can achieve large-scale carbon emission reductions for existing fossil fuel ships, there are problems such as high energy consumption, captured carbon dioxide can only be stored in storage tanks, large storage space, and low utilization value, making it difficult to meet the actual needs of ships. Application requirements.

The applicant has long been committed to technology development and equipment development in the field of CCUS, adjusting and optimizing equipment structure and control for different application scenarios, and therefore provides a ship carbon dioxide tail gas utilization and processing device, which can form a ship carbon dioxide tail gas with a CCS capture device The treatment system uses electrocatalytic reduction technology to apply high-performance, high-selectivity and long-life electrochemical catalysts to the tail gas utilization treatment device to realize the electrical conversion of carbon dioxide tail gas into liquid organic liquids based on formic acid/formate. The product is stored or directly discharged to replace the existing CCS solution of liquefied storage, which reduces energy consumption and storage space. At the same time, the product has a higher economic value compared to liquid carbon dioxide.

technical problem

The purpose of the invention 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 shipbuilding industry, and to provide a new ship carbon dioxide tail gas treatment system.

Technical solutions

In order to solve the above technical problems, the present invention provides a ship carbon dioxide tail gas treatment system, which includes a desulfurization tower, a carbon capture reaction tower and an electrocatalytic reaction integrated device. The desulfurization tower is connected to the carbon capture reaction tower through pipelines, and undergoes desulfurization and denitrification. The exhaust gas enters the carbon capture reaction tower through the pipeline for carbon dioxide capture. The carbon capture reaction tower is connected to the electrocatalytic reaction integrated device through the pipeline. The products converted by the electrocatalytic reaction integrated device can be directly discharged into the sea or Connected to the ship's ballast tanks through pipelines for storage.

Among the gas components captured through the carbon capture reaction tower, the volume concentration of carbon dioxide is >65%, the volume concentration of sulfur dioxide is <100ppm, and the volume concentration of oxygen is <10%.

Wherein, the ship carbon dioxide exhaust gas treatment system may also include a carbon dioxide storage tank.

Wherein, the electrocatalytic reaction integrated device specifically includes a reaction material supply device, a plurality of carbon dioxide reactors, a reaction material collection device and a container shell. The reaction material supply device, carbon dioxide reactor and reaction material collection device are arranged and fixed respectively. within the container shell.

Among them, the specific structure of the carbon dioxide reactor includes: 2 end plates, 2 insulating plates, n cathode gas flow field plates, n cathode gas diffusion electrodes, n cathode electrolyte flow field plates, and n ion exchange membranes , n anode gas diffusion electrodes, n anolyte flow field plates and sealing gaskets, 2 end plates on the outermost side, 2 insulation plates each adjacent to an end plate, cathode gas flow field plate and anode electrolyte flow field plate Each is adjacent to an 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 anolyte flow field plate, the cathode electrolyte flow field plate and the cathode gas diffusion electrode are closely adjacent, and the ion exchange membrane is arranged on Between the catholyte flow field plate and the anode gas diffusion electrode, there are sealing gaskets between every two plates, n≤20.

Wherein, the reaction material supply device includes a carbon dioxide gas supply device, a catholyte supply device and an anolyte supply device, and the carbon dioxide gas supply device, catholyte supply device and anolyte supply device are each passed through a pipeline Connect to the corresponding feed ports on the carbon dioxide reactor, and control and monitor the feed flow and pressure of carbon dioxide gas, the feed of anolyte and catholyte through the proportional valve, pressure sensor and flow sensor set on the pipeline Flow and pressure, thereby controlling electrocatalytic reaction efficiency and power utilization efficiency.

Wherein, 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.

Wherein, the catholyte supply device includes a cathode storage tank, a delivery pump, a proportional valve, a flow sensor, a pressure sensor and connecting pipelines.

Wherein, the anolyte supply device includes an anode storage tank, a transfer pump, a solenoid valve, a pressure sensor, a flow sensor and a connecting pipeline.

Among them, the catholyte circulates for 3-7 days, and the anolyte circulates for 10-25 days.

beneficial effects

The invention provides a ship carbon dioxide tail gas treatment system, which converts high-concentration carbon dioxide captured by a traditional CCS capture device into liquid organic products based on formic acid/formate salts using electricity through electrocatalytic reduction technology. Storage or direct emission to replace the existing liquefied storage CCS solution reduces energy consumption and storage space, and the product has a higher economic value compared to liquid carbon dioxide.

Description of drawings

Figure 1 is an overall structural diagram of the ship carbon dioxide exhaust gas treatment system of the present invention;

Figure 2 is a top view of the electrocatalytic reaction integrated device of the present invention;

Figure 3 is a front view of the electrocatalytic reaction integrated device of the present invention;

Figure 4 is an overall structural diagram of the electrocatalytic reaction integrated device of the present invention.

Best Mode of Carrying Out the Invention

The invention provides a ship carbon dioxide tail gas treatment system, which includes a desulfurization tower, a carbon capture reaction tower and an electrocatalytic reaction integrated device. The desulfurization tower is connected to the carbon capture reaction tower through pipelines, and the exhaust gas after desulfurization and denitrification passes through the pipelines. It enters the carbon capture reaction tower to capture carbon dioxide. The carbon capture reaction tower is connected to the electrocatalytic reaction integrated device through pipelines. The products converted by the electrocatalytic reaction integrated device can be directly discharged into the sea or connected to the ship through pipelines. It is stored in the ballast tank and used to convert it into higher value products after landing. It can be used as a carbon source for the biological fermentation system to convert into multi-carbon products.

The gas components entering the carbon capture reaction tower through the desulfurization tower have a sulfur dioxide concentration between 10ppm and 100ppm, and a carbon dioxide volume concentration between 1.0% and 5.5%. The method used for carbon capture is the mature liquid amine method.

Due to the limitations of energy consumption and carbon dioxide emission reduction in the ship scenario, the electrocatalytic reaction integrated device cannot convert 100% of the captured carbon dioxide into liquid organic products for large ships. Therefore, the ship carbon dioxide exhaust treatment system can also include a carbon dioxide storage tank. Used to store part of the captured carbon dioxide.

The electrocatalytic reaction integrated device specifically includes a reaction material supply device, multiple carbon dioxide reactors, a reaction material collection device and a container shell. The reaction material supply device, carbon dioxide reactor, and reaction material collection device are respectively arranged and fixed in the container shell.

Different numbers of carbon dioxide reactors are connected according to the processing scale of the electrocatalytic reaction integrated device. The volume of a single carbon dioxide reactor is 0.1-0.3m ³ , the daily processing capacity of a single carbon dioxide reactor is between 180-500kg, and the power is between 8kw-30kw. The carbon dioxide processing capacity and power are related to the number of reactors in series, electrode area, catalyst performance and other factors.

Based on the fact that the power of the backup generator on the ship is usually 700kw, the power allocated to the capture reaction tower is 400kw, which can realize the requirement of capturing <48t of carbon dioxide per day, and the power allocated to the electrocatalytic reaction integrated device is 300kw, according to the electricity provided by the present invention The maximum daily processing capacity of a single carbon dioxide in the catalytic reaction integrated device is 500kg and the power of a single reactor under this processing capacity needs to be at least 8kw-30kw. At present, the daily processing capacity of <20t of carbon dioxide can be achieved, depending on the total number of generators provided by the ship. Power, design and matching of electrochemical reaction integrated device and carbon dioxide storage tank. The specific structure of the single carbon dioxide reactor includes: 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 anolyte flow field plates and sealing gaskets, 2 end plates on the outermost side, 2 insulating plates each adjacent to an end plate, the cathode gas flow field plate and the anode electrolyte flow field plate each Next to an insulating plate, the cathode gas diffusion electrode and the anode gas diffusion electrode are closely adjacent to the cathode gas flow field plate and the anolyte flow field plate, the cathode electrolyte flow field plate and the cathode gas diffusion electrode are closely adjacent, and the ion exchange membrane is arranged on the cathode Between the electrolyte flow field plate and the anode gas diffusion electrode. Among them, there are sealing gaskets between every two boards, n≤20.

Among them, an insulating plate, a cathode gas flow field plate, a cathode gas diffusion electrode, a cathode electrolyte liquid flow field plate, an ion exchange membrane, an anode gas diffusion electrode and multiple sealing gaskets form a single cell module; single cell Modules can be scaled up in series to form a single CO2 reactor as required.

Wherein, the electrolysis voltage can be applied to the entire amplified single carbon dioxide reactor in series or to the single cell module on each carbon dioxide reactor in series.

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

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

The carbon dioxide reactor can also adopt other types of electrolytic cell structures, such as MEA membrane electrode structures. Specifically, the cathode electrolyte flow field plate is removed, 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.

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

Wherein, the ion exchange membrane may be an anion exchange membrane or a proton exchange membrane.

Wherein, the reaction material supply device includes a carbon dioxide gas supply device, a catholyte solution supply device and an anode electrolyte solution supply device, and the carbon dioxide gas supply device, catholyte solution supply device and anolyte electrolyte solution supply device each pass through a pipeline Connect to the corresponding feed ports on the carbon dioxide reactor, and control and monitor the feed flow and pressure of carbon dioxide gas, the feed of anolyte and catholyte through the proportional valve, pressure sensor and flow sensor set on the pipeline Flow and pressure are used to control electrocatalytic reaction efficiency and power utilization efficiency.

Among them, 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. The gas storage tank is connected to the pressure reducing valve through the connecting pipeline, and the pressure reducing valve The valve is connected to the proportional valve through the connecting pipeline, and the proportional valve is connected to the carbon dioxide reactor through the pipeline. A pressure sensor and a flow sensor are provided on this section of pipeline, and the positions of the two are interchangeable.

The carbon dioxide gas supply device may further include a heater. The heater is disposed between the pressure reducing valve and the proportional valve. By heating the temperature of the captured carbon dioxide gas source, the reaction efficiency of the electrochemical catalysis is improved.

The carbon dioxide gas supply device may further include a humidifier, which is disposed between the pressure reducing valve and the proportional valve. By humidifying the captured carbon dioxide gas source, the reaction efficiency of subsequent electrochemical catalysis is improved.

The humidifier mainly includes a gas inlet, a gas outlet, a water inlet, a water outlet, and internal bundled hollow fibers. The specific working principle is: gas and water enter the humidifier through convection, 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 humidifier water inlet. Based on the pressure difference between the inside and outside of the hollow fiber. (The outside is larger than the inside), water passes through the fiber and humidifies the gas.

The catholyte supply device includes a cathode storage tank, a transfer pump, a proportional valve, a flow sensor, a pressure sensor and a connecting pipeline. The cathode storage tank is connected to the transfer pump through the connecting pipeline, and the transfer pump is connected to the connecting pipeline. To the carbon dioxide reactor, a proportional valve, a pressure sensor, and a flow sensor are sequentially installed on the connecting pipeline of this section. The positions of the pressure sensor and the flow sensor are interchangeable.

The anode electrolyte supply device includes an anode storage tank, a transfer pump, a solenoid valve, a pressure sensor, a flow sensor and a connecting pipeline. The anode storage tank is connected to the transfer pump through the connecting pipeline, and the transfer pump is connected to the On the carbon dioxide reactor, a proportional valve, a pressure sensor and a flow sensor are arranged in sequence on the connecting pipeline of this section. The positions of the pressure sensor and the flow sensor are interchangeable.

The carbon dioxide gas supply device, catholyte supply device and anolyte supply device may also include a solenoid valve, which is arranged before the proportional valve and can control the use of the reaction path based on actual needs, thereby maximizing Reduce the use of materials and reduce the cost of ship decarbonization.

The carbon dioxide reactor has three feed ports and three discharge ports. The feed port is specifically a carbon dioxide gas inlet, a catholyte feed port and an anode electrolyte feed port. The discharge port is specifically a carbon dioxide gas outlet. Catholyte outlet and anolyte outlet.

The reaction product collection device includes a carbon dioxide gas circulation device, a cathode outlet product circulation collection device and an anode outlet product circulation collection device.

The purpose of setting up the circulation collection device is firstly to reduce the loss of reaction materials, make full use of the reaction materials and improve the utilization efficiency of the reaction materials. However, the utilization efficiency of electrochemical reaction materials without circulation is low, resulting in huge material losses and material costs. Secondly, the circulation device can also achieve a balance between the utilization efficiency of the reaction materials and the energy conversion efficiency by optimizing the number of cycles of the reaction materials. For the shipping industry, energy consumption has always been an unavoidable issue for ship decarbonization. Energy consumption on ships is limited. How to reduce carbon dioxide emissions within limited energy consumption without affecting normal shipping is the first problem that the industry must solve. Through research and testing, the applicant finds the most reasonable cycle time to ensure the maximum decarbonization of ship carbon dioxide.

Specifically, carbon dioxide gas can be recycled for a long time, preferably the cycle length is 10-30 days, more preferably 15-25 days. After the cycle is terminated, the discharged gas is subjected to alkaline liquid absorption treatment.

Specifically, the number of catholyte circulation times is preferably 3-10 days, more preferably 3-7 days. If the number of cycles is too many, the ionic conductivity will decrease, which will affect the performance of the electrocatalytic reaction. If the number of cycles is too low, the electrolyte cannot Fully utilized, causing costs to rise.

Specifically, the number of anolyte circulation times is preferably 5-20 days, more preferably 8-15 days. Compared with catholyte, only water participates in the reaction of anolyte, which results in less loss and longer cycle time, thereby reducing costs. If the anolyte is circulated too many times, 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 anolyte discharged after circulation can also be used as an alkali solution to absorb _CO2 .

The carbon dioxide gas circulation pipeline includes a gas-liquid separator, a gas reflux pump, a proportional valve and a connecting pipeline. The gas-liquid separator includes a gas-liquid mixing inlet, a gas outlet and a liquid outlet. The gas-liquid mixing inlet and The carbon dioxide cathode gas outlet of the reactor is connected through the connecting pipe. The gas-liquid separator is used to separate the carbon dioxide gas and cathode reaction liquid at the reactor outlet. The gas outlet is recycled to the carbon dioxide cathode gas outlet through the gas reflux pump. The connecting pipeline of the carbon dioxide gas supply device is further passed into the carbon dioxide reactor for circulation reaction, which is beneficial to improving the utilization efficiency of carbon dioxide. The liquid outlet is recycled into the cathode liquid storage tank through the connecting pipeline. .

The cathode outlet product circulation collection device includes a proportional valve arranged in sequence, a gas-liquid separator, a cathode buffer tank, a cathode by-product gas storage tank, a three-way valve, and solenoid valves and connections respectively provided at the two outlets of the three-way valve. pipeline.

Among them, the proportional valve provided in the cathode outlet product collection device can be used to adjust the back pressure to ensure pressure balance inside the reactor.

Among them, the gas-liquid separator is used to separate a small amount of carbon monoxide and hydrogen that are by-products of the cathode reaction. The gas outlet of the gas-liquid separator is connected to the cathode by-product gas storage tank. The cathode by-product gas storage tank is used to store the by-product carbon monoxide and hydrogen. .

Among them, the liquid outlet of the gas-liquid separator is connected to a three-way valve, one outlet of the three-way valve is circulated back to the cathode liquid storage tank for recycling, and the other outlet is connected to the cathode buffer tank.

Among them, the reaction liquid in the cathode buffer tank can be directly discharged to the sea through the pipeline, or it can be stored in the ballast tank through the pipeline.

Among them, the solenoid valves provided in the two outlets of the three-way valve can be used to control the cycle time of the catholyte and improve the utilization efficiency of the reaction materials.

The anode outlet product circulation collection device includes a proportional valve, a gas-liquid separator and a connecting pipeline. The reacted anolyte passes through the anolyte outlet of the carbon dioxide reactor and is circulated and replenished into the anode storage tank through the connecting pipeline. .

The proportional valve provided in the anode outlet product circulation collection device can also be used to adjust the back pressure to ensure the pressure balance of the reactor.

A gas-liquid separation device is provided behind the proportional valve installed in the anode outlet product circulation collection device to separate and discharge the oxygen generated by the anode reaction.

Specifically, the present invention is that a reaction material supply device, a carbon dioxide reactor, and a reaction material collection device are respectively fixed in the container module through optimized design and arrangement. The reaction material supply device transports carbon dioxide gas, cathode electrolyte, and anolyte to In the carbon dioxide reactor, through the catalytic reaction of a high-efficiency catalyst driven by electricity, carbon dioxide gas is reduced to liquid organic/organic salt products, mainly formic acid/formate salts. Then, the reaction product is circulated or collected through the reaction product collection device.

The present invention also provides a method for treating carbon dioxide tail gas using the above-mentioned ship carbon dioxide tail gas treatment system, specifically:

The high-concentration carbon dioxide tail gas obtained through the desulfurization tower and the carbon capture reaction tower in sequence is passed into the gas buffer tank in the electrocatalytic reaction integrated device, and is further passed into the carbon dioxide reactor for electrocatalytic treatment.

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. The electrochemical performance of the reactor is optimized and improved by controlling the flow and pressure of the gas, catholyte and anolyte entering the single carbon dioxide reactor. and energy conversion efficiency.

Based on the large size of the reactor, the gas pressure entering the carbon dioxide reactor is preferably 20-200kpa, and further preferably 20-150kpa; the preferred pressure of the catholyte and anolyte entering the carbon dioxide reactor is also 20-200kpa, and more preferably 20 -150kpa; among which, the carbon dioxide gas side pressure is 5-10kpa higher than the catholyte side pressure. This can not only enhance the diffusion of carbon dioxide gas to the cathode gas diffusion electrode, but also effectively alleviate the diffusion of catholyte to the gas side through the gas diffusion electrode. Reverse osmosis.

The gas flow rate entering the carbon dioxide reactor is preferably 1200L/h-4500L/h, and further preferably 1500L/h-2300L/h; the flow rates of the catholyte and anolyte entering the carbon dioxide reactor are kept consistent, specifically the carbon dioxide gas flow rate 0.1-1 times of the carbon dioxide gas flow rate, and further preferably 0.2-0.4 times of the carbon dioxide gas flow rate;

In addition, overall performance can be improved by controlling the temperature and humidity of the carbon dioxide gas entering the reactor. A certain temperature can improve the kinetics of the reaction and promote the occurrence of the reaction. Appropriate humidity is conducive to the formation of a gas-liquid-solid three-phase interface and is conducive to the progress of the reaction.

Specifically, the temperature of the carbon dioxide gas entering the reactor is preferably 25-60°C, and more preferably 35-50°C;

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

Embodiments of the invention

The following uses examples and drawings to describe the implementation of the present invention in detail, so that the implementation process of how to apply technical means to solve technical problems and achieve technical effects of the present invention can be fully understood and implemented accordingly.

As shown in Figure 1, the present invention provides a ship carbon dioxide tail gas treatment system, which includes a desulfurization tower 2, a carbon capture reaction tower 3, an electrocatalytic reaction integrated device 1 and a carbon dioxide storage tank 4. The desulfurization tower 2 is connected to the carbon capture reaction tower through pipelines. The collection reaction tower 3 is connected, and 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 electrocatalytic reaction integrated device 1 through the pipeline. The captured high-concentration CO ₂ gas is passed into the electrocatalytic reaction integrated device 1. The electrocatalytic conversion product can be directly discharged into the sea or connected to the ship's ballast tank 5 through a pipeline for storage. The carbon capture reaction tower 3 Another pipeline is connected to the carbon dioxide storage tank 4 for storing partially captured carbon dioxide.

As shown in Figures 2 to 4, the electrocatalytic reaction integrated device provided by the present invention specifically includes a reaction material supply device 11, 32 carbon dioxide reactors 12, a reaction material collection device 13 and a container shell 14. The reaction material supply device 11, carbon dioxide reactor 12, and reaction material collection device 13 are respectively arranged and fixed in the container shell 14. The total carbon dioxide processing capacity of the electrocatalytic reaction integrated device is 12.8t/d, and a single carbon dioxide The carbon dioxide processing capacity of the reactor is 400kg/d.

The cathode of the carbon dioxide reactor uses commercially available SnO ₂ (Aldrich) as the supported catalyst, with a loading capacity of 1 mg/cm ² ; the anode uses commercially available IrO ₂ (Macklin) as the catalyst, with a loading capacity of 0.5 mg/cm ² ; the ion exchange membrane Use nafion 115 membrane; use 1M/L KHCO ₃ solution as the catholyte, 1M/L KOH solution as the anolyte, and the single reactor power is 9.35kw.

The reaction material supply device 11 includes a carbon dioxide gas supply device 111, a catholyte supply device 112 and an anode electrolysis supply device 113. The carbon dioxide gas supply device 111, catholyte solution supply device 112 and anode electrolysis supply device 113 are each Connected to the corresponding feed ports of the carbon dioxide reactor through pipelines, the feed flow and pressure of carbon dioxide gas, anolyte and catholyte are controlled and monitored through proportional valves, pressure sensors and flow sensors set on the pipelines. The feed flow and pressure control the electrocatalytic reaction efficiency and power utilization efficiency.

The carbon dioxide gas supply device 111 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. The gas storage tank is connected to the pressure reducing valve through the connecting pipeline. The pressure reducing valve It is connected to the proportional valve through the connecting pipeline, and the proportional valve is connected to the carbon dioxide reactor through the pipeline. A pressure sensor and a flow sensor are provided on this section of pipeline, and the positions of the two are interchangeable.

The catholyte supply device 112 includes a cathode storage tank, a transfer pump, a proportional valve, a flow sensor, a pressure sensor and a connecting pipeline. The cathode storage tank is connected to the transfer pump through the connecting pipeline, and the transfer pump is connected through the connecting pipeline. Connected to the carbon dioxide reactor, a proportional valve, a pressure sensor, and a flow sensor are arranged in sequence on this section of the connecting pipeline. The positions of the pressure sensor and the flow sensor are interchangeable.

The anolyte supply device 113 includes an anode storage tank, a transfer pump, a solenoid valve, a pressure sensor, a flow sensor and a connecting pipeline. The anode storage tank is connected to the transfer pump through the connecting pipeline, and the transfer pump is connected through the connecting pipeline. To the carbon dioxide reactor, a proportional valve, a pressure sensor and a flow sensor are sequentially installed on the connecting pipeline of this section. The positions of the pressure sensor and the flow sensor are interchangeable.

The reaction product collection device 13 includes a carbon dioxide gas circulation device 131, a cathode outlet product circulation collection device 132, and an anode outlet product circulation collection device 133.

The carbon dioxide gas introduced into the carbon dioxide reactor can be circulated for a long time for 15-25 days. After the cycle is terminated, the discharged gas is absorbed by alkali liquid.

The catholyte circulates for 3-7 days, and the anolyte circulates for 10-25 days.

The carbon dioxide gas circulation pipeline 131 includes a gas-liquid separator, a gas reflux pump, a proportional valve and a connecting pipeline. The gas-liquid separator includes a gas-liquid mixing inlet, a gas outlet and a liquid outlet. The gas-liquid mixing inlet The carbon dioxide cathode gas outlet of the reactor is connected through the connecting pipe. The gas-liquid separator is used to separate the carbon dioxide gas and cathode reaction liquid at the reactor outlet. The gas outlet recovers the gas through the gas reflux pump. The connecting pipeline of the carbon dioxide gas supply device is further led into the carbon dioxide reactor for circulation reaction, which is beneficial to improving the utilization efficiency of carbon dioxide. The liquid outlet is recovered to the cathode liquid storage tank through the connecting pipeline. middle.

The cathode outlet product circulation collection device 132 includes a proportional valve, a gas-liquid separator, a cathode buffer tank 1321, a cathode by-product gas storage tank 1322, and a three-way valve arranged in sequence. Electromagnetic valves are respectively provided at the two outlets of the three-way valve. Valves and connecting lines.

The anode outlet product circulation collection device 133 includes a proportional valve, a gas-liquid separator and a connecting pipeline. The reacted anolyte passes through the anolyte outlet of the carbon dioxide reactor and is circulated and replenished to the anode storage tank through the connecting pipeline. middle.

Specifically, the present invention is that the reaction material supply device 11, the carbon dioxide reactor 12, and the reaction material collection device 13 are respectively fixed in the container module 14 through optimized design and arrangement. The reaction material supply device 11 respectively supplies carbon dioxide gas, catholyte and The anolyte is transported to the carbon dioxide reactor 12, and driven by electricity through a catalytic reaction of a high-efficiency catalyst, the carbon dioxide gas is reduced to liquid organic/organic salt products, mainly formic acid/formate. Then, the reacted product is circulated or collected through the reaction product collection device 13 .

Carbon dioxide reactor electrolyte recycling efficiency test

Taking a 2000cm ² cathode gas diffusion electrode as an example, test the electrolyte circulation efficiency of a single carbon dioxide reactor, in which a single reactor is composed of 20 single cell modules mentioned above in series; specifically, the carbon dioxide reactor is composed of 2 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 electrolysis It is composed of a liquid flow field plate; among them, the cathode uses commercially available SnO ₂ (Aldrich) as a supported catalyst, with a loading capacity of 1 mg/cm ² ; the anode uses commercially available IrO ₂ (Macklin) as a catalyst, with a loading capacity of 0.5 mg/cm ² ; The ion exchange membrane uses nafion 115 membrane; 1M/L KHCO ₃ solution is used as the catholyte, and 1M/L KOH solution is used as the anolyte. The capacities of the cathode and anolyte are both 5000L; they are captured after desulfurization and denitrification treatment. The CO ₂ purity is 80%.

The gas flow and pressure entering the reactor are 22560L/h and 100kpa respectively; the flow and pressure of the catholyte and anolyte are the same, 4500L/h and 95kpa respectively; the temperature of the materials entering the reactor is room temperature, CO ₂ gas The humidity is 50%; the fluctuation of all parameters does not exceed 1%. Then operate according to the conditions of different examples in Table 1, set the cycle time of CO ₂ entering the carbon dioxide reactor, catholyte and anolyte, and then explore the impact of different cycle times on the formic acid product.

Faradaic efficiency refers to the percentage of actual products and theoretical products. The amount of theoretical products is the reduction electrons generated by the catalytic electrode using electrical energy. Calculate the number of electron transfers in the catalytic reaction. In theory, all of them are used to reduce CO ₂ The total amount of product that can be produced. The content of the product was detected by liquid chromatography.

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 other conditions, the increase in the cycle time of different materials has a negative impact on the performance of the entire electrochemical reaction and the target reaction product. The impact of Faradaic efficiency is not obvious, so optimizing the recycling time of reaction materials is beneficial to improving the utilization efficiency of reaction materials.

Comparing Example 1, Example 2, Example 3 and Example 4, it can be seen that carbon dioxide gas, catholyte and anolyte have a very low impact on the overall electrochemical reaction performance within a certain cycle. This shows that the cycle time of carbon dioxide gas, catholyte and anolyte can be optimized to achieve full utilization of the reaction materials.

Comparing Example 1, Comparative Example 1 and Comparative Example 2, it can be seen that the cycle length of carbon dioxide has a very small impact on the overall performance. This is mainly because the purity of the carbon dioxide gas itself is relatively high and the carbon dioxide is supplied in sufficient amount.

Comparing Example 3, Comparative Example 3 and Comparative Example 4, it can be seen that the circulation time of the catholyte greatly affects the performance and efficiency of the electrochemical reaction. The difference between the cycle time of 1 day and 5 days is negligible. When the cycle time reaches 10 days, the current density and Faradaic efficiency drop very obviously. This is mainly because the electrolyte cycle time is too long, which will cause salt precipitation in the solution. On the one hand, the ionic conductivity of the solution decreases; on the other hand, the precipitated salt crystals will affect the diffusion of carbon dioxide gas, thereby affecting the performance and efficiency of the electrochemical reaction.

Comparing Example 4, Comparative Example 5 and Comparative Example 6, it can be seen that the circulation time of the anolyte also affects the performance and efficiency of the electrochemical reaction to a certain extent. When the cycle time is not long, its impact on the overall electrochemistry is very low. When the cycle time reaches a certain length, its impact on the decrease in electrochemical current density is very obvious. On the one hand, long-term cycle use will dissolve a large amount of carbon dioxide in the air, reducing the PH value and ionic conductivity of the anode; on the other hand, On the one hand, the reduction of hydroxyl radicals will greatly affect the oxygen evolution reaction of the anode, leading to an increase in overpotential.

Table 1 The impact of different material recycling times on electrochemical performance and target products

Industrial applicability

The present invention proposes a ship carbon dioxide tail gas treatment system, which converts high-concentration carbon dioxide captured by traditional CCS capture devices into liquid organic products based on formic acid/formate salts using electricity through electrocatalytic reduction technology. Storage or direct emission to replace the existing liquefied storage CCS solution reduces energy consumption and storage space, and the product has a higher economic value compared to liquid carbon dioxide.

All of the above are provided primarily for the implementation of this intellectual property and do not set limits on other forms of implementation of such new products and/or new methods. One skilled in the art will utilize this important information and modify the above to achieve similar implementations. However, all modifications or transformations to new products based on the present invention are rights reserved.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention in other forms. Any skilled person familiar with the art may make changes or modifications to equivalent changes using the technical contents disclosed above. Example. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

The ship carbon dioxide tail gas treatment system is characterized by: including a desulfurization tower, a carbon capture reaction tower and an electrocatalytic reaction integrated device. The desulfurization tower is connected to the carbon capture reaction tower through pipelines, and the exhaust gas after desulfurization and denitrification enters through the pipelines. Carbon dioxide is captured in the carbon capture reaction tower. The carbon capture reaction tower is connected to the electrocatalytic reaction integrated device through pipelines. The products converted by the electrocatalytic reaction integrated device can be directly discharged into the sea or connected to the ship's ballast through pipelines. stored in the cabin.
The ship carbon dioxide tail gas treatment system according to claim 1, characterized in that: among the gas components captured by the carbon capture reaction tower, the volume concentration of carbon dioxide is >65%, the volume concentration of sulfur dioxide is <100 ppm, and the volume concentration of oxygen is <10%.
The ship carbon dioxide exhaust gas treatment system according to claim 1 or 2, characterized in that it further includes a carbon dioxide storage tank.
The ship carbon dioxide tail gas treatment system according to claim 1 or 2, characterized in that: the electrocatalytic reaction integrated device specifically includes a reaction material supply device, a plurality of carbon dioxide reactors, a reaction material collection device and a container shell, and the reaction The material supply device, carbon dioxide reactor, and reaction material collection device are respectively arranged and fixed in the container shell.
The ship carbon dioxide exhaust gas treatment system according to claim 1 or 2, characterized in that: the reaction material supply device includes a carbon dioxide gas supply device, a catholyte supply device and an anode electrolysis supply device, and the carbon dioxide gas supply device, The catholyte supply device and the anode electrolysis supply device are each connected to the corresponding feed port on the carbon dioxide reactor through pipelines, and the feed of carbon dioxide gas is controlled and monitored through proportional valves, pressure sensors and flow sensors provided on the pipelines. Flow and pressure, the feed flow and pressure of anolyte and catholyte, control the electrocatalytic reaction efficiency and electric energy utilization efficiency.
The ship carbon dioxide exhaust gas treatment system of claim 5, wherein 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.
The ship carbon dioxide exhaust gas treatment system according to claim 5 or 6, characterized in that: the catholyte supply device includes a cathode storage tank, a transfer pump, a proportional valve, a flow sensor, a pressure sensor and a connecting pipeline.
The ship carbon dioxide exhaust gas treatment system according to claim 5 or 6, characterized in that the anolyte supply device includes an anode storage tank, a transfer pump, a solenoid valve, a pressure sensor, a flow sensor and a connecting pipeline.
The method for carbon dioxide treatment using the ship carbon dioxide exhaust gas treatment system according to any one of claims 1 to 8 is characterized by:

The high-concentration carbon dioxide tail gas obtained through the desulfurization tower and the carbon capture reaction tower in sequence is passed into the gas buffer tank in the electrocatalytic reaction integrated device, and is further passed into the carbon dioxide reactor for electrocatalytic treatment. In the carbon dioxide reactor, The catholyte circulates for 3-7 days, and the anolyte circulates for 10-25 days.
The carbon dioxide treatment method according to claim 9, characterized in that: the gas pressure entering the carbon dioxide reactor is 20-200kpa, the pressure of the catholyte and anolyte entering the carbon dioxide reactor is 20-200kpa, and the side pressure of the carbon dioxide gas is 20-200kpa. 5-10kpa higher than the catholyte side pressure.