Carbon dioxide capture solvent metal corrosion evaluation device and evaluation method

Abstract

The application provides a device and a method for evaluating metal corrosion of a carbon dioxide capture solvent, and the device comprises a visual reaction kettle, a condensation recovery module and a temperature rising injection module, wherein the condensation recovery module comprises a condensation recovery device, an air inlet of the condensation recovery device is connected with an air outlet of the visual reaction kettle, and a liquid outlet of the condensation recovery device is connected with a liquid return port of the visual reaction kettle. The application truly simulates a carbon dioxide absorption-desorption process and temperature, contact form and material composition, investigates corrosion of an absorption solvent on metal fillers, realizes full-closed circulation, simulates an actual carbon dioxide absorption process, and solves the problem that a capture solvent corrosion experiment is greatly different from an actual application scene.

Description

Technical Field

[0001] This invention relates to the field of carbon dioxide capture technology, specifically to a device and method for evaluating the corrosiveness of carbon dioxide capture solvents to metals. Background Technology

[0002] Carbon capture and storage (CCS) is recognized as one of the three major carbon reduction pathways and is currently the best option for achieving large-scale zero-emission utilization of fossil fuels. Carbon capture accounts for more than 50% of the total cost of CCS and is the focus of current research and development, as well as a prerequisite for the widespread application of CCS technology.

[0003] Among existing carbon dioxide capture technologies, solvent absorption is the most mature and widely used. However, in current applications and research, the corrosion of metal packing materials by the capture solvent, and the resulting solvent loss, are significant factors limiting its large-scale application. Currently, laboratory experiments are primarily used to evaluate the corrosion of metal packing materials by carbon dioxide capture solvents and to examine the effectiveness of corrosion inhibitors. Common methods include chemical immersion, salt spray, atmospheric exposure, electrochemical methods, polarization curves, and linear polarization methods. However, in actual processes, metal corrosion typically occurs at the water-air interface. The aforementioned experimental methods examine the corrosion of metals by solvents in a single phase under static conditions, which cannot reflect the actual carbon dioxide absorption process scenario and differs significantly from reality in terms of temperature, contact form, and material composition. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a device and method for evaluating the corrosivity of carbon dioxide capture solvents to metals. This method realistically simulates the carbon dioxide absorption-desorption process, including temperature, contact patterns, and material composition. It examines the corrosion of the metal packing material by the absorption solvent and achieves a fully closed-loop circulation to simulate the actual carbon dioxide absorption process. Furthermore, it integrates the absorption and desorption processes into a single reaction vessel and ensures that the metal packing material is positioned at the water-gas interface, thus resolving the significant discrepancy between the captured solvent corrosion experiment and actual application scenarios.

[0005] To achieve the above objectives, the present invention provides a device for evaluating the metal corrosivity of carbon dioxide capture solvents, comprising: a visualization reaction vessel, a condensation recovery module, and a heating injection module.

[0006] The condensation recovery module includes a condensation recovery unit, the air inlet of which is connected to the air outlet of the visual reaction vessel, and the liquid outlet of which is connected to the liquid return outlet of the visual reaction vessel.

[0007] The heating injection module includes a booster pump, a buffer tank, and a heater connected in sequence. The inlet of the booster pump is connected to the outlet of the condenser recovery unit, and the outlet of the heater is connected to the inlet of the visual reactor.

[0008] In the carbon dioxide capture solvent metal corrosion evaluation device of the present invention, the visualization reactor is used to simulate the absorption process of carbon dioxide and the corrosion process of metal by the capture solvent, the condensation and recovery module is used to condense and recover the capture solvent entrained in the carbon dioxide absorption tail gas, and the heating injection module is used to heat and pressurize the added carbon dioxide and the condensed absorption tail gas. In order to fully simulate the actual absorption-desorption process conditions, the heating temperature is preferably 100-120°C, more preferably 110°C.

[0009] In the aforementioned carbon dioxide capture solvent metal corrosion evaluation device, preferably, the buffer tank is further provided with a gas replenishment port. The gas replenishment port is used to introduce carbon dioxide from an external gas source to replenish losses and maintain the reaction pressure in the visualized reaction vessel.

[0010] In the aforementioned carbon dioxide capture solvent metal corrosivity evaluation device, preferably, the interior of the visualization reactor is equipped with a packing baffle, and metal packing is filled above the baffle. The packing baffle is used to support the metal packing, and the filling height of the metal packing is preferably one-third to one-half of the height of the visualization reactor body.

[0011] In the aforementioned carbon dioxide capture solvent metal corrosivity evaluation device, preferably, the visualization reactor is further provided with a liquid inlet and a liquid phase sampling port. The liquid phase sampling port is used to collect samples of the captured solvent for analysis and testing.

[0012] In the aforementioned carbon dioxide capture solvent metal corrosion evaluation device, preferably, the visualization reactor is further equipped with a safety valve. This safety valve is used for emergency venting of the visualization reactor.

[0013] In the aforementioned carbon dioxide capture solvent metal corrosivity evaluation device, preferably, a gas flow meter is installed on the pipeline between the inlet of the booster pump and the condenser. This gas flow meter is used to measure the flow rate and velocity of the carbon dioxide gas after condensation and separation.

[0014] In the aforementioned carbon dioxide capture solvent metal corrosion evaluation device, preferably, the condensation recovery module further includes a circulation pump and a chiller coupled to the condensation recovery unit. The chiller provides a low-temperature water area to the condensation recovery unit, and the circulation pump injects circulating water cooled by the chiller into the condensation recovery unit.

[0015] Preferably, the carbon dioxide capture solvent metal corrosion evaluation device described above also includes valves installed on each pipeline.

[0016] The present invention also provides a method for evaluating the metal corrosivity of carbon dioxide capture solvents, which uses the above-mentioned carbon dioxide capture solvent metal corrosivity evaluation device.

[0017] Preferably, the above-mentioned method for evaluating the corrosivity of carbon dioxide capture solvents to metals includes the following steps:

[0018] (1) Fill the visual reactor with metal packing to a predetermined height, open all valves, connect all modules of the carbon dioxide capture solvent metal corrosion evaluation device, connect to the external carbon dioxide gas source, use carbon dioxide gas to purge the entire device, and exhaust the air.

[0019] (2) Close all valves, fill the buffer tank with carbon dioxide gas to the reaction pressure, and add preheated trapping solvent to the visual reactor through the liquid inlet to the predetermined height;

[0020] (3) Turn on the refrigeration unit and the circulation pump to cool the condenser to the preset temperature;

[0021] (4) Close the external connection valve, open the valves between each module, and inject the carbon dioxide gas heated by the heating injection module into the visualization reactor at a predetermined gas rate to start the process simulation; if the pressure inside the reactor drops during the reaction, open the external connection valve and replenish the buffer tank with carbon dioxide gas to atmospheric pressure;

[0022] (5) Collect simulation process parameters at predetermined time intervals, as well as capture solvent samples and produced gas samples;

[0023] (6) Conduct corrosion analysis of metal fillers and solvent composition analysis.

[0024] In the aforementioned methods for evaluating the corrosivity of carbon dioxide capture solvents to metals, preferably, the corrosion analysis of the metal filler employs at least one of the following: gravimetric method, polarization curve method, and scanning electron microscopy (SEM). The gravimetric method can comprehensively evaluate the degree of corrosion and loss of the metal filler; the polarization curve method can quantitatively evaluate the metal corrosion rate, analyze the corrosion state and changes; and SEM can analyze the corrosion type and changes in the metal's surface morphology. Furthermore, solvent component analysis involves real-time collection of capture solvent samples in the reaction vessel, analysis of the concentrations and changes of absorbent, metal ions, dissolved carbon dioxide, carbonate, and bicarbonate, and quantitative evaluation of the metal filler's participation in the chemical reaction to generate soluble inorganic salts.

[0025] This invention achieves a realistic simulation of the carbon dioxide absorption-desorption process, including temperature, contact mode, and material composition, providing practical measures for simulating the actual carbon dioxide absorption process and offering a reliable device and method for evaluating the corrosion of carbon dioxide capture solvents under actual conditions.

[0026] The technical solution provided by this invention has the following beneficial effects:

[0027] 1. The carbon dioxide capture solvent metal corrosion evaluation device of the present invention integrates the absorption and desorption processes into a single reactor using a visualized reactor, ensuring that the metal packing is at the water-gas interface. It also adds a condensation recovery module and a heating injection module to dynamically simulate the carbon dioxide capture process of a solvent-based packed absorption tower under near-realistic conditions and to quantitatively evaluate the corrosion of the metal packing in real time. Compared with static corrosion evaluation methods, the present invention can completely simulate the gas-liquid contact state and process parameters during the absorption process, and the corrosion evaluation results of the metal packing are closer to the real absorption-desorption process.

[0028] 2. The condensation recovery module and heating injection module of the present invention can realize the closed circulation of reaction raw materials and the constant and controllable reaction conditions, while simultaneously isolating the external air from interference with the simulation process, so as to fully evaluate the corrosion reaction between the captured solvent and the metal filler.

[0029] 3. The evaluation method of the present invention is based on the simulation of a closed process under real conditions, and can collect parameters of metal packing and collecting solvent. Compared with conventional hanging plate method and electrochemical method, the evaluation method of the present invention can simultaneously and quantitatively evaluate the corrosion reaction and phenomenon on metal packing and in collecting solvent, and the evaluation results are closer to the real process and more comprehensive. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the carbon dioxide capture solvent metal corrosion evaluation device in Example 1;

[0031] Figure 1 Explanation of Chinese icon symbols:

[0032] 1. Visualized reaction vessel; 21. Condensation recovery unit; 22. Refrigeration unit; 23. Circulation pump; 24. Gas flow meter; 31. Booster pump; 32. Buffer tank; 33. Heater; 4. Gas valve;

[0033] Figure 2 The corrosion situation observed in the metal corrosion test conducted by the evaluation device of the present invention in Example 2;

[0034] Figure 3 This describes the corrosion conditions observed during a routine static corrosion test. Detailed Implementation

[0035] In order to provide a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention will now be described in detail below, but it should not be construed as limiting the scope of implementation of the present invention.

[0036] Example 1

[0037] This embodiment provides a device for evaluating the metal corrosivity of carbon dioxide capture solvents, such as... Figure 1 As shown, it includes: a visual reaction vessel 1, a condensation recovery module, and a heating injection module, wherein:

[0038] The visual reactor 1 is equipped with an air inlet at the bottom and an air outlet and safety valve at the top. The visual reactor 1 is also equipped with a liquid inlet, a liquid return inlet and a liquid phase sampling port. It is filled with a packing baffle, and metal packing is filled on the top of the packing baffle. The height of the packing is half the height of the reactor.

[0039] The condensation recovery module includes a condenser 21, a refrigerator 22, a circulating pump 23, and a gas flow meter 24. The refrigerator 22 and the circulating pump 23 are coupled to the condenser 21. The condenser 21 is provided with an air inlet, an air outlet, and a liquid outlet. The air inlet of the condenser 21 is connected to the air outlet of the visual reactor 1, and the liquid outlet of the condenser 21 is connected to the liquid return outlet of the visual reactor 1. The gas flow meter 24 is installed on the pipeline connected to the liquid outlet of the condenser 1.

[0040] The heating injection module includes a booster pump 31, a buffer tank 32 and a heater 33 connected in sequence. The inlet of the booster pump 31 is connected to the outlet of the condenser recovery unit 21, and the outlet of the heater 33 is connected to the inlet of the visual reactor 1. The buffer tank 32 is also provided with a gas replenishment port.

[0041] Gas valve 4 is also installed on the gas pipeline.

[0042] Example 2

[0043] This embodiment provides a method for evaluating the metal corrosivity of carbon dioxide capture solvents, which uses the carbon dioxide capture solvent metal corrosivity evaluation device of Example 1, and specifically includes the following steps:

[0044] (1) Fill the visual reactor 1 with metal packing to a predetermined height, open all valves, connect all modules of the carbon dioxide capture solvent metal corrosion evaluation device, connect to the external carbon dioxide gas source, use carbon dioxide gas to purge the entire device, and exhaust the air.

[0045] (2) Close all valves, fill the buffer tank 32 with carbon dioxide gas to the reaction pressure, and add the preheated collection solvent to the visual reactor 1 through the liquid inlet to the predetermined height;

[0046] (3) Turn on the refrigeration unit 22 and the circulation pump 23 to cool the condenser 21 to the preset temperature;

[0047] (4) Close the external connection valve, open the valve between each module, and inject the carbon dioxide gas heated by the heating injection module into the visualization reactor 1 at a predetermined gas rate to start the process simulation; if the pressure inside the reactor drops during the reaction, open the external connection valve and replenish the buffer tank 32 with carbon dioxide gas to atmospheric pressure.

[0048] (5) Collect parameters such as injection gas rate, injection gas volume, output gas rate, output gas volume, internal temperature and liquid level at predetermined time intervals, and collect samples of the captured solvent and output gas.

[0049] (6) The corrosion of metal fillers is analyzed and evaluated based on two evaluation methods: corrosion analysis of metal fillers and solvent composition analysis.

[0050] like Figure 2 As shown, stress corrosion cracking, pitting corrosion, intergranular corrosion, and friction corrosion were found on the metal filler after the experiment. The evaluation results of this invention are closer to the actual process, with higher accuracy and more comprehensive coverage. In contrast, conventional static corrosion evaluation methods only found pitting corrosion and intergranular corrosion on the metal filler after the experiment. Figure 3 As shown.

Claims

1. A device for evaluating the corrosivity of carbon dioxide capture solvents to metals, comprising: Visualized reaction vessel, condensation recovery module, and heating injection module. The interior of the visualization reactor is equipped with a packing baffle, and metal packing is filled above the baffle. The filling height of the metal packing is one-third to one-half of the height of the visualization reactor body. The visualization reactor is used to dynamically simulate the absorption process of carbon dioxide and the corrosion process of metal by the capture solvent under near-realistic conditions, and to place the metal packing at the gas-liquid interface to fully simulate the gas-liquid contact state and process parameters during the absorption process. The condensation recovery module includes a condenser, the inlet of which is connected to the outlet of the visual reactor for condensing and recovering the capture solvent entrained in the tail gas, and the outlet of which is connected to the return outlet of the visual reactor. The heating injection module includes a booster pump, a buffer tank, and a heater connected in sequence. The inlet of the booster pump is connected to the outlet of the condenser recovery unit, and the outlet of the heater is connected to the inlet of the visual reaction vessel. The heating injection module is used to heat and pressurize the added carbon dioxide and the condensed absorption tail gas to achieve a fully closed-loop circulation of the reaction raw materials. The heating temperature of the heater is 100-120℃.

2. The carbon dioxide capture solvent metal corrosion evaluation device according to claim 1, wherein, The buffer tank is also equipped with a gas replenishment port.

3. The carbon dioxide capture solvent metal corrosion evaluation device according to claim 1, wherein, The visualization reactor is also equipped with a liquid inlet and a liquid phase sampling port.

4. The carbon dioxide capture solvent metal corrosion evaluation device according to claim 1, wherein, The visualized reactor is also equipped with a safety valve.

5. The carbon dioxide capture solvent metal corrosion evaluation device according to claim 1, wherein, A gas flow meter is installed on the pipeline between the inlet of the booster pump and the condenser.

6. The carbon dioxide capture solvent metal corrosion evaluation device according to claim 1, wherein, The condensation recovery module also includes a circulation pump and a chiller coupled to the condensation recovery unit.

7. A method for evaluating the metal corrosivity of carbon dioxide capture solvents, wherein the method employs the metal corrosivity evaluation apparatus for carbon dioxide capture solvents as described in any one of claims 1-6.

8. The method for evaluating the corrosivity of carbon dioxide capture solvents to metals according to claim 7, wherein, It includes the following steps: (1) Fill the visual reactor with metal packing to a predetermined height, open all valves, connect all modules of the carbon dioxide capture solvent metal corrosion evaluation device, connect to an external carbon dioxide gas source, use carbon dioxide gas to purge the entire device, and exhaust air. (2) Close all valves, fill the buffer tank with carbon dioxide gas to the reaction pressure, and add preheated trapping solvent to the visual reactor through the liquid inlet to the predetermined height; (3) Turn on the refrigeration unit and the circulating pump to cool the condenser to the preset temperature; (4) Close the external connection valve, open the valve between each module, and inject the carbon dioxide gas heated by the heating injection module into the visualization reactor at a predetermined gas rate to start the process simulation; if the pressure inside the reactor drops during the reaction, open the external connection valve and replenish the buffer tank with carbon dioxide gas to atmospheric pressure; (5) Collect simulation process parameters at predetermined time intervals, and collect solvent samples and product gas samples; (6) Conduct corrosion analysis of metal fillers and solvent composition analysis.

9. The method for evaluating the corrosivity of carbon dioxide capture solvents to metals according to claim 7 or 8, wherein, Corrosion analysis of metallic fillers employs at least one of the following methods: gravimetric method, polarization curve method, and scanning electron microscopy.

Images