A method and system for preparing laser-etched modified fillers to promote CO2-rich liquid desorption

Abstract

This invention discloses a method and system for preparing laser-etched surface-modified fillers to promote CO2 desorption in rich solutions, belonging to the field of carbon dioxide desorption technology. The method utilizes a high-frequency pulsed laser to perform ordered etching on the surface of a metal or alloy filler, constructing a microstructure array with a deep cavity structure to enhance the CO2 desorption process. The preparation steps include filler surface pretreatment, laser etching under a controlled atmosphere, and post-treatment; the system consists of a laser processing system and a laser etching container. The microstructure constructed by laser etching can capture gas to form gas nuclei, significantly promoting bubble nucleation and detachment, increasing the peak CO2 desorption rate by up to 114.4%. It also has the advantages of simple process, no chemical pollution, low cost, and high stability, effectively solving the problems of complex processes, coating peeling, and environmental risks associated with existing catalytic coating modification technologies. It is suitable for enhancing CO2 desorption processes based on organic amine solutions in the fields of CO2 capture, utilization, and storage.

Description

Technical Field

[0001] This invention belongs to the field of carbon dioxide desorption technology, specifically relating to a method and system for preparing laser-etched modified fillers that promote CO2-rich liquid desorption. Background Technology

[0002] CO2 capture, utilization, and storage (CCUS) technology is a core means of controlling CO2 emissions. Among these, chemical absorption based on organic amine solutions has become the mainstream choice for current industrial applications due to its high capture efficiency and technological maturity. However, this technology faces problems such as high energy consumption for absorbent regeneration. Generally, the energy consumption of the desorption process can account for more than 60% of the total system energy consumption. Regulating the chemical reaction rate and gas-liquid mass transfer efficiency of the desorption process to enhance the carbon dioxide desorption process is one of the effective ways to solve the above problems.

[0003] To enhance the desorption process, existing research focuses on surface modification techniques for tower packing. For example, patent application CN115254142B discloses a catalytic desorption functional packing and its preparation method. Through a binder-impregnation-calcination process, mesoporous materials and metal oxides are loaded onto the packing surface, increasing the peak CO2 desorption rate by 59.8% and reducing the desorption temperature by 5.2℃. Patent application CN113318697A discloses SO4-loaded materials for CO2 desorption from amine solutions. 2- / Metal oxide fillers and their preparation methods, including loading metal oxides and sulfate SO4 onto the surface of ceramic fillers via an impregnation-calcination process. 2- This technology utilizes chemical catalysis to enhance the desorption process, achieving a 13.5%–24.3% reduction in CO2 desorption energy consumption. Patent application CN113351149A discloses a filler loaded with metal oxides / metal sulfides and its preparation method. This involves loading metal oxides and metal sulfides onto the surface of a ceramic filler through impregnation-calcination-sulfidation treatment. The catalytic filler effectively reduces desorption temperature and energy consumption. While the above technologies enhance the desorption process from a chemical catalytic perspective, three technical bottlenecks remain: first, the preparation process is complex, generally requiring 2-3 impregnation-calcination cycles, resulting in a lengthy process and high production costs; second, the coating interface adhesion is insufficient, and the catalytically active components are easily detached due to absorbent erosion or thermal stress, affecting long-term operational stability; and third, it has poor environmental friendliness, with some processes involving the use of toxic gases such as H2S, posing environmental safety risks.

[0004] Therefore, there is an urgent need to develop an efficient, low-cost, and environmentally friendly method for modifying filler surfaces in order to overcome the current technological bottlenecks. Summary of the Invention

[0005] The purpose of this invention is to provide a surface modification method based on laser etching, which can be used in carbon dioxide desorption systems to significantly improve the CO2 desorption rate and reduce desorption energy consumption. This surface modification method constructs a microstructure array with a deep cavity structure on the filler surface, eliminating the need for a catalytic coating. Furthermore, laser etching is a chemically pollution-free process, avoiding the risk of coating detachment and the complexity of chemical modification processes. Metal fillers such as stainless steel treated by this method can promote rapid nucleation, growth, and desorption of CO2 during carbon dioxide-rich solution desorption, thereby significantly improving the desorption rate and efficiency, reducing the CO2 absorbent regeneration temperature and energy consumption, and ultimately lowering the cost of carbon capture.

[0006] To achieve the above objectives, the present invention provides a method for preparing laser-etched modified fillers that promote CO2-rich liquid desorption. The method is characterized by using a high-frequency pulsed laser to perform ordered etching on the filler surface to obtain a microstructure array surface with a deep cavity structure.

[0007] This invention also provides a specific method for preparing laser-etched modified fillers that promote CO2-rich liquid desorption, comprising the following steps:

[0008] S10. Pre-treat the surface of the packing material to remove contaminants and oil stains, and obtain a pre-treated sample.

[0009] S20. Place the pre-treated sample in a laser etching container with a controllable atmosphere and place it below the optical focusing lens. Adjust the three-dimensional displacement platform so that the surface of the pre-treated sample to be processed is located at the laser focal length.

[0010] S30. A laser processing system is used to process the pre-treated sample. The output parameters of the laser and the laser processing parameters are set so that the laser scans and processes the surface of the pre-treated sample according to the preset parameters to obtain a microstructure array surface with a deep cavity structure.

[0011] S40. Post-process the surface of the processed microstructure array.

[0012] Preferably, the filler material in step S10 is metal or alloy, and the filler material is iron, aluminum, copper, zinc, nickel, titanium, cobalt, chromium, stainless steel or aluminum alloy.

[0013] Preferably, the pretreatment method in step S10 involves sequentially ultrasonically cleaning the material with deionized water, anhydrous ethanol, and then drying it. The ultrasonic cleaning time is 5-60 minutes, the drying temperature is 50-100°C, and the drying time is 0.5-5 hours. The optimal ultrasonic cleaning time is 10 minutes, the drying temperature is 60°C, and the drying time is 1 hour.

[0014] Preferably, in step S20, the processing atmosphere is air, nitrogen, or argon.

[0015] Preferably, in step S30, the laser is a nanosecond pulsed laser, and the output parameters of the laser are: laser wavelength 355-1064nm, repetition frequency 30-120kHz, pulse width 1-100ns, and laser power 5-50W; the laser processing parameters are: scanning speed 100-1200mm / s, scanning spacing 10-100μm, number of repeated scans 5-50 times, and scanning interval 100ms-10s.

[0016] Preferably, in step S30, the microstructure array is a strip groove, a square array, or a pyramid array structure; the deep cavity structure is a concave cavity that can capture gas to form gas nuclei and promote bubble nucleation.

[0017] Preferably, in step S40, the post-treatment involves sequentially ultrasonic cleaning with anhydrous ethanol and deionized water, followed by drying. The ultrasonic cleaning time is 10-30 minutes, the drying temperature is 50-80°C, and the drying time is 0.5-2 hours.

[0018] The present invention also provides a laser etching modified filler preparation system for promoting CO2-rich liquid desorption, characterized in that it includes a laser processing system and a laser etching container;

[0019] The laser processing system includes a laser, a galvanometer, and a focusing lens; the laser is used to output pulsed laser light, the galvanometer is used to control the scanning path of the laser beam, and the focusing lens is used to focus the laser beam onto the sample surface.

[0020] The laser etching container includes a glass window, a sample stage, and a gas nozzle; the glass window allows the laser to pass through and be focused, the sample stage is used to place and position the sample, and the gas nozzle is used to adjust the processing atmosphere.

[0021] Preferably, the laser is adapted to nanosecond, picosecond, or femtosecond laser types, and the wavelength range of the output laser is 355–1064 nm.

[0022] Preferably, the laser etching container is a sealed processing cavity, and the sample fixing stage is used in conjunction with a three-dimensional displacement platform to adjust the sample surface to the laser focal length.

[0023] Preferably, the processing atmosphere in the laser etching container is air, nitrogen, or argon, and is regulated by a gas nozzle.

[0024] Compared with the prior art, the present invention has the following significant advantages:

[0025] (1) This invention provides a surface modification method based on laser etching, which constructs a microstructure array with deep cavity on the filler surface by changing parameters such as laser power, repetition frequency, scanning speed, and scanning line spacing, and is applicable to various metal or alloy fillers.

[0026] (2) The filler treated by the surface modification method provided by the present invention can significantly promote the nucleation, growth and detachment of CO2 bubbles in the rich liquid desorption process, increase the peak desorption rate of CO2 by 114.4%, thereby reducing desorption energy consumption.

[0027] (3) The surface modification method provided by the present invention is a green processing process without chemical pollution. The preparation process is simple and controllable, reducing the cost of filler modification.

[0028] The following will further explain the concept, specific structure, and technical effects of the present invention in conjunction with the accompanying drawings, so as to fully understand the purpose, features, and effects of the present invention. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the laser processing system of the present invention;

[0030] The components include: 1. Laser; 2. Galvanometer; 3. Focusing lens; 4. Laser etching container; 5. Glass window; 6. Sample stage; and 7. Gas nozzle.

[0031] Figure 2 This is a SEM image of the microstructure of the laser-etched stainless steel filler in Embodiment 1 of the present invention;

[0032] Figure 3 This is a SEM image of the deep cavity cross-section of the laser-etched stainless steel filler in Embodiment 1 of the present invention;

[0033] Figure 4 The graph shows the evaluation results of CO2 desorption performance of laser-etched stainless steel filler in Examples 1 and 2 of this invention. Detailed Implementation

[0034] The following description, with reference to the accompanying drawings, illustrates several preferred embodiments of the present invention to make its technical content clearer and easier to understand. The present invention can be embodied in many different forms, and the scope of protection of the present invention is not limited to the embodiments mentioned herein.

[0035] In the accompanying drawings, components with the same structure are indicated by the same numerical designation, and components with similar structures or functions are indicated by similar numerical designations. The dimensions and thicknesses of each component shown in the drawings are arbitrary, and the present invention does not limit the dimensions and thicknesses of each component. To make the illustrations clearer, the thickness of some components has been appropriately exaggerated in the drawings.

[0036] This invention aims to address the technical bottlenecks of existing CO2 desorption filler modification technologies, such as complex processes, poor stability, high environmental risks, and neglect of gas-liquid mass transfer enhancement. It provides a filler surface modification method and dedicated system based on laser etching, which promotes bubble nucleation and enhances gas-liquid mass transfer by constructing specific microstructures on the filler surface, thereby improving the CO2 desorption rate and reducing desorption energy consumption.

[0037] The core technical idea of ​​this invention is to utilize the high precision and programmability of laser etching to construct a microstructure array with a deep cavity structure on the surface of metal or alloy filler. By capturing gas through the deep cavity, the nucleation barrier of bubbles is reduced, the generation and detachment of CO2 bubbles are accelerated, and the desorption process is enhanced.

[0038] The present invention provides a method for preparing laser-etched modified fillers that promote CO2-rich liquid desorption, comprising the following steps:

[0039] Step S10: Pretreatment of filler surface

[0040] The purpose of this step is to remove contaminants (such as oxide layers, dust) and oil stains (processing residue, fingerprint grease, etc.) from the filler surface, ensuring the stability of the laser etching process and the consistency of the microstructure.

[0041] Filler material: Metals or alloys are selected, specifically including iron, aluminum, copper, zinc, nickel, titanium, cobalt, chromium, molybdenum, and various stainless steels (such as 304 and 316 stainless steel). The above materials have good laser absorption and mechanical strength, and are suitable for the desorption environment of organic amine solutions.

[0042] Pretreatment method: A three-stage ultrasonic cleaning process is adopted, specifically as follows:

[0043] Deionized water ultrasonic cleaning: removes soluble inorganic matter and particulate impurities from the surface, ultrasonic power 300-500W, time 5-60min (preferably 10min);

[0044] Anhydrous ethanol ultrasonic cleaning: Utilizing the strong penetrating power of ethanol to dissolve surface oil stains, ultrasonic power 300-500W, time 5-60min (preferably 10min);

[0045] Secondary ultrasonic cleaning with deionized water: Removes residual ethanol and dissolved oil stains, with the same parameters as the first step.

[0046] Drying treatment: After cleaning, the sample is placed in a forced-air drying oven and dried at 50-100℃ (preferably 60℃) for 0.5-5 hours (preferably 1 hour) to ensure that there is no moisture residue on the surface and to avoid steam interference during laser etching.

[0047] Step S20: Sample positioning and atmosphere control

[0048] The pretreated sample is placed in the laser etching container to complete the parameter calibration and environmental preparation before processing.

[0049] Laser etching container: It is a sealed cavity structure equipped with a glass window (made of quartz glass, with a light transmittance of >90% @ 355~1064nm), a sample stage, and a gas nozzle (with an adjustable flow rate of 0~SL / min).

[0050] Positioning adjustment: The sample position is adjusted by a three-dimensional displacement platform so that the surface to be processed is in the laser focusing plane, ensuring uniform etching depth.

[0051] Atmosphere control: Gas is introduced into the container through a gas nozzle. The atmosphere can be air, nitrogen or argon. The gas flow rate is 1 to 3 L / min. After replacing the air in the chamber 3 to 5 times, a stable atmosphere is maintained to avoid excessive oxidation of the sample surface or the generation of harmful gases during the processing.

[0052] Step S30: Laser etching process

[0053] A laser processing system is used to perform programmed scanning of the sample surface to construct a microstructure array:

[0054] The laser processing system consists of a laser, a galvanometer (scanning speed 0-5000mm / s, positioning accuracy ±0.001mm), and a focusing lens (focal length 100-200mm, spot diameter 10-50μm).

[0055] Laser parameters:

[0056] Laser type: nanosecond laser (preferred), picosecond laser or femtosecond laser, among which nanosecond laser has the advantages of both processing efficiency and cost, making it suitable for industrial production;

[0057] Output parameters: wavelength 355nm, 532nm or 1064nm, repetition frequency 30~120kHz, pulse width 1~100ns, laser power 5~50W.

[0058] Processing parameters:

[0059] Scanning speed: 100~1200mm / s, which determines the laser interaction time per unit area and affects the etching depth;

[0060] Scanning interval: 10–100 μm, controlling the arrangement density of microstructure units;

[0061] Number of repeated scans: 5 to 50, used to adjust the depth of the microstructure;

[0062] Scanning interval: 100ms to 10s, to avoid sample overheating caused by continuous processing.

[0063] Microstructure features: By programming and controlling the laser scanning path, structures such as strip grooves, square arrays or pyramid arrays can be formed. Its core feature is that it contains a concave cavity (cavity depth 100-200μm, cavity bottom diameter 1-5μm), which can capture gas and form a stable gas nucleus.

[0064] Step S40: Post-processing

[0065] Remove slag and debris generated during processing to ensure the integrity of the microstructure:

[0066] Cleaning process: Use anhydrous ethanol (to dissolve organic residues) and deionized water (to remove inorganic impurities) for ultrasonic cleaning in sequence, with a power of 300-500W and a time of 5-60 minutes (preferably 10 minutes);

[0067] Drying treatment: Same as step S10, dry at 50-100℃ for 0.5-5h to finally obtain a laser-etched modified filler with a clean surface.

[0068] like Figure 1 As shown, the present invention also provides a dedicated preparation system, comprising:

[0069] Laser processing system: The laser provides pulsed laser output, the galvanometer controls the laser scanning trajectory according to the preset pattern, and the focusing lens focuses the laser beam onto the sample surface to form a high-energy spot;

[0070] Laser etching container: As a closed processing environment, the glass window ensures laser transmission without attenuation, the sample fixing stage and the three-dimensional displacement platform achieve high-precision positioning, and the gas nozzle regulates the atmosphere inside the chamber through the flow controller.

[0071] The specific content of the present invention will be illustrated below through specific embodiments.

[0072] Example 1

[0073] This embodiment describes a method for preparing laser-etched modified fillers that promote CO2-rich liquid desorption, comprising the following specific steps:

[0074] Step S10: Pre-treat the 304 stainless steel filler to remove surface contaminants and oil. Clean the sample sequentially with deionized water, anhydrous ethanol, and then deionized water using ultrasonic cleaning for 10 minutes each. After cleaning, place the sample in a drying oven and dry at 60°C for 1 hour to obtain a clean stainless steel sample.

[0075] Step S20: Fix the clean stainless steel sample described in step S10 onto the sample fixing stage 6 in the laser etching container 4, adjust the three-dimensional displacement platform so that the laser beam is focused on the sample surface through the glass window 5, and blow it through the gas nozzle 7 to control the processing atmosphere in the laser etching container 4 to be air.

[0076] Step S30: The sample is processed using a laser processing system. The output parameters and laser processing parameters of laser 1 are preset. The laser wavelength is 1064nm, the repetition frequency is 60kHz, the pulse width is 100ns, and the laser power is 20W. The scanning speed is 400mm / s, the scanning interval is 50μm, the number of repeated scans is 25, and the scanning interval is 10s. Laser 1 is turned on, and the output laser is dynamically deflected by galvanometer 2 and then focused by focusing lens 3 to form a focused spot. The sample is scanned and processed according to the processing parameters described in step S30.

[0077] Step S40: The processed sample is ultrasonically cleaned with anhydrous ethanol and deionized water for 10 minutes in sequence and then dried to remove residual impurities on the surface.

[0078] Figure 2 and 3 The image shown is an SEM image of the laser-etched stainless steel packing in Example 1. It can be seen that the packing surface has a typical ridge-groove array structure and the unit cavity is a concave deep cavity. The deep cavity can effectively capture gas to form initial gas nuclei, promote rapid nucleation and release, and improve the overall desorption rate.

[0079] Example 2

[0080] This embodiment describes a method for preparing laser-etched modified fillers that promote CO2-rich liquid desorption, comprising the following specific steps:

[0081] Step S10: Pre-treat the 304 stainless steel filler to remove surface contaminants and oil. Clean the sample sequentially with deionized water, anhydrous ethanol, and then deionized water using ultrasonic cleaning for 10 minutes each. After cleaning, place the sample in a drying oven and dry at 60°C for 1 hour to obtain a clean stainless steel sample.

[0082] Step S20: Fix the clean stainless steel sample described in step S10 onto the sample fixing stage 6 in the laser etching container 4, adjust the three-dimensional displacement platform so that the laser beam is focused on the sample surface through the glass window 5, and blow it through the gas nozzle 7 to control the processing atmosphere in the laser etching container 4 to be air.

[0083] Step S30: The sample is processed using a laser processing system. The output parameters and laser processing parameters of the laser 1 are preset. The laser wavelength is 1064nm, the repetition frequency is 60kHz, the pulse width is 100ns, and the laser power is 20W. The scanning speed is 800mm / s, the scanning interval is 70μm, the number of repeated scans is 25, and the scanning interval is 10s. The laser 1 is turned on, and the output laser is dynamically deflected by the galvanometer 2 and then focused by the focusing lens 3 to form a focused spot. The sample is scanned and processed according to the processing parameters described in step S30.

[0084] Step S40: The processed sample is ultrasonically cleaned with anhydrous ethanol and deionized water for 10 minutes in sequence and then dried to remove residual impurities on the surface.

[0085] Performance testing

[0086] To evaluate the promoting effect of laser-etched modified fillers on CO2 desorption, performance tests were conducted on the surface-modified fillers of Examples 1 and 2 of this invention using a self-built CO2 desorption apparatus. A control group without modified fillers was also included. The experimental conditions for the control group were the same as those for Examples 1 and 2, except that the filler was omitted. The desorption experiment procedure was as follows: 400 ml of carbon dioxide-rich solution was added to the reaction vessel, along with a certain amount of the modified filler from the examples. The solution was heated to 90°C for 60 min to desorb. The carbon dioxide-rich solution was a 30 wt% ethanolamine (MEA) solution with a CO2 loading of 0.53 mol CO2 / mol MEA. The amount of modified filler added was based on the total etched area, which was 1.5 cm². 2 .

[0087] The CO2 concentration change curve is recorded using a CO2 infrared gas analyzer, and the CO2 desorption rate per unit time is calculated according to the following formula to obtain the maximum value in the desorption curve, i.e., the CO2 peak desorption rate. This parameter is an important indicator for measuring the desorption effect.

[0088]

[0089] in, (L / min) is the flow rate of N2. (%) represents the CO2 concentration measured by the CO2 gas analyzer.

[0090] Figure 4 The results show the evaluation of CO desorption performance of laser-etched stainless steel fillers in Examples 1 and 2. The results indicate that, compared with the control group, the modified fillers used in Examples 1 and 2 significantly increased the CO2 desorption rate in the initial stage of desorption, increasing the peak CO2 desorption rate by 114.4% and 78.8%, respectively. This demonstrates that the presence of the deep cavity microstructure has a significant promoting effect on CO2 desorption. Although the desorption rates of each group gradually converged after the peak value, the early enhancement effect helped to shorten the desorption time and reduce the overall energy consumption.

[0091] Although the present invention preferably employs laser etching to construct microstructure arrays with deep cavity structures, other micro / nano fabrication techniques, such as micro / nano imprinting and wet etching, can also be considered to achieve similar structures. Each of these methods has its advantages, but compared to laser etching, it offers advantages such as no need for masks, flexible processing, programmable patterns, and environmental friendliness, making it more suitable for complex structure designs and rapid industrial fabrication needs.

[0092] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A method for preparing laser-etched modified filler to promote CO2-rich liquid desorption, characterized in that, A microstructure array surface with a deep cavity structure is obtained by using a high-frequency pulsed laser to perform ordered etching on the filler surface. A laser processing system was used to process the pretreated sample. The output parameters of the laser and the laser processing parameters were set as follows: laser wavelength 355–1064 nm, repetition frequency 30–120 kHz, pulse width 1–100 ns, and laser power 5–50 W; laser processing parameters were: scanning speed 100–1200 mm / s, scanning spacing 10–100 μm, number of repeated scans 5–50, and scanning interval 100 ms–10 s; the microstructure array was a strip groove, square array, or pyramid array structure; the deep cavity structure was a concave cavity with a bottom dimension of less than 6 μm, which could effectively capture gas to form gas nuclei and promote bubble nucleation.

2. A method for preparing laser-etched modified filler to promote CO2-rich liquid desorption, characterized in that, Includes the following steps: S10. Pre-treat the surface of the packing material to remove contaminants and oil stains, and obtain a pre-treated sample. S20. Place the pre-treated sample in a laser etching container with a controllable atmosphere and place it below the optical focusing lens. Adjust the three-dimensional displacement platform so that the surface of the pre-treated sample to be processed is near the laser focusing point. S30. A laser processing system is used to process the pretreated sample. The output parameters of the laser and the laser processing parameters are set so that the laser scans and processes the surface of the pretreated sample according to the preset parameters to obtain a microstructure array surface with a deep cavity structure. The laser is a nanosecond pulsed laser. The output parameters of the laser are: laser wavelength 355-1064nm, repetition frequency 30-120kHz, pulse width 1-100ns, and laser power 5-50W. The laser processing parameters are: scanning speed 100-1200mm / s, scanning spacing 10-100μm, number of repeated scans 5-50 times, and scanning interval 100ms-10s. The microstructure array is a strip groove, square array, or pyramid array structure. The deep cavity structure is a concave cavity with a bottom dimension of less than 6μm, which can effectively capture gas to form gas nuclei and promote bubble nucleation. S40. Post-process the surface of the processed microstructure array.

3. The preparation method according to claim 2, characterized in that, The filler material mentioned in step S10 is metal or alloy.

4. The preparation method according to claim 3, characterized in that, The filler material is made of iron, aluminum, copper, zinc, nickel, titanium, cobalt, chromium, molybdenum, stainless steel, or aluminum alloy.

5. The preparation method according to claim 2, characterized in that, The pretreatment method described in step S10 involves ultrasonically cleaning the material and drying it sequentially with deionized water, anhydrous ethanol, and deionized water.

6. The preparation method according to claim 5, characterized in that, The ultrasonic cleaning time is 5-60 min, the drying temperature is 50-100℃, and the drying time is 0.5-5 h.

7. The preparation method according to claim 2, characterized in that, In step S20, the processing atmosphere is air, nitrogen, or argon.

8. The preparation method according to claim 2, characterized in that, In step S40, the post-processing involves sequentially ultrasonic cleaning with anhydrous ethanol and deionized water, followed by drying.

9. The preparation method according to claim 8, characterized in that, The ultrasonic cleaning time is 10-20 min, the drying temperature is 50-80℃, and the drying time is 0.5-2 h.

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