Nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent, and preparation method and application thereof

Abstract

The application discloses a kind of nanoparticle enhanced functionalized ionic liquid liquid-liquid phase change absorbent and its preparation method and application, absorbent is composed of functionalized ionic liquid, nanoparticle, phase change promoter and solvent;The molar concentration of functionalized ionic liquid is 0.05~0.35mol·kg ‑1 ;The mass concentration of nanoparticle is 0.05~0.45wt%;The mass ratio of phase change promoter and solvent is 3:7~8:2;Functionalized ionic liquid is [tetraethylene five amine][1,2,3-triazole];Nanoparticle is titanium dioxide;Phase change promoter is 1-methoxy-2-propanol;Solvent is water.The absorbent of the application shows ideal carbon dioxide capture performance such as high cycle capacity, low regeneration energy consumption, moderate rich phase volume, low rich phase viscosity, always having phase change ability in long-term cyclic use, fast phase separation rate, stable and clear phase interface and high thermokinetics performance.

Description

Technical Field

[0001] This invention relates to the field of carbon dioxide capture and separation technology, specifically to a nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent, its preparation method, and its application. Background Technology

[0002] The International Energy Agency (IEA) reports that global energy-related CO2 emissions reached a record 37.8 Gt in 2024, a 0.8% increase year-on-year. This significant increase in greenhouse gases exacerbates climate-related risks, highlighting the urgent need for efficient, low-carbon CO2 capture, utilization, and storage technologies. While amine-based CO2 chemical absorbents, such as monoethanolamine (MEA), are commercially mature due to their good reactivity and extensive industrial infrastructure, they still face significant limitations in meeting stringent emission targets. Key challenges include low regeneration efficiency, large liquid volumes required for operation, and excessively high solvent content without CO2 components during regeneration, leading to high operating energy consumption. For a baseline of 30.0 wt% MEA / water, the energy consumption per tonne of CO2 is 3.6–4.0 GJ. Furthermore, operational issues such as component loss and equipment corrosion further limit their practical application. Therefore, the development of advanced absorbents with lower energy consumption is urgently needed.

[0003] During carbon dioxide absorption, the phase change absorbent spontaneously separates into a carbon dioxide-rich phase and a carbon dioxide-lean phase, requiring only the regeneration of the rich phase to complete the closed loop. This method fundamentally reduces heat load and pump power by significantly decreasing the amount of liquid requiring thermal regeneration. Therefore, this technology is attracting increasing attention for achieving high-efficiency, low-energy carbon capture. Compared to solid-liquid systems that often form viscous solids, liquid-liquid phase change absorbents, with their easily separable and transportable rich and lean phases, are considered the most promising route for industrial-scale expansion due to their easier continuous operation and simpler equipment modifications. To further reduce absorbent volatilization and degradation, amino-functionalized ionic liquids can be used as the reactive main agent in liquid-liquid phase change absorbents. Amino-functionalized ionic liquids possess high structural tunability, rapid carbon dioxide reactivity, excellent thermal stability, and near-zero vapor pressure. These characteristics collectively balance the absorbent's carbon dioxide capture performance, energy efficiency, and environmental safety. When amino-functionalized ionic liquids are synthesized from low-cost precursors via a simple route, this liquid-liquid phase change absorbent based on amino-functionalized ionic liquids promises to keep the preparation cost within a commercially acceptable range.

[0004] However, the industrial application of liquid-liquid phase change absorbents still faces challenges due to bottlenecks caused by their phase change behavior. During the phase change process, liquid-liquid phase change absorbents form a distinct liquid-liquid interface and generate a high-viscosity rich phase, increasing resistance to heat and mass transfer and reducing carbon dioxide capture and phase change efficiency. Furthermore, spontaneous phase separation driven solely by gravity and concentration gradients is inherently slow and inefficient. This often leads to a blurred and unstable interface between the lean and rich phases, hindering stable operation. In addition, during cyclic operation, the phase change performance of the absorbent can be further impaired or even lost due to dynamic changes in operating parameters, component types and ratios, and the physicochemical properties of the liquid-liquid phase change absorbent.

[0005] Current industrial practices primarily rely on optimization strategies to enhance the phase change behavior of liquid-liquid phase change absorbers (LCBs) through improvements in phase separation equipment. These techniques aim to accelerate the precipitation rate of rich-phase droplets while reducing their residence time in the lean phase, thereby improving the phase separation efficiency of LCBs. However, such methods inevitably lead to a significant increase in operating energy consumption and investment costs. Fundamentally, the theoretical upper limit of phase change behavior remains constrained by intrinsic physicochemical properties, including interfacial tension, density difference, and component diffusion coefficients. Regardless of the magnitude of applied external forces, equipment improvements can only approach, but not exceed, this inherent limit. Furthermore, equipment optimization cannot improve the intrinsic mass-heat transfer characteristics of LCBs, nor can it offset the gradual decay of phase change capacity during cyclic operation.

[0006] Therefore, how to enhance the heat and mass transfer within the liquid-liquid phase change absorber from a new dimension of material design to comprehensively optimize phase change behavior and carbon capture capacity, and break through the technical bottlenecks that restrict the industrial-scale application of phase change absorption methods, has become an urgent problem to be solved. Summary of the Invention

[0007] To address the problems of unsatisfactory phase change behavior of traditional liquid-liquid phase change absorbents and the limitations of traditional equipment optimization and improvement methods, the present invention aims to provide a nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent, its preparation method, and its application. This absorbent has strong absorption performance, high cycle capacity, low regeneration energy consumption, good thermo-dynamic performance, and good phase change behavior. It can maintain the ability of liquid-liquid phase change during long-term continuous operation, with fast phase separation rate and stable and clear two-phase interface.

[0008] To achieve the above objectives, the first aspect of the present invention provides a nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent, which mainly comprises a functionalized ionic liquid, nanoparticles, a phase change promoter, and a solvent; wherein the molar concentration of the functionalized ionic liquid is 0.05–0.35 mol·kg⁻¹. -1The nanoparticles have a mass concentration of 0.05–0.45 wt%; the phase change promoter to solvent mass ratio is 3:7–8:2; the functionalized ionic liquid is [tetraethylenepentamine][1,2,3-triazole], wherein the cationic precursor is tetraethylenepentamine and the anionic precursor is 1,2,3-triazole; the nanoparticles are titanium dioxide; the phase change promoter is 1-methoxy-2-propanol; and the solvent is water.

[0009] This invention achieves high carbon dioxide capacity and reliable phase change by selecting [tetraethylenepentamine][1,2,3-triazole], which can generate highly polar, multi-charged carbon dioxide products and possesses polyamine groups and a linear structure; it optimizes carbon capture efficiency and phase change behavior by using titanium dioxide nanoparticles to enhance the mass and heat transfer performance of the absorbent; it reduces solvent loss by using high-boiling-point 1-methoxy-2-propanol and optimizes the absorption-regeneration performance of the system through hydroxyl and ether bonds; it uses water to reduce viscosity and promote the formation of carbonate products; and it fully utilizes the synergistic effect of different components and achieves a balance of various physicochemical properties by adjusting the ratio between functionalized ionic liquid, nanoparticles, phase change promoter, and solvent. Ultimately, this nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent exhibits ideal carbon dioxide capture performance, including high cycle capacity, low regeneration energy consumption, moderate rich phase volume, low rich phase viscosity, consistent phase change capability during long-term cycling, fast phase separation rate, stable and clear phase interface, and high thermo-dynamic performance.

[0010] The polyamine structure of tetraethylenepentamine enhances the reactivity of carbon dioxide and increases the carbon dioxide loading; its flexible framework prevents solid formation, ensuring a liquid-liquid phase transition. The high steric hindrance of 1,2,3-triazole reduces the stability of the cation's carbamate products, thus solving the problem of carbamate aggregation at the cation, which is detrimental to regeneration; the corrosion resistance of 1,2,3-triazole reduces equipment and material wear. The high dipole moment and multi-charged carbon dioxide products of [tetraethylenepentamine][1,2,3-triazole] significantly increase solution polarity, ensuring the triggering of the phase transition. The hydroxyl group of 1-methoxy-2-propanol reacts with carbon dioxide to form alkyl carbonates and promotes the decomposition of carbon dioxide products through proton transfer, while the ether bond prevents the hydrogen bond network from becoming too dense, lowering the molecular rotation barrier and thus reducing the absorbent viscosity when saturated with carbon dioxide. Furthermore, the boiling point of 1-methoxy-2-propanol is above 120°C, which minimizes latent heat requirements during regeneration and reduces component loss during long-term absorbent cycling. The presence of water can promote the formation of easily desorbed carbonate carbon dioxide products and reduce viscosity, thereby further optimizing the carbon dioxide capture performance of the absorbent.

[0011] The key point is that titanium dioxide nanoparticles can reduce viscosity and improve absorbent fluidity through a series of enhancement mechanisms such as surface activity, Brownian motion, and microconvection effect. They can also increase the physical and chemical properties (such as viscosity, density, and pH) of the lean and rich phases to promote the formation and separation of the rich phase, enhance the mass and heat transfer performance and thermo-dynamic performance of the absorbent, thereby comprehensively optimizing the carbon capture capacity and phase change behavior of the absorbent.

[0012] Optionally, the preferred molar concentration of the functionalized ionic liquid is 0.10–0.25 mol·kg⁻¹. -1 The preferred mass concentration of the nanoparticles is 0.10–0.30 wt%; the mass ratio of the phase change promoter to the solvent is 6:4–7:3.

[0013] A second aspect of this invention provides a method for preparing a nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent. This method is simple, easy to operate and implement, and includes:

[0014] The cationic and anionic precursors were dissolved in a mixed solvent of water and ethanol and subjected to a first water bath stirring treatment to obtain solution one; solution one was subjected to vacuum rotary evaporation to obtain solution two; solution two was subjected to vacuum drying to obtain a functionalized ionic liquid; the functionalized ionic liquid, phase change promoter and solvent were mixed in proportion and subjected to a second water bath stirring treatment to obtain solution three; nanoparticles were added to solution three and subjected to ultrasonic treatment to obtain a nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorber.

[0015] Optionally, the mass ratio of the cationic precursor to the anionic precursor is 7:3 to 3:7; the mass ratio of water to ethanol in the mixed solvent is 0:10 to 10:0; the temperature of the first water bath stirring is 20 to 60°C; and the stirring speed of the first water bath stirring is 400 to 1000 r·min. -1 The duration of the first water bath stirring is 12–36 h; the temperature of vacuum rotary evaporation is 50–100℃; the duration of vacuum rotary evaporation is 4–10 h; the temperature of vacuum drying is 70–120℃; the duration of vacuum drying is 12–36 h; the temperature of the second water bath stirring is 30–50℃; the stirring speed of the second water bath stirring is 500–800 r·min. -1 The second water bath stirring time is 1–6 hours; the ultrasonic treatment power is 20–35 W·L. -1 The duration of ultrasonic treatment is 0.5 to 2 hours.

[0016] The third aspect of the present invention provides the application of the nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent provided in the first aspect of the present invention in carbon dioxide capture.

[0017] Optionally, the absorption temperature of the nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent is 30–60°C; the regeneration temperature of the nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent is 100–140°C.

[0018] Optionally, the nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent is applied to treat mixed flue gas containing carbon dioxide, which contains 10-15 vol% carbon dioxide, 75-85 vol% nitrogen, 0-5 vol% water, and 0-5 vol% impurities composed of sulfur dioxide, soot, and other substances.

[0019] Optionally, the carbon dioxide absorption load of the nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent is 1.50–2.10 mol·kg⁻¹. -1 The volume percentage of the enriched phase is 40.00–60.00 vol%, the carbon dioxide loading percentage of the enriched phase is 95.00%–99.99%, the viscosity of the enriched phase is 20.0–40.0 mPa·s, the carbon dioxide regeneration efficiency is 80.00%–95.00%, and the carbon dioxide circulation capacity is 1.60–1.80 mol·kg⁻¹. -1 The energy consumption for carbon dioxide regeneration is 1.80–2.40 GJ·t. -1 .

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] This invention provides a nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent, its preparation method, and its application. A [tetraethylenepentamine][1,2,3-triazole] functionalized ionic liquid is used as the main agent, titanium dioxide nanoparticles as an auxiliary agent, 1-methoxy-2-propanol as a phase change promoter, and water as a solvent to construct a mixed nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent. This absorbent exhibits excellent carbon dioxide absorption performance (absorption load of 1.50–2.10 mol·kg⁻¹). -1 The absorbent exhibits good carbon dioxide regeneration performance (regeneration efficiency of 80.00%–95.00%), a moderate rich phase volume percentage (40.00–60.00 vol%), a high rich phase carbon dioxide loading percentage (95.00%–99.99%), low rich phase viscosity (20.0–40.0 mPa·s), and rapid phase separation (5–10 min). After 10 absorption-regeneration cycles, the changes in various performance indicators of the absorbent were all within 10% of the initial values. At 168 h, 4 Nm·h -1In small-scale continuous cyclic operation, the absorbent exhibited moderate phase change capability, and its various operating performance parameters remained stable without significant fluctuations. Life cycle assessment results showed that the environmental friendliness of this absorbent was significantly higher than the benchmark 30.0 wt% monoethanolamine / water. The absorbent system involved in this invention has the potential for large-scale industrial application.

[0022] Other features and advantages of the present invention will be described in detail in the following detailed description section with reference to the accompanying drawings. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the nanoparticle enhancement mechanism of the nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorber described in this invention.

[0024] Figure 2 Thermogravimetric and differential scanning calorimetric data of the [tetraethylenepentamine][1,2,3-triazole] functionalized ionic liquid and its precursor in the nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent of the present invention.

[0025] Figure 3 The conductivity data of the [tetraethylenepentamine][1,2,3-triazole] functionalized ionic liquid and its precursor in the nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent described in this invention are as follows:

[0026] Figure 4 The data on various carbon dioxide capture indicators of the nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent described in this invention during 10 absorption-regeneration cycles.

[0027] Figure 5 These are physical images of the nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent described in this invention during various stages of carbon dioxide capture.

[0028] Figure 6 The carbon capture performance data of the nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorber described in this invention under continuous cyclic operation on a pilot-scale platform.

[0029] Figure 7 This diagram illustrates the phase transition behavior of the nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent described in this invention during continuous cyclic operation on a small-scale testing platform. Detailed Implementation

[0030] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0031] The first aspect of this invention provides a nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent, which mainly comprises a functionalized ionic liquid, nanoparticles, a phase change promoter, and a solvent; the molar concentration of the functionalized ionic liquid is 0.05–0.35 mol·kg⁻¹. -1 The nanoparticles have a mass concentration of 0.05–0.45 wt%; the phase change promoter to solvent mass ratio is 3:7–8:2; the functionalized ionic liquid is [tetraethylenepentamine][1,2,3-triazole], wherein the cationic precursor is tetraethylenepentamine and the anionic precursor is 1,2,3-triazole; the nanoparticles are titanium dioxide; the phase change promoter is 1-methoxy-2-propanol; and the solvent is water.

[0032] According to the present invention, the preferred molar concentration of the functionalized ionic liquid is 0.10–0.25 mol·kg⁻¹. -1 The preferred mass concentration of the nanoparticles is 0.10–0.30 wt%; the mass ratio of the phase change promoter to the solvent is 6:4–7:3. Through the above preferred embodiments, the proportions of the functionalized ionic liquid, nanoparticles, phase change promoter, and solvent within the above range can fully leverage the synergistic effect of the four components, resulting in a faster absorption rate, higher absorption load, more thorough regeneration, higher cycle capacity, lower regeneration energy consumption, better thermodynamic performance, and more ideal phase change behavior in the nanoparticle-enhanced functionalized ionic liquid-liquid phase change absorbent.

[0033] A second aspect of this invention provides a method for preparing a nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent, the method comprising:

[0034] The cationic and anionic precursors were dissolved in a mixed solvent of water and ethanol and subjected to a first water bath stirring treatment to obtain solution one; solution one was subjected to vacuum rotary evaporation to obtain solution two; solution two was subjected to vacuum drying to obtain a functionalized ionic liquid; the functionalized ionic liquid, phase change promoter and solvent were mixed in proportion and subjected to a second water bath stirring treatment to obtain solution three; nanoparticles were added to solution three and subjected to ultrasonic treatment to obtain a nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorber.

[0035] According to the present invention, optionally, the mass ratio of the cationic precursor to the anionic precursor is 7:3 to 3:7; the mass ratio of water to ethanol in the mixed solvent is 0:10 to 10:0; the temperature of the first water bath stirring is 20 to 60°C; and the stirring speed of the first water bath stirring is 400 to 1000 r·min. -1The duration of the first water bath stirring is 12–36 h; the temperature of vacuum rotary evaporation is 50–100℃; the duration of vacuum rotary evaporation is 4–10 h; the temperature of vacuum drying is 70–120℃; the duration of vacuum drying is 12–36 h; the temperature of the second water bath stirring is 30–50℃; the stirring speed of the second water bath stirring is 500–800 r·min. -1 The second water bath stirring time is 1–6 hours; the ultrasonic treatment power is 20–35 W·L. -1 The duration of ultrasonic treatment is 0.5 to 2 hours.

[0036] The third aspect of the present invention provides the application of the mixed organic amine absorbent provided in the first aspect of the present invention in carbon dioxide capture.

[0037] According to the present invention, optionally, the absorption temperature of the nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent is 30-60°C; and the regeneration temperature of the nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent is 100-140°C.

[0038] According to the present invention, optionally, the nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent is applied to treat mixed flue gas containing carbon dioxide, wherein the mixed flue gas contains 10-15 vol% carbon dioxide, 75-85 vol% nitrogen, 0-5 vol% water, and 0-5 vol% impurities composed of sulfur dioxide, soot, etc.

[0039] The present invention will be further illustrated by the following examples, but the present invention is not limited thereto.

[0040] Example 1

[0041] The cationic precursor tetraethylenepentamine and the anionic precursor 1,2,3-triazole were dissolved in a mixed solvent of water and ethanol and subjected to a first water bath stirring treatment to obtain solution one. Solution one was then subjected to vacuum rotary evaporation to obtain solution two. Solution two was then subjected to vacuum drying to obtain a functionalized ionic liquid. The functionalized ionic liquid, phase change promoter, and solvent were mixed in a certain proportion and subjected to a second water bath stirring treatment to obtain solution three. Nanoparticles were added to solution three and subjected to ultrasonic treatment to obtain a nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorber.

[0042] In the preparation method of the nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent, the mass ratio of the cationic precursor to the anionic precursor is 5:5; the mass ratio of water to ethanol in the mixed solvent is 5:5; the temperature of the first water bath stirring is 40℃; and the stirring speed of the first water bath stirring is 500 r·min. -1The first water bath stirring time was 24 hours; the vacuum rotary evaporation temperature was 80℃; the vacuum rotary evaporation time was 6 hours; the vacuum drying temperature was 100℃; the vacuum drying time was 24 hours; the second water bath stirring temperature was 40℃; the stirring speed for the second water bath stirring was 500 r / min. -1 The second water bath stirring time was 1 hour; the ultrasonic treatment power was 35 W·L. -1 The duration of ultrasonic treatment is 1 hour.

[0043] In the nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent, the molar concentration of the functionalized ionic liquid is 0.10 mol·kg⁻¹. -1 The mass concentration of nanoparticles is 0.20 wt%; the mass ratio of phase change promoter to solvent is 6:4.

[0044] Nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent was used to treat mixed flue gas containing carbon dioxide under operating conditions of absorption temperature of 40℃ and regeneration temperature of 120℃.

[0045] The mixed flue gas treated by the nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent contains 10-15 vol% carbon dioxide, 75-85 vol% nitrogen, 0-5 vol% water, and 0-5 vol% impurities composed of sulfur dioxide, soot, and other substances.

[0046] Comparative Example 1

[0047] Comparative Example 1 is a functionalized ionic liquid-liquid phase change absorbent without the addition of titanium dioxide nanoparticles.

[0048] The cationic precursor tetraethylenepentamine and the anionic precursor 1,2,3-triazole were dissolved in a mixed solvent of water and ethanol and subjected to a first water bath stirring treatment to obtain solution one; solution one was subjected to vacuum rotary evaporation to obtain solution two; solution two was subjected to vacuum drying to obtain a functionalized ionic liquid; the functionalized ionic liquid, phase change promoter and solvent were mixed in proportion and subjected to a second water bath stirring treatment to obtain a functionalized ionic liquid liquid-liquid phase change absorbent.

[0049] In the preparation method of the functionalized ionic liquid liquid-liquid phase change absorbent, the mass ratio of the cationic precursor to the anionic precursor is 5:5; the mass ratio of water to ethanol in the mixed solvent is 5:5; the temperature of the first water bath stirring is 40℃; and the stirring speed of the first water bath stirring is 500 r·min. -1The first water bath stirring time was 24 hours; the vacuum rotary evaporation temperature was 80℃; the vacuum rotary evaporation time was 6 hours; the vacuum drying temperature was 100℃; the vacuum drying time was 24 hours; the second water bath stirring temperature was 40℃; the stirring speed for the second water bath stirring was 500 r / min. -1 The second water bath stirring time is 1 hour.

[0050] In the functionalized ionic liquid liquid-liquid phase change absorbent, the molar concentration of the functionalized ionic liquid is 0.10 mol·kg⁻¹. -1 The mass ratio of the phase change promoter to the solvent is 5:5.

[0051] The functionalized ionic liquid liquid-liquid phase change absorbent is used to treat mixed flue gas containing carbon dioxide under operating conditions of absorption temperature of 40°C and regeneration temperature of 120°C.

[0052] The mixed flue gas treated by the functionalized ionic liquid liquid-liquid phase change absorbent contains 10-15 vol% carbon dioxide, 75-85 vol% nitrogen, 0-5 vol% water, and 0-5 vol% impurities composed of sulfur dioxide, soot, and other substances.

[0053] Comparative Example 2

[0054] Comparative Example 2 is a baseline of 30.0 wt% monoethanolamine / water organic amine homogeneous absorbent.

[0055] The main agent, monoethanolamine, was dissolved in water and subjected to water bath stirring to obtain a homogeneous organic amine absorbent.

[0056] In the preparation method of the organic amine homogeneous absorbent, the water bath stirring temperature is 40°C; the stirring speed of the water bath stirring is 500 r·min. -1 The water bath stirring time is 0.5 hours.

[0057] In the homogeneous organic amine absorbent, the mass concentration of the main agent is 30.0 wt%.

[0058] The organic amine homogeneous absorbent treats mixed flue gas containing carbon dioxide under operating conditions of absorption temperature of 40°C and regeneration temperature of 120°C.

[0059] The mixed flue gas treated by the organic amine homogeneous absorbent contains 10-15 vol% carbon dioxide, 75-85 vol% nitrogen, 0-5 vol% water, and 0-5 vol% impurities composed of sulfur dioxide, soot, and other substances.

[0060] Data Comparison and Analysis

[0061] Define the following concepts for carbon dioxide capture performance indicators:

[0062] Carbon dioxide absorption load (mol·kg) -1 ): The amount of carbon dioxide absorbed by a unit mass of absorbent.

[0063] Rich phase volume percentage (vol%): The proportion of the rich phase volume to the total volume of the absorbent.

[0064] Carbon dioxide load ratio in the enriched phase: the proportion of carbon dioxide contained in the enriched phase to the total amount of carbon dioxide contained in the absorbent.

[0065] Rich phase viscosity (mPa·s): The dynamic viscosity of the rich phase.

[0066] Carbon dioxide regeneration efficiency: The ratio of the carbon dioxide load after the absorbent absorbs carbon dioxide for the (n+1)th time after regeneration to the carbon dioxide load after the absorbent absorbs carbon dioxide for the nth time.

[0067] Carbon dioxide cycle capacity (mol·kg) -1 ): The difference between the carbon dioxide load after the absorbent absorbs carbon dioxide for the nth time and the residual carbon dioxide load after the absorbent is regenerated.

[0068] Energy consumption for carbon dioxide regeneration (GJ·t) -1 Energy required for the absorbent to regenerate a unit mass of carbon dioxide.

[0069] The carbon dioxide capture performance indicators of the absorbents prepared in Example 1 and Comparative Examples 1-2 were measured and calculated, and the results are shown in Table 1.

[0070] Table 1

[0071]

[0072] As can be seen from Table 1, the nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent described in Example 1 of the present invention has higher cycle capacity and regeneration efficiency, moderate rich phase volume and rich phase viscosity, and lower carbon dioxide regeneration energy consumption compared with the functionalized ionic liquid liquid-liquid phase change absorbent described in Comparative Example 1 and the organic amine homogeneous absorbent described in Comparative Example 2.

[0073] like Figures 2-3 As shown, the [tetraethylenepentamine][1,2,3-triazole] functionalized ionic liquid in the nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorber can be successfully synthesized, and its thermal stability and ion transport capacity are significantly improved compared with the precursor.

[0074] like Figure 4As shown, the nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent exhibits excellent cycle stability under the optimal mass ratio and optimal total mass concentration of the functionalized ionic liquid, nanoparticles, phase change promoter, and solvent. The variation of each carbon dioxide capture performance index compared to the initial value is within 10%.

[0075] like Figure 6 As shown, the nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent exhibits significantly better carbon dioxide capture performance on the pilot-scale platform than the functionalized ionic liquid liquid-liquid phase change absorbent described in Comparative Example 1 and the organic amine homogeneous absorbent described in Comparative Example 2. The optimal liquid-to-gas ratio on the absorption side is reduced, and the carbon dioxide absorption load is increased; the optimal heating power on the regeneration side is reduced, the carbon dioxide regeneration energy consumption is decreased, and the residual carbon dioxide load after regeneration is reduced.

[0076] like Figure 7 As shown, the nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorber exhibits significantly improved phase change behavior compared to the functionalized ionic liquid liquid-liquid phase change absorber described in Comparative Example 1 during pilot-scale operation. The volume of the enriched phase is reduced, and the interface between the two phases is clearer and more stable. Furthermore, the nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorber maintains its liquid-liquid phase change capability throughout the entire pilot-scale operation.

[0077] In summary, the nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent described in this invention exhibits significantly better carbon dioxide capture performance than the commercially available 30.0 wt% monoethanolamine / water organic amine absorbent, and its phase change behavior is ideal, making it valuable for large-scale industrial applications.

[0078] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0079] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0080] Furthermore, various embodiments of the present invention can be combined arbitrarily, as long as they do not violate the spirit of the present invention, and should also be considered as part of the content disclosed in the present invention. That is, equivalent changes and modifications made in accordance with the scope of the patent and the description of the present invention should still fall within the scope of the present invention.

Claims

1. A nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent, characterized in that, Including functionalized ionic liquids, nanoparticles, phase change promoters and solvents; The functionalized ionic liquid is [tetraethylenepentamine][1,2,3-triazole]; The nanoparticles are titanium dioxide; The phase change promoter shown is 1-methoxy-2-propanol.

2. The nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent as described in claim 1, characterized in that, The solvent is water.

3. The nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent as described in claim 1, characterized in that, The molar concentration of the functionalized ionic liquid in the nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent is 0.05~0.35 mol·kg⁻¹. -1 ; The nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent has a nanoparticle mass concentration of 0.05~0.45 wt%. In the nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent, the mass ratio of the phase change promoter to the solvent is 3:7~8:

2.

4. The nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent as described in claim 3, characterized in that, The preferred molar concentration of the functionalized ionic liquid in the nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent is 0.10~0.25 mol·kg⁻¹. -1 ; The preferred mass concentration of nanoparticles in the nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent is 0.10~0.30 wt%. In the nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent, the mass ratio of the phase change promoter to the solvent is 6:4 to 7:

3.

5. A method for preparing a nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent as described in any one of claims 1 to 4, characterized in that, Includes the following steps: The cationic and anionic precursors were dissolved in a mixed solvent of water and ethanol and subjected to a first water bath stirring treatment to obtain solution one. Solution 1 was subjected to vacuum rotary evaporation to obtain solution 2; Solution 2 was subjected to vacuum drying to obtain a functionalized ionic liquid; Functionalized ionic liquid, phase change promoter and solvent are mixed in proportion and subjected to a second water bath stirring treatment to obtain solution three; Nanoparticles were added to solution 3 and subjected to ultrasonic treatment to obtain a nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent.

6. The preparation method according to claim 5, characterized in that, The mass ratio of cationic precursor to anionic precursor is 7:3 to 3:

7. The temperature for the first water bath stirring is 20~60 ℃, and the stirring speed for the first water bath stirring is 400~1000 r·min. -1 The duration of the first water bath stirring is 12-36 hours; The temperature for vacuum rotary evaporation is 50~100 ℃, and the duration of vacuum rotary evaporation is 4~10 h; The vacuum drying temperature is 70~120 ℃, and the vacuum drying time is 12~36 h; The temperature for the second water bath stirring is 30~50 ℃, and the stirring speed for the second water bath stirring is 500~800 r·min. -1 The second water bath stirring time is 1~6 hours; The power of ultrasonic treatment is 20~35 W·L -1 The duration of ultrasonic treatment is 0.5 to 2 hours.

7. The application of the nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorber as described in any one of claims 1 to 4 in carbon capture.

8. The application as described in claim 7, characterized in that, Specifically, it includes: A mixed flue gas containing carbon dioxide is passed into a nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent to perform an absorption stage in which the nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent captures and separates carbon dioxide, and a regeneration stage in which the nanoparticle-enhanced functionalized ionic liquid liquid-liquid phase change absorbent releases carbon dioxide and collects and stores the released carbon dioxide.

9. The application as described in claim 8, characterized in that, The absorption temperature is 30~60 ℃, and the regeneration temperature is 100~140 ℃.

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