Enhanced CO2 Absorption Research Articles

Experimental investigation of CO2 absorption enhancement with functionalized MWCNT

Experimental investigation of CO2 absorption enhancement with functionalized MWCNT

CO2 absorption performance of biogas slurry enhanced by biochar as a potential solvent in once-through CO2 chemical absorption process

Carbon capture, utilization, and storage (CCUS), offers a promising avenue for mitigating CO2 emissions, in which the big challenge is the high CO2 capture cost. A novel CCUS technology called once-through CO2 chemical absorption using biogas slurry, could potentially reduce the CO2 capture cost through decreasing the energy consumption greatly during CO2 capture. This technology, however, is constrained by the CO2 absorption capacity of biogas slurry. To enhance the CO2 capture capacity of this innovative technology, we proposed a method to enhance CO2 absorption by integrating biochar into biogas slurry. Results indicated that the CO2 absorption capacity of biogas slurry improved by biochar varied with the type of biochar adopted. Among all the investigated biochar, the wood biochar like sea buckthorn and sand willow exhibited the lowest CO2 capture enhancement, with 0.82±0.19 mmol/g and 0.81±0.30 mmol/g, respectively. Biochar from C4 plants like corn stalks and cobs demonstrated the highest enhancement, with 2.11±0.24 mmol/g and 2.47±0.86 mmol/g, respectively. The enhancement driven by C3 plant biochar like millet stalks and shells was intermediate, with 1.62±0.47 mmol/g and 1.62±0.46 mmol/g, respectively. The primary factor for promoting CO2 absorption in the biochar-based biogas slurry was the increase in pH of biogas slurry. The total pore volume of biochar was the principal material property that enhanced CO2 absorption, followed by the EC and BET surface areas of biochar. Increasing the carbonization temperature of biochar could also enhance the CO2 absorption capacity by biogas slurry. In CO2-rich biochar-based biogas slurry, CO2 primarily existed as HCO3− and carbamate. However, for the influence of the biochar's pore structure, CO2 in the CO2-rich biochar-based biogas slurry was more stable than that in CO2-rich biogas slurry.

Biomimetic CO2 Capture Unlocked through Enzyme Mining: Discovery of a Highly Thermo- and Alkali-Stable Carbonic Anhydrase.

Taking immediate action to combat the urgent threat of CO2-driven global warming is crucial for ensuring a habitable planet. Decarbonizing the industrial sector requires implementing sustainable carbon-capture technologies, such as biomimetic hot potassium carbonate capture (BioHPC). BioHPC is superior to traditional amine-based strategies due to its eco-friendly nature. This innovative technology relies on robust carbonic anhydrases (CAs), enzymes that accelerate CO2 hydration and endure harsh industrial conditions like high temperature and alkalinity. Thus, the discovery of highly stable CAs is crucial for the BioHPC technology advancement. Through high-throughput bioinformatics analysis, we identified a highly thermo- and alkali-stable CA, termed CA-KR1, originating from a metagenomic sample collected at a hot spring in Kirishima, Japan. CA-KR1 demonstrates remarkable stability at high temperatures and pH, with a half-life of 24 h at 80 °C and retains activity and solubility even after 30 d in a 20% (w/v) K2CO3/pH 11.5 solution─a standard medium for HPC. In pressurized batch reactions, CA-KR1 enhanced CO2 absorption by >90% at 90 °C, 20% K2CO3, and 7 bar. To our knowledge, CA-KR1 constitutes the most resilient CA biocatalyst for efficient CO2 capture under HPC-relevant conditions, reported to date. CA-KR1 integration into industrial settings holds great promise in promoting efficient BioHPC, a potentially game-changing development for enhancing carbon-capture capacity toward industrial decarbonization.

EXPERIMENTAL INVESTIGATION OF AMINE-BASED GRAPHENE NANOSUSPENSION FOR CO2 ABSORPTION

Absorption is the most widely used carbon dioxide (CO2) removal technology. The CO2 absorption performance of monoethanolamine (MEA), the most commonly used CO2 absorbent, can be improved by suspending nanoparticles. This work examined the performance of graphene nanoplatelets (GNPs) as additives to enhance CO2 absorption in MEA. The GNPs were characterized by HRTEM, FTIR, and XRD. The study examined the influence of GNP concentrations on CO2 absorption at room temperature. The images from HRTEM confirmed that the implemented graphene consists of several layers of graphene sheets. Increasing the loading of particles increased the solubility of CO2 until the optimum concentration was reached. From this work, it is evident that incorporating GNPs into MEA enhances the CO2 absorption performance of MEA. Thus, the addition of nanoparticles to the absorbent can enhance its CO2 absorptivity.

Improving O₂ Absorption in PVDF Membrane with Cross-Linked Polymer Coatings

Surface modification of polyvinylidene fluoride (PVDF) membranes using various polymers, including chitosan, nylon, dopamine, and EDA, was examined through SEM and FTIR analyses. SEM imaging unveiled the preservation of membrane porosity post-modification, affirming successful polymer integration without pore obstruction. Nylon coatings induced alterations in surface morphology, with enlarged pore apertures and roughened surfaces attributed to formic acid exposure during dissolution. FTIR spectroscopy confirmed the presence of the respective polymers, exhibiting characteristic peaks for each. Notably, membranes coated with EDA exhibited enhanced CO2 absorption flux owing to their inherently hydrophilic nature and larger pore dimensions. Optimization of EDA coating parameters, including deposition time and concentration, revealed a direct correlation between increased EDA deposition and enhanced CO2 absorption flux, emphasizing the significant impact of these parameters on membrane performance in gas absorption. Consequently, tailored surface modifications offer a promising avenue for enhancing membrane functionality in gas separation applications

Dicationic ionic liquid‐grafted UiO‐66 as efficient catalyst for CO2 conversion into cyclocarbonate under cocatalyst‐free and solventless conditions

CO2 chemical fixation offers a feasible approach for carbon mitigation and high‐value utilization, but it is still challenging to develop an efficient catalyst for CO2 conversion into cyclic carbonate. Herein, the triethylenediamine‐derived dicationic ionic liquids (DIL‐X, X = Cl, Br, and I) were grafted into UiO‐66 linkers through self‐assembly of Zr4+ ions and the mixed ligands of terephthalic acid and DIL‐bearing dicarboxylic acid, resulting in UiO‐66‐DIL‐Xn, (n designated as molar amount of the feeding DIL‐X). Their catalytic performance was evaluated by the epoxide cycloaddition reaction in the absence of solvent and cocatalyst. Among them, the UiO‐66‐DIL‐Cl0.4 catalyst exhibited outstanding performance, with a chloropropene carbonate yield of 92% and a high selectivity of 99% under 0.1 MPa CO2 at 110 °C for 16 h. Its high activity could be ascribed to the cooperativity among Lewis acidity of MOF nodes, the enhanced CO2 absorption, and the strong nucleophilicity offered by halogen ions of ionic liquid‐modified MOF. Moreover, UiO‐66‐DIL‐Cl0.4 presented excellent recyclability and substrate extension. A potential catalytic mechanism for the epoxide‐CO2 cycloaddition into cyclic carbonate has been proposed. This work will shed light on the rational design of functionalized MOFs‐based catalysts for CO₂ utilization.

Enhanced CO2 absorption in amine-based carbon capture aided by coconut shell-derived nitrogen-doped biochar

The sluggish CO2 absorption kinetics and constrained CO2 absorption capacity diminish the practicality of using amine-based absorption for CO2 capture, impeding progress toward carbon neutrality goals. This study aims to develop a catalytic CO2 absorption process to promote CO2 absorption by introducing a solid base catalyst, namely, coconut shell-derived nitrogen-doped biochar (NBC), into an amine-based solution. The coconut shells were modified with urea and activated with KOH to prepare an NBC catalyst with improved basic characteristics. The findings showed that compared to non-catalytic absorption, the NBC catalyst increased the CO2 absorption amount, CO2 absorption rate, and absorption efficiency of the monoethanolamine (MEA) solution by 16.9 %, 43.4 %, and 13.1 %, respectively. The basic sites on the NBC surface provided extra electrons to motivate the formation of MEACOO- and HCO3-. NBC’s large surface area and porous structure also advanced the gas–liquid mass transfer, accelerating the CO2 absorption rate. Furthermore, the NBC exhibited excellent cyclic stability and facilitated the subsequent CO2 desorption process. This work develops a promising and practical approach to significantly improve the amine-based absorption and reuse of waste biomass resources for efficient CO2 capture.

Environmental Impact Evaluation of CO2 Absorption and Desorption Enhancement by Membrane Gas Absorption: A Life Cycle Assessment Study

Membrane gas absorption technology has been considered a promising approach to mitigate CO2 emissions from power plants. The aim of this study is to evaluate the environmental impacts of CO2 absorption and desorption processes by hollow fiber membrane contactors using a life cycle assessment methodology. On the basis of the ReCipe 2016 Midpoint and the ReCipe 2016 Endpoint methods, the research results show that membrane gas absorption systems exhibit the lowest environmental impacts across the majority of assessed categories in comparison with chemical absorption and membrane gas separation systems. The CO2 capture process via membrane gas absorption has the most significant impact on the METP category, with heat consumption as the primary contributing factor accounting for 55%, followed by electricity consumption accounting for 43.1%. According to the sensitivity analysis, heating by natural gas shows better performance than other heat supply sources in improving overall environmental impacts. In addition, the increasing utilization of renewable energy in electricity supply reduces the global warming potential, fossil resource consumption and ozone formation.

Dual p-n Z-scheme heterostructure boosted superior photoreduction CO2 to CO, CH4 and C2H4 in In2S3/MnO2/BiOCl photocatalyst

The creation of a Z-scheme heterojunction is a sophisticated strategy to enhance photocatalytic efficiency. In our study, we synthesized an In2S3/MnO2/BiOCl dual Z-scheme heterostructure by growing BiOCl nanoplates on the sheets of In2S3 nanoflowers, situated on the surface of MnO2 nanowires. This synthesis involved a combination of hydrothermal and solution combustion methods. Experiments and density functional theory (DFT) calculations demonstrated that the In2S3/MnO2/BiOCl composite exhibited notable photo reduction performance and photocatalytic stability. This was attributed to the pivotal roles of BiOCl and MnO2 in the composite, acting as auxiliaries to enhance the electronic structure and facilitate the adsorption/activation capacity of CO2 and H2O. The yield rates of CO, CH4, and C2H4 over In2S3/MnO2/BiOCl as the catalyst were 3.94, 5.5, and 3.64 times higher than those of pure In2S3, respectively. Photoelectrochemical analysis revealed that the dual Z-scheme heterostructure, with its oxygen vacancies and large surface area, enhanced CO2 absorption and active sites on the nanoflower/nanowire intersurfaces. Consequently, the dual Z-scheme charge transfer pathway provided efficient channels for boosting electron transfer and charge separation, resulting in high C2H4, CH4, and CO yields of formed and exihibits an promising photoreduction rate of CO2 to CO (51.2 µmol/g.h), CH4 (42.4 µmol/g.h) and C2H4 (63.2 µmol/g.h), respectively. DFT, in situ Diffuse reflectance infrared fourier transform spectroscopy, and temperature-programmed desorption tests were employed to verify the intermediates pathway. The study proposed a potential photocatalytic mechanism based on these findings.

Transport and Optical Properties of n-Butylamine + Alkanols (C3–C4) Mixtures for Enhanced CO2 Absorption

Transport and Optical Properties of n-Butylamine + Alkanols (C3–C4) Mixtures for Enhanced CO2 Absorption

Enhancing Natural Rubber Composites with Spent Coffee Ground: Physical Properties, Odor Absorption, and Processing

AbstractThis research aims to enhance natural rubber (NR) properties by incorporating spent coffee grounds (SCGs). Scanning electron microscope (SEM) reveals well‐dispersed SCG particles in the NR matrix without interaction. Shore A hardness notably increases by up to 49.90 (19% higher than unmodified), but tensile and tear strength decline with higher SCG levels. Optimal tear strength occurs at 10 phr of SCG due to uniform dispersion. The 300% modulus remains unchanged. The odor of composites (CO2 absorption) sees a 69.2% increase at 25 phr, while odor absorption efficiency peaks at 2%. Additionally, unmodified SCG affects scorch time (2.12%–23.40% increase from 1 to 20 phr) and cure time (3.12% to 76.82% improvement from 1 to 20 phr). These findings showcase improved hardness, enhanced CO2 absorption capacity, and effective odor control. Additionally, this study sheds light on the influence of SCG on processing times, contributing valuable insights for eco‐friendly applications.

CO2 absorption enhancement with MEA in micropacked bed reactors: Mass transfer experiment and model study

Micropacked bed reactors (μPBRs) shows excellent mass transfer characteristics, but related mass transfer experimental and models are inadequate for CO2 absorption. Herein, a gas-side overall volumetric mass transfer coefficient (KGa) model of μPBRs was developed based on the two-film theory. Effects of bed inner diameter and water contact angle (CA) of particle on effective interfacial area (a) were discussed. Then, the mass transfer model was validated by MEA-CO2 absorption efficiency (η) with AARD of 7.72%. The KGa of μPBRs (2.16–13.16 kmol/(m3·h·kPa)) is much larger than that of the traditional multiphase reactors. The ceramic beads with big water CA for dc/dp more than 10 and glass beads with small water CA for dc/dp less than 10 can enhance CO2 absorption efficiency in μPBRs. Additionally, the empirical correlation of a and KGa were proposed.

Confined bismuth single atoms and nanoparticles dual-sites constructed via reverse etching for CO2 photoreduction to CH4

Synchronizing the directional photogenerated transfer of electrons and regulating the CO2 photocatalytic reduction process are key to achieving the efficient and highly selective photocatalytic reduction of CO2. The design of highly-dispersed active sites and the efficient collaboration of multiple sites are of great importance in attaining the above target. Herein, a reverse etching route was first proposed to confine Bi single atoms and nanoparticles as dual-sites for assisting CO2 photoreduction on TiO2, avoiding the mutual masking of the active sites. The Synergism of the dual-sites achieves the hydrodeoxygenation of * COOH and ushers the directional conversion of CO2 to CH4. Highly dispersed single Bi atoms could induce the transfer of photogenerated electrons, enhance CO2 absorption, and further provide active sites for reducing CO2 to *COOH intermediates. Besides, appropriate Bi nanoparticles could promote the separation and transfer of photogenerated and inhibit the formation of hydroxyl groups; more importantly, they could promote the release of protons, which would further accelerate the conversion of *COOH to CH4. After being integrated, the optimized dual-Bi/TiO2 catalyst achieves a CH4 generation rate of 103.89 μmol·g−1·h−1 with an impressive selectivity of 96.87 % as well as remarkable durability for photocatalytic CO2 reduction. This work provides new insights into developing robust catalysts through the artful design of synergistic catalytic sites for efficient photocatalytic CO2 conversion.

Effects of nitrogen supply on hydrogen-oxidizing bacterial enrichment to produce microbial protein: Comparing nitrogen fixation and ammonium assimilation

To investigate the effects of nitrogen source supply on microbial protein (MP) production by hydrogen-oxidizing bacteria (HOB) under continuous feed gas provision, a sequencing batch culture comparison (N2 fixation versus ammonium assimilation) was performed. The results confirmed that even under basic cultivation conditions, N2-fixing HOB (NF-HOB) communities showed higher levels of CO2 and N2 fixation (190.45 mg/L Δ CODt and 11.75 mg/L Δ TNbiomass) than previously known, with the highest biomass yield being 0.153 g CDW/g COD-H2. Rich ammonium stimulated MP synthesis and the biomass accumulation of communities (increased by 7.4 ～ 14.3 times), presumably through the enhancement of H2 and CO2 absorption. The micro mechanism may involve encouraging the enrichment of species like Xanthobacter and Acinetobacter then raising the abundance of nitrogenase and glutamate synthase to facilitate the nitrogen assimilation. This would provide NF-HOB with ideas for optimizing their MP synthesis activity.

CO2 absorption enhancement of fluorinated ionic liquids on nonaqueous biphasic absorbents: Experimental and theoretical study

Nonaqueous biphasic absorbent decreasing the regeneration heat consumption by phase separation (lean-phase and rich-phase) and water evaporation elimination is a promising CO2 capture absorbent, but the low CO2 loading capacities are of great challenges. In this study, ionic liquids (IL) were proposed as catalysts for enhancing the CO2 loading in monoethanolamine (MEA)-1-Butanol nonaqueous biphasic absorbents. Three types of fluorinated IL including 1‑butyl‑3-methylimidazolium tetrafluoroborate ([Bmim][BF4]), 1‑butyl‑3-methylimidazolium hexafluorophosphate ([Bmim][PF6]), and 1‑butyl‑3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([Bmim][TF2N]) under different concentrations (0–10wt%) were detailly analyzed to explore the catalyzation of IL on phase separation behavior and absorption performance. Phase separation study showed that the MEA-1-Butanol-IL system exhibited the wonderful phase separation behavior with a volume ratio (rich-phase) between 30 and 40 %. Three phases were observed in MEA-1-Butanol-[Bmim][BF4] and MEA-1-Butanol-[Bmim][PF6] systems after CO2 absorption and the components of each phase were identified by 13C nuclear magnetic resonance (NMR) spectroscopy. In absorption study, the absorption enhancement of IL was in this order: [Bmim][TF2N] > [Bmim][BF4] > [Bmim][PF6]. MEA-1-Butanol-10wt% [Bmim][TF2N] system could improve 35.9 % CO2 loading and 24.2 % absorption rate compared to basic MEA-1-Butanol. A molecular scale understanding of the three-steps reaction mechanism of MEA-1-Butanol-IL absorbing CO2 was revealed, and the different catalyzation of three types of IL can be attributed to the different affinity for CO2. This study provides new insights into designing nonaqueous biphasic solvents and a promising MEA-1-Butanol-IL system with high CO2 capture performance.

CO2 absorption and desorption performance by ChCl-MEA-PZ deep eutectic solvent aqueous solutions

With the increasingly serious climate problem, carbon dioxide capture has been paid more and more attention. Deep eutectic solvent (DES), which is environmentally friendly and simple to synthesize, has attracted considerable attention as a new type of carbon dioxide absorbent. Choline chloride (ChCl) - monoethanolamine (MEA) - piperazine (PZ) DESs were prepared. The chemical reaction between ChCl-MEA-PZ DES and CO2 was confirmed to be the zwitterionic mechanism by NMR spectrum analysis. The influences of molar ratio between ChCl, MEA and PZ, gas–liquid flow rates, water content and CO2 concentration on CO2 absorption character were studied by a microchannel reactor. Under appropriate conditions, CO2 absorption efficiency could reach 99.95 %. The addition of promoter PZ could significantly enhance CO2 absorption performance. Additionally, desorption energy consumption of DES solution after CO2 saturation is lower than that of the standard 30 wt% MEA solution, which proves process friendliness of the DES. This study not only provides technical support but also sheds light on the potential applications of DESs in CO2 capture.

Designing back propagation neural network to predict CO2 mass transfer enhancement factor of TiO2-MEA/MDEA blended amine nanofluids

This study presented a novel methodology to predict the CO2 absorption enhancement performance of TiO2-Monoethanolamine/Methyl diethanolamine (MEA/MDEA) blended amine nanofluids using back propagation neural network (BPNN) model in artificial neural networks. The absorption enhancement factor of TiO2-MEA/MDEA nanofluid were determined experimentally by a two-step method with various nanoparticle solid contents (0.4–1.4 ​g/L). The results showed that the enhancement factor was firstly increased and then decreased with the rising nanoparticle solid content, and the extreme point appeared at 0.6 ​g/L. Based on the experimental data, a relevant empirical formula and a back propagation neural network (BPNN) model were used to estimate the enhancement factor of nanofluid and both exhibited good applicability. Additionally, an optimization model incorporating genetic algorithm, particle swarm algorithm and adaptive learning rate (C-BPNN) was also proposed to estimate the enhancement factor. Compared with the empirical formula and BPNN, C-BPNN exhibited a higher prediction accuracy (all data R2 ​= ​0.9966) and a faster prediction rate. The weight analysis of key parameters (nanoparticle solid content, concentration of MEA and MDEA) showed that the relative importance of nanoparticle solid content was foremost (42.63%) in the absorption enhancement process. All these results indicate that the neural network can provide a guiding role for the research in the field of nanofluid transfer.

CO2 absorption enhancement in low transition temperature mixtures-based nanofluids: Experiments and modeling

The enhancement of gas–liquid mass transfer in the CO2 absorption process by Low Transition Temperature Mixtures (LTTMs) based nanofluids was investigated. The effects of loading and size of TiO2 nanoparticles on the CO2 absorption rate were studied experimentally. The absorption rate was found to be improved significantly after adding nanoparticles. The maximum enhancement factor of 1.35 was observed when using nanoparticles with a particle size of 10 nm and a concentration of 0.6 kg/m3. The maximum absorption enhancement factor and mass transfer coefficient were observed when the loading of nanoparticles increased, hence there was an optimal concentration of TiO2 nanoparticles in the CO2 absorption process. For the size of nanoparticles, the CO2 absorption rate was higher when the diameter of nanoparticles decreased. Furthermore, a three-dimensional unsteady mathematical model of gas–liquid mass transfer, which was based on the mechanisms of grazing effect and hydrodynamic effect in the gas–liquid boundary layer, was developed to describe the CO2 absorption enhancement. The model predictions were well consistent with the experimental results, with a maximum deviation of less than 5%, which proved the reliability of the model. Finally, Molecular dynamics simulations were conducted on the absorbent-CO2 system. The results showed that the addition of TiO2 nanoparticles led to a reduction in the simulation box size at the same simulation time, but it did not significantly alter the interaction between LTTMs and CO2. Therefore, it can be inferred that TiO2 nanoparticles enhance CO2 absorption capacity by modifying the mass transfer rate. Through the aforementioned study, this paper explores the experimental and mechanistic aspects of nanoparticle-enhanced absorption of CO2 in LTTMs systems. The research demonstrates the feasibility of nanoparticle-enhanced absorption of CO2 in LTTMs solvents, providing insights into studying nanoparticle-enhanced gas–liquid mass transfer and offering a new research approach for CO2 capture.

Effects of Inorganic and Organic Fertilizers on the Growth of Chickpea Plant and Soil Organic Carbon and Nitrogen Contents

Rapid economic and population growth has led to rising atmospheric greenhouse gas emissions, necessitating adequate soil and crop management for enhanced CO2 absorption. Plant and soil microorganisms have various effects on atmospheric CO2 capturing. Chickpea (Cicer arietinum L.), a leguminous plant, establishes a symbiotic association with rhizobium bacteria and mycorrhizal fungi, enabling it to fix atmospheric nitrogen (N2) and sequester more CO2 into the biomass and then to the soil. However, the application type of fertilizers influences this plant’s growth and soil’s capacity to retain carbon (C). In this background, the current research aimed to explore the impact of various organic and inorganic fertilization methods on the growth and nutrient content of chickpea plants and nitrogen content and soil organic carbon. A long-term field trial was started in 1996 at Çukurova University Research Center, with the five treatments such as Control (without fertilizer), Animal manure (25 t ha-1), Mineral fertilizer (NPK), Compost (25 t ha-1), and Mycorrhiza + Compost (10 t ha-1). Chickpeas were planted and harvested in 2020. During harvesting, plant samples at 1 m2 area, and soil samples at 0 to 15 cm and 15 to 30 cm depths were taken. The shoot, root and pod fresh biomass and tissue C, P, K, N, and Zn concentrations were determined. Similarly, the soil P, organic C and total N concentrations were determined. The results of the study indicate that mineral fertilizer resulted in a notable enhancement in the shoot, root and seed biomass of chickpea plants. Furthermore, mineral fertilizer resulted in a higher concentration of carbon in the roots, while the treatments involving animal manure, compost +AMF, and compost showed higher concentrations of K in both shoots and seeds. Seed P concentration was higher when animal manure was applied and exhibited similarity to the compost treatment. In terms of soil properties, the application of animal manure led to increased levels of soil organic carbon and P. Moreover, the compost treatment showed an increase in organic carbon in deeper soil depth. At 15-30 cm soil depth, both animal manure and compost treatments contributed to improved levels of total nitrogen. The good effects of organic fertilizers on soil fertility and nutrient levels in sustainable farming practices are highlighted by these findings. When compared to mineral fertilizer, animal dung specifically showed considerable improvements in soil organic carbon, nitrogen, and phosphorus.

High performance CO2 Absorption/Desorption using Amine-Functionalized magnetic nanoparticles

In the current study, for the first time, a variety of amino acid groups, including arginine, histidine, and glycine, were added to Fe3O4 nanoparticles to achieve desired mass and heat transfer properties in CO2 absorption/desorption experiments. For this purpose, different concentrations of synthesized nanoparticles were employed in base fluid (10 wt% methyldiethanolamine) in a semi batch experiment at ambient pressure for CO2 absorption and desorption. The experimental results clearly indicated that modification of iron oxide nanoparticles could enhance CO2 absorption and stripping significantly, as a result of higher stability of nanoparticles and presence of amino groups at the nanoparticles' structure. Compared to bare Fe3O4, Fe3O4@arginine, Fe3O4@histidine, and Fe3O4@glycine demonstrated 23%, 17%, and 10% increase in CO2 absorption capacity, respectively. By using chemical agent as stabilizer species and by modified thermal properties of solution, magnetic nanoparticles promoted CO2 desorption to a great extent. Therefore, Fe3O4@arginine, Fe3O4@histidine, and Fe3O4@glycine nanofluids improved CO2 desorption enhancement by 48.2%, 47.2%, and 46.1% at 70 °C, respectively.