Materials For CO2 Storage Research Articles

The Potential Use of Fly Ash from the Pulp and Paper Industry as Thermochemical Energy and CO2 Storage Material

As a part of our research in the field of thermochemical energy storage, this study aims to investigate the potential of three fly ash samples derived from the fluidized bed reactors of three different pulp and paper plants in Austria for their use as thermochemical energy (TCES) and CO2 storage materials. The selected samples were analyzed by different physical and chemical analytical techniques such as X-ray fluorescence spectroscopy (XRF), X-ray diffraction (XRD), particle size distribution (PSD), scanning electron microscopy (SEM), inductively coupled plasma atomic emission spectroscopy (ICP-OES), and simultaneous thermal analysis (STA) under different atmospheres (N2, CO2, and H2O/CO2). To evaluate the environmental impact, leaching tests were also performed. The amount of CaO as a promising candidate for TCES was verified by XRF analysis, which was in the range of 25–63% (w/w). XRD results indicate that the CaO lies as free lime (3–32%), calcite (21–29%), and silicate in all fly ash samples. The results of STA show that all fly ash samples could fulfill the requirements for TCES (i.e., charging and discharging). A cycling stability test of three cycles was demonstrated for all samples which indicates a reduction of conversion in the first three reaction cycles. The energy content of the examined samples was up to 504 kJ/kg according to the STA results. More energy (~1090 kJ/kg) in the first discharging step in the CO2/H2O atmosphere could be released through two kinds of fly ash samples due to the already existing free lime (CaO) in those samples. The CO2 storage capacity of these fly ash samples ranged between 18 and 110 kg per ton of fly ash, based on the direct and dry method. The leaching tests showed that all heavy metals were below the limit values of the Austrian landfill ordinance. It is viable to say that the valorization of fly ash from the pulp and paper industries via TCES and CO2 storage is plausible. However, further investigations such as cycling stability improvement, system integration and a life cycle assessment (LCA) still need to be conducted.

(Invited) Catalyst Design and Development for Highly Selective Photocatalytic Conversion of CO2 By H2o As an Electron Donor

The reduction in human-induced emissions of CO2 from automobiles, factories, power stations etc., over the next 15 years is currently one of the most important issues facing the planet. We should therefore attempt to develop industrial processes using CO2 as a feedstock to build a sustainable society. Linear CO2 molecules adsorbed on the surface of the solid bases are converted into unique structures, such as bicarbonate and carbonate species possessing lattice oxygen atoms. We believe that the process involves the capture and distortion of CO2 upon adsorption on a solid base through activation by photoirradiation. These days, we succeeded in designing highly selective photocatalytic conversion of CO2 by H2O as the electron donor, by the simultaneous use of an inhibitor of the production of H2 and a material for CO2 capture and storage. An isotope experiment using 13CO2 and mass spectrometry clarified that the carbon source of the evolved CO is not the residual carbon species, but the CO2 introduced in the gas phase. In addition, stoichiometric amounts of O2 were generated together with CO.

Controllable crystallization of pure vaterite using CO2-storage material and different Ca2+ sources

The controllable synthesis of pure vaterite with the good properties and broad application prospects is considered as an important, yet a challenging task because the product properties are greatly affected by reaction conditions. In the present work, the controllable synthesis of pure vaterite crystals was explored with four different Ca2+ sources including CaCl2, Ca(NO3)2, CaBr2 and Ca(Ac)2 using an CO2-storage material (CO2SM) prepared by an indirect CO2 utilization approach as the CO32− source. The effects of five major reaction conditions including reaction medium, hydrothermal reaction temperature, hydrothermal reaction time, Ca2+ concentration and sources, and pH and conductivity on the crystallization of CaCO3 were systemically investigated. It is found that the amounts of CO2SM required for the formation of pure vaterite phase are in the order of CaBr2 (20 g/L CO2SM) > Ca(NO3)2 (16 g/L CO2SM) > Ca(Ac)2 (8 g/L CO2SM) due to the effects of ethylenediamine (EDA), diethylene glycol (DEG) and their anions. Especially, vaterite was not found in CaCl2 system. The effects of Ca2+ sources on the crystal phase composition of CaCO3 are revealed for the controllable synthesis of CaCO3 crystals. Our work not only provides a controllable synthesis method of pure vaterite, but also an indirect CO2 utilization strategy.

Synthesis of polyurethane based on indirect utilization strategy of CO2

A novel indirect utilization route of carbon dioxide (CO2) was developed to synthesis CO2-based polyurethane (PU) under mild conditions. A series of PUs were successfully synthesized by the inner-molecular dehydration of the CO2-storage materials (CO2SMs), which were prepared by the absorption of CO2 with diamine + glycol systems at room temperature, using N,N-diisopropylcarbodiimide (DIC) as the dehydrating agent. The optimal conditions for the strategy were determined as follows: reaction temperature 90 °C, dehydrating agent 10 mL DIC, CO2SM 3 g, and reaction time 12 h. The yields of PUs were found to be 2.13–2.54 g/3 g CO2SM under the optimal synthesis conditions. The average molecular weights of the as-synthesized PUs ranged from 10,400 g/mol to 12,700 g/mol and all of the PUs exhibited high thermal stability. This work has provided scientific foundation for the development of synthesis routes of PUs from CO2. And it realizes the synthesis of CO2-based PU at low temperature and atmospheric pressure, which is of significance for energy conservation and emission reduction via the indirect utilization of CO2.

Study of Amine Functionalized Mesoporous Carbon as CO2 Storage Materials

Carbon sequestration via the carbon capture and storage (CCS) method is one of the most useful methods of lowering CO2 emissions in the atmosphere. Ethylenediamine (EDA)- and triethylenetetramine (TETA)-modified mesoporous carbon (MC) has been successfully prepared as a CO2 storage material. The effect of various concentrations of EDA or TETA added to MC, as well as activated carbon (AC), on their CO2 adsorption capacity were investigated using high-purity CO2 as a feed and a titration method to quantitatively measure the amount of adsorbed CO2. The results showed that within 60 min adsorption time, MCEDA49 gave the highest CO2 capacity adsorption (19.68 mmol/g), followed by MC-TETA30 (11.241 mol/g). The improvement of CO2 adsorption capacity at low TETA loadings proved that the four amine functional groups in TETA gave an advantage to CO2 adsorption. TETA-functionalized MC has the potential to be used as a CO2 storage material at a low concentration. Therefore, it is relatively benign and friendly to the environment.

DFT-D3 calculations of the charge-modulated CO2 capture of N/Sc-embedded graphyne: Compilation of some factors

The increasing greenhouse gases, including CO2 in the atmosphere, have a devastating effect on the ecosystem. Therefore, scientists are trying to provide new materials for CO2 capture, storage, and conversion. In this work, we consider CO2 capture behavior of N, Sc, and Sc/N embedded graphyne (GY) for neutral and negatively charge states by DFT-D3 calculations. It is found that in the most stable structures with single N (N1-GY) or Sc (Sc1-GY) and in Sc/N-GY, N and Sc atoms prefer to stand in the chains and the H1 sites of GY, respectively. Eads values of CO2 onto pristine GY (PGY) and N1-GY in neutral or negatively charged states are low (physisorption) (‒0.212 to ‒0.286 eV); while insertion of Sc causes that CO2 capture improves even in neutral state to ‒0.726 eV for Sc1-GY and promotes considerably in ‒2 e negatively charged Sc/N-GY1 up to ‒3.186 eV. It can say that synergistic effect of N and Sc insertion and ‒2 e negatively charged on the PGY causes a 1500% increasing of CO2 adsorption energy. Evaluation of the CO2 adsorption/desorption mechanism for negatively charged Sc1-GY and Sc/N-GY1 structures represents that choosing the proper charge state is very effective on the CO2 regeneration process.

Exploring CO2 @sI Clathrate Hydrates as CO2 Storage Agents by Computational Density Functional Approaches.

The formation of specific clathrate hydrates and their transformation at given thermodynamic conditions depends on the interactions between the guest molecule/s and the host water lattice. Understanding their structural stability is essential to control structure-property relations involved in different technological applications. Thus, the energetic aspects relative to CO2 @sI clathrate hydrate are investigated through the computation of the underlying interactions, dominated by hydrogen bonds and van der Waals forces, from first-principles electronic structure approaches. The stability of the CO2 @sI clathrate is evaluated by combining bottom-up and top-down approaches. Guest-free and CO2 guest-filled aperiodic cages, up to the gradually CO2 occupation of the entire sI periodic unit cells were considered. Saturation, cohesive and binding energies for the systems are determined by employing a variety of density functionals and their performance is assessed. The dispersion corrections on the non-covalent interactions are found to be important in the stabilization of the CO2 @sI energies, with the encapsulation of the CO2 into guest-free/empty cage/lattice being always an energetically favorable process for most of the functionals studied. The PW86PBE functional with XDM or D3(BJ) dispersion corrections predicts a lattice constant in accord to the experimental values available, and simultaneously provides a reliable description for the guest-host interactions in the periodic CO2 @sI crystal, as well as the energetics of its progressive single cage occupancy process. It has been found that the preferential orientation of the single CO2 in the large sI crystal cages has a stabilizing effect on the hydrate, concluding that the CO2 @sI structure is favored either by considering the individual building block cages or the complete sI unit cell crystal. Such benchmark and methodology cross-check studies benefit new data-driven model research by providing high-quality training information, with new insights that indicate the underlying factors governing their structure-driven stability, and triggering further investigations for controlling the stabilization of these promising long-term CO2 storage materials.

Reversible CO2 storage and efficient separation using Ca decorated porphyrin-like porous C24N24 fullerene: a DFT study.

The search for novel materials for effective storage and separation of CO2 molecules is a critical issue for eliminating or lowering this harmful greenhouse gas. In this paper, we investigate the potential application of a porphyrin-like porous fullerene (C24N24) as a promising material for CO2 storage and separation using thorough density functional theory calculations. The results show that CO2 is physisorbed on bare C24N24, implying that this material cannot be used for efficient CO2 storage. Coating C24N24 with Ca atoms, on the other hand, can greatly improve the adsorption strength of CO2 molecules due to polarization and charge-transfer effects. Furthermore, the average adsorption energy for each of the maximum 24 absorbed CO2 molecules on the fully decorated Ca6C24N24 fullerene is −0.40 eV, which fulfills the requirement needed for efficient CO2 storage (−0.40 to −0.80 eV). The Ca coated C24N24 fullerene also have a strong potential for CO2 separation from CO2/H2, CO2/CH4, and CO2/N2 mixtures.

Different Benzendicarboxylate-Directed Structural Variations and Properties of Four New Porous Cd(II)-Pyridyl-Triazole Coordination Polymers.

Four new different porous crystalline Cd(II)-based coordination polymers (CPs), i. e., [Cd(mdpt)2]·2H2O (1), [Cd2(mdpt)2(m-bdc)(H2O)2] (2), [Cd(Hmdpt)(p-bdc)]·2H2O (3), and [Cd3(mdpt)2(bpdc)2]·2.5NMP (4), were obtained successfully by the assembly of Cd(II) ions and bitopic 3-(3-methyl-2-pyridyl)-5-(4-pyridyl)-1,2,4-triazole (Hmdpt) in the presence of various benzendicarboxylate ligands, i.e., 1,3/1,4-benzenedicarboxylic acid (m-H2bdc, p-H2bdc) and biphenyl-4,4′-bicarboxylate (H2bpdc). Herein, complex 1 is a porous 2-fold interpenetrated four-connected 3D NbO topological framework based on the mdpt− ligand; 2 reveals a two-dimensional (2D) hcb network. Interestingly, 3 presents a three-dimensional (3D) rare interpenetrated double-insertion supramolecular net via 2D ···ABAB··· layers and can be viewed as an fsh topological net, while complex 4 displays a 3D sqc117 framework. Then, the different gas sorption performances were carried out carefully for complexes 1 and 4, the results of which showed 4 has preferable sorption than that of 1 and can be the potential CO2 storage and separation material. Furthermore, the stability and luminescence of four complexes were performed carefully in the solid state.

Hydrogen and CO2 storage in high surface area covalent triazine–based frameworks

Hydrogen storage and CO2 capture are of great importance for efficient fuel usage and environmentally clean methods. Here, we report a series of 7,7,8,8-tetracyanoquinodimethane-derived covalent triazine frameworks (TCNQ-CTFs) with different specific surface areas for hydrogen and CO2 storage. Such TCNQ-CTFs exhibit maximum H2 and CO2 adsorption capacities up to 2.79 wt% (77 K, 1 bar) and 5.99 mmol/g (273 K, 1 bar), respectively, which are the highest values among reported covalent triazine frameworks.Theory simulation by using the Grand Canonical Monte Carlo (GCMC) method revealed that abundant nitrogen and defects induced by annealing treatment are the reasons for the high adsorption capacity of the material. This work not only contributes a superior material for both hydrogen and CO2 storage under ambient conditions but also deepens the knowledge on its adsorption mechanism, thus guiding people to engineer more efficient storage materials.

Novel Core-Shell (ε-MnO2/CeO2)@CeO2 Composite Catalyst with a Synergistic Effect for Efficient Formaldehyde Oxidation.

A novel core-shell (ε-MnO2/CeO2)@CeO2 composite catalyst with a synergistic effect was prepared by hydrothermal reaction and thermal decomposition and its application to high-efficiency oxidation removal of formaldehyde (HCHO) was systemically investigated. The (MnCO3/CeO2)@CeO2 precursor was prepared first by the one-pot hydrothermal reaction of Mn2+ and Ce3+ solutions with a CO2-storage material (CO2SM) without any external templates or surfactants required. The thermal decomposition of the precursor afforded the core-shell (ε-MnO2/CeO2)@CeO2 composite catalyst with excellent catalytic performance. HCHO in the feed gas (180 ppm HCHO, 21% O2, N2 balanced) at a gas hourly space velocity of 100 L/(gcat h) is 100% converted over the catalyst at 80 °C. The conversion rate remains above 95% in 72 h and above 73.8% in 140 h, suggesting the strong stability of the catalyst at high gas flow rates and relatively low temperatures. The synergistic mechanism of the catalyst was explored by X-ray diffraction, Raman, Brunauer-Emmett-Teller, transmission electron microscopy, and X-ray photoelectron spectroscopy. The number of defects in the catalyst and the strength of the Mn-O bond in ε-MnO2 can be tuned by adjusting the synthesis conditions. More oxygen vacancies on the surface of CeO2 can make the synergistic effect of the catalyst stronger, which significantly improves the lattice oxygen (Olatt) activity on the surface of ε-MnO2. Our work has provided new insights into the preparation of the desired composite catalysts with excellent performances.

(Invited) Efficient CO Production from CO2 and H2o By the Aid of Artificial Photosynthesis

The reduction in human-induced emissions of CO2 from automobiles, factories, power stations etc., over the next 15 years is currently one of the most important issues facing the planet. We should therefore attempt to develop industrial processes using CO2 as a feedstock to build a sustainable society. Linear CO2 molecules adsorbed on the surface of the solid bases are converted into unique structures, such as bicarbonate and carbonate species possessing lattice oxygen atoms. We believe that the process involves the capture and distortion of CO2 upon adsorption on a solid base through activation by photoirradiation. These days, we succeeded in designing highly selective photocatalytic conversion of CO2 by H2O as the electron donor, by the simultaneous use of an inhibitor of the production of H2 and a material for CO2 capture and storage. An isotope experiment using 13CO2 and mass spectrometry clarified that the carbon source of the evolved CO is not the residual carbon species, but the CO2 introduced in the gas phase. In addition, stoichiometric amounts of O2 were generated together with CO.

(Invited) Catalyst Design and Development for Highly Selective Photocatalytic Conversion of CO2 By H2o As an Electron Donor

The reduction in human-induced emissions of CO2 from automobiles, factories, power stations etc., over the next 15 years is currently one of the most important issues facing the planet. We should therefore attempt to develop industrial processes using CO2 as a feedstock to build a sustainable society. Linear CO2 molecules adsorbed on the surface of the solid bases are converted into unique structures, such as bicarbonate and carbonate species possessing lattice oxygen atoms. We believe that the process involves the capture and distortion of CO2 upon adsorption on a solid base through activation by photoirradiation. These days, we succeeded in designing highly selective photocatalytic conversion of CO2 by H2O as the electron donor, by the simultaneous use of an inhibitor of the production of H2 and a material for CO2 capture and storage. An isotope experiment using 13CO2 and mass spectrometry clarified that the carbon source of the evolved CO is not the residual carbon species, but the CO2 introduced in the gas phase. In addition, stoichiometric amounts of O2 were generated together with CO.

In Situ Cu-Loaded Porous Boron Nitride Nanofiber as an Efficient Adsorbent for CO2 Capture

Porous boron nitride (BN) materials have been considered as a promising material for CO₂ capture and storage. It was found that the Cu²⁺ ion can modify the nucleation mechanism during the synthetic reaction between boric acid and melamine leading to the formation of Cu-loaded BN nanofibers with uniform and smaller diameter. Interestingly, the introduction of Cu was found to dramatically enhance the CO₂ adsorption capacity of the BN nanofibers from 1.34 to 2.77 mmol g–¹ (at 1 bar, 273 K). The Cu-loaded BN nanofiber not only shows a CO₂ adsorption capacity comparable to those of state-of-the-art BN-based CO₂ absorbents but also shows unprecedented high recyclability for repeated uses. The mechanisms of the copper-induced CO₂ adsorption capacity enhancement were investigated with density-functional theory calculations. It was found that the incorporation of Cu can change the electron transfer between porous BN and CO₂ to promote the affinity and adsorption capacity of CO₂.

Porous carbon frameworks with high CO2 capture capacity derived from hierarchical polyimide/zeolitic imidazolate frameworks composite aerogels

Zeolitic imidazolate frameworks (ZIF) are widely regarded as promising materials for CO2 capture and storage because of their high specific surface areas and ordered pore structures. However, ZIF are manufactured as a fine powder, and as a result it is often challenging to process them efficiently into functional materials for practical application. Therefore, the objective of this work is to demonstrate a facile direct mixing, supercritical CO2 drying, and carbonization process for preparing a novel porous carbon materials based on polyimide/ZIF (PI/ZIF) composite aerogels. An interesting finding is that the organometallic frameworks are unstable and can collapse as mixing with the polyamic acid (PAA) solution due to the strong complexation between carboxyl group in polyamic acid chains and metal ions, which shows a great effect on the microporous structure of PI/ZIF composite aerogels. Accordingly, the resultant carbon aerogels displayed a complex hierarchical porous structure, which can be altered via ZIF loading amount (up to 20 wt%) and type of ZIF used. Although the CO2 capture performance of as-prepared PI aerogels was not significantly improved via the direct addition of ZIF, subsequent carbonization resulted in dramatic enhancements at concentrations above 10 wt% of ZIF, reaching up to 50 cm3/g (2.23 mmol/g, 298 K). Overall, we report a direct production process for preparing hierarchical PI aerogels which can be further carbonized for enhanced CO2 capture performance, demonstrating their practical functionality for CO2 adsorption.

Density, viscosity, surface tension and intermolecular interaction of triethylene glycol and 1,2-diaminopropane binary solution & its potential downstream usage for bioplastic production

In this work, triethylene glycol (TEG) and 1,2-diaminopropane (DAP) binary mixture was proposed as a novel CO2 capturing solution. In order to understand the binary system better, the key physical and chemical properties of TEG and DAP binary solution including the density, viscosity and surface tension were determined and analyzed. The excess molar volume (VmE), viscosity deviation (Δη) and surface tension deviation (Δγ) of the solution were calculated and fitted by Redlich-Kister (R-K) equation to evaluate the factor and standard deviations between the experimental and calculated quantities. Meanwhile, the as-determined UV–Vis, FTIR, and Fluorescence spectra suggested that intermolecular hydrogen bonds were formed within the binary solution. In term of the excess molar volume, the intermolecular bonds were closely formed when the molar ratio of TEG to DAP was at 1: 1. This system showed strong CO2 capture capability, in which about 0.34 g CO2 was absorbed by per gram of DAP and TEG system. The resulting CO2-Storage Material (CO2SM) was further applied as potential carbon source for Poly-β-hydroxybutyrate (PHB, bioplastic) production by a photoautotrophic-cyanobacterium, and intracellular content of 12.92 wt% was achieved. This work used new biological methods to convert CO2, the fundamental, physical and chemical properties of the alcohol-amine system were studied, further, the basic data as the reference were provided for PHB downstream synthesis optimization.

Energy-consumption analysis of carbon-based material for CO2 capture process

Few studies have been reported on optimizing the energy consumption of the CO2 capture process. Thus neglecting that the scale of industrial application of adsorption technology depends on the energy consumption of the process. In this work, 98 different types of porous carbon materials were constructed. The quantitative relationship between the material properties and structure was established through analysis of the adsorption capacity, selectivity, and energy consumption by molecular simulation. In our work, we establish a set of evaluation criteria for carbon-based material for CO2 capture and storage by combining the adsorbent structure (pore properties and surface chemical properties) and operating conditions (temperature, pressure, and temperature and pressure coupling) with the evaluation criteria for the adsorption process (working capacity, selectivity, and energy consumption).

Charge-regulated CO2 capture capacity of metal atom embedded graphyne: A first-principles study

There are increasing concerns about the environmental impact of rising atmospheric carbon dioxide (CO2) concentrations, thus it is necessary to develop new materials and technologies for efficient CO2 capture and conversion. In this work, we investigated CO2 capture on different metal embedded graphynes (M-GYs) under different charge states via density functional theory (DFT) calculations. It was found that the neutral Ti, V, Cr and Mn embedded GYs could effectively capture CO2 molecules, and the adsorption energy of CO2 was dramatically enhanced on negatively charged M-GYs. The process of CO2 capture/release on Fe or Co embedded GY occurs spontaneously once extra electrons are introduced/removed. Therefore, Fe- and Co-GYs are promising materials for reversible efficient CO2 storage. Ti-GY has the largest CO2 adsorption capacity. By comparing the adsorption of CO2 by non-noble metals and noble metals, it is found that non-noble metals are more conducive to large-scale practical application for CO2 capture due to their high sensitivity to CO2 and low cost. This investigation provides valuable information for designing reusable CO2 storage materials.

Comparing Fly Ash Samples from Different Types of Incinerators for Their Potential as Storage Materials for Thermochemical Energy and CO2.

This study aims to investigate the physical and chemical characterization of six fly ash samples obtained from different municipal solid waste incinerators (MSWIs), namely grate furnaces, rotary kiln, and fluidized bed reactor, to determine their potential for CO2 and thermochemical energy storage (TCES). Representative samples were characterized via simultaneous thermal analysis (STA) in different atmospheres, i.e., N2, air, H2O, CO2, and H2O/CO2, to identify fly ash samples that can meet the minimum requirements, i.e., charging, discharging, and cycling stability, for its consideration as TCES and CO2-storage materials and to determine their energy contents. Furthermore, other techniques, such as inductively coupled plasma optical emission spectroscopy, X-ray fluorescence (XRF) spectrometry, X-ray diffraction (XRD), scanning electron microscopy, leachability tests, specific surface area measurement based on the Brunauer–Emmett–Teller method, and particle-size distribution measurement, were performed. XRF analysis showed that calcium oxide is one of the main components in fly ash, which is a potentially suitable component for TCES systems. XRD results revealed information regarding the crystal structure and phases of various elements, including that of Ca. The STA measurements showed that the samples can store thermal heat with energy contents of 50–394 kJ/kg (charging step). For one fly ash sample obtained from a grate furnace, the release of the stored thermal heat under the selected experimental conditions (discharging step) was demonstrated. The cycling stability tests were conducted thrice, and they were successful for the selected sample. One fly ash sample could store CO2 with a storage capacity of 27 kg CO2/ton based on results obtained under the selected experimental conditions in STA. Samples from rotary kiln and fluidized bed were heated up to 1150 °C in an N2 atmosphere, resulting in complete melting of samples in crucibles; however, other samples obtained from grate furnaces formed compacted powders after undergoing the same thermal treatment in STA. Samples from different grate furnaces showed similarities in their chemical and physical characterization. The leachability test according to the standard (EN 12457-4 (2002)) using water in a ratio of 10 L/S and showed that the leachate of heavy metals is below the maximum permissible values for nonhazardous materials (except for Pb), excluding the fly ash sample obtained using fluidized bed technology. The leachate contents of Cd and Mn in the fly ash samples obtained from the rotary kiln were higher than those in other samples. Characterization performed herein helped in determining the suitable fly ash samples that can be considered as potential CO2-storage and TCES materials.

Utilization of a CO2 Storage Material: Shape-Controlled Preparation of CaCO3 Microspheres

Homogeneous CaCO3 microspheres were controllably synthesized via a simple hydrothermal method without using extraneous additives by Ca(OH)2 saturated solution reacted with CO2 storage material (CO2SM), which was obtained by absorbing CO2 gas in a system containing equimolar ethylenediamine (EDA) and polyethylene glycol 400 (PEG). Specifically, homogeneous pure vaterite spheres were obtained by using 160 g/L CO2SM solution at 100 °C and a reaction time of two hours. It is noteworthy that the EDA and PEG, which are released from CO2SM, have dual functions as a CO2 absorber and crystal regulator in the process of controlling the crystallization of CaCO3 crystals.