Effect Of Pore Structure Research Articles

Machine learning, experiments and molecular simulation demonstrate the adsorption mechanism of acetone on porous carbon at different pressures

The scientific design and preparation of porous carbon with high VOCs (such as acetone) adsorption capacity are crucial for waste gas treatment. However, it is still challenging to explain the microscopic mechanism of acetone uptake on porous carbon because of the different adsorption conditions, as well as various chemical properties and different pore structures of porous carbon. Here, the prediction model of the adsorption conditions, nitrogen/oxygen groups and pore structures on acetone adsorption capacity was established by machine learning, and the contribution of the nitrogen/oxygen groups and pore structures of porous carbons to the acetone adsorption capacity at different adsorption pressures was discussed. The results display that the nitrogen/oxygen groups and micropore volume are the main factors affecting the adsorption capacity of acetone at relatively low pressure, while the adsorption capacity at relatively high pressure is determined by total pore volume. Subsequently, three kinds of porous carbon with different oxygen content and gradient pore size distribution were synthesized, and acetone adsorption isotherms were tested. The effects of chemical properties and pore structure on acetone adsorption at different pressure were studied, and the results were consistent with those of machine learning. However, the results are challenging to illustrate the effect of single pore size and functional group type on acetone adsorption performance. Finally, molecular simulation was used to calculate acetone adsorption isotherms with various nitrogen/oxygen groups and different pore sizes, further revealing the adsorption mechanism of acetone with nitrogen/oxygen groups and pore size. Based on machine learning and molecular simulation results, new insights into the adsorption behavior of acetone were revealed, providing theoretical support for the sustainable development of carbon-based adsorbents for acetone waste gas treatment.

Effect of pore structure on compressive strength and permeability of planting recycled concrete

The relationship between strength, permeability, and pore structure of planting recycled concrete (PRC) was investigated using industrial computed tomography non-destructive testing technology and image analysis methods. An increase in the aggregate particle size and porosity increased the pore size and fractal dimension, and the relationship between the compressive strength and porosity conformed to the Ryshkewitch model. The fractal dimension had a weaker influence on compressive strength and permeability than did aperture size and porosity. Although vegetation growth reduced the compressive strength and permeability coefficient of PRC, the rainwater infiltration and vegetation compatibility of PRC was confirmed.

Effects of pore structure on the hysteretic water retention behaviour of silty sand at different stresses

Effects of pore structure on the hysteretic water retention behaviour of silty sand at different stresses

NMR-Mapped Distributions of Dielectric Dispersion

Combinations of NMR and dielectric measurements frequently address challenging saturation and wettability determinations in conventional reservoirs. When pore structure effects are addressed, the nuclear magnetic resonance (NMR) characteristics are interpreted based on the evaluations of surface relaxivity, and the dielectric structural response is attributed to the “texture” of the rock matrix. Both pore structure descriptors can be improved if the molecular motions and charge mobility common to the measurements are considered. Similar to the dipolar relaxation equivalence of NMR and dielectric correlation time measurements in the Bloembergen, Purcell, and Pound (BPP) model, we develop a relaxation time correlation assuming representative Maxwell-Wagner relaxations. Dielectric dispersion curves for the carbonate matrix and vug pore components demonstrated by Myers are quantified using a dielectric relaxation time (DRT) model. The modeled pore system fractions are spectrally mapped to the NMR T1 or T2 distributions based on enhanced Debye shielding distances correlated with the conductivity. The characterized NMR distributions are validated with micro-CT pore-size determinations and diffusion correlations. The mapped distributions provide petrophysical insight into the frequently used Archie exponent combination (mn) associated with conductivity tortuosity and additional wettability screening criteria.

Enhanced electrocatalytic activity of 2D ordered mesoporous nitrogen-rich carbon nanosheets functional NiFe2O4 nanospheres for ultrasensitive detection of chlorogenic acid in natural samples

Two-dimensional (2D) porous carbon nanosheets loaded with bimetallic oxide nanospheres are expected to be very attractive electrocatalysts. In this work, we constructed ordered mesoporous nitrogen-rich carbon on the surface of ultrathin-reduced graphene oxide (rGO) using the self-assembly of block polymers and compared the effect of pore structure on the sensing performance. The rGO wrapped by N-doped ordered porous carbon possesses a large specific surface area of 784.9 m2/g. The composite with NiFe2O4 nanospheres with rough surfaces effectively prevented the interlayer accumulation of mNPC@rGO. Meanwhile, the multivalent form of metal elements in NiFe2O4 facilitates the redox reaction. These distinct advantages combine to create an active surface that strongly binds to chlorogenic acid molecules (CGA). Importantly, we have computationally analyzed the reaction mechanism of mNPC@rGO/NiFe2O4 electrocatalytic CGA molecules by density functional theory. In the best case, the mNPC@rGO/NiFe2O4/GCE sensor has a limit of detection (LOD) as low as 2 × 10−11 M and a wide linear range (1 × 10−10−2 × 10−5 M). The sensor displays a remarkable level of selective response to CGA in the presence of other co-interfering species. Furthermore, it has superb repeatability and reproducibility for CGA. The sensor has shown outstanding recovery (95.9%−104.9%) in the practical viability of detecting CGA in food, natural products, and biological samples. This work not only provides a new candidate for the accurate detection of CGA, but also provides insight into the exploration of advanced sensing materials.

Fluoride removal from water using Zr-modified meso- and macroporous carbons: Effect of pore structure and adsorption conditions

We investigated the effects of the pore structure and adsorption conditions (pH and coexisting anions) on the fluoride (F–) removal capacity of Zr-modified porous carbons. The porous carbons used in this study possessed well-defined pore structures created by the template technique with pore diameters of 10, 30, and 150 nm. These porous carbons were oxidized to functionalize them with oxygen-containing groups before being modified with Zr4+. Zr4+ modification improved the F– removal capacity of porous carbons. The maximum amount of F– adsorbed increased by approximately 3–10 times by Zr4+ modification. The F– adsorption capacity depends on the pore size. The samples with larger pore diameters (smaller specific surface areas) exhibited higher F– adsorption capacities than the samples with smaller pore diameters. This tendency can be explained using the theory of liquid imbibition in porous media. The adsorption capacities at pH 7.0 and 11.1 were lower than those at pH 3.1. This tendency can be interpreted based on competition between F– and OH– on adsorption sites and attractive/repulsive interactions between F– and protonated/deprotonated adsorbent surfaces. The coexisting carbonate anions notably suppress the F– adsorption. This suppressive effect can be explained by the competitive bonding of F– and CO32– to the adsorption sites.

Electrode particulate materials for advanced rechargeable batteries: A review

The demand for large-scale energy storage is increasing due to the decreasing non-renewable resources and deteriorating environmental pollution. Developing rechargeable batteries with high energy density and long cycle performance is an ideal choice to meet the demand of energy storage system. The development of excellent electrode particles is of great significance in the commercialization of next-generation batteries. The ideal electrode particles should balance raw material reserves, electrochemical performance, price and environmental protection. Among them, the development of electrode particulate materials with excellent electrochemical properties is the top priority at present. In this review, the typical researches of electrode materials are summarized in terms of crystal structure, morphology, pore structure, surface and interface regulation. Firstly, the structural characteristics and improvement methods of transition metal oxides, polyanionic compounds, Prussian blue and their analogues are introduced. Then, the different effects of particulate morphology, pore, surface and interface structure on the performance of electrode materials are discussed. For designing high-performance electrode materials, preparation route should be set according to the particle properties of the materials and the synergistic effect of various optimization methods should be adopted. At the same time, in addition to the electrode materials, other components of the rechargeable batteries, such as current collector, separator and electrolytes, should be optimized to improve the overall performance of the batteries. This review would provide important guiding principle for designing high-performance electrode particulate materials.

Effect of pore structure on the thermal stability of shape-stabilized phase change materials

To attain the increasing demand for energy in addition with an aim of resolving environmental concerns, a transition from traditional energy systems to renewable resources is crucial. However, renewable energy needs the proper mechanism of harvesting on availability and suitable storage capabilities until it's utilizable necessity. Therefore, effective and consistent energy storage frameworks are crucial for the utilization of stowed renewable energy at a maximum capacity. Pondering that, this study has been focused on the utilization of biochars for efficacious thermal energy storage applications. The shape stabilization efficiency of commercial softwood biochar (EB) has been compared with synthesized bamboo biochar (BA). Both biochars have demonstrated porous and channel-like morphologies and the BET surface areas are measured to be 41.1676 and 9.7213 m2/g, respectively. Paraffin as a phase change material (PCM) is melted and permeated into the biochars to synthesize the biochar composite PCMs. Paraffin to biochar in a 3:1 ratio has been realized as the optimum for both composite PCMs. Maximum heat charging and discharging enthalpies are found to be 96.71 and 94.97 J/g for 1:3 EB-PCM as well as 77.78 and 75.06 J/g for 1:3 BA-PCM composites, respectively. The highest encapsulation ratios are calculated to be 53.49 and 43.02% for 1:3 EB-PCM and 1:3 BA-PCM composites, respectively. Although the enthalpies and encapsulation ratios are found higher in EB-PCM composites, BA-PCM composites have demonstrated superior thermal stability owing to the smaller pore sizes and that has resulted in higher surface tension, capillary action, and effective surface functionalities.

Facile demineralization of biochar and its catalytic upgrading of bio-oil from fast pyrolysis of bagasse

Catalytic conversion of volatiles from biomass pyrolysis over biochar and its mechanism are important to the efficient utilization. The properties of biochar including alkali/alkaline earth metallic species (AAEMs) and pore structure exert the influence on bio-oil quality. In this work, a facile demineralization method by CO2-enhanced water leaching (CEWL) of biochar from bagasse pyrolysis was first applied to catalytic upgrading of pyrolysis bio-oil. The effect of AAEMs content and pore structures in biochar catalysts on upgrading performances was investigated. The results show that the CEWL of biochar can effectively remove most inherent AAEMs without obviously destroying pore structures. Pore structure of catalysts plays a dominant role in increasing phenols contents to 47.7% over CO2-activated biochar from 25.8% without biochar. The reaction mechanism was proposed that AAEMs enhanced the polymerization of aromatic hydrocarbons and the decarbonylation of the oxygenated compounds. High temperature is profitable to the generation of phenols and polycyclic aromatic hydrocarbons owing to easier decarbonylation of ketones and demethylation or demethoxylation of phenols.

Research on pore structures of fine-grained carbonate reservoirs and their influence on waterflood development

Abstract Carbonate reservoir has complex pore structures. At present, the influence of pore structure on water flooding mechanism of carbonate reservoirs is insufficient. In this article, a systematic workflow was designed in combination with scanning electron microscope, particle size, physical properties, and water flooding experiments to study the effect of pore structure on water flooding mechanism of fine-grained carbonate rocks. Due to the small particle size and strong heterogeneity, the acid fracturing operations, rather than hydraulic fracturing alone, are necessary to achieve increased production and reservoir reconstruction of carbonate reservoirs. Through this study, the mathematical model of reservoir physical parameters (permeability and porosity) was proposed, and the accuracy of the model was verified by comparing the simulated oil recovery with the experimental results. According to the comparison results, the experimental results are consistent with the simulation results, and their oil recovery efficiency is 33.62 and 31.87%, respectively. Finally, the effect of injection rate on oil production was discussed. It is shown that with the increase in injection rate, the output of displaced oil increases significantly. The cumulative oil production increases from 62.5 to 256.31 mL when the injection rate increases from 100 to 400 mL/min. The findings of this study can help for better understanding of the influencing factors and mechanisms of the development efficiency of carbonate reservoirs.

Effects of Porogen PEG and Pore Structure of PVDF Substrates on the Permeability–Selectivity Trade-off of TFC-NF Membranes

Thin-film composite (TFC) nanofiltration (NF) has been widely utilized to separate monovalent ions from multivalent ions in industrial wastewater treatment. In this study, the pore properties of polyvinylidene fluoride (PVDF) substrates were adjusted by varying the content and molecular weights (MWs) of porogen polyethylene glycol (PEG). The TFC membranes fabricated on different substrates showed distinguishable permeance and selectivity. The PVDF membranes with 2 kDa PEG of 0.5–3.0 wt % and 20 kDa PEG of 0.2 wt % were fit for the substrates of the TFC NF membrane. These substrates are usually characterized by evenly distributed surface pores with porosity of 7–12% and tiny finger-like pores of less than 15 μm length. Such pore structures in the substrates are fit for the storage and migration of amine monomers, resulting in a defect-free PA layer. In a 6 h filtration of mining wastewater using an optimized TFC membrane, the permeance remained around 5 LMH/bar and the separation factor of SO42–/Cl– stayed over 13.39 with a maximum value over 30. This study shed light on improving NF membrane performance by simply adjusting the porogen in the substrate casting solution.

Zeolite membrane separators for fire-safe Li-ion batteries – Effects of crystal shape and membrane pore structure

The state-of-the-art lithium-ion batteries (LIB) use carbonate-based liquid electrolytes and polymeric separators which pose safety issues including fire-hazard. The use of fire-retarding salt-concentrated electrolytes can address the safety issues of LIBs, but these electrolytes have high viscosity and low wettability with polymeric separators making it difficult to fabricate high performance LIBs with the electrolytes. Here we report development of zeolite membrane separators with tailored pore structure and surface chemistry for preparation of fire-safe LIBs using salt-concentrated electrolytes. The zeolite membrane separators are made of zeolite particles with a specific zeolite structure, Si/Al ratio, and different particle shapes, coated on cathode by a scalable blade coating method. Intermediate pore, pure silica MFI-type zeolite (silicalite) was selected as the fire-proof material for membrane separators which also offer high wettability for the fire-retarding salt-concentrated electrolyte of lithium bis(fluorosulfonyl)imide (LiFSI) in tri-methyl phosphate solvent (TMP) solvent. Two silicalite membrane separators of similar pore size but different porosity and tortuosity were coated on cathode (LiNi0.5Mn0.3Co0.2O2 or NMC) using plate-shaped silicalite particles of low aspect ratio (LAR) and high aspect ratio (HAR). Both zeolite separators show significantly better wettability for the LiFSI/TMP electrolyte than the commercial polypropylene (PP) separator allowing fabrication of high-performance NMC/LiFSI-TMP/graphite cells with the non-combustible silicalite separator. The new fire-safe zeolite-membrane-based LIBs with the fire-retarding electrolyte exhibit excellent charge and discharge characteristics and cycle performance (similar to the state-of-the-art, but fire-unsafe LIBs with LiPF6-carbonate electrolyte and polymer separator). The membrane separators made of HAR plate-shaped zeolite showing low interparticle porosity and high tortuosity perform better than the membrane made of LAR zeolite particles, due to a more uniform lithium-ion flux from both interparticle pores and intraparticle zeolitic pores at the separator/anode interface.

Efficient recovery of highly viscous crude oil spill by superhydrophobic ocean biomass-based aerogel assisted with solar energy

The crude oil spills is one of the crucial ocean environmental disaster. The low fluidity of high-viscosity crude oil poses significant challenges for its penetration into conventional porous adsorption materials. Fortunatelly, the viscosity of crude oil is especially temperature-sensitive, leading to the extensive research on porous materials that utilize solar heat for heat generation. In this work, we propose a biodegradable marine bio-based aerogel (PDMS-Ink@CS) with aligned channel structure via directional freeze casting technique, primarily composed of chitosan and cuttlefish ink. The PDMS-Ink@CS demonstrates excellent photothermal conversion and oil adsorption performance. We systematically investigated the effects of sunlight intensity and pore structure on the viscosity-reduction and adsorption rate of crude oil. Under simulated sunlight intensity of 1 kW m−2, the surface temperature of PDMS-Ink@CS aerogel reaches approximately 70 ℃ within 60 s, allowing to absorb crude oil 18 times its weight and recover via extrusion. When combined with a vacuum pump device, the PDMS-Ink@CS aerogel realizes the continuous recovery of crude oil from the seawater surface. Moreover, the separation efficiency of PDMS-Ink@CS aerogel for W/O emulsions can reach 99 %, which greatly broadens its range of applications. Particularly noteworthy is the fact that the PDMS-Ink@CS aerogel biodegrades within 30 days without causing environmental pollution. Thus, this super-hydrophobic ocean biomass-based chitosan aerogel exhibits vast potential for oil spill recovery applications.

Effect of Chitosan as Active Bio-colloidal Constituent on the Diffusion of Dyes in Agarose Hydrogel.

Agarose hydrogel was enriched by chitosan as an active substance for the interactions with dyes. Direct blue 1, Sirius red F3B, and Reactive blue 49 were chosen as representative dyes for the study of the effect of their interaction with chitosan on their diffusion in hydrogel. Effective diffusion coefficients were determined and compared with the value obtained for pure agarose hydrogel. Simultaneously, sorption experiments were realized. The sorption ability of enriched hydrogel was several times higher in comparison with pure agarose hydrogel. Determined diffusion coefficients decreased with the addition of chitosan. Their values included the effects of hydrogel pore structure and interactions between chitosan and dyes. Diffusion experiments were realized at pH 3, 7, and 11. The effect of pH on the diffusivity of dyes in pure agarose hydrogel was negligible. Effective diffusion coefficients obtained for hydrogels enriched by chitosan increased gradually with increasing pH value. Electrostatic interactions between amino group of chitosan and sulfonic group of dyes resulted in the formation of zones with a sharp boundary between coloured and transparent hydrogel (mainly at lower pH values). A concentration jump was observed at a given distance from the interface between hydrogel and the donor dye solution.

Photoinduced enhanced catalytic activity for Suzuki-Miyaura coupling reaction using porous poly(lactic acid) fiber with palladium/graphitic carbon nitride

The development of photocatalytic Suzuki-Miyaura coupling reaction for CC bond formation in organic synthesis will be beneficial to solve environmental problems and reduce production costs. Herein, the porous poly(lactic acid) fiber of graphitic carbon nitride (g-C3N4) coupled with palladium (T-Pd@CN/PLA) was prepared by centrifugal-electrostatic spinning and the alkali treatment, where palladium supported on g-C3N4 (Pd@CN) was synthesized by microwave-assisted deposition. T-Pd@CN/PLA porous fibers showed enhanced catalytic activity and broad substrate applicability for Suzuki-Miyaura coupling reaction with aryl bromides and phenylboronic acid as the substrates at room temperature in air under LED light. The electrons generated by g-C3N4 could be efficiently and rapidly transferred to Pd, and more active sites could be exposed due to the porous structure of the fiber. This work may serve as a guideline on the design of catalytic fibers for the Suzuki-Miyaura coupling reaction, highlighting the effect of light and pore structure on the efficiency.

Experimental and theoretical calculations insight into acetone adsorption by porous carbon at different pressures: Effects of pore structure and oxygen groups

The influence of different pore size and oxygen groups for porous carbons on acetone adsorption at different pressure was studied by using experimental data and theoretical calculation, and the results were applied to prepare carbon-based adsorbents with superior adsorption capacity. First, we successfully prepared five types of porous carbons with different gradient pore structure but similar oxygen contents (4.9 ± 0.25 at.%). We found that the acetone uptake at different pressure depends on the different pore sizes. Besides, we demonstrate how to accurately decompose the acetone adsorption isotherm into multiple sub-isotherms based on different pore sizes. Based on the isotherm decomposition method, the acetone adsorption at 18 kPa is mainly in the form of pore-filling adsorption in the pore size range of 0.6–2.0 nm. When the pore size is greater than 2 nm, the acetone uptake mainly depends on the surface area. Second, porous carbons with different oxygen content, similar surface area and pore structure were prepared to study the influence of oxygen groups on acetone adsorption. The results show that the acetone adsorption capacity is determined by the pore structure at relatively high pressure, and the oxygen groups only slightly increase the adsorption capacity. However, the oxygen groups can provide more active sites, thereby enhancing acetone adsorption at low pressure.

Effects of sintering temperature on the properties and the pore evolution of microporous MgAl2O4 aggregates

It is of great significance to develop new types of refractories by replacing the traditional refractory aggregate with a porous refractory aggregate, which enables long-lived operation of high-temperature industries and low carbon emissions. In this study, microporous MgAl2O4 aggregates containing sub-micron pores were successfully prepared from magnesite and boehmite using an in-situ decomposition pore-forming method. The effects of sintering temperature on the phase compositions, sintering properties, and microstructure of aggregates were reported for the first time. The resulting aggregates sintered at 1500 °C showed superior comprehensive performance with a median equivalent pore diameter of 10.75 μm, corresponding to a bulk density and closed porosity of 2.27 g cm−3 and 8.7%, respectively. Meanwhile, several sub-micron pores were observed in microporous MgAl2O4 aggregates, which contributed to a lower thermal conductivity of 1.932 W m−1 k−1 at 500 °C and a higher compressive strength of 40.8 MPa. In addition, the formation mechanism of sub-micron pores was proposed, and the effects of pore structure on the thermal conductivity and compressive strength were discussed.

Multi-scale model investigating the effects of pore structure and drying-wetting cycles on diffusion in concrete

In order to further explore the transport mechanism of sulfate in concrete under the alternate dry-wet environment, it is imperative to establish a multi-scale analysis method combining sulfate macroscopic migration and microscopic morphology evolution. A model considering convection, diffusion of moisture and sulfate was proposed to represent the macroscopic sulfate transport under drying-wetting cycles. The relationship between pore characteristics and microscopic diffusion behavior was investigated through numerical method and fractal theory. Furthermore, the model was validated by previous experimental results. The results revealed that diffusion behavior in concrete was correlated with both pore structure and fractal dimension. The macroscopic transport model exhibited good applicability and concise form. Sensitivity analysis indicated that the model was sensitive to the dry-to-wet ratio, diffusion coefficient of moisture and sulfate. The findings are expected to help combine experimental and numerical methods in a multi-scale range, thus refining the transport mechanism of sulfate under drying-wetting cycles.

Realizing Ultrafast and Robust Sodium-Ion Storage of Iron Sulfide Enabled by Heteroatomic Doping and Regulable Interface Engineering.

Fe-based sulfides are a promising type of anode material for sodium-ion batteries (SIBs) due to their high theoretical capacities and affordability. However, these materials often suffer from issues such as capacity deterioration and poor conductivity during practical application. To address these challenges, an N-doped Fe7S8 anode with an N, S co-doped porous carbon framework (PPF-800) was synthesized using a template-assisted method. When serving as an anode for SIBs, it delivers a robust and ultrafast sodium storage performance, with a discharge capacity of 489 mAh g-1 after 500 cycles at 5 A g-1 and 371 mAh g-1 after 1000 cycles at 30 A g-1 in the ether-based electrolyte. This impressive performance is attributed to the combined influence of heteroatomic doping and adjustable interface engineering. The N, S co-doped carbon framework embedded with Fe7S8 nanoparticles effectively addresses the issues of volumetric expansion, reduces the impact of sodium polysulfides, improves intrinsic conductivity, and stimulates the dominant pseudocapacitive contribution (90.3% at 2 mV s-1). Moreover, the formation of a stable solid electrolyte interface (SEI) film by the effect of uniform pore structure in ether-based electrolyte produces a lower transfer resistance during the charge-discharge process, thereby boosting the rate performance of the electrode material. This work expands a facile strategy to optimize the electrochemical performance of other metal sulfides.

Model for Predicting CO2 Adsorption in Coal Left in Goaf Based on Backpropagation Neural Network

Injecting power plant flue gas into a goaf stores CO2 in the flue gas and effectively prevents the spontaneous combustion of the coal remaining in the goaf. Here, we investigated the adsorption behavior of three types of coal at normal temperature and pressure using a self-developed adsorption experimental device. We used a specific surface area and porosity analyzer to study the effects of pore structure, mineral content, and moisture content on CO2 adsorption in coal. Based on the experimental data, we designed a multifactor CO2 adsorption prediction model based on a backpropagation (BP) neural network. The results indicated that the pore size of most micropores in coal was in the range of 0.5–0.7 and 0.8–0.9 nm. The specific surface area and pore volume were positively correlated with the CO2-saturated adsorption capacity, whereas the mean pore diameter, mineral content, and moisture content were inversely associated with the CO2-saturated adsorption amount. The accuracy of the multifactor BP neural network prediction model was satisfactory: the determination coefficients (R2) of the training and test sets were both above 0.98, the root mean square error (RMSE) and mean absolute error (MAE) of the test set were both less than 0.1, and the prediction results satisfied the requirements. To optimize the prediction performance of the model, we used the random forest algorithm to calculate the importance of each factor. The sum of the importance weights of the specific surface area, moisture content, and pore volume was 91.6%, which was much higher than that of the other two factors. Therefore, we constructed an optimization model with specific surface area, moisture content, and pore volume as input variables. The R2 values of the training and test sets in the simplified model were improved compared with those of the multifactor model, the RMSE and MAE were reduced, and the fitting effect was ideal. The prediction model of CO2 adsorption in coal based on the BP neural network can predict the CO2 adsorption capacity of coal under different physical and chemical conditions, thereby providing theoretical support for the application of CO2 storage technology in goafs.