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The design of novel materials for sulfur dioxide (SO2) capture and conversion with considerable efficiency under mild conditions is of great significance for human health and environmental protection yet highly challenging. Herein, we report a series of triazine‐based multicomponent metallacages via coordination‐driven self‐assembly of 2,4,6‐tri(4‐pyridyl)‐1,3,5‐triazine, cis‐Pt(PEt3)2(OTf)2 and different tetracarboxylic ligands. As the increase of the length of the tetracarboxylates, the structures of the metallacages change from pyramids to extended octahedrons. Owing to their N‐rich structure, these metallacages are further used for selective SO2 capture, showing good adsorption capacity and remarkable SO2/CO2 selectivity in ambient conditions, suggesting their potential applications toward real flue gas desulfurization. The metallacages are further employed for the conversion of SO2 into value‐added compounds, showing exceptional efficiency even dilute SO2 is used as the reactant. This study represents a type of structure‐tunable triazine‐based metallacages for SO2 capture and conversion, which will pave the way on the applications of metal‐organic complexes for gas adsorption. [ABSTRACT FROM AUTHOR]

In this study, fly ash was modified with NaOH and Ca(OH)2 and discussed the feasibility of its adsorption of SO2 from flue gas in electrostatic precipitator (ESP). The optimal modification conditions were determined by comparing the changes of SO2 adsorption performance of different modified fly ashes in flue gas. The effect of modification and adsorption of SO2 before and after on the electrical conductivity of fly ash was investigated by testing the specific resistance characteristics. The results showed that when the solid–liquid ratio was 1:5 and the modification time was 90 min, the Ca(OH)2 modified fly ash has the best adsorption capacity for SO2 in flue gas, and the adsorption capacity of SO2 was 31.44 mg/g. Compared with the raw fly ash, the adsorption capacity increased by 141.85%. The modified fly ash has better conductivity than that before modification, and the peak-specific resistance can be reduced by two orders of magnitude. After SO2 adsorption, the specific resistance of alkali modified fly ash was increased, but it was still lower than that of the raw fly ash, which was favorable to be removed in the dust removal stage. [ABSTRACT FROM AUTHOR]

The rapid and low-cost preparation of powder activated coke (PAC) is very important for the promotion of fluidized dry desulfurization technology of activated coke. In order to explore the effect of rapid pyrolysis process on SO2 adsorption capacity of PAC, the fractal analysis of PAC prepared under different atmospheres was carried out. The Frenkel–Halsey–Hill (FHH) method was used to determine two fractal dimensions D1 and D2, under relative pressures of 0–0.5 and 0.5–1, respectively. The results indicate that the fractal dimensions were influenced by the concentrations of activation agents with D1 ranging from 2.1838 to 2.8643 and D2 ranging from 2.7485 to 2.9257. The effect of steam on the fractal dimension of PAC sample is small, but oxygen has a great promotion effect on the fractal dimension. An n-shaped curve-based relationship between fractal dimensions and coke yields is observed with a peak values of fractal dimensions appearing around 64% yield. The SO2 adsorption capacity shows a consecutively positive linear correlation with D2, while it illustrates distinctly different linear rates with D1 in intervals of 2–2.6 and 2.6–3, respectively. Taking advantage of fractal analysis as research method, this paper clarified the influence of activation atmosphere and ablative degree on the SO2 adsorption capacity of PAC, and the research conclusion provided a basis for the PAC preparation with high SO2 capacity. [ABSTRACT FROM AUTHOR]

The amino group in the MOF NH2‐MIL‐101(Cr) was post‐synthetically converted into urea‐groups partially using either ethyl isocyanatoacetate, furfuryl isocyanate, p‐toluenesulfonyl isocyanate or 3‐(triethoxysilyl)propyl isocyanate in acetonitrile. The derived four novel urea‐MOFs exhibit the expected lower BET surface areas and pore volumes than MIL‐101(Cr) and NH2‐MIL‐101(Cr) MOFs but the partially p‐toluenesulfonyl‐urea‐modified MOF exhibits an outstanding SO2 adsorption capacity of 823 cm3 g−1 (corresponding to 36.7 mmol g−1 or 70 wt.% at T=0 °C and 0.9 bar), which is the second highest SO2 uptake of any known material today – surprisingly even better than for highly porous MIL‐101(Cr) with an uptake of 645 cm3 g−1 SO2 under the same conditions. The high uptake is linked to the favorable dipole interactions of SO2 with the sulfonyl group of the p‐toluenesulfonyl‐modified MOF. [ABSTRACT FROM AUTHOR]

Sulphur dioxide (SO2) is an important atmospheric pollutant, and capture of SO2 is of great importance for the environment, human health and market. Carbon based materials, especially activated carbon, are mostly used for adsorption purposes. However, there is a notable lack on adsorption of SO2 on graphene oxide (GO) fibers and fiber web surface. In this study, the effect of addition of activated carbon, pH of GO dispersions, hydrazine reduction and oxygen/argon plasma treatment on SO2 adsorption of GO fiber web surface were evaluated. It was seen that GO fiber web surface with activated carbon provides high SO2 adsorption (896 mg SO2/g) which is very higher than many of carbon based materials presented in the literatures. Single coagulation bath increases surface roughness of fiber and provides higher functional group than three coagulation baths leading to higher SO2 adsorption capacity. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fibrous and porous carbon microspheres was used to load deep eutectic solvent. • NCMs-DESs can be used as a novel adsorbent for highly-efficient SO 2 capture. • NCMs-DESs showed excellent properties of selectivity and reuse for SO 2 adsorption. Deep eutectic solvents (DESs) are promising absorbents for SO 2 capture. However, the high viscosity of DESs limits their applications in the SO 2 separation industry. In this study, nanofibrous and porous carbon microspheres (NCMs) with a large surface area (344.5 m2·g−1) were prepared from chitin and used to load [emim]Cl + imidazole DESs for the first time using a physical dispersion process. The DESs were uniformly adsorbed onto the nanofibrous carbon surfaces, and a novel adsorbent (NCMs- x DESs) was formed with a three-dimensional hierarchical porous structure. NCMs showed high loading capacity for DESs (the ideal load ratio was 5:1) and exhibited an appropriate solid-state with significantly decreased DESs viscosity. NCMs- x DESs were used to capture SO 2 , and the results showed that NCMs-5DESs had the highest adsorption capability for SO 2 compared with other NCMs- x DESs. The adsorption capacity of NCMs-5DESs for pure SO 2 reached up to 14.66 mol/kg under 25 ℃ and 1 bar conditions. The adsorption capacity remained at 2.89 mol/kg even at low-content SO 2 (1,700 ppm) in the mixed gas, which was higher than most solid adsorbents reported in the literature. The excellent adsorption capability was due to the porous structure of the NCMs and the multiple interactions between DESs and SO 2. The DESs contained the strong electron-donating ability of Cl−1 and weakly basic tertiary N that can interact with SO 2 via electron deficiency and Lewis acids. H-bonding interactions also formed between the DESs and SO 2. Additionally, the NCMs-DESs absorbent exhibited excellent reversibility and selectivity for SO 2 adsorption after ten cycles. Therefore, the NCMs-DESs absorbent may be a promising candidate for SO 2 capture in polluted gas. [ABSTRACT FROM AUTHOR]

To meet the requirements of efficient adsorption of the atmospheric pollutant SO 2 and low energy consumption regeneration of adsorbents, metal oxide-modified biomass carbon materials were prepared by microwave heating, and the effects of microwave power, iron oxide loading, and calcination time on the activated carbon load with iron oxides (ACIO) were investigated. The desulfurization mechanism of ACIO was characterized by multiple methods, and the process was simulated using density functional theory (DFT). The results indicated that the optimum preparation conditions were as follows: the loading amount of iron oxides was 10 wt%, the microwave power was 500 W, and the calcination time was 10 min. The adsorption capacity of ACIO corresponding to the optimum preparation conditions was 146.31 mg/g, and the thermal conductivity was 0.58 W/(m·K), which led to a reduction in the regeneration energy consumption by approximately 2800 J/g. Furthermore, ACIO exhibited good SO 2 cyclic adsorption-desorption performance, and the SO 2 adsorption capacity after five cycles of adsorption and desorption was maintained at 46.98 mg/g. The DFT calculation results indicate that chemical adsorption between SO 3 and Fe 2 O 3 under anhydrous conditions occurred during the desulfurization process and contributed to the sulfate formation reaction. [Display omitted] • Proposed an iron oxide modified biochar desulfurizer. • SO 2 adsorption capacity of the desulfurizer can reach 146.31 mg/g. • Chemisorption between Fe 2 O 3 and SO 3 exists under anhydrous conditions. • H 2 O alters the pathway of sulfate production. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the adsorption capacity for toluene and SO2 of low cost activated carbons prepared from sewage sludge by chemical activation at different impregnation ratios. Samples were characterized by proximate and ultimate analyses, thermogravimetry, infrared spectroscopy and N2 adsorption. Because of the low carbon content of the raw material, the development of porosity in the activated carbons was mainly of a mesoporous nature, with surface areas lower than 300 m2/g. The study of gas-phase applications for activated carbons from sewage sludge was carried out using both an organic and an inorganic compound in order to screen for possible applications. Toluene adsorption capacity at saturation was around 280 mg/g, which is a good level of performance given the high ash content of the activated carbons. However, dynamic experiments at low toluene concentration presented diffusion problems resulting from low porosity development. SO2 adsorption capacity is associated with average micropore size, which can be controlled by the impregnation ratio used to prepare the activated carbons. [Copyright &y& Elsevier]

[Display omitted] • A novel ultra-stable Zr(IV)-MOF (HBU-20) was synthesized by solvothermal method. • HBU-20 shows highly efficient capture of SO 2 over CO 2 and CH 4. • Theoretical simulations exhibit the importance of host–guest weak interactions. • Gas breakthrough experiments prove its' application in deep desulfurization. Flue gas and natural gas deep desulfurization is still very challenging, so new absorbent is highly desired. In this work, a novel stable porous Zr(IV)-MOF (HBU-20) has been designed and synthesized. HBU-20 possesses a high BET surface area of 1551.1 m2/g and the pore volume achieves 0.896 cm3/g. More importantly, the compound shows a high SO 2 adsorption capacity of 6.69 mmol/g at 298 K and 100 kPa, and the higher IAST selectivitives of SO 2 /CO 2 (v/v, 1:99, 56.7) and SO 2 /CH 4 (v/v 1:99, 246) have been accordingly obtained. Theoretical simulations proved host–guest interactions should be responsible for efficient SO 2 capture. Furthermore, the excellent separation performance of HBU-20 had also been evaluated by dynamic breakthrough experiments under ambient condition. The experimental selectivities of SO 2 /CO 2 and SO 2 /CH 4 (v/v 1:99) achieve 81.1 and 117.6, respectively. The research indicates HBU-20 is a promising absorbent for deep desulfurization of flue gas and natural gas. [ABSTRACT FROM AUTHOR]

Dry regenerative flue gas desulfurization (FGD) is a promising method to tackle industrial issues regarding SO 2 emission into the atmosphere due to its sorbent being highly accessible, the lack of water dependency and reduction in waste management. This study examined the feasibility of using fibrous mesoporous silica KCC-1 which has been reported to possess better properties than several other predecessor mesoporous silica as alternative sorbents for dry FGD. Calcium metal was introduced to overcome the lack of active sites available on KCC-1 while simultaneously providing sufficient basicity to counter the increase in acidity brought by SO 2 adsorption. Three sorbent modification parameters were analyzed: metal loading (5–15 wt %), calcination temperature (823–973 K) and calcination time (5.5–7 h), and the prepared samples were characterized using BET surface area and pore analyzer, FESEM-EDX, XRD and H 2 -TPR. The breakthrough experiment was conducted using a lab scale fixed bed reactor system with 1500 ppm SO 2 /N 2 at 200 mL/min. SO 2 removal was optimized by sorbent prepared with calcium loading of 5 wt %, calcination temperature of 923 K and calcination time of 6.5 h with adsorption capacity of 3241.94 mg SO 2 /g KCC-1. The optimized sorbent demonstrated highest surface area, good pore development, high dispersion of calcium metal, appropriate impregnation of calcium oxide which caused only minor distortion to the silica framework of KCC-1. Subjecting the optimized sample to five consecutive regeneration cycles by heating at 773 K while simultaneously flowing N 2 gas for an hour shows good regeneration performance with a total final reduction of only 25% from the initial adsorption capacity obtained from a fresh sample. [Display omitted] • Dry desulfurization using calcium modified KCC-1 mesoporous silica as sorbent. • Optimized calcium metal loading, calcination temperature and calcination time. • Adsorption capacity of 3241.94 mg/g attained by optimized Ca/KCC-1. • SO 2 removal controlled by surface area, porosity, basicity and crystallite size. • Feasible for regeneration by simple heating at 773 K and nitrogen flow. [ABSTRACT FROM AUTHOR]

Carbon nanotubes are a promising adsorbent for desulfurization and denitrification. In this paper, Cu- and Cr-doped TiO2 supported by multi-walled carbon nanotubes (MWCNTs/Cu-Cr-TiO2) were synthesized by the sol-gel method. Characterizations of the samples were performed by TEM, XPS, XRD, DRS, and BET. The experiments of simultaneous desulfurization and denitrification were conducted in a fixed-bed reactor. The results showed that the adsorbent with a Cu to Cr molar ratio of 3 displays excellent adsorption property. The SO2 and NO adsorption capacity of MWCNTs/Cu-Cr-TiO2 (Cu/Cr = 3) were 36.83 and 12.34 mg/g under the optimal experimental operating parameters (SO2 content: 1575 mg/m3, NO content 736 mg/m3, O2 content 8%, H2O content 5%, and space velocity 1003 h−1). The adsorption capacity of MWCNTs/Cu-Cr-TiO2 was significantly better than that of the adsorbent doped with Cu or Cr alone (MWCNTs/Cu-TiO2 and MWCNTs/Cr-TiO2). Compared with single metal doping, bimetallic multivalent states accelerate the electron migration and separation from holes, which increase the number of oxygen vacancies and enhance the adsorption of SO2 and NO. The kinetic models and the reaction mechanism of the desulfurization and denitrification were also analyzed in this work. [ABSTRACT FROM AUTHOR]

[Display omitted] • Both of physical and chemical properties are improved during the ammonification. • The SO 2 adsorption capacity of SSN800 can reach 175.9 mg/g at 30 °C. • SO 2 adsorption capacity mainly depends on the micropore structure at 30 °C. • The nitrogen functional groups show the importance for the SO 2 adsorption at 120 °C. Multiporous and alkaline carbon-based adsorbents, which generally show abundant pore structures, high surface area and improved surface chemistry characteristics, have a potential to be used for SO 2 adsorption. In this work, biochar, as a precursor, was used to prepare nitrogen-rich and microporous carbon-based adsorbents for SO 2 adsorption by high temperature ammonification with ammonia and physical activation with CO 2. The results show that physical activation with CO 2 can improve the microporous structure of biochar, the micropore area (S mic) increasing from 252.88–481.37 m2/g. However, the high temperature ammonification can not only improve the microporous structure of biochar, S mic increasing from 252.88–488.10 m2/g, but also introduce alkaline nitrogen functional groups on the surface of biochar, nitrogen content increasing from 1.38 to 6.22 wt.%. In addition, the relationship between the SO 2 adsorption and physicochemical properties indicates that the improvement of microporous structure on biochars can enhance the SO 2 adsorption at 30 °C, and the introduction of alkaline nitrogen functional groups can enhance the SO 2 adsorption at 120 °C. The ammonification at 800 °C can make the SO 2 adsorption capacity of biochar increasing from 92.8–175.9 mg/g at 30 ℃, and from 56.3–115.4 mg/g at 120 ℃. [ABSTRACT FROM AUTHOR]

• The newly formed C(CO 2) type functional group was detected by TPD experiment. • The adsorbed SO 2 and regeneration process have pore widening/creating effects. • The C-O content in lactone-like groups increase after the regeneration process. • Higher regeneration temperature can optimize the performance of regenerated coke. Porous carbon materials have emerged as a new technology with tremendous potential as energy-saving and environmentally friendly pathways for SO 2 removal due to its advantages, which include recyclability and a high adsorption capacity. However, the degradation of the performance of adsorbents using thermal regeneration has become a key issue limiting the scaling-up of this new technology. The main purpose of this study is to clarify the effect of the regeneration temperature on the physicochemical properties of activated coke and secondary SO 2 removal performance, as well as explore the mechanism by which the circulating adsorbent is deactivated. Using powdered activated coke (PAC) prepared from coal. Experimental results show that adsorbed SO 2 desorbs at temperatures between 200 and 500 ℃, while both excess CO 2 and CO are released over a wide temperature range owing to the regeneration reaction and decomposition of newly formed oxygen-containing functional groups. The physicochemical properties of PAC are significantly affected by the regeneration temperature. As this temperature rises, the adsorbed sulfuric acid in the pores evaporates and the functional groups decompose, producing several micropores and a large specific surface area. Moreover, the SO 2 adsorption–desorption process increases the number of C–O groups such that the active adsorption sites are occupied and SO 2 adsorption is prevented. The C-O groups decompose to produce CO 2 when exposed to even higher temperatures. The secondary SO 2 adsorption experiment demonstrated that the ability of the adsorbent to perform desulfurization could be recovered completely by controlling the regeneration temperature. [ABSTRACT FROM AUTHOR]

• One-step and two-step rapid activation methods for PAC preparation were compared. • The existence of pyrolysis gas layer influenced the activation of one-step method. • PAC2's performance is better than PAC1's, but its yield is relatively low. • Caking property of coal is an unfavorable factor in the PAC preparation. Activated coke, which is a porous carbonaceous material, can be used in flue gas desulfurization, but its preparation has two primary problems, namely the complex preparation process and the high preparation cost. In this study, two methods were proposed for the rapid preparation of powdered activated coke (PAC), namely one-step rapid activation method and two-step rapid activation method. Shengli (SL) lignite and Jinjie (JJ) bituminous coal were used as raw materials to prepare the PAC in a drop-tube reactor via the two methods. The burn-off, yields and pore structures of the produced PAC using the two methods were compared and analyzed, and their activation mechanisms were speculated. Then, as an evaluation standard method of the SO 2 adsorption performance, all samples were tested for their SO 2 adsorption capacities for 2 h. Results showed that the pore structure and SO 2 adsorption performance of the SL-PACs were much better than those of the JJ-PACs, that is, the PACs prepared from lignite had better properties than that prepared from bituminous coal. Moreover, the PACs prepared using the two-step method had more developed pore structures and higher SO 2 adsorption capacities; however, their yields were relatively low. The one-step method has a simpler process, and its investment and operating costs are lower compared to the two-step method. [ABSTRACT FROM AUTHOR]

Due to the sulfur dioxide (SO 2) negative effects to the environment and human health, its removal is currently of great importance to policy markers and researchers. In this context, the present work had the aim to study the SO 2 dynamic adsorption behavior on two activated carbons rich on calcium species. One material prepared directly from peach stone shell (PC) and the other prepared from raw material treated with CaCl 2 (PCCa) with the purpose to increase the interaction of sulfur with calcium compounds on the surface and to augment its surface area. The obtained activated carbons were characterized using N 2 adsorption at 77 K, IR, XRD and SEM/EDX analysis. PCCa carbon presented the higher adsorption capacity compared with PC material, indicating that the surface area and the increase of calcium groups (Ca(OH) 2 , CaCO 3 , CaO) are playing an important role during the adsorption of SO 2. Additionally, the results demonstrated that as temperature increases the adsorption capacity decreases. On the other hand, the dynamic studies revealed that the residence time reached at 150 mL min−1 flow-rate was the most efficient for the mass transfer processes. Also, the results demonstrated that the presence of moisture decreases the adsorption capacity due to the presence of water molecules on the adsorbent surface. The dynamic adsorption results were modeled using: the Advection-dispersion model, FANN and the conventional models Thomas and Yan. The results shown that the FANN model was the best to correlate the adsorption breakthrough curves of SO 2. ga1 • Novel carbonaceous material from peach stone shell were prepared and characterized. • Influence of calcium species on carbonaceous materials for SO 2 adsorption was studied. • The functionalized material demonstrated an excellent SO 2 adsorption capacity. • Four models for prediction and correlation of SO 2 adsorption were studied. • SO 2 adsorption break-through curves were best correlated with the FANN model. [ABSTRACT FROM AUTHOR]

• Effect of coal types on performance of derived PAC by one-step method was studied. • PAC prepared from low-rank coals had good adsorption performance but low yield. • Hierarchical pore structure was generated in PAC prepared from low rank coals. • PAC performance decreased and its yield increased with the deepening of coal rank. • Coking coal was unsuitable for PAC preparation for its high caking properties. Powdered activated coke (PAC) used for SO 2 adsorption can be prepared using pulverized coal through a one-step method under a high-temperature flue gas atmosphere, and the PAC performance is significantly affected by the coal type. In this study, five coals with different ranks were used to prepare the PACs through this method in a drop-tube reactor. The pore structures, bulk densities, surface morphologies, and chemical functional groups of the PACs were characterized, and their yields and SO 2 adsorption capacities were determined. Results show that the PACs prepared from low-rank coals (IN-coal and ZD-coal) had developed pore structures, abundant oxygen-containing functional groups and high SO 2 adsorption capacities, but their yields were relatively low. As the degree of coalification increased, as in JJ-coal and RU-coal, the pore structure parameters, amount of oxygen-containing functional groups, and SO 2 adsorption capacities of the PACs demonstrated a decreasing trend, whereas the yields increased. Besides, the XW-coal was found to be unsuitable for PAC preparation, because the resulting PAC had an undeveloped pore structure and a low SO 2 adsorption capacity, and caking property of coal is an unfavorable factor in the PAC preparation. These conclusions can provide guidance for the selection of raw materials used to prepare PAC through the one-step method. [ABSTRACT FROM AUTHOR]

• RSM based on CCD was used to optimize the PAC preparation parameters. • Second order models of SO 2 adsorption capacity and burn-off were established. • Effect of reaction temperature on the PAC preparation was the most significant. • Optimal condition of PAC preparation was obtained. Production cost can be reduced in preparation of powdered activated coke (PAC) by achieving higher SO 2 adsorption capacity and lower burn-off. In this study, for the rapid preparation of PAC from pulverized coal, response surface methodology (RSM) based on central composite design (CCD) was used to develop the second order quadratic models of SO 2 adsorption capacity and burn-off. Analysis of variance (ANOVA) was used to determine the effective parameters of the two models, and to explain the accuracy and fitness of them. In addition, the 3D response surface plots illustrated the influencing rules of the variables and their interactions. Further, multi-objective optimization was performed to maximize SO 2 adsorption capacity and minimize burn-off using the desirability function. Optimal process parameters obtained were: reaction temperature, 923.97 ℃; oxygen concentration, 5.89 % and vapor concentration, 20.04 %; and the corresponding prediction results were: SO 2 adsorption capacity, 110.31 mg/g; burn-off, 47.45 %. Confirmation experiment at the optimal condition was carried out, and the experimental results were consistent with the model prediction results, further verifying the accuracy and fitness of the models. The optimization results would provide guidance for the design and operation adjustment of large-scale industrial applications in the future. [ABSTRACT FROM AUTHOR]

The SO2 adsorption efficiency of activated carbons (ACs) is clearly dependent on its physicochemical structure. Related to this, the effect of physical and mechanical activation on the physicochemical structure of coal-based ACs has been investigated in this work. In the stage of CO2 activation, the rapid decrease of the defective structure and the growth of aromatic layers accompanied by the dehydrogenation of aromatic rings result in the ordered conversion of the microstructure and severe carbon losses on the surfaces of Char-PA, while the oxygen content of Char-PA, including C=O (39.6%), C–O (27.3%), O–C=O (18.4%) and chemisorbed O (or H2O) (14.7%), is increased to 4.03%. Char-PA presents a relatively low SBET value (414.78 m2/g) owing to the high value of Non-Vmic (58.33%). In the subsequent mechanical activation from 12 to 48 h under N2 and dry ice, the strong mechanical collision caused by ball-milling can destroy the closely arranged crystalline layers and the collapse of mesopores and macropores, resulting in the disordered conversion of the microstructure and the formation of a defective structure, and a sustained increase in the SBET value from 715.89 to 1259.74 m2/g can be found with the prolonging of the ball-milling time. There is a gradual increase in the oxygen content from 6.79 to 9.48% for Char-PA-CO2-12/48 obtained by ball-milling under CO2. Remarkably, the varieties of physicochemical parameters of Char-PA-CO2-12/48 are more obvious than those of Char-PA-N2-12/48 under the same ball-milling time, which is related to the stronger solid-gas reactions caused by the mechanical collision under dry ice. Finally, the results of the SO2 adsorption test of typical samples indicate that Char-PA-CO2-48 with a desirable physicochemical structure can maintain 100% efficiency within 30 min and that its SO2 adsorption capacity can reach 138.5 mg/g at the end of the experiment. After the 10th cycle of thermal regeneration, Char-PA-CO2-48 still has a strong adsorptive capacity (81.2 mg/g). [ABSTRACT FROM AUTHOR]