BIOMASS & BIOENERGY
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2024
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IF 5.8
Yonghui Xu,Yufei Liu,Wei Zhan,Dingle Zhang,Yiyun Liu,Yi Xu,Zhengshun Wu
This study explores the transformation of peanut shells, an abundant agricultural waste, into high-efficiency activated carbon for CO 2 capture using a two-step pyrolysis and K 2 CO 3 activation method. Observations indicated that with an increasing impregnation ratio, the activated carbon demonstrates remarkable improvements in structural properties, achieving specific surface areas and pore volumes of 1150.02 m 2 /g and 0.46 cm 3 /g, respectively. Among the prepared samples, the activated carbon obtained with a peanut shell to K 2 CO 3 impregnation mass ratio of 1:2 exhibits superior CO 2 adsorption capacity at 1 bar, with values of 3.76 mmol/g at 25 °C and 5.70 mmol/g at 0 °C. The CO 2 adsorption isotherms of the activated carbon conform to the Langmuir and Freundlich models. These results demonstrate the potential of this method in addressing environmental concerns, particularly in mitigating CO 2 emissions, and highlight the broader application prospects of biomass-derived activated carbon in environmental management.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
Molecular Catalysis
·
2025
·
IF 4.9
Shining Zhang,Xikai Qiao,Jiangtao Wei,Guoyue Fu,Zijun Ma,Weiyi Zhang,Jiayu Zheng,Qinglan Hao,Haihong Bao,Jie Chang,Botao Teng
Two-electron water oxidation reaction (2e-WOR) is a promising approach to produce H 2 O 2 under mild conditions without pollution. Despite of the crucial roles of electrolytes in 2e-WOR, the effects of electrolytes on the performance and reaction pathway remain in debate and seldom reported. In this work, the effects of KHCO 3 and K 2 CO 3 electrolytes on the reaction pathways in 2e-WOR reactions were systematically explored using experimental approaches and DFT calculations. Our results highlight that the crucial distinction in 2e-WOR reaction mechanism lies in the formation of CO 3 ·- , which arises from the reactions of ·OH with HCO 3 - in KHCO 3 but ·OH with CO 3 2- in K 2 CO 3 . DFT calculations reveal that H 2 O 2 formation via ·OH+CO 3 2- →CO 3 ·- +OH - in K 2 CO 3 is more thermodynamically favorable than that via ·OH+HCO 3 - →CO 3 ·- +H 2 O in KHCO 3 . This finding aligns well with experimental results showing a significantly higher H 2 O 2 generation rate in K 2 CO 3 compared with KHCO 3 . Moreover, another pathway of OH - -e→·OH followed by 2·OH→H 2 O 2 at the anode was unanimously ruled out, as no H 2 O 2 was detected in KOH electrolyte and the high endothermicity of OH - -e→·OH (Δ E = 2.95 eV) was verified by DFT calculation. ·OH plays a crucial role in 2e-WOR by reacting with CO 3 2- or HCO 3 - to form CO 3 ·- , as well as the subsequent formation of HCO 4 - , which ultimately hydrolyzes to produce H 2 O 2 . This work provides a novel insight into the reaction mechanism of 2e-WOR in different electrolytes, laying a solid foundation for the design of high-efficient electrolytes and the development of high-performing catalysts, as well as the optimization of operational conditions in the 2e-WOR process.
研究领域:
化学
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材料科学
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环境科学
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DOI
高影响因子
CATALYSIS LETTERS
·
2020
·Vol. 150
·期 11
·3174-3183
·
IF 2.482
Wang Xun-Qiang,Li He,Yuan Qi-Yue,Liu Xiao-Qin,Liu Ding-Hua
Abstract Polycarbonate diols (PCDLs) are intermediates used in the synthesis of polyurethanes (PU), and therefore their efficient and green synthesis is a necessity. In this work, KOH/K 2 CO 3 @ γ -Al 2 O 3 catalysts were prepared and employed in the synthesis of PCDLs. A 4 wt% KOH/40 wt% K 2 CO 3 @ γ -Al 2 O 3 catalyst and a DMC: 1,4-BDO molar ratio of 1.25:1 exhibited the best activity for the reaction and gave a PCDL yield of 95% with a molecular weight of 4527 g·mol −1 . Moreover, the catalyst could be reused 4 times without a significant loss of the catalytic activity in transesterification. The effects of the catalyst composition and reaction conditions on the synthesis of PCDLs were investigated. The results indicate that the catalyst amount and the molar ratio of DMC: 1,4-BDO can influence the purity of PCDLs. Graphic Abstract The reaction equation
Catalyst preparation
The synthesis of PCDLs using DMC and 1,4-BDO
研究领域:
材料科学
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催化化学
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DOI
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
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2024
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IF 5.6
Yating Long,Jiahui Wen,Banghui Xu,Liang Zeng,Liangdi Zhu,Mengwu Xiao,Manxia Lu,Zhian Wang,Lanqing Deng
Porous biochar materials (BC) have shown excellent performance in energy storage and water treatment adsorption. Carbonization of agricultural and forestry solid waste and fixation in the form of stable biochar to form biochar materials can achieve green "waste utilization for treatment wastewater". In this study, BC samples were generated by using Camellia oleifera shell (COS) as raw material and K 2 CO 3 as green activator in-situ pyrolysis . The adsorption behavior of COS biochar in aqueous solution was evaluated using phenol as a pollutant probe. The synergistic effect of pyrolysis temperature and K 2 CO 3 activation promoted the development of the pore structure of BC. The X-ray photoelectron spectroscopy results indicated that K 2 CO 3 activation promoted the formation of C-C defects and promoted phenol adsorption. KBC-900 exhibited superior absorption capacity for phenol (300.15 mg/g). The activation of K 2 CO 3 also promoted the adsorption of oxygen. In addition, using H 2 O 2 for regenerating biochar did not show a significant decrease in the adsorption rate after five cycles (decline rate < 5 %). The strong adsorption capacity of KBC-900 for phenol might be due to the presence of π-π interactions, hydrogen bonds , and van der Waals interactions during the adsorption process .
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
Silicon
·
2019
·Vol. 12
·期 7
·1575-1584
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IF 1.21
Zhou Shichao,Chen Zhengjie,Ma Wenhui,Li Shaoyuan,Li Chen,Wu Jijun,Yang Xi
The effect of K 2 CO 3 as an additive agent in the carbothermic reduction process of silicon production is investigated in this study. Using a thermogravimetric analyzer (TGA) in argon atmosphere, different proportions of petroleum coke (PC) and pomelo peel (PP) are used as the carbonaceous reducing agent. Findings show that the additive displays catalytic activities for reductant composition of PC and PP in solid state under high temperature. The maximum mass loss rate of samples with additive is found to increase by 13.7% in the same conditions, compared to samples without the additive. In addition, a homogenous model (HM) is studied as a kinetic model using the Coats-Redfern method to observe and determine the kinetic parameters of all samples. High correlation coefficient values for the pyrolysis stages (R 2 > 0.99) and the carbothermic reduction stage of silicon dioxide (R 2 > 0.98) are obtained for all samples, illustrating that the kinetic model is applicable to this reaction process. According to findings in this study, the additive K 2 CO 3 is determined to positively impact reaction activity, speeding up the rate of pyrolytic reaction and the carbothermic reduction of silica.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2023
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IF 8.6
Yuhang Yang,Chuanwen Zhao,Pengxin Zeng,Yuhao Wang,Xue Qin,Yueyue Gao,Yafei Guo,Ruilin Wang,Jian Sun
Suitable molding and granulation methods are crucial, and an outstanding sphere structure can play a better role in the future scale-up industrial application of K 2 CO 3 -based CO 2 adsorbent. Water will form a large contact angle on the surface of hydrophobic solution and become sphericity water. In this work, hydrophobic powders (polyethylene (PE), TiO 2 , and SiO 2 ) were selected in the hydrophobic interface-assisted method. The CO 2 adsorption capacity of TiO 2 pellets is 0.50 mmol/g, while that of PE pellets is 0.24 mmol/g, and finally that of SiO 2 pellets is 0.36 mmol/g. Then, experiment proved that high temperature (>500 ℃) makes the hydrophobic powders (i.e, TiO 2 and SiO 2 ) lose hydrophobicity which make water molecules diffuse faster, while PE is completely decomposed at high temperature. Compared with the pellets calcined at 300 ℃, the TiO2 pellets calcinated at 500 ℃ have an adsorption capacity of 0.70 mmol/g, which is over 1.72 times that of the original pellets, and the other two hydrophobic surfaces are also improved to some extent. Additionally, the appropriate ratio of low-temperature pore forming agent (i.e., urea) can help improve the adsorption performance, while excessive addition will lead to poor CO 2 adsorption performance. In addition, the K 2 CO 3 /Al 2 O 3 pellets also exhibited desirable mechanical properties, with an optimal compressive strength of 41 Mpa. Therefore, the loss of hydrophobicity leads to more active diffusion of water molecules, which may provide a new idea for the future development of CO 2 adsorbents and other areas.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Pengchao Zang,Jiyun Tang,Yihui Tao,Hao Zhang,Xiaozhe Wang,Lin Cui,Shouyan Chen,Pei Zhao,Yong Dong
Calcium looping (CaL) represents a promising technology for CO 2 capture from flue gas. Nevertheless, CaO-based sorbents, characterized by high theoretical absorption capacities and low costs, experience significant degradation in CO 2 capture capacity during continuous cycling. In the present study, a novel K 2 CO 3 -doped CaO sorbent was synthesized through a concurrent hydrophilic impregnation process, and the performance of consecutive cyclic CO 2 capture was evaluated. The optimal 0.05 K-CaO demonstrated the highest CO 2 sorption (12.4 mmol/g), maintaining about 64 % of the initial sorption after 20 repetitive cycles under N 2 calcination atmosphere, which is 6.6 times greater than that of CaO. These findings indicated that K 2 CO 3 can regulate the particle size and the state of surface oxygen species in CaO-based sorbents while simultaneously enhancing CO 2 diffusivity on the sorbent surface. The DFT calculations indicated that the incorporation of K 2 CO 3 improved the mechanism of CaO chemisorption of CO 2 . Additionally, the vacancies and CO 3 2– generated by K 2 CO 3 doping can enhance the CO 2 sorption energy and reduce the system’s energy level. Notably, the net charge transfer for CO 2 sorption from K 2 CO 3 doping is greater than that from pure CaO, and the O atoms on the surface of K 2 CO 3 -CaO (001) exhibit strong covalent interactions with the C atoms in CO 2 , both of which facilitate CO 2 chemisorption. This study offers a comprehensive theoretical mechanism for the incorporation of K-based alkali metals to enhance the CO 2 capture performance of CaO sorbents.
研究领域:
化学工程
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材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
Carbon Capture Science & Technology
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2024
·
IF 10.4
Pengfei Zhao,Ke Wang,Jie Hong,Edward J. Anthony
The reversible CO 2 absorption/desorption of lithium orthosilicate (Li 4 SiO 4 ) sorbents holds potential for high temperature capture of CO 2 from hot flue gases, sorption-enhanced reforming and solar thermochemical energy storage. In this study, we have prepared a series of Li 4 SiO 4 sorbents using a combination of K 2 CO 3 addition and dry ball-milling procedure to improve the relatively slow kinetics under low CO 2 partial pressure conditions. The synergistic effects of dry ball-milling and K 2 CO 3 addition on the intrinsic properties of Li 4 SiO 4 sorbents were explored by thermogravimetric analysis and structural characterizations. Thermogravimetric analysis indicate that the highest CO 2 uptakes were achieved with dry ball-milling combined with K 2 CO 3 physical addition. The structural characterizations further reveal that this sorbent (P-3K-1.5 M) had the smallest crystallite/particle size, largest surface area, and highest availability of surface alkaline-sites. The kinetics analysis also demonstrates that P-3K-1.5 M exhibited the fastest sorption kinetics during a double process. Additionally, P-3K-1.5 M maintained a high capacity over 10 sorption/desorption cycles. Therefore, this synthesis technique, which is simple, cost-effective, and easily scalable, shows great promise for high-temperature CO 2 capture.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
PROCESS BIOCHEMISTRY
·
2018
·
IF 2.616
Ganggang Chong,Junhua Di,Jianghao Qian,Chu Wang,Yucai He,Xiaoyu Huo,Changhai Wu,Lin Zhang,Ziwei Zhang,Yajie Tang,Cuiluan Ma
To decrease alkaline dosage and increase the enzymatic saccharification of sugarcane bagasse (SB), dilute mixed alkali salts soaking (0.5% K 2 CO 3 , 0.068% K 2 SO 3 ) in an autoclave at 100–125 °C for 10–60 min was attempted to pretreat SB. The increased pretreatment severity at elevated temperatures resulted in the increase of delignification and enzymatic saccharification. It was found the optimum pretreatment temperature and pretreatment time were 120 °C for 40 min. Furthermore, FTIR, XRD and SEM characterized the porosity, morphology, and crystallinity changes of the pretreated SB samples. After the enzymatic in situ saccharification of 50 g/L SB in dilute K 2 CO 3 /K 2 SO 3 (0.35% K 2 CO 3 , 0.048% K 2 SO 3 ) media for 72 h, the reducing sugars and glucose could be obtained at 32.94 and 20.18 g/L, respectively. Finally, the SB-hydrolysates containing 20 g/L glucose were used for ethanol fermentation in the presence of dilute alkali salts. After 48 h, the ethanol yield was 0.394 g ethanol/g glucose, which represents 77.25% of the theoretical yield. In conclusion, an effective process about the biomass pretreatment, enzymatic saccharification and ethanol fermentation was successfully demonstrated in “one-pot” media containing low loading of alkali salts K 2 CO 3 /K 2 SO 3 .
研究领域:
生物能源
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生物质转化
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DOI
高影响因子
LUMINESCENCE
·
2023
·Vol. 38
·期 9
·1639-1646
·
IF 2.9
Baisen Chen,Rongxia Tan,Yufei Hu,Gongke Li
Forchlorfenuron is a low-toxic phenylurea plant growth regulator. Excessive intake of forchlorfenuron can lead to metabolic disorders of the matrix and be harmful to human health. The chemiluminescence intensity of the KIO 4 –K 2 CO 3 –Mn 2+ reaction decreased in the presence of forchlorfenuron. Based on this result, a rapid and sensitive chemiluminescence method was established to determine forchlorfenuron by combining it with a batch injection static device. The injection speed, injection volume and reagent concentration of the forchlorfenuron–KIO 4 –K 2 CO 3 –Mn 2+ chemiluminescence reaction were optimized. Under these optimized conditions, the linear range of the method was 1.0–200.0 μg/L, and the limit of detection was 0.29 μg/L (S/N = 3). The chemiluminescence method for the determination of forchlorfenuron could be completed in 10 s. The method was applied to detect the residual forchlorfenuron in dried fruit samples, and the results are consistent with high-performance liquid chromatography-mass spectrometry. This method has the advantages of high sensitivity, rapid response, less reagent consumption, and convenient operation. It will provide a new perspective for chemiluminescence for the rapid and sensitive determination of forchlorfenuron in various complex samples.
研究领域:
分析化学
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食品安全
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植物生长调节剂检测
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENERGY & FUELS
·
2018
·
IF 3.024
Hai-bo Zhao,Wen-ting Xu,Qiang Song,Jian-kun Zhuo,Qiang Yao
The migration of K during biomass thermal conversion can cause severe ash-related problems. K2CO3 and KCl are two important inorganic forms of K that appear during biomass thermal conversion. In this study, a fixed-bed reactor was used to investigate the effect of H2O vapor and SiO2 on the migration characteristics of these two inorganic K species. The results showed that K is released through the decomposition of pure K2CO3 during pyrolysis. K release from K2CO3 at 800 °C was not obvious, and the release rate increased significantly with temperature but mainly depended on the decomposition rate of K2CO3. The presence of H2O vapor can promote K release by reacting with K2CO3 and forming volatile KOH. When SiO2 was present, a rapid reaction occurred between SiO2 and K2CO3, and this reaction inhibited the release of K significantly. The reaction rate increased significantly with temperature, and H2O vapor promoted the reaction of SiO2 and K2CO3. In a pyrolysis atmosphere, KCl can be released by direct evaporation and cannot react with SiO2; by contrast, KCl can react with SiO2 to form insoluble K silicates in the presence of steam. With increasing temperature, the release rate of KCl increased faster than the K-silicate formation rate, resulting in a decrease in the proportion of insoluble K silicates generated. The results obtained in this work provide a basis for understanding the migration of inorganic K during biomass thermal conversion.
研究领域:
能源化学
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燃烧学
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热力学
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无机化学
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环境工程
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材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Pengxin Zeng,Chuanwen Zhao,Xinmei Wang,Xinzheng Wei,Jian Sun,Ruiling Wang,Yafei Guo
The desirable CO 2 adsorption capacity and mechanical property are both important for the large-scale industrial applications of K 2 CO 3 -based CO 2 adsorbents. In this work, graphite-casted, Al 2 O 3 -supported, K 2 CO 3 -based pellets were prepared for CO 2 adsorption. The prepared K 2 CO 3 -based pellets containing 30 wt% of K 2 CO 3 calcinated at 900 °C exhibit CO 2 adsorption capacity of 1.4 mmol/g, which is over 2.5 times that of the pellets calcinated at 300 °C. It is mainly attributed to the residual graphite coating on the surface of the K 2 CO 3 -based pellets calcinated at 300 °C, which inhibits the diffusion of H 2 O due to the hydrophobicity of graphite and further causes the poor carbonation performance. Moreover, the addition of 40 wt% of microcrystalline cellulose can further enhance the adsorption capacity of the graphite-casted K 2 CO 3 -based pellets to ∼1.95 mmol/g due to the improved pore structure. However, excessive addition of microcrystalline cellulose (50–60 wt%) will lead to poor CO 2 adsorption performance (1.07–1.16 mmol/g) because of the active sites within the pellets being covered by molten K 2 CO 3 . Additionally, the structurally improved K 2 CO 3 -based pellets also exhibit desirable mechanical property with a compression strength of 69.45 MPa. Comprehensively considering the simple and easily scaled-up preparation route of graphite-casting method, the structurally improved, graphite-casted, Al 2 O 3 -supported, K 2 CO 3 -based pellets possess potential practical application prospect.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）