JOM
·
2022
·Vol. 75
·期 4
·1019-1033
·
IF 2.597
Luo Yinbo,He Dongfeng,Zhao Hongbo
Indirect mineral carbonation is considered an ideal CO 2 sequestration strategy because of its high carbonation rate and high value-added products. This research explores the carbonation ability of different carbon species—CO 3 2– ions, HCO 3 – ions, and H 2 CO 3 —in their dominant region. When (NH 4 ) 2 CO 3 was used as the carbon source, the Ca 2+ ions carbonation rate was hardly affected by pH, while NH 4 HCO 3 was the opposite. When the pH of the leachate decreased from 8.67 to 6.20, the carbonation rate of (NH 4 ) 2 CO 3 decreased from 99.32% to 98.42%, while the carbonation rate of NH 4 HCO 3 decreased from 96.28% to 37.71%. Meanwhile, this research also probed the influence of the nucleating agent on the carbonation rate and carbonation products. The addition of nucleating agent can increase the carbonation rate. For a CH 3 COOH concentration of 0.6 M for mixed leaching, the carbonation rate was increased by 26.81% with the addition of nucleating agent. Meanwhile, the nucleating agent can also induce the growth of CaCO 3 toward the crystal form of the nucleating agent itself. When (NH 4 ) 2 CO 3 and NH 4 HCO 3 were used as the carbon sources, CaCO 3 mainly exists in the crystal form of vaterite, and after adding the nucleating agent, the crystal form changes to calcite.
研究领域:
环境科学
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化学工程
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材料科学
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地球化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2021
·
IF 5.909
Xue-Ze Wang,Yang-Hai Zheng,Yun Xue,Yong-De Yan,Fu-Qiu Ma,Mi-Lin Zhang,Hai-Yun Bai,Zi-Qi Kou,Jian-Peng Liu
With the continuous development of the nuclear industry, there is an urgent need to find a method that can safely and efficiently dispose of spent resins. Molten salt oxidation (MSO) is a promising waste treatment technology . In this paper, the newly shipped resins were used to simulate the actual spent ion exchange resins . The destruction of the resins is mainly divided into three stages. The addition of oxygen can increase the activation energy ( E ) required for the reaction. Some solid residues which were proved to be amorphous carbon materials generated after MSO. In the high-resolution XPS spectra of C 1s, the C-S bond disappeared after MSO at 400 ℃ for 2 h proved the destruction of the sulfonic acid groups. The core-level scan XPS spectra of S 2p illustrated that sulfur and sulfonyl bridges were formed after sulfonic acid groups were destroyed. The infrared spectrum also showed that the sulfonic acid groups were destroyed at 400 ℃ to form sulfonyl structure, but sulfur bridges were not found due to its small IR absorptions. In this paper, the ternary eutectic Li 2 CO 3 -Na 2 CO 3 -K 2 CO 3 , can be operated efficiently at a relatively low temperature. The generated sulfur dioxide is captured by the carbonate to form sulfate. These merits make MSO become a promising and environmentally friendly approach for the treatment of sulfur-containing organic waste.
研究领域:
核工业废物处理
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环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Polymer Chemistry
·
2019
·Vol. 10
·期 43
·5905-5912
·
IF 4.76
Chuanzhi Wei,Xinhui Kou,Shaofeng Liu,Zhibo Li
Ring-opening polymerization (ROP) is a powerful method used for converting cyclic monomers to polymers, but ethylene carbonate (EC), which has a five-membered ring, is an exception owing to the unfavorable thermodynamics of its ring-opening reaction unless the release of CO2. This behavior stems from the faster cyclization to form a stable five-membered ring in comparison to the direct ring-opening reaction. Hence, many attempts have been made to copolymerize EC with other cyclic monomers such as cyclic esters to overcome the thermodynamic barrier. In this context, the copolymerization of EC with various cyclic esters, including ε-caprolactone (CL), δ-valerolactone (VL) and L-lactide (LLA), has been successfully achieved using an organocatalytic phosphazene superbase, such as a cyclic trimeric phosphazene base (CTPB). The random copolymerizations proceeded fast with a turnover frequency (TOF) of 19 800 h−1 under mild polymerization conditions and afforded the corresponding copolymers without formation of the ether unit. Under all kinds of experimental conditions, no homopolymerization of EC occurred. The molecular structures of the obtained P(EC-co-CL) copolymers were characterized using 1H NMR and 13C NMR, which demonstrated that ca. 38 mol% EC can be incorporated within the copolymer chain depending on the different ratios of the EC and CL monomers. With the same catalytic system and under similar conditions, the amounts of EC incorporated into EC/VL (up to 26 mol%) and EC/LLA (ca. 4.8 mol%) copolymerizations were lower than that for the EC/CL copolymerization. 2D NMR (1H–1H correlated spectroscopy (COSY), 1H–13C heteronuclear single quantum coherence (HSQC) and 1H–13C heteronuclear multiple bond correlation (HMBC)) were performed to confirm the assignments in the 1H NMR and 13C NMR spectra of the copolymers and to better understand the chain structures of the copolymers. Therefore, polycarbonate/polyester copolymers with greater incorporation of EC were realized using a fast, selective and metal-free process.
研究领域:
高分子化学
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有机催化
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 18
·10072-10080
·
IF 3.049
Xin Niu,Liguo Wang,Junya Cao,Yan Cao,Peng He,Junya Zhou,Huiquan Li
A novel approach for the synthesis of epoxybutane via decarboxylation of butenyl carbonate derived from butanediol was developed for the first time. For the carbonylation of butanediol with dimethyl carbonate, NaAlO2 has exhibited excellent catalytic activity under mild reaction conditions. The yield of butenyl carbonate reached as high as 96.2%. NaAlO2 provides suitable acid–base active sites to promote the transesterification reaction of butanediol and dimethyl carbonate. For the following step of decarboxylation of butenyl carbonate, ionic liquid 1-butyl-3-methylimidazolium bromide could effectively catalyze the decarboxylation process both in batch or continuous processes. Moreover, the catalytic mechanism for the crucial step of decarboxylation of butenyl carbonate over 1-butyl-3-methylimidazolium bromide was explored using DFT calculations. The results showed that the electrostatic and hydrogen-bond effects of 1-butyl-3-methylimidazolium bromide played a crucial role for the generation of epoxybutane. Briefly, the Br anion of the ionic liquid attacks the methylene of the ring and the H of the ionic liquid cation attacks the carbonyl oxygen, which facilitated the five-ring opening and subsequent decarboxylation to form BO. This study not only provided a new and green synthetic route for producing epoxybutane, but also contributed to the effective utilization of butanediol, which is inevitably produced as by-product in the process of coal to ethylene glycol, suggesting a promising application in the clean manufacture of epoxybutane with inexpensive cost.
研究领域:
化学工程
·
绿色化学
✓ 已验证
DOI
高影响因子
JOURNAL OF CRYSTAL GROWTH
·
2021
·
IF 1.797
Ming Ma,Bing Zhang,Weipeng Lu,Yihu Wang,Xiaofeng Cao,Yanchuan Guo
Calcium carbonate (CaCO 3 , CC) distributes diversely among the abiotic and biogenic minerals/biominerals. It has six phases (three anhydrous crystalline, two hydrates and one amorphous). Phase selectivity of the synthetic CC is of considerable interest and determines its physicochemical properties and destinated applications. In the present study the reactive crystallization process of CC has been subjected to the treatment of different disturbances, i.e., mechanical stirring (ms), ultrasonication (us), and composed ms + us at lower temperature (0 ± 1℃) and higher supersaturation condition (initial concentration of Ca 2+ is 0.1 M), in comparison with the quiescent condition. In order to gain insight on the role of these disturbances in controlling the crystallization process, nature, crystal habits of precipitated CC and their consecutive phase transformation, samples were collected at different time intervals (30 s, 1 min, 5 min, 10 min, 20 min, 45 min and 60 min) for investigation. Results reveals that these disturbing ways play a significant role on the CC crystallization process and can stabilize the amorphous calcium carbonate (ACC) phase for prolonged periods of time (1–60 min) in aqueous solution, which will be a powerful way for large-scale fabrication of pure ACC nanoparticles (about 100 nm) without addition of any chemicals. Longer disturbing time tends to transform the pure and spherical ACC nanoparticles competitively into spherical vaterite particles and rhombohedral calcite particles through the self-assembly of nanoparticles aggregation or Ostwald ripening mechanism, respectively. The investigation also suggested that the reactive crystallization of CC with the three disturbances undergoes a non-classical crystallization pathway to crystallize CC particles, in comparison with the quiescent reference condition. To the best of our knowledge, the report on reactive crystallization of CC crystallites as a function of different disturbances is first of its kind in the literature.
研究领域:
材料科学
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化学工程
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
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2018
·
IF 1.712
Ying Qing,Houfang Lu,Yingying Liu,Changjun Liu,Bin Liang,Wei Jiang
The biodiesel production technology catalyzed by 1,8-diazabicycloundec-7-ene (DBU) is developed in this work. Crude glycerol containing DBU and DBU/glycerol/CO 2 (DGC) ionic compounds reacts directly with dimethyl carbonate (DMC) to produce high value-added glycerol carbonate (GC) catalyzed by DBU and DGC. The catalytic performance of DBU and DGC, as well as the kinetics of the reaction catalyzed by DBU, were investigated. The results show that DGC has a weak catalytic effect on the transesterification of glycerol and DMC. When the temperature is higher than 60 °C, DGC catalyzes the reaction jointly with DBU, which is produced from the decomposition of DGC. DBU has a good catalytic effect on the reaction between glycerol and DMC, with 90% conversion of glycerol and 84% selectivity to GC under the following conditions: DMC-to-glycerol molar ratio of 3:1, 4.0% DBU (based on glycerol mass), reaction time of 60 min, and reaction temperature of 40 °C. The apparent kinetics results show that the activation energies are 30.95 kJ·mol − 1 and 55.16 kJ·mol − 1 for the forward and reverse GC generation reactions, respectively, and the activation energy of the decomposition reaction of GC to glycidol (GD) is 26.58 kJ·mol − 1 .
研究领域:
化学工程
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催化科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2018
·
IF 2.631
Lin Mou,Yuying Chai,Guizeng Yang,Quan Xia,Qingshan Liu,Qige Zheng,Qingguo Zhang
Two hydrophobic ionic liquids (ILs) 1-alkyl-2, 3-dimethylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([C 2 mmim][NTf 2 ] and [C 4 mmim][NTf 2 ]) were synthesized. The binary mixtures of the two ILs were prepared with dimethyl carbonate (DMC) or diethyl carbonate (DEC) over the entire mole fraction range, respectively. The density and viscosity of the binary mixtures were investigated at temperature ranging from 293.15 to 328.15 K. The excess molar volumes and viscosity deviations were calculated for the four binary mixtures. The effects of the extension of the alkyl chain of the cation on the above properties are discussed. The Redlich-Kister equation was used for the fitting of the excess molar volumes and viscosity deviations versus mole fraction. The thermal expansion coefficients of the systems were obtained according to the density.
研究领域:
化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2023
·
IF 4.2
Tao Shen,Jiawen Wu,Qingya Liu,Zhenyu Liu
Conversion of calcium carbonate (CaCO3) to calcium oxide and methane (CH4) by renewable hydrogen is promising to retrofit the current CaCO3 decomposition processes in many industries and, at the same time, to replace their carbon dioxide emission by CH4 generation. This work studies CaCO3 hydrogenation by a liquid organic hydrogen carrier, 9,10-dihydrophenanthrene (DHP), and the catalytic effect of nickel carbonate (NiCO3) at 400 °C. It is found that NiCO3 in situ forms Ni particles of 200–900 nm in size that promote CH4 formation from CaCO3. At the NiCO3:CaCO3:DHP molar ratios of 1:10:55 and 400 °C, the total CO32– conversion, CH4 selectivity, and CH4 formation from CaCO3 are 89.5, 40, and 80.3%, respectively, in 40 min.
研究领域:
化学工程
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能源科学
✓ 已验证
产品关联
DOI
高影响因子
HYDROMETALLURGY
·
2021
·
IF 4.156
Fangjia Yan,Xiaojuan Zhang,Edouard Asselin,Dongping Duan,Zhibao Li
Two interconnected reactors were used to produce high quality SrCO 3 by leaching celestite in NaHCO 3 solution at elevated temperature of 363.15 K. This new method avoids undesirable polluting by-products generated in the widely used black ash process. The precipitation kinetics of celestite (SrSO 4 ) leaching in NaHCO 3 at various temperatures was investigated with a view to industrial application. It was found that high temperature significantly enhanced the leaching conversion while initially concentrated Na 2 SO 4 in leaching solution has limited influence on the leaching reaction. The new process overcomes the key disadvantage of high energy consumption during sodium sulfate recovery that is inherent in the soda ash process. Having studied the effects of NaHCO 3 concentration and temperature on the leaching reaction, a shrinking core model was established with an apparent activation energy of E a = 86.6 kJ/Mol. The rate-determining step was the diffusion of ions through the product layer. Saleable Na 2 SO 4 products were successfully obtained via evaporative cooling crystallisation
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
DESALINATION
·
2024
·
IF 8.3
Hui Yang,Baozhong Ma,Shuyang Shi,Qinqing Zhao,Chengyan Wang,Yongqiang Chen
The continuous development of lithium-ion batteries (LIBs) manufacturing industry calls for the mass production of Li 2 CO 3 , which serves as a pivotal raw material for LIBs. In our previous study, Li was successfully precipitated as intermediate product Li 2 SiO 3 from an alkaline solution containing Si by the hydrothermal precipitation method, realizing the preliminary separation of Li and impurities. In this research, H 2 SO 4 digestion-water leaching-Na 2 CO 3 precipitation process was proposed to manufacture Li 2 CO 3 from the intermediate product Li 2 SiO 3 . Firstly, the reaction feasibility of H 2 SO 4 digestion-water leaching and direct H 2 SO 4 leaching for Li 2 SiO 3 were comparatively evaluated through thermodynamic calculation and experimental research. Compared to direct H 2 SO 4 leaching, H 2 SO 4 digestion-water leaching process is preferred in view of its excellent filtration properties. Subsequently, systematic digestion and leaching experiments showed that up to 97.1 % of Li was extracted under the optimized conditions, and the concentration of Li in the leach liquor is as high as 29.33 g/L. After pH adjustment and Al removal, Na 2 CO 3 precipitation were adopted for Li 2 CO 3 production. The equilibrium relationship in Li 2 SO 4 -Na 2 CO 3 -H 2 O system was analyzed to predict the precipitation behavior of Li and select appropriate operation window for Li 2 CO 3 preparation. Finally, with an additional carbonation-decomposition process, a Li 2 CO 3 product with a purity of 99.51 % is produced. This process realizes efficient synthesis of battery-grade Li 2 CO 3 from the intermediate product Li 2 SiO 3 .
研究领域:
材料科学
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化学工程
✓ 已验证
DOI
高影响因子
GREEN CHEMISTRY
·
2024
·
IF 9.3
Nan Hu,Lijuan Su,Hongyan Li,Ning Zhang,Yongqin Qi,Hongliang Wang,Xiaojing Cui,Xianglin Hou,Tiansheng Deng
Various excellent catalysts have been explored for the methanolysis of polycarbonate (PC), but it is still challenging to develop green and economical catalysts for solvent-free PC methanolysis to recover both bisphenol A (BPA) and dimethyl carbonate (DMC). Herein, green, efficient and solvent-free degradation of PC to BPA and DMC was achieved using urea as a cheap green catalyst. At 140 °C for 3 h, PC was completely degraded to BPA and DMC with yields of 93.4% and 74.7%, respectively. A possible catalytic degradation mechanism of PC was proposed by kinetic experiments and NMR, where urea, methanol and carbonate formed a six-membered ring in the reaction. It was found that the increase of urea concentration significantly reduced the activation energy, which was attributed to the fact that the increase of urea concentration made the six-membered ring easier to form and activated the carbonate bond. The degradation system can be reused directly up to 10 times and 100% degradation rate can be maintained. This work provides a simple, green and economical method for industrial PC recycling.
研究领域:
环境科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·Vol. 141
·期 14
·e55186
·
IF 2.7
Yong Wang,Liang Wen,Jiajian Liu,Chuncheng Li,Tian Yin,Yaonan Xiao,Zhikui Jiang,Shaohua Wu,Zijian Zhang,Bo Zhang
Bio-based copolymers with excellent mechanical properties and biodegradability are highly desired for packaging and agricultural applications. In this work, a series of high molecular weight bio-based poly(ester-carbonate)s are synthesized using glycolic acid (GA), dimethyl carbonate (DMC), and 1,4-butanediol (BDO). The intrinsic viscosity ([ η ]) of these copolymers ranges from 0.70 to 1.11 dL/g. The tensile strength, elastic modulus, and elongation at break of PBCGA10 are 19.69 ± 2.40 MPa, 151.20 ± 37.17 MPa, and 1173 ± 142%, respectively, which are superior to the mechanical properties of PBAT. The degradation weight loss of PBCGA10 and PBCGA20 after 30 days can reach 8% and 40%, respectively, indicating excellent degradation performance of the copolymers. Moreover, copolymers undergo degradation through a surface degradation mechanism. The main products of copolymer degradation are BDO, CO 2 , and H 2 O, which do not cause harm to organisms and the environment.
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）