JOURNAL OF MOLECULAR LIQUIDS
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2024
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IF 5.3
Xiao-Han Wang,Bingyou Jiang,Chunshan Zheng,Gaochao Pan,Shiju Wang,Yi Zhang,Ben Ji
The pore and wetting characteristics of bituminous coal and anthracite treated with different proportions of tetrasodium iminodisuccinate (IDS) and sodium dodecyl sulfate (SDS) were measured. The pore structure characteristics of the coal were studied via low-temperature nitrogen adsorption analysis and the Frenkel-Halsey-Hill fractal theory. Zeta potential measurements were conducted to quantitatively analyze the degree of aggregation or dispersion of coal particles dissolved in solution. Changes in the coal surface morphology were observed and analyzed by scanning electron microscopy (SEM). The results show that when the ratio of IDS:SDS is 1:3, the specific surface area (SSA) values of bituminous coal and anthracite are the lowest. The composite reagent has a greater effect on improving the pore structure of anthracite than bituminous coal. Compared with bituminous coal, anthracite has better pore connectivity and a wider pore network. The absolute zeta potentials of bituminous coal and anthracite reach the maximum at an IDS:SDS ratio of 1:3, with values of 91.08 mV and 91.35 mV, respectively. The electrostatic potential distributions of the molecules show that the advantages of the electrostatic potential difference with water molecules enable IDS and SDS molecules to effectively attract water molecules and form hydrogen bonds, thus revealing the optimization mechanism of coal wettability .
研究领域:
矿物学
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表面化学
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产品关联
DOI
高影响因子
FUEL
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2020
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IF 5.578
Hongliang Li,Hua Han,Yue Wang,Xianshu Dong,Hongli Yang,Minqiang Fan,Yang Hu,Zeyu Feng
In coal beneficiation, the clean coal would be easily contaminated with the super fine montmorillonite particles coating on it. This interaction between coal (hydrophobic) and montmorillonite (hydrophilic) surfaces is the interactions between the asymmetric systems. Previous studies detected the force between the montmorillonite and graphite or between the montmorillonite mounted tip and coal substrate to represent the interactions between 001 surface and coal. However, there is still lack of experimental direct measurement on the interaction between montmorillonite 001 surface and coal macerals. In this study, proposes methods for determinine the interactions between coal macerals and 001 surface of Na-, K- and Ca- montmorillonite directly by using an atomic force microscope (AFM). The results indicate that the 001 surface of Na- and Ca- montmorillonite served as the chaotropic and kosmotropic surface when it is adjacent to coal surfaces, with an attractive force and repulsive force occurring between them, respectively. The 001 surface of K-montmorillonite served as the chaotropic surface and kosmotropic surface while it is close to liptinite and inertinite, respectively. This chaotropic or kosmotropic property of the surface is determined by the coordination number of the cations and wettability of the hydrophobic surface simultaneously.
研究领域:
矿物学
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表面科学
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产品关联
DOI
高影响因子
CHEMICAL PHYSICS LETTERS
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2021
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IF 2.328
Wenjie Zhang,Xian Xie,Xiong Tong,Shengdong Zhang,Yunpeng Du,Yang Cao,Dongxia Feng
The extraction kinetics of lanthanum (III) from a chloride medium by bis(2-ethylhexyl) phosphate(HDEHP) and dimethylheptyl methyl phosphate(P350) in the presence of sulfonated kerosene are investigated using a Lewis cell. The effects of the stirring rate, temperature, and specific interfacial area on the extraction rate are investigated. The results show that the extraction process is controlled by diffusion and chemical reactions in the interfacial area rather than in the bulk phase. The apparent activation energy and the changes in the enthalpy, entropy, and Gibbs free energy of the extraction reaction are calculated using the Arrhenius equation and transition state theory. The rate equation derived from the experimental results is similar to that of the interface reaction model. A mass transfer model with a rate-control step is proposed. This study provides guidance and data support for an HDEHP-P350 system in industrial production applications.
研究领域:
化学工程
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物理化学
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DOI
高影响因子
RAPID COMMUNICATIONS IN MASS SPECTROMETRY
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2018
·Vol. 32
·期 17
·1521-1528
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IF 1.97
Sheng-Kang Wang,Xian-Yong Wei,Sheng Li,Fang-Jing Liu,Yu-Gao Wang,Zhan-Ku Li,Chong Shi,Zheng Yang,Zhi-Min Zong
Rationale Coal oxidation produces carboxylic acids (CAs), including aliphatic acids, benzoic acids, and benzenepolycarboxylic acids, which are important fine chemicals which could be used to understand the structural features of coals. However, detecting CAs usually presents great challenges due to extremely troublesome pretreatments. Therefore, it is essential to develop an analytical method for the rapid detection of CAs from coal oxidation. Methods A series of model compounds (MCs) of oxidation products and two practical samples were investigated by direct analysis in real time time-of-flight mass spectrometry (DART-TOFMS) under three different analytical conditions (ionizing gas temperature, organic solvent, and MC concentration). Results Ionizing methyl benzoate, dimethyl phthalate, and dimethyl adipate produces typical ions of methyl esters, including [M − OCH 3 ] + , [M + H] + , and [M + NH 4 ] + . In contrast, the characteristic ions generated from CAs are polymer ions, such as [2 M + NH 4 ] + , [3 M + NH 4 ] + , [4 M + NH 4 ] + , and [5 M + NH 4 ] + , indicating the strong intermolecular hydrogen-bond interaction among CAs. Conclusions Results suggest that DART-TOFMS could rapidly analyze CAs or esters in coal oxidation products according to their typical ions to further gain deep insights into the coal structure.
研究领域:
分析化学
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能源化学
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DOI
PubMed
高影响因子
HYDROMETALLURGY
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2012
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IF 2.027
Wang Li,Yimin Zhang,Tao Liu,Jing Huang,Yi Wang
Leaching of roasted stone coal with sulfuric acid results in a mixed vanadium solution containing Fe(III), Fe(II), Al(III) and Mg(II). Separation of V from synthetic sulfate solution containing these impurities has been investigated by ion exchange and solvent extraction . In ion exchange experiments, anion exchange resin ZGA414 was tested as its optimum adsorption capacity compared with D202, D453, D301FC and ZGA351 resins, and D2EHPA and TBP diluted with kerosene were employed in solvent extraction. Ion exchange tests indicated that only V(V) was loaded from the synthetic solution at pH > 1.5, while it was difficult to separate V(V) from Fe(III), which also made resin toxic. Solvent extraction experiments revealed that V(IV) had a better extraction ratio than that of V(V), while Fe(III) had a serious effect on the extraction of V(IV). The co-extraction ratio of Al(III) and Mg(II) can be decreased by controlling their concentrations lower than 10 g/L. Counter-current experiments with D2EHPA presented that 99% of V(IV) was extracted from the real leach solution after reduction process, leaving most of Fe(II), Al(III) and Mg(II) in the raffinate.
研究领域:
化学工程
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环境科学
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产品关联
DOI
高影响因子
Minerals
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2022
·Vol. 12
·期 8
·994
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IF 2.818
Qiuyu Zeng,Jun Xie,Wei Zhou,Jinbo Zhu,Liangliang Liu,Jianqiang Yin,Wenliang Zhu
The distortion process of kaolinite annealed from 25 °C to 550 °C for different holding times can be characterized using a thermogravimetric/differential scanning calorimeter (TG/DSC) for thermal analysis, X-ray diffraction (XRD) for establishing the crystal structure, the Fourier transform infrared spectrum (FTIR) for identifying the functional groups, and a scanning electron microscope (SEM) for establishing the microstructure. Dehydroxylation is the main reaction during annealing from 25 °C to 550 °C and leads to kaolinite crystal distortion. A stable crystal structure during distortion was obtained by optimizing the bulk phase with quantum chemistry. Then, the crystal structure was studied by using ab initio multiple scattering calculations for X-ray absorption of the fine structure (XAFS). The results of X-ray absorption near the edge structures (XANES) determined that peak shifts and intensity phases slightly increased. The crystal structure distortion of kaolinite during annealing can be explained by the experimental and simulation results. This work provides theoretical support for identifying kaolinite with different degrees of distortion and has the potential for further developments in coal gangue separation.Keywords:coal and gangue;kaolinite;distortion;multiple scattering computation
研究领域:
矿物学
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材料科学
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产品关联
DOI
高影响因子
Polymers
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2022
·Vol. 14
·期 19
·3970
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IF 4.967
Ming Chang,Xiaomin Ma,Xianshu Dong,Yuping Fan,Ruxia Chen
It is important to identify an environmentally friendly and efficient flocculant that can replace polyacrylamide for the solid–liquid separation of coal wastewater. In this study, to explore whether chitosan can be used as an environmentally friendly and efficient flocculant for the solid–liquid separation of coal wastewater, AlCl3–chitosan was used to conduct flocculation–sedimentation and dewatering tests under different chitosan dosages and shear-strength conditions for the prepared coal wastewater. Focused beam reflectance was measured to dynamically monitor the number of refractory fine particles, and the settled flocs were photographed and analyzed with microscopy to explore the effect of AlCl3–chitosan on the flocculation settlement effect and floc characteristics. The synergistic mechanisms of AlCl3and chitosan were investigated using quartz crystal dissipative microbalance and zeta potential measurement. The results showed that the addition of chitosan can significantly improve the flocculation–sedimentation and dewatering effects of coal wastewater. A reasonable dosage under a certain shear strength is conducive to the reduction of fine slime particles, which results in a compact floc structure, increases the floc size, and improves the settling effect. The synergistic effect of AlCl3–chitosan improved the electric neutralization and adsorption bridging abilities of the chitosan, and the mixed solution of AlCl3and chitosan had stronger adsorption on the carbon surface. This study provides a new approach to the selection of flocculants for coal wastewater treatment.Keywords:coal wastewater;chitosan;solid–liquid separation;FBRM;QCM−D
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
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2022
·
IF 16.744
Rihong Xiao,Yili Zhang,Shuzhou Wei,Xing Chuai,Xiangzheng Cui,Zhuo Xiong,Junying Zhang,Yongchun Zhao
Massive Hg emissions from coal-fired units cause serious environmental pollution and result in a substantial waste of Hg resources. In this study, the prepared millimeter-grade Se/SiO 2 adsorbent was applied as a filler to adsorb mercury in a fixed-bed reactor to obtain the high value-added product HgSe, which solved the problem of short contact time and secondary pollution caused by the traditional injection mercury removal adsorbents. Experimental Hg removal showed that the 25 % Se-loaded adsorbent exhibited excellent Hg removal performance at 150 °C, with a saturation adsorption capacity of mercury was as high as 101.04 mg/g, nearly 300 times that of commercial activated carbons. Additionally, the influence of the flue gas composition on the Hg removal performance of Se/SiO 2 was studied. The results showed that O 2 , NO, and HCl increased the efficiency of Hg removal and SO 2 and SO 3 had trivial impact on the Hg removal performance. The Hg temperature-programmed desorption test results showed that the adsorbed Hg appeared predominantly as HgSe on the sample surface. DFT calculations verified that Se loading improved Hg removal performance and defined the adsorption mechanism. Moreover, the prepared Se/SiO 2 adsorbent carrier was soluble SiO 2 , which provided a good condition for the subsequent high-purity collection of HgSe. Finally, the technological process of Hg removal via Se-loaded adsorbents and the recovery of HgSe were proposed, which could offer a new way to achieve the resource utilization of Hg.
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
CHEMICAL PHYSICS LETTERS
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2021
·
IF 2.328
Hongming Rui,Licheng Zhang,Lijuan Li,Lixia zhu
The present work used solvent extraction method to extract lithium from hydrochloric acid leaching solution of high-alumina coal fly ash. In extraction stage, the optimum conditions were explored, at 20 ℃ and O/A = 1:4, using 70%(Vol.) tributyl phosphate-30%(Vol.) sulfonated kerosene-0.36 mol/L Fe 3+ as extractant, extraction of lithium could reach 99% by two-stage extraction. In scrubbing stage, 95% of Al 3+ in loaded organic phase was scrubbed with 6 mol/L HCl at O/A = 40:1, then 97% of Ca 2+ in the loaded organic phase was scrubbed by three-stage countercurrent scrubbing with 5.5 mol/L LiCl + 0.5 mol/L HCl at O/A = 30:1. In stripping stage, 99% of Li + in scrubbed organic phase was stripped by five-stage countercurrent stripping with 6 mol/L HCl at O/A = 10:1. In regeneration stage, 2 mol/L NaOH was used as regenerant to remove free acid and exchange H + of extractive compound. There were no third phase, emulsification and solid deposition during the whole experiment. The structure of extractive compound was determined by slope method, and extracted complex ratio of Li + , Fe 3+ , and TBP was 1:1:1. The extraction process was found to be exothermic and spontaneous by thermodynamic study. Therefore, it’s a promising method to recover lithium from hydrochloric acid leaching solution of high-alumina coal fly ash by TBP-FeCl 3 -sulfonated kerosene extraction system.
研究领域:
化学工程
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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
FUEL
·
2021
·
IF 6.609
Kun Zhao,Xiaojie Fang,Zhen Huang,Guoqiang Wei,Anqing Zheng,Zengli Zhao
Chemical looping gasification provides a novel technology to enable clean conversion of coal with inherent CO 2 capture. In this study, four types of NiFe 2 O 4 and CuFe 2 O 4 synthesized by sol–gel method and solid-phase method were used as oxygen carriers to promote the H 2 production from gasification of lignite. The effects of the types of oxygen carrier and oxygen carrier to coal (O/C) ratio on chemical looping gasification of lignite were first investigated by a thermogravimetric analyzer (TGA) combing with various analytical methods. The results show that, among four types of oxygen carrier, the NiFe 2 O 4 synthesized by sol–gel method exhibits the highest gasification reactivity with lignite char at an O/C ratio of 1, since its highly cubic spinel structure is beneficial to improve the mobility of lattice oxygen. Furthermore, the operating conditions for chemical looping gasification of lignite were optimized and the gasification performance of four types oxygen carriers was compared by using a fixed bed reactor. It is found that NiFe 2 O 4 synthesized by sol–gel method exhibits the highest total gas yield of 24.47 mol/kg and H 2 /CO ratio of 0.77 during chemical looping gasification of lignite under the optimal operating conditions, ascribed to Fe-Ni synergistic effect which provided higher gasification reactivity with lignite char. The addition of steam drastically improves the total gas yield and H 2 /CO ratio of syngas from 24.47 mol/kg and 0.77 to 64.98 mol/kg and 2.79, suggesting that the H 2 /CO ratio of syngas can be flexibly adjusted to meet the need of downstream process via controlling the amount of steam added. These findings provide an efficient method to obtain H 2 -rich syngas via chemical looping gasification of lignite.
研究领域:
能源科学
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材料科学
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2020
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IF 5.774
Zonglin Pan,Fangpeng Yu,Lin Li,Ming Liu,Chengwen Song,Jiawei Yang,Hanxu Li,Chunlei Wang,Yanqiu Pan,Tonghua Wang
A novel electrochemical filtration carbon membrane (ECM) was developed from caking coal via self-bonding in this work. The evolutions of chemical structure, morphology, carbon microstructure from nonconductive precursor membrane to conductive ECM during carbonization were systemically investigated by FTIR, SEM, Raman and XRD. The evolution mechanism of electrical conductivity and electrochemical performance of ECM was proposed and discussed. The electrochemical filtration performance of ECM was evaluated by using the phenol as simulated pollutant in wastewater treatment. It was found that the precursor membrane underwent the violent thermal decomposition and condensation during carbonization. The electrical conductivity and electrochemical performance of ECM depended strongly on carbonization temperature (CT), which was attributed to the evolution of carbon microstructure such as the growth of the conductive carbon clusters and defect graphite lattices (active sites) as CT increased. The electrochemical filtration performance of ECM on phenolic water was strongly correlated to its electrochemical properties. The higher electrochemical activity of ECM would result in the better electrochemical filtration performance. The ECM obtained at 950 °C exhibited the optimal overall performance, and its phenol and COD removal rates were up to 91.65% and 81.89% under the applied voltage of 2.0 V, respectively. The mechanism of electrochemical oxidation involved in ECM included the direct oxidation and indirect oxidation, in which the indirect oxidation was caused by the electro-catalytic activity of minerals existed in ECM.
研究领域:
环境科学
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材料科学
✓ 已验证
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Bang Wu,Xin Guo,Xulinjia Liu
The effect of calcium on the synergy evolution mechanism of Zhundong coal and polyethylene (PE) co-pyrolysis was explored by thermogravimetric (TG), fixed-bed experiments, and the ReaxFF simulation method. The weight loss characteristics of coal and PE pyrolysis, obtained through ReaxFF simulations, exhibited good agreement with TG experimental results. The distribution of coal/PE co-pyrolysis products was examined via fixed-bed fast pyrolysis experiments and Reaxff isothermal pyrolysis simulation. The results reveal that calcium substantially reduces co-pyrolysis tar while simultaneously enhancing co-pyrolysis char and gas to varying extents. Besides, the experimental temperature of 973 K and the simulated temperature of 2600 K yield the highest decrease in co-pyrolysis tar, with reductions of 9.52 % and 14.03 %, respectively. It is discovered that the addition of calcium enhances the synergy degree to 100 % between coal and PE molecules, which means that coal molecules become more firmly attached to PE molecular fragments. Additionally, calcium induces polymerization in co-pyrolysis char, causing the char molecules to become larger and increasing their average molecular weight. Ca-containing tars are rich in aliphatic hydrogens, and synergistic molecules prefer light tars, whereas Ca-free tars have a slightly broader range of aromatic hydrogens, and synergistic molecules favor heavy tars, indicating that the addition of calcium may promote the ring-opening process of coal molecules, releasing more branched-chain hydrogen. In the Ca-free and Ca-containing systems, 24.67 % and 29.51 % of the hydrogen content of the coal molecules migrated toward the co-pyrolysis tar, respectively. The proportion of coal tar fragments decreases while the proportion of PE tar and synergistic tar fragments increases in Ca-containing tar when compared to Ca-free tar, indicating that calcium promotes the polymerization of coal tar molecules with PE tar molecules, which leads to larger char molecules and smaller gas molecules.
研究领域:
能源科学
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化学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）