ENERGY & FUELS
·
2021
·
IF 3.605
Shuai Chen,Wei Zhou,Yani Ding,Guangbo Zhao,Jihui Gao
Understanding the evolution of carbon structure in coal-assisted water electrolysis for hydrogen production (CAWE) is essential for seeking strategies to improve the rate of CAWE and getting more insight into the potential significance of CAWE. In this work, 13C nuclear magnetic resonance (NMR) is used to make out the evolution of carbon structure in CAWE. First, the electrolysis characteristics of three different-rank coals are revealed using electrochemical methods. Then, before and after electrolysis, the evolution of carbon structure is analyzed. The results show that CAWE is a process of reducing carbon and increasing oxygen, and the accumulation of oxygen-containing groups is mainly owing to the increase of oxygen aliphatic carbons and oxygen aromatic carbons. After CAWE, the aromatic cluster size decreases and increases for low-rank coals and high-rank coals, respectively.
研究领域:
能源科学
·
材料化学
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DOI
高影响因子
FUEL
·
2020
·
IF 5.578
Liang Shen,Chuanzhen Wang,Fanfei Min,Lingyun Liu,Changguo Xue
Low rank coal contains a large number of pores and cracks which have an adverse influence on its flotation behavior. Effects of pores on the hydration layer and flotation behavior of low-rank coal were studied by molecular dynamics method and experiments in this paper. A specific surface area/pore analyzer was employed to determine the pore structure. Pore distribution analysis indicated that the pores in the low-rank coal are mainly micropores. Pore volume and average pore diameter in low-rank coal can be reduced by pore compression pretreatment. Coal-bubble attachment experiments were conducted to study the effect of pores on the effect of pores on particle bubble adhesion process. Results showed that coal particles with less pores were more likely to adhere to the surface of the bubble. And a probable mechanism for the effect of pores on the adhesion of coal particles to bubbles was proposed. Molecular dynamics simulation results revealed that the pores on the surface of low-rank coal reduce the mobility of water molecules and form a more stable hydration layer. Flotation results indicated that reducing the pore content in low-rank coal could reduce the collector dosage in flotation process and improve the flotation behavior of low-rank coal.
研究领域:
矿业工程
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
2022
·Vol. 27
·期 14
·4392
·
IF 4.927
Yangchao Xia,Dan Fang,Pengcheng Qu,Yonggai Li
Fatty acids, which are enriched in vegetable oil, have attracted much attention in low-rank coal flotation because of their unique chemical structure. In this study, density functional theory calculations, molecular dynamics simulations, and atomic force microscopy were employed to investigate the adsorption structure and forces between collectors and hydrophilic surfaces. The results show that fatty acids can be easily adsorbed onto surfaces through hydrogen bonds, and can cover the oxygen sites. The existence of hydration film on hydrophilic surfaces prevented nonpolar molecules from being able to adsorb, while polar fatty acids could adsorb and expel water molecules. The adhesion force between the RCOOH-terminated probe and the surface appeared in the retraction process, which differed significantly from that of the RCH3-terminated probe, indicating that polar fatty acids are more suitable as flotation collectors for low-rank coal than nonpolar hydrocarbon oil. The simulation and AFM test revealed the mechanisms of polar fatty acids, and can provide guidance for low-rank coal flotation applications.Keywords:flotation;low-rank coal;fatty acid collector;computer simulation;force measurement
研究领域:
矿物加工工程
·
表面化学
✓ 已验证
DOI
PubMed
高影响因子
ACS Omega
·
2023
·
IF 4.1
Xicheng Bao,Junling Liu,Shasha Wang,Dongqin Chen,Wenjin Xu,Deke Zhang,Jihui Li,Yaowen Xing,Mengdi Xu
Efficient flotation of low-rank coal is of great significance for the development of green and low-carbon cycles. Temperature is a crucial parameter of flotation, but the mechanism of its effect on flotation lacks understanding. In this paper, the mechanism was studied by kinetic flotation, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy, low-temperature liquid-nitrogen adsorption (LP-N2A), X-ray photoelectron spectroscopy (XPS), and molecular dynamics simulation. The flotation combustible recovery gradually decreases as temperature rises. Compared with 60 °C, the combustible recovery at 5 °C increases by 18.13%. The desorption energy for oil droplets decreases as the temperature rises. As a result, the oil droplets are easier to desorb at high temperatures. The SEM and LP-N2A results demonstrate that the pores and fractures of the coal sample are well developed. Also, the oil–water interfacial tension and viscosity of oil droplets decrease as the temperature rises, while the diffusion ability increases. These increase the volume of oil droplets that penetrate into the pores, resulting in poor spreadability of oil droplets on the coal surface. The average volume of bubbles gradually increases as temperature rises, which renders the flotation foam unstable and worsens the flotation. Therefore, the flotation performance is better at low temperatures.
研究领域:
矿物加工工程
·
表面化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
International Journal of Minerals Metallurgy and Materials
·
2019
·Vol. 26
·期 12
·1512-1522
·
IF 1.221
Zhao Jun,Zuo Hai-bin,Wang Jing-song,Xue Qing-guo
The high-value utilization of low-rank coal would allow for expanding energy sources, improving energy efficiencies, and alleviating environmental issues. In order to use low-rank coal effectively, the hypercoals (HPCs) were co-extracted from two types of low-rank coal and biomass via N-methyl-2-purrolidinone (NMP) under mild conditions. The structures of the HPCs and residues were characterized by proximate and ultimate analysis, Raman spectra, and Fourier transform infrared (FT-IR) spectra. The carbon structure changes within the raw coals and HPCs were discussed. The individual thermal dissolution of Xibu (XB) coal, Guandi (GD) coal, and the biomass demonstrated that the biomass provided the lowest thermal dissolution yield Y 1 and the highest thermal soluble yield Y 2 at 280°C, and the ash content of three HPCs decreased as the extraction temperature rose. Co-thermal extractions in NMP at various coal/biomass mass ratios were performed, demonstrating a positive synergic effect for Y 2 in the whole coal/biomass mass ratios. The maximum value of Y 2 was 52.25wt% for XB coal obtained with a XB coal/biomass of 50wt% biomass. The maximum value of Y 2 was 50.77wt% for GD coal obtained with a GD coal/biomass of 1:4. The difference for the optimal coal/biomass mass ratios between XB and GD coals could be attributed to the different co-extraction mechanisms for this two type coals.
研究领域:
能源化学
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煤化工
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生物质转化
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热化学转化
·
资源综合利用
✓ 已验证
DOI
高影响因子
FOOD RESEARCH INTERNATIONAL
·
2026
·
IF 8.8
Chunqing Ai,Lu Wang,Xingchen Ye,Xiaomeng Ren,Shuang Song,Xuelu Li
Fucoidan (GKP) alleviates OVX-induced bone loss by suppressing osteoclastogenesis. • GKP improves systemic metabolism and identifies betaine as a key metabolite effector. • Betaine attenuates osteoclastogenesis by regulating the OPG/RANK/RANKL signaling. Postmenopausal osteoporosis (PMOP), characterized by excessive bone resorption and impaired bone remodeling, remains a significant global health challenge. This study investigated the protective effects of fucoidan from giant kelp (GKP) against PMOP and its underlying mechanisms in ovariectomized mice. GKP supplementation attenuated bone loss by preserving trabecular microarchitecture, normalizing systemic mineral homeostasis, and suppressing osteoclastogenesis, as evidenced by the downregulation of osteoclast-related genes. 16S rRNA gene sequencing revealed that GKP reshaped the gut microbiota by decreasing the Bacteroidota/Firmicutes ratio and enriching beneficial taxa, which promoted short-chain fatty acid production. Targeted metabolomics revealed that GKP induced profound systemic metabolic reprogramming, particularly amino acid metabolism, and identified betaine as a key systemic metabolite effector upregulated following GKP treatment. In vitro assays demonstrated that betaine suppressed receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation and mitigated inflammation. In vivo validation demonstrated that betaine intervention recapitulated the osteoprotective phenotype observed in GKP-treated mice, which was associated with regulation of the osteoprotegerin/RANKL/RANK signaling axis. These results indicate that GKP exerts anti-osteoporotic effects in association with changes in gut microbiota and systemic metabolism, while betaine-mediated regulation of the OPG/RANKL/RANK signaling may contribute to its osteoprotective activity. Download: Download high-res image (177KB) Download: Download full-size image
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2026
·
IF 12.5
Sheng Zhu,Yani Zhang,Shuhao Zhang,Chong Guan,Gaoyi Han,Bing Deng,Jiangfeng Ni
Ultrafast Joule heating integrated molten-salt technique is developed. • This technique can transform bituminous coal into carbon materials in seconds. • The carbon material exhibits desirable capacitive energy storage performance. • Life-cycle assessment highlights both economic and environmental advantages. Low-rank bituminous coal remains largely underexploited for producing high-value carbon materials, primarily because its high ash content imposes energy-intensive purification steps and intricate downstream processing. Here, we have developed a catalyst-free, one-pot molten-salt synthesis protocol to convert raw coal directly into oxygen-rich, hierarchically porous carbons in a matter of seconds. Mechanistically, the exceptionally rapid heating and cooling rates (>100 K s −1 ) prove pivotal in generating curved nanosheet morphologies with hierarchical pore networks and an oxygen-enriched surface, both of which are instrumental in enhancing pseudocapacitive charge storage. When tested in 6 M KOH, the resultant carbon affords a specific capacitance of 264.1 F g −1 , appreciably higher than the 203.5 F g −1 obtained from carbons prepared via conventional molten-salt routes. Additionally, the ample oxygen-containing functionalities firmly immobilize polyoxometalate redox species within the porous matrix, and the substantial adsorption energies not only raise the capacitance further but also ensure outstanding cyclability. A thorough life-cycle assessment reinforces the pronounced economic and environmental merits of this methodology, thereby establishing it as a scalable and sustainable solution for valorizing low-rank coal into functional carbons. A catalyst-free, one-step strategy that integrates flash Joule heating into molten-salt synthesis has been proposed. This rapid activation process directly converts raw bituminous coal into high-purity, oxygen-rich hierarchical porous carbon in a short duration of seconds. The resulting material delivers a high capacitance of 264.1 F g −1 , markedly surpassing carbons produced by conventional molten-salt methods. Download: Download high-res image (105KB) Download: Download full-size image
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2024
·
IF 5.3
Chuandong Ma,Wenqi Zhang,Zhisen Li,Jida Niu,Qingbiao Wang,Zhenhua Wang,Lin Li,Xiaofang You
In this study, the slurry formation properties and multi-phase dispersion mechanism of hydrocarbon modified low-rank coal (LRC) were explored by combining experiments and simulations, aiming to provide some theoretical guidance for the slurrying of surface-modified LRC. The experimental results revealed that compared with the LRC water slurry (LRCWS), the consistency of the diesel modified low-rank coal water slurry (M−LRCWS) is decreased, the pseudo plasticity is enhanced, and the constant viscosity concentration is increased by 1.89 %. The results of XPS analysis indicated that the surface C/O of M−LRC increases from 5.67 (LRC) to 6.83, and the content of oxygen-containing groups decreases by 3.10 %, indicating that the surface non-polarity is enhanced. In molecular dynamics simulation, compared with the two dispersed systems of COAL/ Sodium poly[(naphthaleneformaldehyde) sulfonate] (MF)/H 2 O (CMW) and COAL/ Dodecane (DD)/MF/H 2 O (CDMW), the E bin of water molecules in both of systems is negative, indicating that water molecules are easy to combine with the coal surface. The absolute E bin of the CDMW system is 2612.56 kcal/mol lower than that of CMW. The adsorption force of coal molecules to water molecules is weakened, which leads to a decrease in the content of water molecules adsorbed on coal. The results show that the surface hydrophobicity of LRC modified by DD is enhanced, so the proportion of free water in the system increases, which is beneficial to increase the concentration of coal water slurry. The simulation results confirm the experimental results.
研究领域:
能源科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2025
·
IF 2.2
Houchun Yan,He Ma,Xuqiang Li,Shaolong Dong,Qingsong Li
To separate higher-rank phenols from the coal tar, the model oil was constructed, and the separation efficiency of various solvents was analyzed using solvent power, selectivity, and performance index. The liquid-liquid equilibrium data of cumene + {4-ethylphenol, 4-propylphenol, 2-allylphenol, and 2-isopropylphenol} + ethanolamine was measured at 298.2 K and 101.3 kPa, and the distribution coefficient and separation factor were calculated. Furthermore, the NRTL and UNIQUAC models were correlated with the LLE data, and the model parameters were tested by the GMcal_TieLinesLL tool, which shows that the results meet the Gibbs stability criteria. The separation mechanism was explored by analyzing σ-profile, deformation charge density, interaction energy, and RDG analysis.
研究领域:
化学工程
·
分离科学
·
物理化学
·
煤化学
·
热力学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2020
·
IF 4.982
Yankun Xiong,Lijun Jin,He Yang,Yang Li,Haoquan Hu
Aromatic skeleton structure of Naomaohu (NMH) coal was investigated by a step-wise oxidation degradation and XRD , Raman and XPS characterization. Coal was first oxidized with H 2 O 2 to result in breakage of only bridged bonds and side chains, then the oxidation residue was further degraded through controlling alkali-oxygen (A-O) oxidation to avoid ring-open of polyaromatics and the conversion of coal sample exceeded 97.4 wt%. Synchronous fluorescence spectrometry (SFS) analysis of the oxidation products inferred that the aromatic structures in NMH coal mainly involve 1–4 rings compounds, among which single-ring structures are dominant accounting for 54.4 mol%. The results of XRD, Raman and XPS showed that NMH coal has a turbostratic structure, an intermediate state between the amorphous state and graphite, comprised by amorphous carbons and orderly aromatic clusters. The heteroatoms mainly exist in the forms of carbonyl, hydroxyl , pyrrolic nitrogen, mercaptan or thiophenol , thiophene , sulfoxide and sulfone . A simplified model of coal skeleton structure was proposed based on the complementary information from various techniques. Moreover, SFS analysis of A-O oxidation products clearly exhibits the gradual cracking process of polyaromatics, which provides an efficient method for controllable production of benzene carboxylic acids by preventing excessive or incomplete oxidation.
研究领域:
煤化学
·
材料科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2017
·
IF 4.601
Shiwei Wang,Longfei Tang,Xiuxiang Tao
In this paper, effect of surfactants on the hydrophobicity of low rank coal particles by sliding time measurements was investigated. X-ray photoelectron spectrometer (XPS) analysis indicated that the surfaces of low rank coal particle consisted of many hydrophilic functional groups. It was observed that the sliding time of low rank coal particles in 2-ethyl hexanol solution was the shortest than that of low rank coal particles in dodecyl amine hydrochloride (DAH) and sodium dodecyle sulfate (SDS) solutions. Moreover, the maximum touching angle (θ T ) of low rank coal particles observed in 10 −2 mol/L of 2-ethyl hexanol solution was about 80°, which was the greatest than that of low rank coal particles, about 39° in 10 −3 mol/L of DAH and 35° in 10 −4 mol/L of SDS solutions, respectively. Therefore, the sliding time results indicated that the hydrophobicity of low rank coal was enhanced by 2-ethyl hexanol and DAH and reduced by SDS. However, it was noted that the hydrophobicity of low rank coal was depressed when the DAH concentration increased to 10 −2 mol/L. The flotation performances were consistent with the results of sliding time measurements. Therefore, effect of surfactants on the hydrophobicity of low rank coal particles can be characterized by sliding time measurements.
研究领域:
化学工程
·
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Yang-Yang Xu,Xing Fan,Wen-Long Mo,Turghun Muhammad,Xiang Bai,Binoy K. Saikia,Xian-Yong Wei,Feng-Yun Ma
Three soluble fractions (SFs) of a low-rank coal were obtained by sequential thermal dissolution (TD) using cyclohexane, toluene and methanol as the solvent. SFs were further separated using preparative high-performance liquid chromatography (HPLC) to obtain subfractions. Both SFs and subfractions were characterized by gas chromatography/mass spectrometry (GC/MS). Low polar compounds such as alkanes and arenes were enriched by cyclohexane. A large number of arenes and esters were detected in toluene extracts. Strong polar compounds like phenols were concentrated by methanol. After the separation by using preparative HPLC, more phenols, alcohols, esters and ketones were identified in subfractions, and the number of compounds detected by GC/MS increased by around 3 times. In addition, two trace compounds, (2,6-dimethoxybenzoyl chloride and tetrachloro-o-benzoquinone), were identified and one compound, 1,4-benzene-dicarboxylic acid-bis(2-ethylhexyl) ester, was enriched to 89.9% after separation. Two unsupervised analysis methods, hierarchical cluster analysis and principal components analysis, revealed the differences in distributional and compositional features of SFs and subfractions.
研究领域:
煤炭化学
·
分析化学
✓ 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）