FUEL PROCESSING TECHNOLOGY
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2021
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IF 7.033
He Li,Shisheng Liang,Yucui Hou,Yupeng Wang,Shuhang Ren,Weize Wu
Direct coal liquefaction (DCL) is not only for fuel but also for chemicals, which shows high efficiencies in atom utilization and energy. The study on coal structure is important to select coal for direct liquefaction . Naomaohu coal is a kind of subbituminous coal and a typical coal for direct liquefaction . In this work, the structure of Naomaohu coal was investigated via alkali‑oxygen oxidation , ruthenium ion catalyzed oxidation and physical analyses and a representative structural model with a model size of 128,755 amu was constructed. The structural characteristics show that the ratio of single-, double-, triple-, and quadruple-aromatic rings is 149:164:102:63. The triple- and quadruple-rings aromatic structures are mainly connected by C C bonds of 2–4 carbon atoms. The single- or double-ring is connected on the triple- and quadruple-rings aromatic structures through ether or ester bonds , which can be broken easily under mild conditions. Long alkyl side chains with carbon atoms from 13 to 25 accounting for 0.91 wt%. The high H/C, high oxygen content (mainly weak bonds such as ether and ester bonds between aromatic clusters), abundant single-, double-, triple, and quadruple-aromatic rings, and alkyl bridge bonds of 2–4 carbon atoms are beneficial to the mild liquefaction of Naomaohu coal
研究领域:
化学工程
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2024
·
IF 8.1
Xizhuang Qin,Tao Shen,Guanbo Li,Lei Shi,Zhenyu Liu,Qingya Liu
In order to obtain chemically meaningful and extendable kinetics for direct coal liquefaction (DCL) the experimental coal conversion ( X C ) and oil yield ( Y O ) are correlated with coal constituents and the conditions. The coal is assumed to have three constituents mimicking its maceral constituents liptinite, vitrinite and inertinite. The quantities of them are estimated based on the TG curve of coal, and correlated with the X C and Y O by non-linear regression. For Naomaohu (NMH) coal that is dominant with the vitrinite and Shangwan (SW) coal that has similar contents of vitrinite and inertinite, the three-constituent kinetics model is significantly better than that of traditional single-component kinetics model that requires the regression-determined maximum conversion X C,M and maximum oil yield Y O,M . The k 1 for the vitrinite-like component a 1 is always much larger than k 2 for the inertinite-like component a 2, and k 1 usually shows a better relationship with 1/T than k 2 . The E a of NMH for X C and Y O are close to each other, suggesting a high content of weak bonds in the structure; whereas the E a of SW for Y O is significantly larger than that of X C , suggesting that many oil originates from the secondary reaction rather than the primary covalent bond cleavage.
研究领域:
化学工程
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
POWDER TECHNOLOGY
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2018
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IF 3.23
Yonggai Li,Jiawei Li,Peng Chen,Jianzhong Chen,Lijuan Shen,Xiangnan Zhu,Gan Cheng
In this study, X-ray Photoelectron Spectroscopy (XPS) was used to analyze the elements on the surface of subbituminous coal , and reverse flotation was introduced to float subbituminous coal. The effect of ultra-fine coal on the flotation behavior of silica in coal reverse flotation was discussed by comparing the flotation performance with two different artificial mixed flotation feedings, with ultra-fine coal (UFC, −45 μm) or without ultra-fine coal. The comparison results showed that the existence of UFC reduced the flotation rate and the recovery of silica, as well as the separation efficiency of subbituminous coal reverse flotation. Compared to the flotation performance of feeding with UFC, the concentrate ash content of feeding without UFC was lower (9.18%), and the separation efficiency was higher (68.69%). Total Organic Carbon Analyzer was used to test the adsorption quantity of collector by coal and silica to explain the mechanism. Conclusions were obtained that ultra-fine coal particles could adsorb more collector due to their larger specific surface area, leading to less collector left in the pulp to float silica particles. Selective flocculation reverse flotation method could increase the separation efficiency of coal reverse flotation with appropriate dosage flocculant .
研究领域:
矿物加工工程
·
煤炭科学与技术
✓ 已验证
产品关联
DOI
高影响因子
Journal of Building Engineering
·
2025
·
IF 7.4
Qingping Wang,Zhiwei Cheng,Feifei Zhou,Jingyi Cai,Liang Yuan,Xiujuan Feng,Luyao Wang,Jiayao Zhang,Xiang Li
Research on anti-dispersion grouting materials helps improve the retention and durability of grout under water-bearing or flowing-water conditions, reduce material consumption and environmental risks, and provide technical and theoretical support for the reliability and sustainability of ground reinforcement projects. This research utilized coal gangue (CG), fly ash (FA), and silica fume (SF) as raw materials rich in silicon and aluminum. Alkali activators with varying concentrations were prepared by mixing sodium silicate solution with NaOH, and a small quantity of admixture was added to develop a cost-effective anti-dispersion grouting material (AGM). The macro tests evaluating fluidity, setting time, water-to-land strength ratio under static water conditions, and retention rate under flowing water conditions of AGM were designed using the response surface method. The reaction mechanism of AGM was investigated XRD, FTIR, SEM-EDS, and NMR techniques. The results indicate that when the content of hydroxyethyl methyl cellulose (HEMC) is 0.5 %, the modulus of water glass is 1.53M, and the concentration of alkali activator is 0.45, the optimal formula can be achieved. This material exhibits excellent flowability during construction, ensuring smooth grouting operations. It also demonstrates outstanding resistance to water scouring, forming a high-strength underwater consolidation body in static water environments.
✓ 已验证
DOI
高影响因子
ADVANCED POWDER TECHNOLOGY
·
2024
·
IF 4.2
Wenqi Zhang,Chuandong Ma,Zhisen Li,Meng He,Qingbiao Wang,Lin Li,Xiaofang You
In this study, modified low rank coal water slurry (M-LRCWS) was prepared by using diesel modified low rank coal (LRC) and compared with low LRC water slurry (LRCWS) to investigate the slurry formation mechanism and combustion characteristics of coal water slurry. Meanwhile, the combustion kinetics of coal-water slurry was investigated using kinetic methods to probe the combustion reaction mechanism. The results showed that the slurry formation concentration of LRC was 70 %, while the slurry formation concentration of M-LRCWS was 72 %, which was an increase of 2 %. The diesel modification positively affected the stability of CWS. The comprehensive combustion characteristics index of the same slurry deteriorated with increasing heating rate. At the same heating rate, M-LRCWS has better combined combustion performance, higher flammability and more stable ignition performance. Combustion kinetics calculations showed that the reaction activation energies were 105.50 kJ/mol for M-LRCWS and 99.59 kJ/mol for LRCWS using the FWO method, and 93.48 kJ/mol for M-LRCWS and 92.68 kJ/mol for LRCWS using the Starink method. The activation energy of M-LRCWS is slightly higher than that of LRCWS, which indicates that the diesel fuel is encapsulated in the coal particles and it is difficult to activate the substance. As a result, the dispersion system is more stable and favorable for storage and transportation. The physical functions of LRCWS and M-LRCWS were calculated using the Achar differential equation and the Coats-Redfern integral equation, and the results showed that both LRCWS and M-LRCWS followed the tertiary reaction (F3) mechanism.
研究领域:
能源科学
·
化学工程
✓ 已验证
DOI
高影响因子
FUEL
·
2023
·
IF 7.4
Xizhuang Qin,Qingya Liu,Jiachen Yu,Lei Shi,Zhenyu Liu
To understand the main reactions in direct coal liquefaction and to find out the temperature at which condensation reactions become significant, the liquefaction of a vitrinite-rich coal, Naomaohu (NMH), is studied at 380–460 °C in tetrahydronaphthalene (THN). The main focuses are on the trends of products yield and evolution of solid residues’ composition and structure. It is found that NMH is very active at 420 °C with a conversion of >90 wt% and an oil-plus-water yield of 39 wt% in 40 min. The reaction, especially the condensation behaviors at temperatures lower than 420 °C are different from those at higher temperatures as indicated by the trends in products yield and in the residue’s morphology and properties. The residues obtained at 440–460 °C contain mesophase pitch spherules. The changes in residues’ volatiles content, H/C and O/C ratios, FTIR and Raman spectra, and ESR parameters are slow at 380–420 °C but much fast at 440–460 °C. These different trends are clearly evidenced by plotting the residues’ characterization parameters against the decreasing residue yield during the reaction.
研究领域:
化学工程
·
能源科学
✓ 已验证
DOI
高影响因子
JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
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2023
·
IF 2.2
Lun Du,Guanghua Zhang,Shining Hu,Jie Luo,Wanbin Zhang,Ce Zhang,Junguo Li,Junfeng Zhu
The hydrophilic surface and developed pore structure restricted the application of abundant low rank coals (LRC) for the preparation of coal water slurry (CWS) with high concentration. In this work, emulsified asphalt was applied as an effective and low cost modifier to modify coal surface and improve the slurry making performance of LRC. The successful modification was verified by various technologies, such as chemical titration, X-ray photoelectron spectroscopy (XPS) and Zeta potential measurements. The results revealed that the oxygen containing groups located at LRC surface were covered by emulsified asphalt, which further caused the decrease of Zeta potential. The influence of modification on wettability of coal was also evaluated by contact angle and moisture re-adsorption. It showed that the hydrophobicity of LRC significantly increased, which is accompanied with the reduction of inherent moisture. Besides, the results of nitrogen adsorption and scanning electron microscope (SEM) verified that the hydrophobic layer formed by emulsified asphalt blocked the pores of LRC. The modified LRC also exhibited better adsorption ability to the widely used anionic dispersant naphthalene sulfonate formaldehyde condensate (NSF) than that of raw coal (RC) and microwave dehydration coal (MDC). Anyhow, modified LRC possessed the characteristics as high rank coal. Afterwards, modified coal was applied to prepare CWS. The results showed that CWS prepared by modified LRC exhibited superior slurry making performance as compared to RC and MDC. The surface modification reduced the inherent moisture and promoted the adsorption of dispersant, which increased the free water amount and enhanced electrostatic repulsion and steric hindrance among coal particles. Accordingly, the maximum concentration for CWS increased, and the static stability enhanced.
研究领域:
能源科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Xiaofang You,Wenqi Zhang,Xiaoteng Li,Chuandong Ma,Zhisen Li,Qingbiao Wang,Zhenhua Wang,Lin Li
In this study, alkali-modified municipal sludge (AS) was mixed with low-rank coal to prepare AS-coal water slurry (ASCWS). The influence of AS on the slurrying performance of coal water slurry (CWS) was investigated, and the slurrying mechanism of municipal sludge-CWS (SCWS) was elucidated. Research on the alkali modification of municipal sludge showed that the effectiveness of the modifiers was in the order Ca(OH) 2 > NaOH > KOH > K 2 CO 3 . Considering the apparent viscosity of the slurry as the evaluation criterion, the optimal alkali modification scheme was determined through the response surface optimization test, and 19.99 % Ca(OH) 2 was suitable to modify the sludge for 14.61 h Compared with the unmodified sludge, the content of oxygen-containing functional groups on the surface of AS was reduced, and the flocculent structure was disrupted, which helped improve the slurry formation performance of the SCWS. Blending the sludge with the CWS enhanced the stability of the slurry, and the water separation rates for the SCWS and ASCWS decreased from 18.62 % to 5.00 % and 5.26 %, respectively. The mechanism study showed that the zeta potential values of SCWS and ASCWS decreased from −10.67 mV to –32.23 mV and −39.22 mV, respectively. The increased electronegativity of the slurry owing to the addition of sludge facilitated particle dispersion and enhanced slurry stability. The adsorption patterns of sodium poly[(naphthaleneformaldehyde)sulfonate] (MF) on coal, sludge, and modified sludge were consistent with the Langmuir adsorption model. The pseudo-second-order kinetic model accurately described the adsorption process of MF on coal, sludge, and modified sludge.
研究领域:
能源科学
·
环境工程
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
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
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2016
·
IF 2.75
Yi Li,Muhammad Nadeem Amin,Xingmei Lu,Chunshan Li,Fuqiang Ren,Suojiang Zhang
The catalyst NiO/MgO–Al 2 O 3 was prepared by loading magnesium and nickel onto the surface of γ-Al 2 O 3 beads, respectively, and was adapted to in situ upgrade the high temperature pyrolysis vapor derived from coal pyrolysis. The catalyst synthesis process, and structural variation were characterized by the XRD, SEM, and physical adsorption analyzer. In order to examine the catalytic effect on the different nickel loading ratio in the catalysts, the solid–liquid–gas product distribution, variation of gas and components of coal tar were studied by simulated distillation, GC/MS, elemental analysis and so on. The results shows both the tar yield and the content of the light fraction in the tar can be increased by catalytic up grade. The catalyst has a strong ability to convert the heavy component and polycyclic aromatic hydrocarbons in the tar to lower molecular weight components.
研究领域:
化学工程
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Jun Zhao,Hong Liu,Haochen Zhang,Xiaolin Song,Haibin Zuo,Guangwei Wang,Zhigao Xu,Ming Wu,Zhenyue Zhang,Ru'an Chi
This study aimed to effectively utilize low-rank coal and biomass residue in the coking process. Hypercoal was produced through co-thermal extraction, and its performance as a component in the coking process was investigated. The effects of the amount of hypercoal extracted from 80 wt% low-rank coal and 20 wt% biomass residue on the coke strength and structure were investigated. Raman spectroscopy, optical microscopy, and scanning electron microscopy were used to analyze the carbonaceous, optical, and pore structures of the hypercoal coke. The optimal ratio of the coal blend contained 15 wt% hypercoal, with compressive and drum strengths of 7.76 MPa and 86 %, respectively. The vitrinite content and average maximum vitrinite reflectance of the hypercoal were 95 % and 0.352, respectively. High vitrinite contents in hypercoal contribute to the formation of mosaics within the coke, which can improve its cold strength. Moreover, the evolution of the hypercoal coke structure at various addition ratios was explored.
研究领域:
冶金学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
MINERALS ENGINEERING
·
2025
·
IF 5
Zhenchao Ma,Zhe Li,Yingying Wang,Mengdi Xu,Ying Zhou,Xuesong Yang,Lei Wang,Yaowen Xing,Bobo Zhou,Xiahui Gui
The presence of unburned carbon seriously restricts the reasonable disposal and utilization of coal gasification fly ash (CGFA), leading to resources waste and environmental pollution. Due to the abundant micropores and hydrophilic structures on the surface of unburned carbon, the conventional flotation decarburization efficiency of CGFA is low. In this study, the stirred mill and saline water were synergistically applied to enhance the flotation decarburization efficiency. The synergistic mechanism between stirred mill and saline water was revealed through comprehensive characterization of surface morphologies, particle size distribution, pore structure evaluation, contact angle measurement, and surface property assessment. The results demonstrated that CGFA achieved a decarburization efficiency of 87.85 % by stirring mill grinding at 600 rpm for 10 min. There are three key reasons: preferential exposure of carbonaceous components, median particle size reduction to 8.11 µm with specific surface area decrease to 21.277 m 2 /g, and an increase in contact angle of 29.73°. Subsequent saline water treatment further improved efficiency to 94.41 % (0.8 mol/L Na + ) and 96.16 % (0.4 mol/L Mg 2+ ). This is caused by three complementary mechanisms: surface tension reduction, foam stabilization, and Zeta potential modulation. Consequently, the synergistic collaboration of stirred mill and saline water exhibit remarkable performances and can be used as an ideal candidate for flotation decarburization of CGFA.
研究领域:
环境科学
·
材料科学
✓ 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）