ACS Omega
·
2025
·
IF 4.3
Yong Qu,Jingmei Liu,Xiaodong Zhou,Lang Liu,Ruitao Ma,Yongguo Su,Chunmei Ma,Pengtao Sun
Low-temperature coal tar (LTCT) is the preferred raw material for the catalytic hydrogenation of coal tar. In order to study and popularize the technology of preparing fuel oil by hydrogenation of LTCT, it is necessary to research its composition and structural characteristics. Heavy hydrogenated coal tar (HHCT) from a company in Xinjiang, which is a mixture of hydrorefined tail oil distillate (>350 °C) and hydrotreated circulating tail oil (>350 °C). To make scientific and customized use of HHCT, the chemical composition and molecular structure characteristics of HHCT and its subcomponents were investigated by using elemental analysis (EA), infrared analysis (FT-IR), and nuclear magnetic resonance (1H NMR and 13C NMR) through fraction separation. Compared to other low-temperature coal tar (LTCT), the content of saturates (SA) in HHCT is 95.01 wt %, considerably higher than other LTCT samples, and the content of aromatics (AR), resins (RE), and asphaltenes (AS) is all much lower than other LTCT samples. Compared with the basic properties, elemental content, and refining performance of other crude oils, HHCT is good-quality oil with relatively small density, high H/C ratio, fewer heteroatoms, and low metal impurities, and is easy to refine and process. FT-IR and NMR results show that HHCT and SA are primarily constituted of long-chain n-alkanes possessing longer aliphatic chains and fewer branched chains. Aromatics are predominantly present in AR and mainly encompass bicyclic and tricyclic aromatics. HHCT and other fractions contain a small quantity of aromatic structures.
研究领域:
能源化学
·
石油加工
·
燃料化学
·
分析化学
·
煤化工
·
有机地球化学
·
材料化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POWDER TECHNOLOGY
·
2018
·
IF 3.23
Zhilin Xi,Liwei Jin,J.Y. Richard Liew,Ding Li
A foam sol clay (FSC) mixture, mainly composed of fly ash (FA), surfactant ( n -amylamine) and polyethylene oxide (PEO), was proposed for coal dust control. The FA surface, modified by a FSC solution, stability and foamability were investigated. It was found that the FA surface in alkaline solution was deprotonated to form a negative charge, which could be adsorbed by the polar head group of n -amylamine via electrostatic interactions . As a result, with increasing surfactant, the particles gradually converted from hydrophilic to hydrophobic and attached at gas-liquid interfaces so that the contact angle, zeta potential , froth stability and foamability increased. At a surfactant concentration (c a ) of 35 g/L, a monolayer three-dimensional network was formed and the maximum foamability and half-life were obtained. Upon further increasing c a , a bilayer and particle clusters were formed by surfactant chain-chain interaction, resulting in particles becoming hydrophilic again, and the FSC solution having stronger mechanical resistance against flowing, so that the viscosity rapidly increased and the diffusion of free surfactant molecules was hindered at the froth surfaces. Thus, the contact angle, froth stability and foamability decreased. PEO could bond sodium dodecyl sulfate and water to form a dual adsorption layer and hydrogen, respectively, which enhanced the wettability of the FSC on coal dust surfaces. PEO could adsorb and curl FA particles to form a thin layer of armor after froth air-drying. It was concluded that the froth generated by the FSC solution, including 200 g/L FA, 35 g/L c a and 1 g/L PEO, could control coal dust with a long-term effect.
研究领域:
环境工程
·
矿物加工
·
胶体与界面化学
·
粉尘防治
·
资源利用
✓ 已验证
DOI
高影响因子
ACS Omega
·
2021
·
IF 3.512
Qiming Zhuo,Wenli Liu,Hongxiang Xu,He Zhang,Xiaopeng Sun
Attachment behavior is a key component of flotation and has a decisive influence on flotation performance, and the experiment research on the attachment between mineral particles and bubbles still needs further research. In this work, a particle–bubble attachment apparatus and multiple target tracking software were developed. Coal particles were used as the subjects, and the effect of particle properties on the attachment performance was studied from the perspective of the particle group. The particle–bubble attachment experiments indicated that the collision position had an effect on the attachment efficiency, and the attachment efficiency decreased with an increase in the collision angle. The efficiency-weighted attachment angle was proposed to quantitatively describe the attachment performance of coal samples. The efficiency-weighted attachment angle of low-density coal samples was greater than that of high-density coal samples. For particles with different sizes, the efficiency-weighted attachment angle of fine particles was greater than that of coarse particles. Furthermore, SDS weakened the attachment performance between coal particles and bubbles via adsorption on the bubble, and the efficiency-weighted attachment angle decreased as the concentration of the SDS solution increased. CTAB adsorbed on coal particles and bubbles, and the efficiency-weighted attachment angle first increased and then decreased with increasing CTAB concentration.
研究领域:
矿物加工工程
·
表面化学
✓ 已验证
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Xu Zhao,Fuxin Yang,Zhenghong Li,Houzhang Tan
The emission of polycyclic aromatic hydrocarbons (PAHs) poses a significant risk to the ecological environment. Therefore, it is of great importance to investigate the formation characteristics of PAHs during the coal and biomass utilization. The formation of PAHs is primarily attributed to the incomplete combustion of fuels. In this work, the organic components of raw bituminous coal (BC), wheat straw (WS), and corn straw (CS) were analyzed and the formation characteristics of PAHs were explored using a fixed-bed pyrolysis system. The emission characteristics of particulate matter (PM) and PAHs were investigated in a drop-tube furnace. The results indicate that BC contains a higher proportion of aliphatic hydrocarbons, and the oxygen-containing functional groups of WS and CS are more complex. The content of PAHs in the extracts of raw BC, WS, and CS is 24.16 µg/g, 0.39 µg/g, and 0.41 µg/g, respectively. During the pyrolysis, the PAHs formation characteristics of coal are comparable to biomass. The content of PAHs in pyrolysis gas is significantly higher than that in the char. With the increase of temperature, the PAHs content in pyrolysis gas increases and then decreases, reaching a maximum value at 1000℃. At the low temperatures, the primary source of PAHs is the decomposition of the organic component of fuels. At the high temperatures, the rupture of the basic backbone and the condensation polymerization reaction are the important factors influencing PAHs emissions. The maximum PAHs emissions of BC, WS and CS are 4196.94 µg/g, 4426.78 µg/g, and 5479.50 µg/g, respectively. During the combustion, with the increase of oxygen content, the emissions of PM and PAHs gradually decrease. The proportion of low-ring PAHs increases, while the proportion of high-ring PAHs decreases. Furthermore, PM 1-2.5 accounts for 52.34–84.37 % of total PM emissions. PAHs are more easily enriched in these fine particles with the proportion of 53.71–71.09 % of the total PAHs emissions.
研究领域:
环境科学
·
能源科学
✓ 已验证
DOI
高影响因子
International Journal of Coal Preparation and Utilization
·
2025
·
IF 2.1
Shengchao Yang,Sheng Dong,Jinpeng Qiao,Chao Kang,Yuqian Zhao,Yanze Wang,Jianrong Liu,Chenlong Duan,Sabereh Nazari,Miao Pan
Aiming at the problems of high quartz content, high ash content and difficult leaching of aluminum and gallium in some coal gangue, NaF-strengthened coal gangue calcination-hydrochloric acid leaching process was adopted, and the occurrence state of gallium in coal gangue was explored. The residue was analyzed by XRD and SEM, and the mechanism of NaF-strengthened coal gangue acid leaching was explored. The results show that the addition of m (NaF): m (coal gangue) = 0.06 can increase the leaching rate of aluminum in coal gangue from 33.72% to 62.03%, and the leaching rate of gallium from 43.17% to 70.15%. NaF as an additive can react with hydrochloric acid to form HF to destroy the coal gangue structure, so that hydrochloric acid can react with metakaolinite inside the quartz accumulation layer, which improves the leaching rate of aluminum and gallium. Finally, the process factors were studied separately to reveal the pattern in response to them, and it was found that the acid leaching reaction was greatly affected by internal diffusion, which provided a reference for the subsequent complexation adsorption of gallium.
研究领域:
冶金工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2021
·
IF 6.609
Yong Wei,Guijian Liu,Biao Fu,Yuan Liu,Xuan Xue
Fine particulate matter (PM) emitted from coal-fired power plants (CFPPs) has aroused widespread environmental and human health concerns. Cadmium (Cd), as one of the prime toxic air pollutants, which exists in fine PM intensifies its toxicity. In this research, three particle sizes of PM (PM 1 , PM 2.5 , and PM 10 ) at the outlet of electrostatic precipitator (ESP), along with feed coal, bottom ash, and ESP ash, were collected from a 300-MW pulverized CFPP. Results showed that Cd was more enriched in the fly ash than in bottom ash. With the PM diameter decreasing, the relative enrichment index (REI) value of Cd increases from 2.30 to 7.84. The concentration of Cd was found to be intimately related to Ti in the PM. Abundant Ti-rich particles were identified in the PM 1 , having quite different chemical compositions as compared to particles larger than 2.5 μm. The major processes governing the formation of Ti-rich particles included melting of silicate-bound Ti and heterogeneous condensation of gaseous Ti from the decomposition of organic-associated Ti in coal. The transformation behavior of Cd to PM in a coal combustion process was discussed based on its occurrence mode in coal, thermodynamic property, and the possible interactions with ash particle compositions. The retention of Cd (g) by Ti-rich particle were probably dominated by chemisorption at high temperature; at lower temperature, physical adsorption or condensation may be the primary mechanisms for capturing CdCl 2 (g).
研究领域:
环境科学
·
化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2024
·
IF 5.8
Yang-Yang Xu,Xing Fan,Feng-Yun Ma,Hai-Xu Zou,Xian-Yong Wei
Directly converting lignite into arenes as commodity chemicals and drop-in fuels is a highly desirable target for researchers. However, this is severely limited by the presence of stable inter unit C-O linkages in lignite. Herein, a highly active catalyst, Co-MoS 2 , has been designed and prepared to be used for the selective catalytic cleavage of inter unit C-O bridged bonds (BBs) in the conversion of Naomaohu (NMH), a lignite, to yield arenes. Both catalytic hydrogenation conversion (CHC) and thermal dissolution (a non-catalytic process, named NCHC) of NMH were conducted using n-hexane as the solvent. The soluble fractions from the first stage of NCHC (SF NCHC-1 ) and CHC (SF CHC-1 ), as well as the second stage of NCHC (SF NCHC-2 ) and CHC (SF CHC-2 ) were obtained using the same solvent. After the first-stage catalytic treatment, the relative contents of arenes and alkanes in SF CHC-1 increased by 16.7 % and 9.3 %, respectively, compared to those in SF NCHC-1 , and the relative content of oxygen-containing compounds (OCCs), such as alcohols, phenols , esters, ketones , acids, and furans, decreased by 13.2 %. For the second-stage conversion, the relative contents of arenes and alkanes in SF CHC-2 were 53.5 % and 15.5 % higher than those in SF NCHC-2 , and the relative contents of OCCs was only 6.6 % in SF CHC-2 . The catalytic mechanisms of cleavage of C-O BBs and deoxygenation were proposed based on the CHC of model compounds and density functional theory (DFT) calculation. The adsorption of OCCs and the activation of released hydrogen radical (H·) by Co-MoS 2 , followed by H· addition to the carbon atom connected to oxygen in C-O BBs and oxygen-containing functional groups, are crucial for the cleavage of C-O BBs and formation of deoxygenated compounds, particularly arenes.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2024
·
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
·
表面化学
✓ 已验证
产品关联
DOI
高影响因子
HYDROMETALLURGY
·
2012
·
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
·
环境科学
✓ 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
·
材料科学
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2020
·
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
·
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
·
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）