FUEL
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2023
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IF 7.4
Zehao Han,Lun Pan,Kang Xue,Jisheng Xu,Qing Liu,Ying Xu,Zhouyang Shen,Xiangwen Zhang,Ji-Jun Zou
Polycyclic alkanes are not only the important components of high-density fuels, but also can be used to cool the overheating parts of hypersonic vehicle through catalytic endothermic dehydrogenation reaction. However, the dehydrogenation performances of cycloalkanes with different molecule structures vary widely. Herein, we investigated the effects of cycloalkane structures, including the length of branched chains, the number of branched chains, the number of rings, and the shape of rings, on the dehydrogenation performance. The results show that cyclohexane (CH) exhibits the best dehydrogenation performance (600 °C, 3 MPa) with >99% conversion, >99% benzene selectivity, and highest total heat sink of 4.47 MJ/kg. The branched chains, ring number and five-membered rings all have negative effects on dehydrogenation. Among them, the number of rings has the minimum negative impact. Moreover, we correlated the density, volumetric net heat of combustion (NHOC) and heat sink with the molecular structure of the cyclic alkanes and found that the polycyclic alkanes with low H/C ratio and high M have both high density, high volumetric NHOC and high heat sink. This work can provide guidance for development and design of advanced fuels for endothermic dehydrogenation.
研究领域:
化学工程
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燃料科学
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产品关联
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
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2025
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IF 6.2
Feng Wang,Shouhui Jiao,Xiaoqi Zhang,Ying Yang,Xiaohan Jin,He Liu,Zongxian Wang,Aijun Guo
Although highly reactive olefinic species are abundant in thermally cracked oil, previous studies have predominantly focused on the macroscopic fouling effects of aliphatic olefins during transportation/storage. In contrast, the molecular-level mechanisms by which aromatic olefins promote coking during thermal conversion remained unclear. This work systematically investigated how aromatic olefins drive molecular growth and coke formation of heavy aromatic fractions. Thermal conversion experiments with vacuum residue (VR), resins (Re), and asphaltenes (Asp) mixed with olefin model compounds revealed that aromatic olefins accelerated coking compared to aliphatic olefins, with the coking-promoting effect intensifying as the number of aromatic rings in the molecule increased. At 410°C for 60 min, the addition of 5 wt% 9-vinylanthracene to VR increased the coke yield from 1.35 wt% to 5.72 wt%, versus 1.68 wt% with the addition of 5 wt% 1-octene. Similarly, the addition of 5 wt% 9-vinylanthracene elevated the coke yields for Re and Asp systems from 0.66 wt% and 41.28 wt% to 5.13 wt% and 50.84 wt%, respectively, compared to 1.08 wt% (Re) and 43.36 wt% (Asp) observed with the addition of 1-octene. Model compound system studies demonstrated that, aromatic olefins, unlike 1-octene, could further react with primary addition products formed by their initial co-addition with conventional aromatics, leading to the formation of secondary and high-order addition products. Notably, aromatic olefins exhibited increasing reactivity in continuous co-addition reactions as the number of aromatic rings increased. This was supported by 42.2 % high-order addition products detected in the toluene/9-vinylanthracene system versus 30.1 % in the toluene/styrene system. This study elucidated that aromatic olefin promoted molecular growth through continuous co-addition reactions, ultimately triggering phase separation and coke formation. The findings provided molecular-level insights into the adverse impacts of aromatic olefins on industrial processing of thermally cracked oil.
✓ 已验证
产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2022
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IF 10.753
Taiguang Li,Mingyong Wang,Yongmei Hao
A novel magnetic core-shell Fe 3 O 4 @SiO 2 @CdS embedded graphene oxide (GO) composite was prepared for the visible-light-driven photodegradation of high ring number polycyclic aromatic hydrocarbons (PAHs). The potential application of GO-Fe 3 O 4 @SiO 2 @CdS was evaluated through the photodegradation of phenanthrene and pyrene in deionized water, tap water , and lake water, respectively. It was found that GO-Fe 3 O 4 @SiO 2 @CdS could remove 86.4 % of phenanthrene and 93.4 % of pyrene, suggesting its potential for the degradation of high-ring number PAHs. The density functional theory (DFT) calculations demonstrate that pyrene has more active sites attacked by free radicals. The photoelectrochemical measurement and quenching experiments indicate that GO can transfer photoelectrons efficiently, resulting in the crucial radicals ( O 2 − , OH and 1 O 2 ). More importantly, the photocatalytic activity kept almost constant during five cycles, confirming the significant anti-photocorrosion of GO-Fe 3 O 4 @SiO 2 @CdS. This work provides some new insights into the removal of PAHs with high-ring numbers in the natural water environment.
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
JOURNAL OF CHROMATOGRAPHY A
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2022
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IF 4.601
Yao Sun,Zhi'an Sun,Chaozhan Wang,Yinmao Wei
Aromatic phase, as one type of reversed-phase stationary phases, shows complementary selectivity to the n -alkyl counterparts especially for certain challenging separation tasks. However, effect of phenyl numbers in aromatic ligands on retention behaviors has rarely been addressed compared with the alkyl stationary phases. To illustrate the issue, a series of polyphenyl stationary phases were facially prepared via the coupling chemistry of isocyanate with amine, including aniline (π 1 ), 4-aminobiphenyl (π 2 ), 4-amino- p -terphenyl (π 3 ) and [1,1′:4′,1′':4′',1′''-quaterphenyl]-4-amine (π 4 ), respectively. The chromatographic behaviors of the new stationary phases as well as the traditional C18 were systematically compared in terms of retention mode, hydrophobic and aromatic selectivity, shape selectivity and π-π interaction by various analytes, including alkylbenzenes , polycyclic aromatic hydrocarbons congeners and substituted benzenes with electron-withdrawing groups. Due to the homologous structure of four polyphenyl ligands, the hydrophobic selectivity, aromatic selectivity and shape selectivity of stationary phases increase with phenyl numbers in the bonded polyphenyl ligands, whereas the increment becomes insignificant from U-π 3 to U-π 4 . This phenomenon is explained by the insertion degree of analytes in the polyphenyl ligand brushes. Compared with the homemade C18, the polyphenyl phases indicate insignificant changes of shape selectivity with temperature. Notably, the new polyphenyl phases demonstrate the great selective separation towards the electron-deficient compounds through the π-π interaction. These findings make up for the understanding of the retention behavior of aromatic stationary phases.
研究领域:
色谱学
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分析化学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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