Molecular Catalysis
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2023
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IF 4.6
Na Ji,Alazar Alemayehu,Hanyang Li,Poknam Ri,Xinyong Diao
The production of phenol from lignin or its model compounds, instead of cumene oxidation is very interesting from the viewpoint of sustainability and economics. The selective demethylation of anisole was an efficient but challenging route to produce phenol. In this work, we demonstrated the fabrication of nickel sulfide (Ni 9 S 8 +Ni x S 6 ) nanoparticles on Al 2 O 3 matrix by a facile in situ sulfidation of NiAl hydrotalcite and announced that nickel sulfide can serve as efficient active site for the demethylation of anisole for the first time. The as-designed 4Ni1Al-S catalyst exhibited a hierarchical morphology with a high particle density and high dispersion, affording a 95.6% yield of phenol in the demethylation of anisole under relative milder reaction temperature (270 °C) when compared to the reported state-of-the-art results. By comprehensive characterizations and experiments, we inferred that the nickel sulfide exsolved from the LDH structure exhibited stronger metal-support interaction than that obtained from the impregnation method, which not only benefits the uniform dispersion of active nickel sulfide but also results in the electronic transfer from Ni center to Al 2 O 3 support. As a consequence, enhanced demethylation activity was achieved on 4Ni1Al-S in comparison to Ni-S/Al 2 O 3 -IM.
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JOURNAL OF MOLECULAR LIQUIDS
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2021
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IF 6.165
Wanbo Zhang,Ping Guo,Xingbo Ge,Jianfen Du,Zhouhua Wang
In CO 2 enhanced oil recovery process, the interactions between CO 2 and oil components are complex since crude oil is a mixture of n-alkanes, cycloalkanes , aromatics, resin, asphaltene and other compounds. To investigate the effects of temperature, pressure and molecular structure on CO 2 solubility in cycloalkanes and the resulting cycloalkane volume expansion, the solubility of near critical and supercritical CO 2 in cyclopentane (CP), cyclohexane (CH), methylcyclohexane (MCH), methylcyclopentane (MCP) and ethylcyclohexane (ECH) and the volume expansion factor of cycloalkanes at diverse temperature and pressure were measured. It was observed that increasing temperature decreases CO 2 solubility, while CO 2 solubility increases with pressure increasing. Compared with CP and CH, it's harder for CO 2 to dissolve in their methyl or ethyl substituents. For homologues, CO 2 solubility decreases with carbon number increasing. The volume expansion factor and solubility have a same variation tendency with temperature, pressure and molecular structure. The experimental results of solubility were correlated with Fornari's model and PR equation of state with the maximum average absolute relative deviation (AARD) of 2.8% and 6.8%, respectively. The excess molar volume of CO 2 + cycloalkane mixtures was calculated to be negative and increases with pressure.
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JOURNAL OF CHEMICAL THERMODYNAMICS
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2021
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IF 3.178
Feifan Niu,Yuanmeng Liu,Xiaoning Wang,Xunqiu Wang
Isobaric vapor–liquid equilibrium (VLE) data for the binary system of (methylcyclopentane + methylcyclohexane) and the ternary system of (methylcyclopentane + cyclohexane + methylcyclohexane) were measured at 101.3 kPa with a dynamic recirculating apparatue, and the temperature ranged from 344.79 to 373.85 K, and the thermodynamic consistency of the experimental date was checked by the Herington area method and Van Ness method. The experimental date was correlated with NRTL, Wilson and UNIQUAC activity coefficient models. The binary VLE date predicted by the binary interaction parameters agreed well with the experimental and literature data. Then, Aspen plus V11 software was used to establish batch distillation model simulation calculation. The experimental results show that the products separated by the batch distillation model meet the requirements. Finally, two sets of 1300 kg/hr separation process were designed and the process was optimized. The energy consumption of scheme I was slightly less than scheme II.
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TALANTA
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2021
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IF 6.057
Zhenyu Lu,Xiaotian Lu,Ling Xia,Yanhui Zhong,Gongke Li,Yufei Hu
In this work, a catalytic material of cobalt doped nitrogenous porous carbon (Co/NPC) was fabricated from covalent organic frameworks (COFs) and cobalt ion via directly carbonization . Attribute to the excellent selective catalytic performance towards n -hexane, Co/NPC was employed in cataluminescence (CTL) for rapid and sensitive determination of n -hexane. Moreover, the detection conditions of CTL were evaluated, including temperature, flow rate and detecting wavelength. Under optimized conditions, a good linear relation between signal intensity of CTL and n -hexane concentration was obtained in the linear range of 0.4–250.0 mg/L and the limit of detection (LOD, S/N = 3) was 0.13 mg/L. Furthermore, the Co/NPC based CTL sensor was successfully applied to the determination of n -hexane in edible oil samples with the recoveries in the range of 92.0%–104.0%. The method comparison results of GC/MS and CTL on real sample analysis further proved the accuracy of the developed Co/NPC based CTL method. Additionally, the possible catalytic mechanism of n -hexane on the surface of Co/NPC was investigated, assisting by GC/MS on intermediation products identification. Overall, the Co/NPC based CTL sensor has been confirmed excellent performance in the n -hexane determination, which revealing extensive application in rapid residual n -hexane analysis in edible oil .
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PubMed
高影响因子
FUEL
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2020
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IF 5.578
Yiying Dai,Genkuo Nie,Si Gong,Li Wang,Lun Pan,Yunming Fang,Xiangwen Zhang,Ji-Jun Zou
Synthesis of jet fuel with high density, good low-temperature property and high thermal stability is significant to aerospace industry. Here, a great-performance jet fuel blending including bi- and tri-cyclic hydrocarbons (C10 ~ C16) is synthesized with high yield through reduced graphene oxide (rGO) assisted H 2 SO 4 catalytic one-pot reaction of cyclopentanol and methylcyclopentane. The reaction occurs through a consecutive way of dehydration, alkylation, rearrangement and hydrogen transfer. Carbon-based materials especially rGO are used as additive to increase the carbon yield by promoting the emulsification of reactants in sulfuric acid. Promoted emulsification improves the alkylation of cyclopentanol with methylcyclopentane and makes the hydrogen transfer easier, which highly increases the conversion of methylcyclopentane (54.9%), the carbon yield (83.2%) and the selectivity (97.3%) of products. Finally, a jet-fuel-ranged blending with overall yield of 71.8% is obtained by distillation, which shows high density of 0.90 g/mL, low freezing point of ＜-72 °C and a high oxidation onset temperature of 195.0 °C. This work provides a simple, efficient and low-cost way to synthesize high performance jet fuel from biomass.
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BIORESOURCE TECHNOLOGY
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2019
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IF 6.669
Lele Jin,Wenzhi Li,Qiying Liu,Longlong Ma,Chao Hu,Ajibola T. Ogunbiyi,Mingwei Wu,Qi Zhang
In this study, the Mo-promoted Ir/SiO 2 (Ir-MoO x /SiO 2 ) catalysts combined with the zeolite HZSM-5 were used for the direct conversion of microcrystalline cellulose (MCC) to liquid fuel (C 5 /C 6 alkanes) in n-dodecane/H 2 O system. A synergistic effect was formed between the partially reduced MoO x species and the Ir particles, which effectively promoted the catalytic activity of Ir/SiO 2 catalyst. When the Mo/Ir molar ratio was 0.5, a high yield of C 5 /C 6 alkanes (91.7%) was achieved at 210 ℃ for 12 h. In addition, the main component of C 5 /C 6 alkanes was n-hexane, which was proven to be obtained by the hydrogenolysis of the key intermediate, sorbitol, formed from the hydrolysis and hydrogenation of MCC.
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PubMed
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FUEL
·
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.
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CHEMICAL ENGINEERING JOURNAL
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2019
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IF 8.355
Mei Xiang,Dongfang Wu
A detailed investigation was carried out to develop novel pore- and morphology-controllable ETS-10 zeolite. The XRD , N 2 adsorption/desorption, SEM, TEM and 29 Si NMR MAS results proved that a series of hierarchical ETS-10 zeolites was successfully synthesized and more importantly, their morphologies and pore sizes can be freely confined in the desired range under the mesoporogen, morphology- and structure-directing actions of different additives. What's more, the close relationship between various additives and raw materials especially titanium source was discussed, which played an active part in morphology change and hierarchical pores formation. This can be ascribed to the special reducibility of inorganic Ti source, system liquidity and pH, and the enhanced inorganic species dissolution. Finally, the synthesized hierarchical ETS-10 materials were used as heterogeneous catalysts for different biomass-derivatives hydrogenation. Remarkably catalytic performance can be attributed to the unique TiO 6 octahedra carrying two negative charges that strengthens the interaction with active metal species, and thus improves their dispersion. Moreover, the inherent strong Lewis basicity and moderate Lewis acidity favor the oriented conversion of reactants. The controllably hierarchical structure and morphology benefit exposure of more highly dispersed active sites and prolong the catalyst life circle. Especially, an analogous molecular-recognition pattern was found by using sodium lignosulphonate, which is identified as the leading role in noticeably enhancing the catalytic activity and selectivity of the correspondingly ETS-10-based catalyst.
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FUEL PROCESSING TECHNOLOGY
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2019
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IF 4.507
Lele Jin,Wenzhi Li,Qiying Liu,Longlong Ma,Song Li,Yang Liu,Baikai Zhang,Qi Zhang
The liquid fuel (made of C 5 /C 6 alkanes) was obtained directly from the hydrogenolysis of microcrystalline cellulose (MCC) with Ir-VO x /SiO 2 combined with HZSM-5 as the composite catalyst in a biphasic system (n-dodecane + H 2 O). The performance of the catalyst was investigated by carrying out a series of experiments using various V/Ir molar ratios , catalyst dosages, reaction temperatures, reaction time, hydrogen pressure and substrates. At the optimized conditions, the cellulose was almost completely converted, and at the same time, a high C 5 /C 6 yield of 85.1% was obtained at 210 °C for 24 h and 6 MPa with the V/Ir molar ratio being 0.13. These results not only proved that Ir-VO x /SiO 2 (V/Ir = 0.13) has excellent performance for the hydrogenolysis of MCC to liquid alkanes, but also indicated that vanadium is a good metal promoter for iridium . In addition, it was proven the C5/C6 alkanes were obtained via sorbitol through the combined effect of Ir-VO x /SiO 2 and HZSM-5.
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ORGANIC GEOCHEMISTRY
·
2024
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IF 2.6
Wenna Liu,Wanglu Jia,Qiang Wang,Jian Chen,Jinbu Li,Ping’an Peng
The isotopic fractionation of organic compounds during evaporation is one of the most critical issues in the field of stable isotopes. The hydrogen (H) isotopic compositions of light hydrocarbons (LHs) in oil have gained increasing interest in the research of oil genesis in recent years. However, compared to carbon (C) isotopes, our understanding of H isotopic fractionation patterns and influences for various types of LHs during evaporation is limited. In this study, we performed evaporation experiments at a constant temperature on LHs in three systems: single compound, alkane mixture, and light oil. We assessed the contents and H isotopic compositions of individual LHs in the residual liquid phase. The degree of H isotopic fractionation and influencing factors are studied combined with C isotopes. The H isotopic fractionation of LHs exhibits “inverse isotope fractionation” characteristics (a depletion in D in the residual LHs) with progressive evaporation, which is opposite to the C isotopic fractionation. The degree of isotopic fractionation is influenced by the evaporation system, the compounds’ molecular weight, and their structure. (1) The isotopic fractionation degree of H and C decreases in the following order: light oil > alkane mixture > single compound system. This difference may be related to the unsaturation level of the evaporative system and the evaporation matrix. (2) For LHs with the similar structure in the same evaporation system, the degree of H isotopic fractionation increases with increasing molecular weight due to the buffering effect of the sample pool, while the magnitude of C isotopic fractionation decreases. (3) For LHs with the same C number, methylcyclohexane (MCH) has a lower evaporation rate and less isotopic fractionation than the other C 7 compounds like 3-methylhexane (3-MH), n -heptane ( n C 7 ), and toluene (Tol). The distinctive fractionation characteristics of H isotopes make them very useful in geological applications. Combining H and C isotopic compositions of the same compound with the commonly used molecular ratios of LHs (e.g., n C 7 /MCH, Tol/ n C 7 ) enables full differentiation of three critical processes controlling oil formation: evaporation, thermal maturation, and biodegradation. Furthermore, the differences in H isotopic compositions between C 7 LHs (3-MH, n C 7 , and Tol) may be changed by evaporation, but the variation range is much smaller than that caused by source differences. Therefore, combining H and C isotopes may have great potential for oil source characterizations.
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