Defence Technology
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2022
·
IF 4.035
Jin-hu Liang,Shu-tong Cao,Fei Li,Xiao-liang Li,Rui-ning He,Xin Bai,Quan-De Wang,Yang Li
The pyrolysis of cyclohexane, methylcyclohexane, and ethylcyclohexane have been studied behind reflected shock waves at pressures of 5 and10 bar and at temperatures of 930–1550 K for 0.05% fuel diluted by Argon. A single-pulse shock tube (SPST) is used to perform the pyrolysis experiments at reaction times varying from 1.65 to 1.74 ms. Major products are obtained and quantified using gas chromatography analysis. A flame ionization detector and a thermal conductivity detector are used for species identification and quantification. Kinetic modeling has been performed using several detailed and lumped chemical kinetic mechanisms. Differences in modeling results among the kinetic models are described. Reaction path analysis and sensitivity analysis are performed to determine the important reactions controlling fuel pyrolysis and their influence on the predicted concentrations of reactant and product species profiles. The present work provides new fundamental knowledge in understating pyrolysis characteristics of cyclohexane compounds and additional data set for detailed kinetic mechanism development.
研究领域:
化学工程
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燃烧科学
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DOI
高影响因子
Nature Communications
·
2024
·Vol. 15
·期 1
·1-11
·
IF 14.7
Fan Yaqi,Tang Xiaomin,Hu Junyi,Ma Ye,Yang Jiabao,Liu Fengqing,Yi Xianfeng,Liu Zhiqiang,Song Lijuan,Zheng Anmin,Ma Yanhang
The efficient purification of cyclohexane is critical, serving as an essential feedstock to produce resins, nylon fibers and pharmaceutical intermediates. However, efficient purification remains a challenging task due to the similarity of cyclohexane and benzene molecules in terms of size and boiling point. In this work, we reported on the synergy of pore size and silanols inside an -SVR-type zeolite for the efficient production of ultrapure cyclohexane (benzene <1 ppm) from benzene/cyclohexane mixture. Under ambient conditions, the SSZ-74 zeolite demonstrated the highest mass-based productivity of 14.5 L/kg for ultrapure cyclohexane among several common zeolites with a considerable dynamic selectivity of ~9.5. The separation ability was evaluated through density functional theory (DFT) calculations and ab initio molecular dynamics (AIMD) simulations. The unique ordered silanols inside the zeolite frameworks demonstrated strong but reversible interactions with benzene through SiOH…π interactions, as revealed by in situ Fourier Transform infrared (FTIR) spectra.
研究领域:
化学工程
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材料科学
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DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2015
·
IF 2.037
Xiong Zheng,Ying Zhang,Maogang He
The speed of sound in hexane and heptane (mass purity > 0.990, GC) was measured using the Brillouin light scattering method at T = (300.15 to 506.15) K for hexane, (302.15 to 536.15) K for heptane), and p = (1.0 to 8.5) MPa, including saturated liquid, saturated vapor, and compressed liquid. The expanded relative uncertainty (k = 2) of the speed of sound was estimated to be less than 1.0% over the whole investigated range of states. Polynomial representations for the speed of sound in hexane and heptane were fitted to the experimental results. A comparison of the speed of sound data with the correlation shows that, for hexane, the AAD is 0.67% for the saturated liquid, 0.36% for the saturated vapor and 0.57% for the compressed liquid respectively, and for heptane, the AAD is 0.46% for the saturated liquid, 0.38% for the saturated vapor and 0.41% for the compressed liquid, respectively.
研究领域:
物理化学
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热力学
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DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2021
·
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.
研究领域:
化学工程
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热力学
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DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2024
·
IF 2.2
Xuyao Tang,Yang Wang,Junwei Cui,Ke Zhang,Shengshan Bi
In this work, n -hexane, cyclohexane and 2-methylpentane were selected to represent linear-alkane, cycloalkane and branched-alkane, respectively. Based on the dynamic light method (DLS), the viscosity, interfacial tension and diffusion coefficient of n -hexane/CO 2 , cyclohexane/CO 2 and 2-methylpentane/CO 2 systems under saturation condition were measured in order to explore the change trend of thermophysical properties of the systems with the same carbon atom number but different molecular structures. The experiments were conducted at the temperatures of 303, 343 and 383 K and at pressures up to 5.64 MPa. The expanded uncertainties（ k = 2）of dynamic viscosity, interfacial tension and diffusion coefficient were 3 %, 3 % and 4.4 % respectively. The experimental results show that n -hexane and 2-methylpentane with similar molecular structure have more similar value of the properties. The effects of different alkane structures on system viscosity, interfacial tension, and diffusion coefficient were explained at the molecular level through radial distribution function, interface thickness, and CO 2 coordination number. At 303.15 K and 4 MPa, the peak radial distribution function of CO 2 /cyclohexane is 1.845, which is greater than that of CO 2 /n-hexane and CO 2 /2-methylpentane molecules. It has been proven that the arrangement of CO 2 /cyclohexane is more orderly, resulting in higher viscosity and lower diffusion coefficient of the system. The interface thickness of CO 2 /cyclohexane is 6.13 nm, which is smaller than CO 2 / n -hexane (7.53 nm) and CO 2 /2-methylpentane (6.3 nm). The smaller the interface thickness, the more compact the structure, the stronger the intermolecular forces, and the greater the interfacial tension. At 303.15 K and 2 MPa, the number of CO 2 coordination sites within 1 nm around liquid phase alkanes is 3.96, which is smaller than 4.78 for cyclohexane and 6.62 for 2-methylpentane. Prove that the coordination number is directly proportional to the diffusion coefficient and inversely proportional to viscosity and interfacial tension.
研究领域:
化学工程
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物理化学
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DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2014
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IF 2.045
Xiaodong Jiang,Guijin He,Xi Wu,Yongsheng Guo,Wenjun Fang,Li Xu
Experimental data of density, viscosity, refractive index, and freezing point have been measured for the binary mixtures of 1,1′-bicyclohexyl with methylcyclohexane, ethylcyclohexane, and butylcyclohexane at different temperatures from T = (293.15 to 318.15) K and the pressure p = 0.1 MPa. The values of density, viscosity, and refractive index at a given temperature, along with the freezing point, increase continuously versus the increasing mole fraction of 1,1′-bicyclohexyl in the binary mixtures. The excess molar volumes (VmE), the viscosity deviations (Δη), and the refractive index deviations (ΔnD) are then calculated and are fitted to the Redlich–Kister equation. All of the VmE and Δη values are observed to be negative for these three binary systems over the whole composition range, which are discussed from the molecular interactions and structural effects. The fundamental data are provided for the preparation of advanced hydrocarbon fuels.
研究领域:
物理化学
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燃料科学
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DOI
高影响因子
FLUID PHASE EQUILIBRIA
·
2024
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IF 2.8
Yuxuan Chen,Wanlin Xu,Mengyi Wang,Xiong Zheng
Thermal conductivity is a very important thermal property parameter in the process of hydrocarbons transportation, storage, combustion and cooling. Therefore, accurate thermal conductivity is important in the utilization of hydrocarbons. In this work, the thermal conductivity of n-hexane and n-heptane in the temperature range of 298.15 K∼523.15 K and pressure range of 0.1 MPa∼15.0 MPa was studied by using transient hot-wire method. In order to facilitate engineering application, function polynomials of temperature and pressure are fitted and correlated with experimental data. The average absolute error of the experimental data and fitting data of n-hexane and n-heptane are 0.72 and 0.61 %, respectively, which proves that the function polynomial can describe the experimental data well. In addition, we compare the collected literature data with our results and find that the literature data is very close to our results. This work is expected to expand the range of available data on the thermal conductivity of n-hexane and n-heptane and contribute to the industrial applications of these two substances.
研究领域:
热物理学
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工程热物理
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DOI
高影响因子
RESEARCH ON CHEMICAL INTERMEDIATES
·
2015
·Vol. 42
·期 3
·2211-2220
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IF 1.221
Liu Shuilin,You Kuiyi,Jian Jian,Luo Qing,Liu Pingle,Ai Qiuhong,Luo He’an
A simple and effective approach for highly selective preparation of nitrocyclohexane from cyclohexane using tert-butyl nitrite as a nitrating agent under atmospheric pressure has been successfully developed in this work. The results indicate that the N -hydroxyphthalimide catalyst gave the best results with 27.3 % of cyclohexane conversion and 88.0 % of selectivity to nitrocyclohexane under optimal reaction conditions. The present reaction provides a novel strategy for the synthesis of nitroalkanes from the nitration of low-carbon alkanes because of the mild reaction condition, simple experimental procedure and high selectivity towards the desired product. This method may be very significant to establish such a synthesis method for aliphatic nitro-compounds from the low-carbon alkanes in organic fields.
研究领域:
有机化学
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合成化学
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DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
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2020
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IF 2.627
Xiujuan Li,Le Chen,Dandan Zhu,Song Yang,Zhong Wu,Mingyang He,Zhihui Zhang,Qun Chen
A novel ZIF-8-CMC hybrid material was fabricated from the hybridization of ZIF-8 and carboxymethylcellulose (CMC) by impregnation method for n -hexane/3-methylpentane separation. The surface properties of ZIF-8 were tailored by introducing CMC into ZIF-8 nanoparticles . In this work, adsorption separation of n -hexane ( n HEX) and 3-methylpentane (3MP) on ZIF-8-CMC were investigated by batch vapor-phase adsorption and liquid-phase breakthrough adsorption. The adsorption selectivity of n HEX/3MP reversed from preferable adsorption of n HEX to preferable adsorption of 3MP upon the increasing of CMC containing in the hybrid materials. As the temperature increases, the adsorption amounts of n HEX and 3MP decrease. With the increasing of CMC contents, the n HEX uptake decreased, the uptake capacity of 3MP increased gradually. For liquid-phase breakthrough adsorption, the dynamic adsorption capacity of n HEX also decreased with the increasing of temperature.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2017
·
IF 2.323
Qingsong Li,Midong Shi,Liping Wang,Gaoyin He,Fan Gan
The liquid–liquid equilibrium (LLE) experiments for n-butanol + n-hexane + ethylene glycol were carried out and LLE data were measured at 298.15, 303.15, 308.15, 313.15, and 323.15 K under atmospheric pressure. The analysis results of the effects of n-butanol content and temperature on extraction showed that high n-butanol content was not favorable for extraction, and temperature had little effect on extraction. Moreover, the NRTL and UNIQUAC models were applied to correlate the LLE data, and the correlated data indicated that the UNIQUAC model showed a better correlation performance.
研究领域:
化学工程
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物理化学
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Laigang Hu,Weiwei Wang,Xiaozeng Miao,Min Hu,Dong Luo,Wenhao Wu,Daohui Lin,Kun Yang
Benzene (Bz) vapor poses significant health risks to humans, even at trace concentrations. Additionally, the separation and recycling of Bz and cyclohexane (Cy) is challenging due to their similar kinetic diameters and boiling points. Developing an adsorption-separation material with stronger interactions with Bz than with Cy could serve as a viable strategy for trace Bz adsorption and Bz/Cy separation. In this study, we present a novel aluminum-based metal–organic framework, ZJU-521(Al), composed of tetrakis (4-carboxyphenyl)methane and a helical chain [Al 5 (OH) 7 (−COO) 8 ] ∞ , featuring a simple network of one-way rods and tetrahedra. This framework exhibited a uniform micropore size of 7.23 Å and a specific surface area of 1,248 m 2 g −1 , demonstrating excellent trace Bz adsorption (4.18 mmol g −1 ) at P/P 0 = 0.01, attributed to its straight channel and orthogonal-array pocket pore structure. The ideal adsorbed solution theory selectivity and separation factor values of ZJU-521(Al) for Bz/Cy were 22.50 and 6.20, respectively, indicating its potential as a material for Bz/Cy separation. Multicomponent simulations showed that Bz molecules were preferentially adsorbed in the pocket due to stronger interactions, such as Al–π interactions. Thus, ZJU-521(Al) exhibits stronger interactions with Bz than with Cy, facilitating effective Bz/Cy separation.
研究领域:
材料科学
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化学工程
·
环境科学
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DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2022
·
IF 4.326
Yuen Bai,Dongyang Liu,Liang Zhao,Jinsen Gao,Chunming Xu,Haitao Pang,Xuhui Gao
The influences of different B (Brønsted) acid site concentrations and the ratio of L (Lewis)/B (Brønsted) on the cracking pathways and product distributions in hexane cracking reactions as a model component of naphtha were investigated. The sodium-modified ZSM-5 catalysts were prepared by the wet impregnation method, and the Si–OH–Al groups of ZSM-5 were broken in the post-treatment process, resulting in a decrease in the number of strong B acid sites (SBAS) and an increase in the number of strong L acid sites (SLAS). The correlations between the n-hexane catalytic cracking reaction pathways and the catalyst acid properties were established. The reduced SBAS inhibits secondary reactions of light olefins such as hydrogen transfer, oligomerization, cyclization, and aromatization, while the increased SLAS and the ratio of SLAS/SBAS promoted the β scission reactions that significantly improved the yields of light olefins. Consequently, the appropriate SBAS and SLAS/SBAS ratios are desirable for the production of ethylene and propylene. The optimal SBAS concentration and SLAS/SBAS ratio ranged from 4.44 to 6.69 μmol/g and 9.18–11.86 for maximum ethylene and propylene yields of 16.14% and 14.63% in hexane catalytic pyrolysis reactions, respectively. Furthermore, the optimally prepared catalysts illustrated superior reactivities and catalytic stabilities in naphtha catalytic pyrolysis reactions under industrial conditions.
研究领域:
化学工程
·
催化材料
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DOI
高影响因子
危险品化学品经营许可证（带存储）