FLUID PHASE EQUILIBRIA
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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
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2025
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IF 2.1
Yue Wang,Wenxiu Li,Saisai Wang,Pengfei Wang,Tao Zhang
Ionic liquids (ILs) exhibited enhanced extraction performance compared with traditional organic solvents in azeotropic separation processes. In this paper, three kinds of ILs: 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]), 1-butyl-3-methylimidazolium diethylphosphate ([BMIM][DEP]), and 1-hexyl-3-methylimidazolium hexafluorophosphate ([HMIM][PF6]) were considered as extractants for separate n-heptane and acetone. The effect of temperature (298.15, 303.15, and 308.15 K) on the selectivity and distribution coefficients was then investigated. Liquid–liquid equilibrium (LLE) experiments demonstrated that three ILs proved the separation efficiency for acetone. The experimental data were then regressed and validated using the Othmer–Tobias equation and the Hand equation. In addition, the NRTL (nonrandom two liquids) model was used to correlate the LLE experimental data, and the NRTL parameters are verified through the “GMcal_TieLinesLL” tool. Finally, molecular interaction mechanisms were further elucidated through surface electrostatic potential mapping (ESP) and an independent gradient model based on Hirshfeld partition analysis (IGMH) analysis. This research establishes a theoretical framework for industrial-scale separation of ketone/alkane mixtures while providing valuable insights into structure–property relationships of ILs in separation processes.
研究领域:
化学工程
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分离技术
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物理化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2018
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IF 2.196
Ying Zhang,Yutian Chen,Taotao Zhan,Maogang He
The speed of sound in n-heptane was measured by the Brillouin light scattering (BLS) method. The examined region is T = (513.40 to 650.90) K along seven isobaric lines at p = (2.5, 3.0, 4.0, 5.0, 6.0, 8.0, and 10.0) MPa, which was near the critical point of n-heptane. The relative expanded uncertainty (k = 2) of BLS experimental system is estimated to be <0.013 for the speed of sound measurement. The variation tendencies of the speed of sound with increasing temperature and pressure were illustrated. Moreover, the calculated results from the multiparameter equation of state (EOS) proposed by Span and Wagner were employed to assess the experimental data in this paper. The absolute average of the deviations (AAD) between the experimental data and the calculated results is 1.22% in the whole investigated p–T region.
研究领域:
热力学
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物理化学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
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2024
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IF 3.9
Wen-Xia Zhang,Xi Zhao,Lin-Ya Xu,Shuang Xia,Yu-Fen Zhou,Chong-Lai Chen,Hai-Hua He,Meng-Fei Luo,Jian Chen
The surface Pt species and adsorbed oxygen on the Pt/ZrO 2 catalyst were successfully modulated by altering the preparation methods, resulting in distinct catalytic behaviors for CO, n-heptane, and toluene oxidation. The Pt/ZrO 2 catalyst was initially prepared via wetness impregnation and subsequently reduced in an H 2 atmosphere to obtain the Pt/ZrO 2 -R catalyst. In contrast, the Pt/ZrO 2 -E catalyst was synthesized using ethanol solvent (also serving as a reducing agent) instead of water during wetness impregnation. Moreover, the pre-prepared Pt nanoparticles were loaded onto the ZrO 2 surface using polyvinylpyrrolidine (as a protective and structure directing agent) dissolved in ethanol solvent to fabricate the Pt/ZrO 2 -EP catalyst. Among these catalysts, the Pt/ZrO 2 -R exhibits superior catalytic activity towards CO oxidation due to its abundant metallic Pt species. It is found that activity of Pt/ZrO 2 catalyst for n-heptane oxidation is positively correlated with its surface adsorbed oxygen concentration, thus the highest activity is achieved over the Pt/ZrO 2 -EP catalyst possessing a higher concentration of surface adsorbed oxygen species. Unlike CO and n-heptane oxidation, toluene oxidation activity is affected by multiple factors, it is primarily promoted by synergistic catalysis between metallic Pt species (Pt 0 ) and surface adsorbed oxygen species over the Pt/ZrO 2 -EP catalyst. Our preliminary findings underscore that precise modulation of sensitive active sites on surfaces plays a critical role in specific catalytic reactions.
研究领域:
催化化学
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材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
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2020
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IF 2.888
Midong Shi,Wei Zeng,Shixian Song,Meiting Zhou,Wei Wang
Liquid-liquid equilibrium (LLE) data for {n-heptane + p-xylene (PX) + furfural/dimethyl sulfoxide (DMSO)} ternary systems were measured at 303.15 K and 323.15 K and atmospheric pressure. Extraction performance of furfural and DMSO were evaluated using distribution coefficient (D) and selectivity (S) according to the measured tie-line data. And the results showed that DMSO had better extraction performance than furfural for separation of n-heptane and PX. Both UNIQUAC and NRTL models were used to correlate the experimental LLE data, and relevant interaction parameters were obtained. Consistency between the measured LLE data and the calculated by these two models was well evaluated by RMSD and maximum absolute deviation. Moreover, reliability of binary interaction parameters was confirmed by topological analysis related to the Gibbs tangent plane test.
研究领域:
化学工程
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物理化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
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2022
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IF 3.269
Hengfei Zhang,Taotao Zhan,Junshuai Chen,Xin Li,Ying Zhang,Maogang He
The speed of sound of the (n-butanol + n-heptane) mixtures was measured by the Rayleigh-Brillouin light scattering method at temperatures ranging from 298.05 to 618.29 K and pressures up to 9.0 MPa. The relative expanded uncertainty of the speed of sound experimental system is 1.2% (coverage factor k = 2). The mixing effects were analyzed from molecular interactions: the trend that speed of sound rises first and then decreases with the n-butanol concentration mainly depends on the rupture of alkanol structures and the molecular association, respectively. Lacking other thermophysical properties of mixtures at high temperature and pressure, six classical speed-of-sound mixing rules only based on pure component properties were evaluated by experimental data, including Wood, Nomoto, Van Dael, Impedance dependence relations, and Time-average model and Volume-average model. It was found that the estimates by Wood’s relation (recognized as Junjie’s relation) agree best with experimental data. The applicability of mixing rules was further evaluated by 21 mixtures of (n-alkanol + n-alkane), where Wood’s relation still obtains great accuracy (average of rRMSDs = 0.91% and maximum = 1.84%). For these (n-alkanol + n-alkane) mixtures of weak interaction, Wood’s relation is expected to give reliable estimates for the under a wide temperature and pressure range, for just insignificant volume change being ignored.
研究领域:
物理化学
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热力学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS SURVEYS FROM ASIA
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2025
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IF 2.3
Zhu Mengxuan,Li Hongqing,Wang Xin,Wang Longyang,Wang Rui,Jiang Heng,Jin Changzi
Design of efficient metal-acid bifunction catalysts is of significance for development of hydroisomerization of linear alkanes. In this study, the spatial configurational construction of Pt-ZSM-5 catalytic system was achieved by fabrication of acidic ZSM-5 zeolite and mesoporous silica core-shell composites equipped with controlled location of Pt sites, which aim to explore the effect of functional sites proximity on isomerization reactivity. A series of characterization techniques such as X-ray diffraction, transmission electronic microscopy, N 2 physical adsorption, NH 3 temperature programmed desorption, X-ray photoelectron spectroscopy and so on had confirmed that the synthesized core-shell bifunctional catalysts with different Pt location possessing similar textural, acid and metal properties. In the catalytic hydroisomerization of n -heptane, however, the catalyst with Pt sites locating at acid zeolite exhibits superior n -heptane conversion and isomerization selectivity, which indicates that proximity of active sites at atomic scale may be more conducive to their synergistic effect when the diffusional limitation from zeolitic channel is minimized. These results had presented new direction for the preparation of efficient bifunctional catalysts in hydroisomerization of linear alkanes.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
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2024
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IF 4.1
Bangjian Liu,Hong Yang,Huiqing Xu,Quanjie Liu,Shuandi Hou,Anfeng Zhang,Xinwen Guo
Effective regulation of acid sites is essential to strengthen the reaction performance and to modulate product distribution of an isomerization reaction. In this study, ZSM-50 (Al-EUO) and Fe-substituted ZSM-50 zeolites, namely FeAl-EUO-n (n = 0.25, 0.50 and 0.75) and Fe-EUO, are synthesized by a seed-assisted hydrothermal method. The study has shown that Fe has effectively entered the Al-EUO framework as a tetrahedrally-coordinated species. More importantly, the Fe-substitution has resulted in a significant increase in the amount of surface weak- and medium-strength Brönsted acids and a reduction in the strength of strong acids of FeAl-EUO-n. This study also evaluates the catalytic performance of Pt/FeAl-EUO-n catalysts in n-heptane hydroisomerization. It shows that the introduction of Fe in ZSM-50 greatly enhances the isomer yield, achieving a maximum yield of 66.1 % at 320 °C over Pt/FeAl-EUO-0.50 compared to 16.4 % at 300°C over Pt/Al-EUO. At the same time, the fraction of multi-branched iso -heptane also increases noticeably in the reaction product.
研究领域:
化学工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
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2023
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IF 3.8
Xiaoxue Zhang,Shuman Xu,Jing Hao,Xiaojin Xie,Fengqiu Chen,Dang guo Cheng
Single-crystalline hierarchical ZSM-5 zeolites with different particle sizes (namely 100, 140, and 200 nm) were successfully prepared by adjusting the amount of tetrapropylammonium hydroxide (TPAOH), and investigated in n -heptane catalytic cracking reaction. Diffusional measurements by zero-length column (ZLC) method showed that the apparent diffusivities of n -heptane decreased with the reduction of particle size, indicating the existence of surface barriers. Moreover, with the decrease of particle size, the additional diffusion path length increased, which meant the influence of surface barriers became more apparent. Despite the change of surface barriers, the intracrystalline diffusion still dominated the overall diffusion. Catalytic performance showed that the zeolite with smaller particle size had better stability.
研究领域:
催化化学
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材料科学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING RESEARCH & DESIGN
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2021
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IF 3.739
Han Wang,Shulan Wang,Jingqiao Zhang,Han Wang,Hui Li,Yi Zhao
Several mesostructured cellular foams (MCFs) were prepared and modified for NO adsorption. TMB, NH 4 F and n -heptane were used as swelling agents, and APTES was used as the modified agent. The morphological structure, chemical composition, thermostability were tested to study the effects of the preparation process on the characterizations of materials. NO adsorption ability of the materials were studied and discussed. NH 4 F and n -heptane had better pore swelling effects compared to TMB, however adding TMB together with NH 4 F and n -heptane could not enlarge the pore structure further. The MCFs materials could keep steady below 800 °C, but after grafting APTES on the surface of the materials, the thermogravimetric curve of materials began to decrease at 300 °C. The materials using NH 4 F and n -heptane as the swelling agents, and modified by APTES had better NO adsorption ability, and the selectivity of the materials were decided by the molecular polarity of the adsorbates. After the modification, the hydrophobic effect of the samples could increase because of the alkyl groups in APTES. The adsorption capacity of the materials could keep steady for ten times without the coexisting component, H 2 O, CO 2 and SO 2 all had negative effects on the regeneration of the materials.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
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2020
·
IF 2.888
Taotao Zhan,Yuqi Su,Ying Zhang,Xiangyang Liu,Maogang He
The mutual diffusion coefficients of ethanol + n-heptane and diethyl carbonate (DEC) + n-heptane binary solutions were measured over the mass fraction from 0.05 to 0.95 at the pressure of 0.101 MPa, and at temperatures T = 288.15 K, 298.15 K, 308.15 K and 318.15 K. The expanded relative uncertainty ( k = 2) of the Mach-Zehnder digital holographic interferometry employed in the measurements was estimated to be less than 2.4% with the confidence level of 0.95. A semi-empirical correlation was used to fit the mutual diffusion coefficients as a function of concentration and temperature, which represents the experimental values with the absolute average relative deviations being 0.94% for ethanol + n-heptane and 0.90% for DEC + n-heptane. The temperature and concentration dependences of the mutual diffusion coefficients were investigated. The strongest non-ideal thermodynamic behaviors appear when the mass fraction of ethanol is within the limits of 0.45 to 0.65 or that of DEC is within the limits of 0.45 to 0.65. Besides, the mutual diffusion coefficients of ethanol + n-heptane and DEC + n-heptane binary solutions are found to be extremely sensitive to the solute concentration over the mass fraction of ethanol and DEC from 0.00 to 0.05, respectively.
研究领域:
物理化学
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热力学
✓ 已验证
DOI
高影响因子
ENERGY & FUELS
·
2020
·
IF 3.421
Chenglong Wen,Jundong Xu,Xueman Wang,Yu Fan
A novel SO42–/ZrO2@SAPO-11 (SZ@SA-11) composite was synthesized via a two-step method, and the corresponding SZ@SA-11 supported Pt catalyst was applied to catalyze n-heptane hydroisomerization. First, UiO-66@SAPO-11 is produced by the growth of UiO-66 on SAPO-11 due to the covalent bonds between Zr and the oxygen in the hydroxyl groups of SAPO-11. Then, UiO-66@SAPO-11 is decomposed to form ZrO2@SAPO-11 via calcination in air, and the SZ@SA-11 composite is obtained by the impregnation of ZrO2@SAPO-11 with (NH4)2SO4 and subsequent calcination. Compared with the physical mixture of SO42–/ZrO2 and conventional SAPO-11 (SZ+SA-11), SZ@SA-11 possesses smaller ZrO2 particles and more tetragonal ZrO2. Moderate and strong Brønsted acid sites (MSBAS) are produced only via interactions between tetragonal ZrO2 and sulfate, so SZ@SA-11 with more tetragonal ZrO2 has a greater amount of MSBAS than SZ+SA-11. These advantages of SZ@SA-11 endow the corresponding Pt/SZ@SA-11 catalyst with a better performance for n-heptane hydroisomerization compared to Pt/(SZ+SA-11). In addition, compared with the other counterparts such as Pt/SZ and Pt/SA-11, Pt/SZ@SA-11 presents higher selectivity for total isomers (91.5%), higher selectivity for multibranched isomers (22.6%), and a lower cracking selectivity (8.1%) in n-heptane hydroisomerization. The strategy proposed herein provides a new insight into the acidity adjustment of the molecular-sieve-based catalysts for hydrocarbon hydroisomerization.
研究领域:
催化化学
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能源化学
✓ 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）