JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2015
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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
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2023
·
IF 4.7
Chuanqi Geng,Xiaojia Wu,Hui Yu,Xinyu Li,Chencan Du,Zhiyong Zhou,Zhongqi Ren
In this study, N-butylpyridinium tetrachloroferrate ([Bpy][FeCl 4 ]), a temperature-responsive solvent, was applied to achieve reversible phase-change extraction with simultaneous solvent recycling for the ethanol/heptane and toluene/heptane systems. The distribution and selectivity coefficients were 7.87 and 0.862, respectively, for ethanol in the 60 mass% ethanol/heptane system; the corresponding values for toluene in the 20 mass% toluene/heptane system were 1.34 and 44.3, respectively, which are significantly better than those for existing conventional solvents. [BPy][FeCl 4 ] was reused five times in each system, and the extraction efficiency remained stable at high values. The experimental results as a function of temperature and solvent:solute mass ratio showed that the reversible phase-change process by [BPy][FeCl 4 ] could be achieved under a range of conditions. This process achieves switchable phase-change extraction and simultaneous solvent recovery, thus offering the possibility of saving energy, reducing equipment requirements, and simplifying operations.
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
FLUID PHASE EQUILIBRIA
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2024
·
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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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
COMBUSTION SCIENCE AND TECHNOLOGY
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2013
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IF 1.011
Ming-Di Li,Zhong Wang,Yang Zhao,Rui-Na Li,Shuai Liu
An experimental study was reported on premixed ethanol/n-heptane/oxygen/argon flames at low pressure (4.655 kPa) with ethanol blending ratios of 0 (Flame 1), 15% (Flame 2), and 30% (Flame 3). The equivalence ratio was 1.0. Flame species were identified using molecular beam mass spectrometry with tunable synchrotron photoionization. The flame temperature profiles were measured with a Pt-6%Rh/Pt-30%Rh thermocouple. The mole fraction profiles of major and intermediate flame species under different ethanol ratios were analyzed in this article. Experimental results showed that the temperature profiles of measured flames fall almost on a single curve, which means that ethanol had little effect on flame temperature. The peak mole fraction of the main combustion products occurred 2–6 mm above the burner. With the increase of ethanol blending ratios, the mole fractions of H2, CO, and CO2 decreased, the mole fraction of H2O increased, and the mole fractions of intermediate combustion products (C2H2, C2H4, HCHO, C3H3) decreased. During the combustion process, the oxygen atom of ethanol partly replaces the O2, thus the final mole fraction of O2 increased with the increase of ethanol ratios.
研究领域:
化学工程
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燃烧学
✓ 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
Junwei Cui,Shengshan Bi,Andreas P. Fröba,Jiangtao Wu
The present work focus on the measurement of viscosity and interfacial tension of n -heptane ( n -C 7 H 16 ) with dissolved carbon dioxide (CO 2 ) by the surface light scattering. The method allows an absolute determination of both properties in a contactless way. The experiments were conducted in macroscopic thermodynamic equilibrium at temperatures from (298 to 473) K and saturation pressures up to 5.5 MPa. For sample preparation of binary mixtures of n -C 7 H 16 with dissolved CO 2 after its addition, the equilibration process could be checked to be completed by showing that viscosity and interfacial tension are independent on time. For reaching equilibrium, at least two hours were elapsed between the addition of CO 2 and the start of the measurement. For both viscosity and interfacial tension, typical expanded uncertainties are 3% on a confidence level of 95%. The viscosity results were correlated with an empirical equation, where the absolute average deviation (AAD) and the maximum absolute deviation (MAD) between experiments and correlation were 1.9% and 7.2%, respectively. For the viscosity, a data comparison was hindered because of the lack of literature data. For the interfacial tension, which can also be represented by an empirical correlation and good agreement with literature can be found.
研究领域:
物理化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
FLUID PHASE EQUILIBRIA
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2014
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IF 2.241
Fufeng Cai,Guomin Xiao
This work demonstrates the capabilities of three phosphoric-based ionic liquids (ILs) as solvents for the extraction of ethanol from its mixture with heptane. The knowledge of liquid–liquid equilibria (LLE) of this mixture is essential for the design of the extraction separation process. For this reason, the experimental LLE data were measured for the ternary systems, {ethanol + heptane + 1,3-dimethylimidazolium dimethylphosphate ([MMIM][DMP]), or 1-ethyl-3-methylimidazolium diethylphosphate ([EMIM][DEP]), or 1-butyl-3-methylimidazolium dibutylphosphate ([BMIM][DBP])}, at T = 298.2 K and atmospheric pressure. The thermodynamic nonrandom two-liquid (NRTL) model was used to correlate the experimental results for the studied ternary systems. The extraction capabilities for the studied ILs were evaluated by solute distribution ratios of ethanol and ethanol/heptane selectivities. Moreover, this extraction capability was also compared with other ILs obtained from the literature. The experimental results show that the studied ILs can be suitable to act as solvents for the separation of the ethanol and heptane in the extraction process. The extraction capabilities for the studied ILs decrease in the following order [MMIM][DMP] > [EMIM][DEP] > [BMIM][DBP].
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
FUEL
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2021
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IF 6.609
Tao Pan,Sida Ge,Mengnan Yu,Yana Ju,Ran Zhang,Pei Wu,Kuanyu Zhou,Zhijie Wu
Zn modified ZSM-5 zeolite supported Ni bifunctional catalysts were prepared by in-situ hydrothermal synthesis (Zn-Ni-ZSM-5), co-impregnation method (Zn-Ni/ZSM-5) as well as combining in-situ hydrothermal synthesis of Zn-ZSM-5 and sequential impregnation of Ni (Ni/Zn-ZSM-5) and used for the selective converting olefin to aromatics applicable for FCC gasoline hydro-upgrading. The Lewis (L) acid sites generated by ZnOH + species and hydrogenation active sites from Ni 0 species were varied with preparation method, in which their locations at the external surface or micropores of zeolite changed the acid properties of catalysts. Comparing to the Zn-Ni/ZSM-5 from the co-impregnation method, direct in-situ hydrothermal method could incorporate Zn and Ni species within zeolite, which makes the strong interaction between the metal species and the framework Al to form medium-strong L acids (ZnOH + /NiOH + ). This leads to the decrease of ratio of Brønsted acid sites to L acid sites (B/L) from 0.40 to 0.12 and the difficulty in reducing of Ni cations to Ni 0 from 57% to 30% Ni 0 percent. Ni/Zn-ZSM-5 sample prepared by incorporating Zn species into micropores and sequential depositing Ni species at the external surface of zeolite possesses a low B/L ratio similar to Zn-Ni-ZSM-5 (0.20 versus 0.12) but a much higher Ni 0 percent (52% versus 30%). Zn-Ni-ZSM-5 shows closer intimacy between Zn and Ni species comparing to Zn-Ni/ZSM-5 and Ni/Zn-ZSM-5. For the 1-hexene aromatization, the formed iso -alkene at acid sites was quickly saturated to iso -alkanes by the adjacent Ni 0 particles over Ni-Zn-ZSM-5 catalyst in hydrogen steam. However, the location of aromatization active sites (ZnOH + , L acid sites) in micropores and hydrogenation active sites (Ni 0 species) on external surface of Ni/Zn-ZSM-5 makes the tandem conversion of n-alkene → iso -alkene → aromatics, rather than the n-alkene → iso -alkene → iso -alkane. Thus, Zn-Ni-ZSM-5 with close intimacy of ZnOH + and Ni 0 particles shows a high iso -alkane selectivity (27.9% iC 4 + ), while Ni/Zn-ZSM-5 exhibits a high aromatics selectivity (39.6 %) in the conversion of 1-hexene in hydrogen steam. Similar results have also found in the conversion of n-heptane. Here, the control of the intimacy of Zn and Ni in ZSM-5 zeolites has been realized to be a good protocol to adjust the selective conversion of olefins/alkanes to aromatics versus iso -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
JOURNAL OF CHEMICAL THERMODYNAMICS
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2022
·
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
JOURNAL OF CHEMICAL THERMODYNAMICS
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2021
·
IF 3.178
Zhang Youqi,Zhang Qinqin,Xin Hua,Lv Meiheng,Zhang Zhigang
Ionic liquids (ILs) have been extensively used in the separation of alkane + alcohol azeotropes as entrainers by liquid–liquid extraction. n-Butanol is widely added to the fuel because of its high calorific value and low volatility. It is of significance to recovery n-butanol from the azeotropic mixture containing n-butanol. In this work, ionic liquids, formed by combining 17 cations and 12 anions, were screened based on the COSMO-RS model. 1-ethyl-3-methylimidazolium dicyanamide [EMIM][DCA], 1-butyl-3-methylimidazolium dicyanamide [BMIM][DCA] and 1-hexyl-3-methylimidazolium dicyanamide [HMIM][DCA] were selected as entrainers. The liquid–liquid equilibrium data of the ternary system {n-heptane + n-butanol + [EMIM][DCA], n-heptane + n-butanol + [BMIM][DCA], n-heptane + n-butanol + [HMIM][DCA]} were measured at 298.15 K and 101.3 kPa. The quality of experimental data was tested by Othmer-Tobias, Bachman and Hand equations. The distribution coefficient (β) and selectivity (S) were calculated to evaluate the separation effect of the three ILs. The NRTL model was used to correlate liquid–liquid equilibrium experimental data. Finally, quantum mechanics calculations were performed to study the interactions between ILs and n-butanol through the reduced density gradient (RDG) function and quantum theory of atom in the molecule (QTAIM). The results of quantum chemistry calculation showed that the separation of n-butanol and n-heptane mixture by ionic liquids with [DCA] anions were dominated by hydrogen bonding. The research process is devoted to the development of green entrainers.
研究领域:
化学工程
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量子化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2020
·
IF 2.369
Ying Zhang,Taotao Zhan,Junshuai Chen,Xin Li,Qi Zhou,Maogang He
The experimental speeds of sound for the binary system of ethanol (1) + n-heptane (2) with the mole fractions of ethanol being (0.100, 0.300, 0.500, 0.700, and 0.900) were measured by Rayleigh-Brillouin light scattering spectroscopy at temperatures from 293.35 to 433.89 K along three isobaric lines from 0.1 to 5.0 MPa. The expanded relative uncertainty for the reported speed of sound is estimated to be 1.6% with the level of confidence of 0.95 (coverage factor k = 2). The experimental data were correlated as a function of temperature and pressure, yielding absolute average percentage deviations of 0.34, 0.20, 0.38, 0.28, and 0.29% for the mole fractions of ethanol being 0.100, 0.300, 0.500, 0.700, and 0.900, respectively. Within the temperature limits of 298.15–318.15 K, the derived thermo-acoustic properties for the binary system of ethanol (1) + n-heptane (2), including the density, the specific isobaric heat capacity, the isentropic compressibility, the isobaric thermal expansivity, the isothermal compressibility, the specific heat ratio, the internal pressure and the free volume at pressures up to 5.0 MPa, and the intermolecular free length under atmospheric pressure were calculated and analyzed.
研究领域:
物理化学
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热力学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING RESEARCH & DESIGN
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2021
·
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
危险品化学品经营许可证（带存储）