INTERNATIONAL JOURNAL OF MASS SPECTROMETRY
·
2014
·
IF 2.227
Y.Y. Wang,X. Kang,Y.W. Liu,W.Q. Xu,L. Wang,C.Z. Hu,J. Chen,F.Y. Liu,L.S. Sheng,X.L. Zhao,P.F. Zhang,L.F. Zhu
Using vacuum ultraviolet photons produced by synchrotron radiation and reflection time-of-flight mass spectrometer, dissociative photoionization of isooctane was measured in the photon energy region of 9.7–15.6 eV under ultrasonic molecular beam. Then the dissociative ionization products at different photon energies were obtained. By measuring the photoionization efficiency curves, the appearance potentials of the dominative ion fragments and the vertical ionization energy of isooctane were determined. In addition, combining with G3 calculations we obtained the structure and energy of the parent, neutral and ion fragments. By comparing the experimental measurements with the theoretical calculations, the dissociative photoionization channels of isooctane were elucidated, and formation enthalpies of the fragmented ions and the dissociation energy of the parent ion were obtained.
研究领域:
化学物理
·
分子光谱学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2017
·
IF 2.323
Ying Zhang,Yutian Chen,Yu Zheng,Xinxin He,Maogang He
The speed of sound in n-octane and isooctane (2,2,4-trimethylpentane) was measured by the Brillouin light scattering (BLS) method. The examined regions for n-octane are T = (297–580) K along five isobaric lines at p = 0.1, 4.0, 7.0, 10.0, and 12.0 MPa for liquid and T = (573–673) K along ten isobaric lines with p = (3.0–10.0) MPa for supercritical fluid. The examined regions for isooctane are T = (294–525) K along five isobaric lines at p = 0.1, 3.0, 6.0, 10.0, and 12.0 MPa for liquid and T = (543–630) K along six isobaric lines with p = (3.0–10.0) MPa for supercritical fluid. The relative expanded uncertainty of the speed of sound is estimated less than 1.3%. Polynomial representations for the speed of sound in liquid n-octane and isooctane were fitted to the experimental results, respectively. The AADs are 0.27% for n-octane and 0.19% for isooctane. The influence of temperature and pressure on the speed of sound was also analyzed. Moreover, the data were also used to assess the predicted ability of three equations of state for n-octane.
研究领域:
物理化学
·
热力学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2025
·
IF 2.1
Xinyu Liu,Yuhang Chen,Zhao Lei,Long Cheng,Maogang He,Ying Zhang
Isooctane is an ideal gasoline component with a high octane number and low volatility. However, there is a lack of research on the thermal properties of isooctane, especially near the critical point. This work uses dynamic light scattering to measure the thermal diffusivity of isooctane in the temperature range of (298.15–583.15) K, along 8 isobaric lines p = (0.1, 2.0, 2.5, 2.7, 3.0, 3.5, 5.0, 7.5) MPa, and analyzes the trend of thermal diffusivity with temperature and pressure. The average relative combined expanded uncertainty of the thermal diffusivity is 0.0214. Meanwhile, the experimental data were compared with the calculated values from thermal conductivity, and the absolute average values of the relative deviation and maximum deviation were 2.88 and 8.22%, respectively.
研究领域:
物理化学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Yuqi Su,Pengcheng Sun,Junshuai Chen,Maogang He,Ying Zhang
The transport properties including thermal diffusivity and Fick diffusion coefficient are of great significance to the optimization of heat and mass transfer processes in the combustion of gasoline. In this work, the thermal diffusivities and Fick diffusion coefficients of ethanol + isooctane binary mixtures were measured by dynamic light scattering method at mole fraction of ethanol x 1 = 0.1, 0.3, 0.5, 0.7 and 0.9, and over the temperature range from 323.15 K to 523.15 K along the isobaric lines including 2.5 MPa, 5 MPa, 7.5 MPa and 10 MPa. The variation of thermal diffusivity and Fick diffusion coefficient with the temperature, pressure and composition was analyzed to guide the optimization of combustion process. Four classic estimation models were used for the calculation of the thermal diffusivities of the binary mixtures of ethanol + isooctane. The Scheffé model has the best calculation performance with the average absolute relative deviations (AARD) of 2.09 %. The UNIDIF model was used to estimate the Fick diffusion coefficients of ethanol + isooctane with the AARD of 4.75 %.
研究领域:
化学工程
·
燃烧科学
·
热力学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2022
·
IF 3.269
Ying Zhang,Songtao Cao,Yuqi Su,Maogang He
The mutual diffusion coefficients of ethanol + isooctane and n- butanol + isooctane mixtures were measured by digital holographic interferometry. The measurements were performed at atmospheric pressure with temperatures ranging from 288.15 K to 318.15 K and mass fractions ranging from 0.05 to 0.95, and the effects of changes in temperature and composition were discussed. Based on the local composition theory, a new model is proposed for predicting mutual diffusion coefficients. Modified from the Vignes model, this model can be used to predict the mutual diffusion coefficient in ideal or non-ideal mixtures within a given deviation range. A comparison of the prediction results for the new model and five other models shows that the new model is far superior to the Darken model and Vignes model, and also has some advantages over the other models.
研究领域:
化学工程
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
FLUID PHASE EQUILIBRIA
·
2023
·
IF 2.6
Yanqiong Bao,An Huang,Guangzhao Qin,Xiong Zheng
As isooctane and n-octanol are widely used in many industrial areas, the thermal conductivity data of these fluids is crucial in the energy conversion process. Therefore, obtaining reliable thermal conductivity data is of great significance for industrial applications. The thermal conductivity of isooctane and n-octanol was measured with a transient hot-wire device, which has a relatively expanded uncertainty of 2.0 % with a confidence level of 0.95 ( k =2). The measurement of these two fluids covers the temperature range from 303.15 to 523.15 K and the pressure range from 0.1 to 15 MPa. The experimental data were fitted into a polynomial with AADs and MDs of 0.35 % and 1.08% for isooctane, and 0.38 % and 0.99 % for n-octanol, respectively. This work is expected to supplement the data blank of the thermal conductivity of isooctane and n-octanol and promote their application.
研究领域:
热物理
·
化学工程
·
工业应用
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF CHEMICAL KINETICS
·
2020
·Vol. 53
·期 3
·428-439
·
IF 1.531
Handong Liao,Haodong Chen,Zhongkai Liu,Ruzheng Zhang,Feng Zhang,Bin Yang
Nonequilibrium plasma has a great potential in the lean combustion of gasoline engines. However, fundamental studies on plasma-assisted combustion on gasoline components are limited. In the present study, Low-temperature oxidation behaviors for n -heptane and iso-octane in a plasma flow reactor were investigated. Species measurements were performed at room temperature and low pressure of 40 mbar using the electron ionization molecular-beam mass spectrometry (EI-MBMS). A total of 72 and 57 species were quantified in n -heptane and iso-octane oxidation, respectively. Based on measured species data, reaction networks of n -heptane and iso-octane in the plasma system were discussed. Particularly, some typical low-temperature intermediates, such as cyclic ethers, diones, and ketohydroperoxides, were observed, suggesting the applicability of the classical low-temperature reaction scheme in the plasma system of large hydrocarbons. The results indicate that the major role of plasma discharge on the low-temperature oxidation of large hydrocarbons is either to breakdown large fuel molecules or to accelerate the chain initiation reactions. We also investigated the parametric effects of voltage, frequency, and residence time on the species pools, and found that the increase of these parameters leads to higher production of intermediates. The whole system reactivity was most sensitive to the plasma voltage. The difference between plasma frequency and residence time on the species formation was found. Moreover, some highly temperature-sensitive reactions, such as the RO 2 → QOOH, proceed at very low temperatures (around 340 K) in the plasma system, which was potentially attributed to the additional energy from plasma-generated species.
研究领域:
化学动力学
·
燃烧学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2021
·
IF 3.178
Yuqi Su,Taotao Zhan,Xiangyang Liu,Maogang He,Ying Zhang
The mutual diffusion coefficients of (isooctane + n-heptane) and (n-decane + 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, respectively. The expanded relative uncertainty of the digital holographic interferometry employed in this measurement was estimated to be 2.6% with the confidence level of 0.95 ( k = 2). The influences of temperature and composition on the mutual diffusion coefficients were discussed. Moreover, the semi-empirical correlations of mutual diffusion coefficients for (isooctane + n-heptane) and (n-decane + n-heptane) binary mixtures were given by fitting the experimental results as a function of temperature and mass fraction. The absolute average of relative deviations of the correlations are 0.72% for (isooctane + n-heptane) and 0.54% for (n-decane + n-heptane), respectively.
研究领域:
化学
·
物理化学
✓ 已验证
DOI
高影响因子
EXPERIMENTAL THERMAL AND FLUID SCIENCE
·
2024
·
IF 2.8
Xuan Zhao,Dandan Qi,Kaixuan Yang,Chen Chen,Lei Xu,Yaoyao Ying,Tianjiao Li,Guangxue Zhang,Dong Liu
The effects of four butanol isomers additions on sooting transition process were studied in iso -octane counterflow diffusion flame combining flame luminosity characteristics and gas-phase combustion chemistry. Flame luminosity characteristics was obtained to determine the sooting transition points of all investigated flames with homemade image processing and transition point extraction methods. The results indicated that the delay effect has occurred on sooting transition point in four blended flames with a little difference. Gas-phase combustion chemistry of the different flames in sooting transition process was studied experimentally by an online GC system as well as numerically by kinetic analysis realized with two distinct kinetic mechanisms. In addition, soot formation characteristics have also been qualitatively analyzed with soot model . Experiments and simulations show that, depending on the butanol isomer, the intermediate species production is clearly different. These different species pools play an important role on soot formation pathways as demonstrated by the simulations. Although n -butanol and sec -butanol were weaker in benzene formation, stronger C 2 H 2 production capacity was dominant in PAHs growth. Tert -butanol had the highest C 6 H 6 concentration with a ratio of 7 %−15 % higher than the other isomers due to the strongest IC 4 H 8 production capacity. Therefore, its flame also has the highest PAHs concentration. Both effect mechanisms existed in iso -butanol blended flame.
研究领域:
能源科学
·
化学工程
·
燃烧学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2022
·
IF 3.119
Ying Zhang,Yongbo Zhang,Yuqi Su,Junshuai Chen,Taotao Zhan,Hengfei Zhang,Maogang He
We report the speeds of sound for the mixtures of ethanol (1) + isooctane (2) at 0.100, 0.300, 0.500, 0.700, 0.900 molar fractions of ethanol, respectively, at temperatures from 298.15 to 605.23 K along three isobaric lines from 3.0 to 7.0 MPa. On the basis of the experimental results and the literature density data, we evaluate the excess free length, excess acoustic impedance, and excess isothermal compressibility of ethanol (1) + isooctane (2) mixtures at 298.15 to 435.15 K and pressures below 5.0 MPa. Moreover, we fit the excess values by the Redlich–Kister polynomial equation. Finally, molecular interactions between ethanol and isooctane are analyzed.
研究领域:
物理化学
·
热力学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2016
·
IF 3.611
Erjiang Hu,Hongzhen Tian,Xinyi Zhang,Xiaotian Li,Zuohua Huang
N -butanol is a promising alternative fuel for automobile whose explosion characteristics should be a major focus before widely used. Unfortunately, limit researches focusing on its explosion characteristics have been launched until now. In this study, the effects of n -butanol addition on the explosive characteristics of iso-octane-air mixtures with various concentrations and initial pressures and temperatures were experimentally investigated and analysed on the basis of combustion pressure history. The explosion pressure p exp and the maximum explosion pressure p max , the maximum rate of pressure rise ( d p / d t ) max , the deflagration index K G , and combustion duration t c as well as flame development period t d , were examined. Results show that with the increase of n -butanol blending ratio, explosion pressure does not change, while explosion duration is decreased, so the maximum rate of pressure rise is increased. It was found that pressure curves of rich mixtures oscillate in the vicinity of pressure peak at elevated pressures, and the pressure oscillation greatly shortens the explosion duration and increases the maximum rate of pressure rise. In addition, with the increase of n -butanol blending ratio, the pressure oscillation intensity is decreased.
研究领域:
能源科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ENERGY
·
2020
·
IF 6.082
Yuchen Ya,Xiaokang Nie,Weiwei Han,Longkai Xiang,Mingyan Gu,Huaqiang Chu
The effects of 2, 5-dimethylfuran (DMF)/ethanol addition on the atomized combustion soot formation characteristics of n-heptane/iso-octane coflow diffusion flames are systemically studied. The changes of soot particles and deposition morphology at different heights in the flame of reference fuel with 15% ethanol (E15) and 15% DMF (DMF15) are analyzed. Results show that the addition of oxygenated fuels can increase the flame heights and decrease the brightness. With the addition of 15% ethanol and DMF, the flame heights are increased by 11.29% and 19.35% respectively, and the brightness of the edge region of the middle section of DMF15 flame is enhanced. At the nozzle, the average temperature of E15 flame increases by 80 K. The high temperature region of E15 flame enlarged and the average temperature difference of different heights is higher than 50 K. As for DMF15, the high temperature region of flame is constant, and the average temperature difference between various heights is smaller than 35 K. For three fuels, the size of the sediment particles formed at the low height above burner (HAB = 20 mm) is large, and the obvious pore structure can be seen at HAB = 60 mm. The addition of oxygenated fuels makes the pore structure distribution regular and the porosity decreases, and DMF15 (porosity = 0.2670) has larger pore structure than E15 (porosity = 0.1557). The oxygenated fuel can inhibit the formation of soot precursors and the agglomeration of soot particles, but the increase of particle size in the middle region of flame is promoted because of the increase of flame height and residence time of soot particles. As a result, the soot particle size of oxygenated fuel is decreased greatly in the oxidation stage, and the soot particle size of DMF15 (40.4%) is decreased more than that of E15 (37.1%). The effect of ethanol and DMF addition on the activation energy of low position soot is not obvious, which is about 130 kJ/mol. In the middle position of the flame, the activation energy of E15 is the highest (159.32 kJ/mol), and the activation energy of DMF15 is the smallest (148 kJ/mol). At the high position, E15 (212.07 kJ/mol) and DMF15 (226.73 kJ/mol) are less than that of DE0 (235.03 kJ/mol) respectively, indicating that the activation energy of the mature soot reduces, which is beneficial to the oxidative removal. Ethanol can dilute the fuel and increase the oxygen concentration in the mixture, while DMF can delay the ignition and prolong the residence time of soot and increase the content of disordered carbon in mature soot particles.
研究领域:
燃烧科学
·
化学工程
·
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）