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
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热力学
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产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2017
·
IF 6.065
Shuyan Zhao,Tao Zhou,Bohui Wang,Lingyan Zhu,Meng Chen,Dandan Li,Liping Yang
Perfluorooctane sulfonamide (PFOSA) is a precursor of perfluorooctane sulfonic acid (PFOS) and can be broken down to PFOS in environment and biota. In the present work, PFOSA was spiked in soil and its biodegradation in soil, uptake and metabolism in wheat ( Triticum aestivum L.) and earthworms ( Eisenia fetida ) were investigated. The results indicated that PFOSA could be biodegraded to highly stable PFOS, which has the same perfluorinated carbon chain length as PFOSA, by microbes in soil. PFOSA could be taken up by wheat root and earthworm from soil with higher bioaccumulation ability than PFOS. In both wheat and earthworms, PFOSA also degraded to PFOS. However, other shorter-chain perfluoroalkane sulfonates (PFSAs), including perfluorohexane sulfonate (PFHxS) and perfluorobutane sulfonate (PFBS), were observed in wheat, but not in soil and earthworms, suggesting that wheat displayed distinctly different degradation mechanisms to PFOSA from soil microbes and earthworms.
研究领域:
环境科学
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植物学
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DOI
高影响因子
JOURNAL OF SOLUTION CHEMISTRY
·
2022
·Vol. 51
·期 7
·752-767
·
IF 2
Li Dan,Pang Yan,Wang Jingying,Sun Danlin,Zhang Xuena,Yue Danwei,Hao Longxia
Three C8 alkanes ( n -octane, iso -octane and ethyl cyclohexane) as additives were blended with methyl laurate to prepare binary systems of fuel blends for density, viscosity and refractive index measurement. The excess properties of volumes and viscosity of the three binary systems (methyl laurate + n -octane), (methyl laurate + iso -octane) and (methyl laurate + ethyl cyclohexane) were obtained and compared, which were also fitted to Redlich–Kister equation. The correlated values from Redlich–Kister equation are in good agreement with those from experimental data. The results can be used for the research of the mixture behaviors and development of biodiesel-diesel fuel blends.
研究领域:
物理化学
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燃料科学
✓ 已验证
产品关联
DOI
高影响因子
Royal Society Open Science
·
2018
·Vol. 5
·期 8
·
IF 2.504
Liuyi Ren,Hang Qiu,Wenqing Qin,Ming Zhang,Yubiao Li,Penggang Wei
The existence of metal ions should not be ignored in both hydrometallurgy and flotation. In this study, the effects of Ca2+, Mg2+ and Fe3+ on the flotation performance of cassiterite using octanohydroxamic acid (OHA) as the collector were investigated by micro-flotation tests, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy, contact angle, zeta (ζ) potential measurements and atomic force microscopy (AFM) imaging. The results of the flotation and contact angle experiments showed that the addition of Ca2+, Mg2+ and Fe3+ significantly decreased both the recovery and contact angle of cassiterite with pH ranged from 6.0 to 12.0 in the presence of OHA collector. ζ-Potential measurements, solution chemistry analysis and FTIR measurements indicated that the flotation recovery of the cassiterite declined due to the CaOH+, MgOH+ and Fe(OH)3 sites on the cassiterite surface. XPS results indicated that the chemisorption of OHA and calcium ions on the cassiterite surface finally changed its chemical properties. The AFM images also revealed that new species Fe(OH)3 of Fe3+ formed and adsorbed on the cassiterite surface at pH 9.0. The adsorption of Fe(OH)3 reduced the adsorption of OHA on the cassiterite surface, thus the hydrophobicity of cassiterite was deteriorated.
研究领域:
矿物加工工程
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表面化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2023
·
IF 2.6
Juan Wang,Zenghui Li,Xianyang Meng,Jiangtao Wu
In this work, liquid densities of n -octane, ethylcyclohexane and their binary mixtures {( x ) n -octane) + (1 − x ) ethylcyclohexane} with mole fraction x = (0.200, 0.400, 0.600, 0.800) are reported. The density measurements were performed with a high-pressure vibrating-tube densimeter at temperatures from (283 to 363) K and pressures up to 60 MPa. The combined expanded uncertainties (0.95 level of confidence, k = 2) are estimated to be 16 mK for temperature, 0.062 MPa for pressure, and up to 0.6 kg/m 3 for density. The experimental densities were correlated using the modified Tait equation. The average absolute percentage deviations of measurement results from the modified Tait equation correlations of n -octane, ethylcyclohexane and their binary mixtures {( x ) n -octane) + (1 − x ) ethylcyclohexane} are all lower than 0.1%. The isothermal compressibility and isobaric expansivity have also been derived from the experimental densities.
研究领域:
化学工程
·
物理化学
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产品关联
DOI
高影响因子
AICHE JOURNAL
·
2019
·Vol. 65
·期 8
·e16625
·
IF 3.463
Zhen Song,Xutao Hu,Yageng Zhou,Teng Zhou,Zhiwen Qi,Kai Sundmacher
Although double salt ionic liquids (DSILs) offer significant advantages over classical two-ion ionic liquids as separation solvents, relevant studies are still scarce and a systematic DSIL selection method is thus highly desirable. In this contribution, a rational method for designing DSILs as extraction solvents is proposed and exemplified by the thiophene/ n -octane separation. The effects of additional degrees of freedom for DSIL design (i.e., double cations and/or anions and the ion ratio) on the thermodynamic properties are first analyzed by COSMO-RS. Then, a multilevel DSIL design method combining the prediction of infinite dilution thermodynamic properties, the estimation of physical properties, the evaluation of phase equilibrium behavior, and the experimental validation is proposed. By applying this method, [C 2 MIm][OAc] x [NO 3 ] 1- x ( x = [0, 1]) and [C 2 MIm][OAc] x [SCN] 1- x ( x = [0.70, 1]) are identified as promising DSIL solvents for the thiophene/ n -octane separation. Correspondingly, the liquid–liquid equilibria of {DSILs + thiophene + n -octane} with the designed DSILs are experimentally studied.
研究领域:
化学工程
·
分离科学
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产品关联
DOI
高影响因子
FLUID PHASE EQUILIBRIA
·
2021
·
IF 2.775
Xiong Zheng,Dan Qu,Fa Zhang,Yu Liu,Guangzhao Qin
Hydrocarbons play an important role in lots of industrial processes. Thermal conductivity is an important thermophysical property of fluids in energy conversion process, such as the design of the heat transfer system and the evaluation of thermodynamic cycle. Thus, it is of great significance to acquire solid experimental data and develop reliable models for achieving accurate thermal conductivity of hydrocarbons. In this work, thermal conductivity of two common fuels, n-octane and n-decane, were studied by combining experimental and theoretical methods. Using the transient hot wire method, the thermal conductivity is measured with temperature ranging from 303 to 523 K and pressures ranging from 0.1 to 15 MPa. Excellent agreement is achieved by comparing our experimental results with literatures. Furthermore, the mechanism for the influence of temperature and pressure on thermal conductivity of liquid n-octane and n-decane was explored preliminarily based on Bridgman's theory. In addition, we proposed a modified model considering the critical thermal conductivity enhancement, with which the average absolute deviations are 0.49% and 0.43% for n-octane and n-decane, respectively. It is shown that our proposed model has better predictive ability for representing thermal conductivity than the four traditional theoretical models (Assael model, Sun and Teja model, Huber and Perkins model, Liu model), especially at the vicinity of the critical point. The achievements in the present study are not only useful for relevant industrial application but also helpful for understanding the thermal conductivity critical enhancement when approaching the liquid-gas critical point for n-alkanes.
研究领域:
化学工程
·
热物理
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产品关联
DOI
高影响因子
Journal of Spectroscopy
·
2020
·
IF 1.243
Liang Zhao,Chaoyu Jing,Yu Jin,Jiangping Chen,Ke Yin,Sujun Yang,Bingqing Liu,Xiao Han,Jianyu Tan
The optical constants of a liquid hydrocarbon such as liquid n-octane are basic material properties that may be used to evaluate their thermal radiation transfer capabilities. In this study, the ellipsometry method was used to measure the optical constants of liquid n-octane in the midinfrared wavelength range of 2.0–16.0 μm at temperatures of 20, 50, and 80°C. Experimental analyses indicate the significant effect of temperature on the refractive index, although it has little effect on the absorption index. With increasing temperature, the refractive index shows a linear decrease, and reduced density leads to weaker absorption intensities. The radiative properties of n-octane droplets, including the absorption and scattering efficiency factors of single droplets with droplet radii r = 10, 20, 50, and 100 μm and the absorption and scattering coefficients in a droplets-air system of droplet volume fractions fv = 2%, 3%, and 4%, were calculated using Mie theory. The numerical results indicate that, with increasing temperature, the absorption efficiency factor slightly decreases, and the variation trend of the scattering efficiency factor is more complicated. With increasing droplet radius, the absorption efficiency factor increases within the studied wavelength range, except for certain absorption peaks, but the scattering efficiency factor tends to decrease. While the absorption is greater, the scattering is weaker for a given droplet radius. With an increasing volume fraction of n-octane droplets, the absorption and scattering coefficients increase linearly within the studied wavelength range.
研究领域:
热物理学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of CO2 Utilization
·
2018
·
IF 5.503
Ke Bei,Junliang Wang,Shuyan Zhou,Guangna Xie,Yanmei Xu,Liang Wang,Zhuoran Jiang,I-Ming Chou,Zhiyan Pan
Accurate expansion data for CO 2 in petroleum model compounds (e.g., alkanes, cycloalkanes and aromatics) are fundamental information for CO 2 sequestration and enhanced oil recovery in oil reservoir. In this study, the volume expansion of the CO 2 + octane mixture was measured using a fused silica capillary cell with in situ Raman spectroscopy. A section of water was loaded between octane and CO 2 in the fused capillary tube to seal the octane whilst allowing the diffusion of CO 2 into the octane. Raman spectroscopy was applied during our experiments to verify that the CO 2 + octane mixture reached phase equilibrium. Moreover, a good quadratic relationship was observed between the Raman peak intensity ratio and volume expansion factor. It was verified that this method can be used not only just to obtain more accurate experimental data, but also to protract additional volume expansion factor curves or curved surfaces from measured Raman peak intensity ratio using this equation. Over an extended temperature and pressure range, this method was thus shown to be more efficient and accurate than the traditional pressure–volume–temperature methods.
研究领域:
化学工程
·
石油工程
✓ 已验证
产品关联
DOI
高影响因子
WATER RESEARCH
·
2024
·
IF 11.4
Yihua Chen,Jiaxin Zhu,Hang Ma,Yurong Gu,Tongzhou Liu
Perfluorooctane sulfonate (PFOS) is a persistent organic pollutant posing a risk in environmental persistence, bioaccumulation and biotoxicity. This study was to reach a comprehensive and deeper understanding of PFOS elimination in a UV 254 photolytic treatment with the co-presence of Fe 2+ and nitrilotriacetic acid trisodium salt (NTA). PFOS defluorination was noticeably enhanced in the UV/Fe 2+ -NTA treatment compared with UV/NTA, UV/Fe 2+ and our previously studied UV/Fe 3+ treatments. UV–vis, FTIR, and UPLC/MS-MS results indicated the formation of PFOS-Fe 2+ -NTA complex in PFOS, Fe 2+ and NTA mixture. The transition energy gap of PFOS-Fe 2+ -NTA decreased below the excitation energy supplied by UV 254 irradiation, corresponding with red shift appearing in UV–vis scanning spectrum. This favored intramolecular electron transfer from Fe 2+ -NTA to PFOS under UV 254 irradiation to form electron-accepting PFOS. Molecular electrostatic potential and atom charge distribution analyses suggested electron density rearrangement and perturbation in the perfluorinated carbon chain of electron-accepting PFOS, leading to the decrease in bond dissociation energies. Intermediate products detection suggested the parallel defluorination pathways of PFOS desulfonation, middle carbon chain scission and direct C-F cleavage. NTA exhibited crucial functions in the UV/Fe 2+ -NTA treatment by holding Fe 2+ /Fe 3+ in soluble form as a chelant and favoring water activation to generate hydrated electrons (e aq − ) under UV irradiation as a photosensitizer. Fe 2+ acting as the conduit for electron transfer and the bridge of PFOS anion and NTA was thought functioning best at 200 µM in this study. The degree of UV/Fe 2+ -NTA -synergized PFOS defluorination also depended on e aq − yield and UV 254 photon flux. The structure dependence on the electron transfer process of PFOS and PFOA was explored incorporating molecular structure descriptors. Because of possessing greater potential to acquire electrons or less likeliness to donate its electrons than PFOA, PFOS exhibited faster defluorination kinetics in the published “reduction treatments” than “oxidation” ones. Whereas, PFOA defluorination kinetics were at similar level in both “reduction” and “oxidation” treatments.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENERGY & FUELS
·
2020
·
IF 3.421
Yangyang Xin,Yufeng Hu,Mengchen Li,Kebin Chi,Shang Zhang,Fei Gao,Siqi Jiang,Yichuan Wang,Chunxiao Ren,Guohua Li
Alkylation catalyzed by concentrated sulfuric acid (H2SO4) is an important process for industrial production of excellent high octane gasoline blending components. This process has some vital drawbacks such as extensive side reactions and high consumption of H2SO4 due to the presence of the most notorious impurities including H2O, acid soluble oil (ASO), and esters. In this study, isobutane alkylation was studied with H2SO4 (275 mL) in a batch reactor at −10 to 0 °C and 0.45 MPa, with the corresponding stirrer speed, feed rate, acid/hydrocarbon volume ratio, and isobutane/isobutylene volume ratio being 3000 rpm, 5.0 mL/min, 1.2, and 14.3, respectively. The effects of the acid strength and composition of acid on the alkylate quality were investigated. The composition of used acid was analyzed. The results show that used acid is mainly composed of roughly 89% free H2SO4, 6% H2O, 2% esters, and 3% ASO. The compounds existing in the ASO extracted from used acid were identified, and their concentrations were quantitatively determined. The results show that the most abundant ASO molecules are five-membered or six-membered cyclic homoannular conjugated olefins such as cyclopentadiene (15.67%) and cyclohexadiene (14.12%). The effects of acid strength, H2O, ASO, and esters on alkylation depend strongly on the concentrations of H2SO4 and these impurities. Therefore, their optimal concentrations were determined to achieve advantageous effects on the alkylation. The results are about 93–95% for H2SO4, 2–4% for H2O, 1.5–2.5% for ASO, and 0.4–1% for esters, beyond which an adverse effect will appear. Under the optimal concentrations, the value of the research octane number, the trimethylpentane (TMP)/dimethylhexane ratio, and the contents of C8 and TMP remained steady at high levels of about 92–93, 5.8–6.3, 68–70, and 58–60%, respectively.
研究领域:
化学工程
·
能源科学
✓ 已验证
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
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