MINERALS ENGINEERING
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2025
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IF 5
Panxing Zhao,Wenbao Liu,Wengang Liu,Lingyun Bao,Yanbai Shen,Stephen Butt,Yahui Zhang
Removal of quartz from hematite by reverse flotation using cationic collectors is an effective approach for iron concentrate upgrading. In this paper, three hydroxyl-containing cationic collectors, i.e., N-Dodecylethanolamine (NDEA), N-Dodecylpropanolamine (NDPA), and N-Dodecylbutanolamine (NDBA), were synthesized and characterized. The flotation performance and the structure-performance relationship of the collectors were systematically investigated by micro-flotation experiments and various surface analysis techniques. At the concentration of 20 mg/L, the flotation recoveries of quartz by NDEA, NDPA, and NDBA were 94.9 %, 93.5 %, and 93.3 %, respectively. Collectors with shorter hydroxyl-substituted carbon chains exhibited stronger collecting ability and enhanced hydrophobicity of quartz surface, as confirmed by contact angle measurements. Zeta potential measurements and molecular simulations revealed that the collectors adsorb onto the quartz surface through electrostatic and hydrogen bonding interactions. The introduced hydroxyl groups could enhance the formation of hydrogen bonds between collectors and mineral surface. However, as the carbon chain length increases, the adsorption area of a single collector on the mineral surface increases, the number of collector molecules adsorbed per unit area decrease, reducing the collecting ability of the collector for quartz. This research could provide theoretical guidance for the design of novel cationic collectors.
研究领域:
矿物加工工程
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表面化学
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DOI
高影响因子
INTERNATIONAL JOURNAL OF THERMOPHYSICS
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2023
·Vol. 44
·期 4
·1-25
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IF 2.2
Liang Ximei,Yang Jian,Meng Xianyang,Wu Jiangtao
A vibrating-wire apparatus was used to measure liquid density and viscosity simultaneously under high-temperature conditions. Densities and viscosities were measured along 11 isotherms at temperatures from (298.15 to 548.15) K and pressures up to 10 MPa for n -dodecane, and over a temperature range of (303.15 to 548.15) K and at equilibrium pressures up to about 6 MPa for carbon dioxide + n -dodecane. The estimated combined expanded uncertainties are 0.24 % for density and 2.2 % for viscosity with a confidence level of 0.95 ( k = 2). In addition, experimental density and viscosity data were correlated with the modified Tait equation and Tait–Andrade equation, respectively, and comparisons with literature data were made. With regard to n -dodecane, the equations present both literature data and our experimental results with deviations almost within 0.2 % for density, and 3.0 % for viscosity. For simplicity, the experimental data of carbon dioxide + n -dodecane were correlated using these two Tait-like equations directly without considering the mole fraction of CO 2 . Both correlations describe our measured data of carbon dioxide + n -dodecane almost within 0.2 % for density and 1 % for viscosity. Graphical Abstract
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
INDUSTRIAL CROPS AND PRODUCTS
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2017
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IF 3.181
Jun Xia,Aiyong He,Rongqing Li,Yang Zhang,Jiaxing Xu,Xiaoyan Liu,Jiming Xu
Oxygen mass transfer is one of the most essential factors affecting microbial cell growth and cellulase fermentation. In this study, an effective approach capable of improving oxygen mass transfer was developed by adding oxygen vectors into the fermentation broth by Trichoderma reesei . With the addition of 1% (v/v) n -dodecane, the volumetric mass transfer coefficient ( k L a ) was increased from 142 h −1 to 185 h −1 at the beginning of the fermentation. In response to the improved oxygen transfer, 44.6% higher FPase activity, 29.2% higher xylanase activity and 42.5% higher saccharification yield of rice straw were obtained. The scanning electron microscopy showed that the addition of n -dodecane did not cause obvious variations on the cell morphology, whereas the comparative proteomics analysis identified 30 protein spots with different expression levels. Among them, exoglucanases (CBH I, CBH II), endoglucanase (EG VI), xylanases (Xyn I, Xyn II, Xyn III), acetyl xylan esterase, swollenin and cellulose induced protein (Cip1) were highly expressed after the addition of n -dodecane, whereas more EG III and β -xylosidase were produced without the addition of n -dodecane. The present study indicated that the addition of n -dodecane was advantageous for cellulase fermentation by T. reesei .
研究领域:
生物工程
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微生物学
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DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
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2022
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IF 3.269
Xin Li,Taotao Zhan,Yongbo Zhang,Yuqi Su,Maogang He,Ying Zhang
As one of higher n -alkanes, n -dodecane is an important component of surrogate fuels for aviation kerosene, of which the accurate knowledge of its thermophysical properties is necessary for industrial application. The speed of sound in n -dodecane was measured by the Brillouin light scattering (BLS) in the vicinity of the critical point, of which the examined regions are T = (433.49 to 678.84) K along seven isobaric lines at p = (1.85, 2.0, 2.2, 4.0, 6.0, 8.0, and 10.0) MPa. The relative expanded uncertainty of BLS experimental system is estimated to be less than 1.2% with the confidence level of 95% (coverage factor, k = 2). Polynomial representations for the speed of sound in liquid n -dodecane was fitted by the experimental results, and the average absolute deviation and maximum absolute deviation are 0.70% and 1.96%, respectively. Moreover, the accuracy of the multiparameter equation of state proposed by Lemmon were assessed by the experimental speeds of sound in the whole investigated p - T region.
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
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2017
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IF 3.582
Shuang Ji,Zhourong Xiao,Haocui Zhang,Ling Li,Guozhu Li,Li Wang,Guozhu Liu
A high surface area (HSA) Ce 0.75 Zr 0.25 O 2 (CZ) support was synthesized by hydrothermal synthesis method with assistance of surfactant (cetyltrimethyl ammonium bromide , CTAB), and then 2.0 wt% Ru was impregnated on it to obtain a steam reforming catalyst for n-dodecane. The surface area of Ru/HSA-CZ catalyst is 107.6 m 2 g −1 , which is ca. three times higher than that prepared through the sol-gel (sg) method (34.3 m 2 g −1 , Ru/CZ-sg) and ca. 40% higher than that without CTAB (76.7 m 2 g −1 , Ru/CZ-wo). Catalytic steam reforming of n-dodecane, shows the completely conversion of n-dodecane over Ru/HSA-CZ and slightly drops about 6% (650 °C, LHSV = 12 mL/g h, S/C = 4, time on stream = 7 h) while 81% and 70% were observed for the Ru/CZ-wo and Ru/CZ-sg but with twice (or triple) deactivation rates. The possible reason for observed better performance of Ru/HSA-CZ should be attributed to the high metal dispersion of Ru over HSA-CZ, and the favorable Ru-support interaction as evidenced by H 2 -Temperature programmed reduction (H 2 -TPR), and high redox ability of high surface area Ce 0.75 Zr 0.25 O 2 support thanks to high Ce 3+ content. Further steam reforming of n-dodecane over Ru/HSA-CZ at higher LHSV (750 °C, LHSV = 36 mL/g h, S/C = 4) exhibits completed conversion and without significant deactivation.
研究领域:
化学工程
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催化材料
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DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
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2021
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IF 3.178
Xiong Zheng,Yanqiong Bao,Dan Qu,Jing Wu,Guangzhao Qin,Yu Liu
With the key role of long-chain hydrocarbons in the wide applications in numerous industrial areas, such as working fluids, phase change materials, fuels, etc ., the knowledge of the thermal conductivity of hydrocarbons is essential in the energy conversion process. Thus, it is of great significance to get reliable experimental data of hydrocarbons’ thermal conductivity for further accurately theoretical predictions and the potential applications. In this work, the thermal conductivities of two long-chain hydrocarbons of n-dodecane and n-tetradecane, are investigated experimentally. The transient hot-wire method was used for the measurement of the thermal conductivity under the conditions of 293–523 K and 0.1–15.0 MPa. By comparing the present work with literature results, the possible reasons for the deviations were analyzed. The results in this study provide accurately measured of the thermal conductivity of the two long-chain hydrocarbons at high temperature and pressure, which are expected to fill the gap in literature.
研究领域:
化学工程
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能源科学
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DOI
高影响因子
ENERGY & FUELS
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2018
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IF 3.024
Dingrui Zhang,Lingyun Hou,Mingyu Gao,Xiaoxiong Zhang
A comprehensive understanding of the thermal cracking behavior of hydrocarbon fuels is important for thermal protection applications and investigations into the combustion of thermally cracked fuels. In the present study, n-dodecane is selected as a surrogate for aviation kerosene and it is subjected to a series of thermal cracking experiments at supercritical pressure. According to variations in chemical heat sink, fuel-conversion rate, and gas-production rate, the thermal cracking of n-dodecane is divided into three regions: primary, secondary, and severe. In the primary cracking region, the fuel-conversion rate is lower than 13%, and the liquid products contain only chain alkanes and alkenes. Owing to the mass fraction of main products being proportional to the fuel-conversion rate, a one-step global reaction kinetics is constructed. The secondary cracking region is characterized by rapidly increasing chemical heat sink, fuel-conversion rates, and gas-production rates with increasing fuel temperature, and the appearance of monocyclic aromatic hydrocarbons (MAHs) and cycloalkenes. A kinetic model containing three reactions is proposed for this region. This also considers the thermal decomposition of chain alkanes and alkenes, which result in the formation of MAHs and cycloalkenes. Severe cracking is observed for fuel-conversion rates above 71% where a rapid increase in the concentration of monocyclic and polycyclic aromatic hydrocarbons (PAHs) occurs. The increasing rate of chemical heat sink slows in this region which is characterized by the formation of MAHs, PAHs, and coke. A three-dimensional numerical model is built for the primary and secondary cracking regions, taking the effects of the flow, heat transfer, and thermal cracking of n-dodecane into consideration. Predicted values for the outlet temperature, fuel-conversion rate, and distribution of the main species in all tested cases agree well with the experimental results, validating the numerical model and kinetics for the primary and secondary thermal cracking of n-dodecane.
研究领域:
化学工程
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燃烧科学
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能源工程
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DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2025
·
IF 2.1
Shengchao Xu,Wanting Ma,Qifeng Wei,Xiulian Ren
Long-chain 1-alkanols and N-dodecyl-2-pyrrolidone (NDP) exhibit significant potential in the field of solvent extraction. Investigating their physicochemical properties is valuable for understanding mass transfer, heat transfer, and the fluid transport process. In this study, we investigated the effect of the alkyl chain length of 1-alkanols (C4/C6/C8/C10) on NDP organic liquid mixtures. The densities and viscosities were measured at temperatures ranging from 303.15 to 323.15 K and atmospheric pressure. Excess properties, including excess molar volume (VmE), viscosity deviation (Δη), and the excess Gibbs free energy of activation of viscous flow (ΔG*E), were calculated and correlated by Redlich–Kister equation to identify the differences between real and ideal solutions. It was found that the steric hindrance increased with the alkyl chain length increasing from C4 to C10 for 1-alkanols, leading to weaker molecular interactions in the mixtures. Furthermore, the Fourier transform infrared spectroscopy (FT-IR) and UV–vis spectra confirmed the presence of intermolecular hydrogen bond interactions between the −OH group of 1-alkanols and the –C═O group of NDP. Finally, the conductor-like screening model for realistic solvation (COSMO-RS) and Gaussian spectra further proved the hydrogen bond interactions. Overall, this study reported a range of physicochemical properties from both experimental and theoretical perspectives, which can be used to guide industrial production.
研究领域:
物理化学
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分子相互作用
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理论计算
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DOI
高影响因子
FUEL
·
2025
·
IF 7.5
Wei Zhang,Yuting Wang,Jiangnan Xiang,Haiying Lu,Wenrui Jin,Yan Wang,Bo Qin,Weijiong Dai,Binbin Fan,Jiajun Zheng,Ruifeng Li
In this paper, a nanoparticle-stacked ZSM-48 molecular sieve is prepared by modifying the gel preparation process through stepwise crystallization. The corresponding bifunctional catalyst is developed for the hydroisomerization reaction of n -dodecane. The physicochemical properties of ZSM-48 are characterized and analyzed using XRD, SEM, NH 3 -TPD, N 2 adsorption–desorption and zero-length column (ZLC) method. The crystal size of Z-48-T2 synthesized via the stepwise synthesis method is reduced to as small as 0.6 μm, and its acidity is lower compared to that of Z-48-C. Meanwhile, Z-48-T2 exhibits the highest HF value and demonstrates excellent diffusion properties. Consequently, the Z-48-T2 catalyst shows superior catalytic activity and isomerization selectivity, achieving the highest iso -C 12 yield of 83.8 %. The outstanding diffusion performance of Z-48-T2 results in a monomethyl isomerization yield approximately 21 % higher than that of conventional ZSM-48 molecular sieves. Despite these improvements, the final mono-branched isomer product distribution remains unchanged, with 5-methylundecane being the predominant mono-branched isomer for both Z-48-T2 and Z-48-C.
研究领域:
催化化学
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材料科学
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DOI
高影响因子
FLUID PHASE EQUILIBRIA
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2017
·
IF 2.473
Tao Jia,Shengshan Bi,Jiangtao Wu
Compressed liquid densities of n -decane + n -dodecane binary mixtures were measured with a vibrating-tube densimeter at temperatures from (283–363) K and pressures from (0.1–100) MPa over the whole range of composition . The binary mixtures n -decane (1) + n -dodecane (2) were prepared at mole fractions of ( x 1 = 0, 0.2297, 0.4436, 0.6433 0.7841, and 1.0), respectively. The experimental densities of binary mixtures were successfully correlated with the Tait-type equation, and the absolute average percentage deviations of the experimental and calculated values were 0.048%, 0.055%, 0.059%, 0.058%, 0.068%, and 0.052%, respectively. In addition, the excess molar volume was calculated for whole range of temperature, pressure and composition.
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
FLUID PHASE EQUILIBRIA
·
2024
·
IF 2.8
Tao Jia,Weixue Jiang,Jia Yu
The compressed liquid densities of n -pentane(1) + n -dodecane(2) binary mixtures were measured using a high pressure vibrating-tube densimeter at temperatures from 283 K to 363 K, pressures up to 100 MPa, and five different compositions ( x 1 = 0.3778, 0.6230, 0.7968, 0.9051, and 1). The densities of binary mixtures were correlated using the modified Tait equation, and the absolute average deviations of the experimental and calculated values were 0.010 %, 0.019 %, 0.016 %, 0.025 %, and 0.017 %, respectively. In addition, the isothermal compressibility and the isobaric thermal expansivity were calculated from the obtained densities.
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
NEW JOURNAL OF CHEMISTRY
·
2019
·Vol. 43
·期 35
·13967-13978
·
IF 3.069
Qiang Ning,Huaike Zhang,Yurong He,Zhiqiang Chen,Suyao Liu,Jie Ren
Small Pt particles (about 1.2 nm) were highly dispersed on ZSM-22 zeolites via a strong electrostatic adsorption (SEA) method and exhibited a promotion effect on the catalytic performance in n-dodecane isomerization in comparison with the conventional catalyst. Several promoters (Ce, La, and Re) were introduced to further improve the aggregation resistance of the small Pt particles. A series of characterization including H2-TPR, XPS and STEM as well as DFT calculations provided solid evidence that the strong interaction between Pt and promoter species not only effectively hinders the Pt aggregation but also alters the electronic state of the Pt sites. Moreover, Ce and La promoters also lead to a slightly improved amount of B acid sites determined by Py-FTIR. Thus, improved activity and selectivity were achieved on a Ce-modified catalyst due to the better balanced bifunctionality between the slightly increased acidity of zeolites and electron-deficiency of Pt. The electron-rich Pt sites are responsible for the significant increase of CH4 selectivity and the decrease of total isomer selectivity in n-dodecane isomerization. In addition, a high-temperature reduction test revealed the higher isomerization activity and selectivity (about 10% higher than the unmodified catalyst) of the Ce-modified catalyst owing to the strong bond of Pt–O–Ce, further confirming the positive effect of the Ce promoter on the sintering resistance of small Pt particles.
研究领域:
催化化学
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材料科学
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计算化学
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DOI
高影响因子
危险品化学品经营许可证（带存储）