Case Studies in Thermal Engineering
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2021
·
IF 4.724
Jing Fan,Han Mu,Chang Gao,Fenhong Song
Recently, biodiesel is considered as a biodegradable, renewable and high-potential fuel which could be used directly in tradition internal combustion engines. Fuel’ transport properties in high pressure are required to model the process of fuel spray, atomization and combustion accurately. This work, three ethyl esters’ liquid thermal conductivity (biodiesel compounds) in the liquid phase was measured by an experiment system which is established based on a transient hot-wire method with a bare platinum hot wire. The measurements were conducted at the temperatures ranging from 292 K to 372 K and pressure up to 15 MPa. The combined expanded uncertainty of the measurement was estimated to be ±2.0% (in the 0.95 confidence level). For interpolation, the relationship between measured results with temperature and pressure were correlated as a polynomial function, and the maximum deviation of correlations were less than 0.30%.
研究领域:
能源科学
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物理化学
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Ruihan Yang,Shafqat Ullah,Yujun Wang,Guangsheng Luo,Zhen Qian
Isoprene is of great importance as a valuable monomer for most chemical industries owing to the increasing demand for synthetic rubber. To obtain polymer-grade olefins, the removal of alkyne compounds from isoprene is mandatory and challenging. Adsorption separation using zeolites is one of the most promising alternatives for alkyne/olefin separation. Herein, a combination of batch, fixed bed column experiments and configurational-bias grand canonical Monte Carlo (CB-GCMC) simulations was applied to study alkyne’s selective adsorption from binary liquid-phase isoprene/1-pentyne mixtures in faujasite (FAU) zeolites. The adsorption separation performance, including the adsorption capacity and selectivity, was obtained based on the liquid-phase measurement method developed in this study. FAU zeolites exhibited 218 mg/g alkyne adsorption capacity and relatively high adsorption selectivity at low alkyne concentrations. Liquid adsorption separation of linear alkyne/olefin mixtures, covering 1-pentyne/1-pentene (C 5 ) and 1-hexyne/1-hexene (C 6 ), in FAU zeolites, was performed further to investigate the separation performance for alkynes and olefins. The binary isotherms for the 1-pentyne/isoprene system and extended studied olefin/alkyne systems were reproduced well by CB-GCMC simulations. The visualized average occupation profiles of adsorbate molecules in FAU zeolites showed that alkyne and olefin molecules were mainly distributed near the 4-rings and 6-rings. The concentrated areas were arranged perpendicular to each other.
研究领域:
化学工程
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材料科学
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2019
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IF 5.107
Zimu Xu,Xiaojuan Xue,Shuheng Hu,Yunxia Li,Jie Shen,Yan Lan,Rongxing Zhou,Fan Yang,Cheng Cheng
Norfloxacin (NOR) is a typical kind of Fluoroquinolone antibiotics which is extensively used around the world. Residues of NOR have been found continuously increasing in the water systems thus posing detrimental effects to the aquatic ecosystem and human health. In this study, the degradation effect and mechanism on NOR in aqueous solution are investigated by gas-liquid phase dielectric barrier discharge (DBD) plasma combined with different catalysts (H 2 O 2 or Fe 2+ ). The concentrations of three representative plasma-generated long-lived reactive species (H 2 O 2 , O 3 and N O 3 - ) were measured in dH 2 O and found enhancing with the lengthening discharge period. Variations on the treatment parameters were carried out in discharge power, initial solution pH and the concentration of catalysts. A discharge power at 60 W provided optimal balance on the degradation effect and energy efficiency would be beneficial, while there is not much impact from the initial solution pH on NOR degradation. Both H 2 O 2 and Fe 2+ at low concentration (0.5–10 mg/L of Fe 2+ , 0.1–1.0 mmol/L of H 2 O 2 ) were observed contributing to the improvement on the NOR degradation rate, while inhibition would occur at high concentration (10–20 mg/L of Fe 2+ , 1.0–2.0 mmol/L of H 2 O 2 ). The DBD/H 2 O 2 (0.5 mmol/L)/Fe 2+ (10 mg/L) system was found the optimal condition to achieve a high NOR degradation rate of more than 98% after plasma treatment for only 0.5 min at discharge power of 60 W. Moreover, 72.3 ± 1.7% of the total organic carbon (TOC) in NOR solution have been removed in the DBD/Fe 2+ (10 mg/L) system at 15 min which signifies a high mineralization efficiency. The cleavage of piperazine ring and quinolone ring, defluorination and hydroxylation are considered the major pathways for NOR degradation. The biological toxicity of the plasma/Fe 2+ -induced degradation intermediates has been detected and it fluctuated with the treatment time and finally declined. Therefore, the DBD/catalyst system could be an effective and promising method on pharmaceutical wastewater treatment in the future.
研究领域:
环境科学
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水处理技术
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产品关联
DOI
高影响因子
RESEARCH ON CHEMICAL INTERMEDIATES
·
2016
·Vol. 42
·期 8
·6681-6693
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IF 1.833
Zhang Qin,Wang Hongqing,Wang Yuyuan,Jing Pengfei,Luo Aoheng,Huang Qiao
A new Schiff base fluorescence probe, 3-Allylsalicylaldehyde salicylhydrazone (L), for Mg 2+ was designed and synthesized. The fluorescence of the sensor L was enhanced remarkably by Mg 2+ with 2:1 binding ratio, and the binding constant was determined to be 1.02 × 10 7 M −1 . Probe L had high sensitivity for Mg 2+ in a solution of DMF/water (4:1, v/v, pH 7.5), and the detection limit was 4.88 × 10 −8 mol/L. Common coexistent metal ions, such as K + , Na + , Ag + , Ca 2+ , Zn 2+ , Ba 2+ , Bi 2+ , Cu 2+ , Ni 2+ , Hg 2+ , Fe 3+ , and Al 3+ , showed little or no interference on the detection of Mg 2+ in solution. The fluorescence probe L, which was successfully used for the determination of trace Mg(II) in real samples, was shown to be promising for liquid-phase extraction coupled with fluorescence spectra.
研究领域:
分析化学
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生物化学
✓ 已验证
DOI
高影响因子
Materials
·
2024
·Vol. 17
·期 5
·987
·
IF 3.1
Yuanwen Pang,Hong Li,Yue Hua,Xiuling Zhang,Lanbo Di
The interactions between plasma and liquids cause complex physical and chemical reactions at the gas–liquid contact surface, producing numerous chemically active particles that can rapidly reduce noble metal ions. This study uses atmospheric-pressure surface dielectric barrier discharge (DBD) plasma to treat ethanol aqueous solutions containing noble metal precursors, and stable gold, platinum, and palladium colloids are obtained within a few minutes. To evaluate the mechanism of the reduction of noble metal precursors by atmospheric-pressure surface DBD plasma, the corresponding metal colloids are prepared first by activating an ethanol aqueous solution with plasma and then adding noble metal precursors. It is found that the long-lived active species hydrogen peroxide (H2O2) plays a dominant role in the synthesis process, which has distinct effects on different metal ions. When HAuCl4and H2PdCl4are used as precursors, H2O2acts as a reducing agent, and AuCl4−and PdCl42−ions can be reduced to metallic Au and Pd. However, when AgNO3is the precursor, H2O2acts as an oxidising agent, and Ag+ions cannot be reduced to obtain metal colloids because metallic Ag can be dissolved in H2O2under acidic conditions. A similar phenomenon was also observed for the preparation of Pd colloid-PA with a plasma-activated ethanol aqueous solution using Pd(NO3)2as a Pd precursor.
研究领域:
化学
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材料科学
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物理化学
✓ 已验证
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Mengxiong Li,Jiangwei Liu,Shaoxue Pan,Jiajia Zhang,Ya Liu,Johan Liu,Hongbin Lu
Graphene-based thermally conductive polymer composites are of great importance for the removal of the excess heat generated by electronic devices. However, due to the orientation of graphene sheets in the polymer matrix, the through-plane thermal conductivity of polymer/graphene composites remains far from satisfactory. We here demonstrate a confined liquid-phase expansion strategy to fabricate highly oriented confined expanded graphite (CEG) aerogels. After being incorporated into epoxy resin (EP), the resulting EP/CEG composites exhibit a high through-plane thermal conductivity (4.14 ± 0.21 W m–1 K–1) at a quite low filler loading of 1.75 wt % (0.91 vol %), nearly 10 times higher than that of neat EP resin and 7.5 times higher than the in-plane thermal conductivity of the composite, indicating that the CEG aerogel has a high through-plane thermal conductivity enhancement efficiency that outperforms those of many graphite/graphene-based fillers. The facile preparation method holds great industrial application potential in fabricating anisotropic thermally conductive polymer composites.
研究领域:
材料科学
·
热管理技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2021
·
IF 5.706
Cen Tang,Fangru Zhou,Yang Wen,Yumeng Xu,Aiping Jia,Mengfei Luo,Jiqing Lu
A series of MoO x -promoted Ir/BN catalysts were tested for liquid phase selective hydrogenation of crotonaldehyde. The MoO x -promotion could significantly improve the reactivity up to 5-fold. Such improvement was mainly due to the formation of Ir-MoO x interfacial sites in the promoted catalyst, which accelerated the adsorption and activation of crotonaldehyde molecule as evidenced by a much lower activation energy (18.9 kJ mol −1 on the 0.3Mo-3Ir/BN versus 38.4 kJ mol −1 on the 3Ir/BN). The kinetic results revealed negative reaction order of crotonaldehyde (up to -1.1) and high reaction order of H 2 (up to 2.2), indicating the high coverage of crotonaldehyde on the catalyst surface suppressed the adsorption of H 2 due to its low solubility in the liquid phase. Therefore, the adsorption and activation of H 2 on the catalyst might be the rate determining step. However, the preferred adsorption of crotonaldehyde on the Ir-MoO x interface alleviated the suppression of H 2 adsorption, which was another reason for the higher activity.
研究领域:
催化化学
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材料科学
·
表面科学
✓ 已验证
产品关联
DOI
高影响因子
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