FLUID PHASE EQUILIBRIA
·
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
·
工程热物理
✓ 已验证
产品关联
DOI
高影响因子
Particuology
·
2020
·
IF 2.787
Zhou Lan,Yangcheng Lu
In this work, we used the inert substances silicone oil and n -hexane to modulate the solvent environment, and in so doing tailor the preparation of magnesium ethoxide (Mg(OEt) 2 ) particles. We found the following: (1) nonpolar n -hexane mainly modulates the polarity of the solvent to control the precipitation rate and size of the Mg(OEt) 2 seeds, thereby triggering accelerated nucleation to form small primary particles; and (2) silicone oil (relatively high polarity and viscosity) facilitates the growth and agglomeration stage, to improve inter-particle dispersion and obtain relatively uniform Mg(OEt) 2 particles. We summarized these findings in a common mechanism for preparing Mg(OEt) 2 particles with uniform morphology, small size, and high bulk density as per the synergistic effect of n -hexane and silicone oil. The ratios of silicone oil and n -hexane are flexible, and afford various regular and well-dispersed Mg(OEt) 2 particles that are 5–30 μm in size and 0.2–0.7 g/cm 3 in bulk density. The nanoparticles thus have the potential to serve in diverse applications such as catalysis.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2017
·
IF 2.323
Qingsong Li,Midong Shi,Liping Wang,Gaoyin He,Fan Gan
The liquid–liquid equilibrium (LLE) experiments for n-butanol + n-hexane + ethylene glycol were carried out and LLE data were measured at 298.15, 303.15, 308.15, 313.15, and 323.15 K under atmospheric pressure. The analysis results of the effects of n-butanol content and temperature on extraction showed that high n-butanol content was not favorable for extraction, and temperature had little effect on extraction. Moreover, the NRTL and UNIQUAC models were applied to correlate the LLE data, and the correlated data indicated that the UNIQUAC model showed a better correlation performance.
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
Journal of Materials Chemistry A
·
2014
·Vol. 2
·期 45
·19298-19307
·
IF 0
Hongning Wang,Mei Tang,Lu Han,Jianyu Cao,Zhihui Zhang,Weiqiu Huang,Ruoyu Chen,Chengzhong Yu
Hollow organosiliceous sphere (HOS) materials have been successfully synthesized by a co-condensation method with tetraethylorthosilicate (TEOS) and organosilane (1,2-bis(triethoxysilyl)ethane, BTSE) as mixed silica sources under acidic conditions. The application of HOSs as adsorbents for the volatile organic compound (VOC) abatement was demonstrated. The HOSs were characterized by transmission electron microscopy (TEM), N2 sorption isotherms, FT-IR spectroscopy, thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS). The results indicated that all samples showed a uniform hollow mesostructure and the organic groups were chemically incorporated into the walls of HOSs. The static adsorption and stability behaviors of water vapor, n-hexane and 93# gasoline on HOSs were investigated, with commercial silica gel (SG) and activated carbon (AC) as references. It was found that the sample with an initial molar ratio BTSE/(BTSE + TEOS) of 25% (HOS-25%) had the largest VOC adsorption capacity (1.36 g g−1n-hexane and 1.35 g g−1 93# gasoline) and the smallest water vapor adsorption capacity (0.0120 g g−1) under static adsorption conditions. The dynamic adsorption behaviors of n-hexane on HOS-25% were evaluated via breakthrough curves. The dynamic adsorption capacities of n-hexane are in the following order: SG < AC < HOS-25% and the stability is in the order of AC < SG < HOS-25%. The larger dynamic VOC capacity of the HOSs may be attributed to the synergetic effect between the unique morphology and hybrid walls. The static and dynamic n-hexane and water vapor competitive adsorption results suggested that HOS-25% had a much higher adsorption tendency for VOCs over water vapor. The HOSs with high hydrophobicity, large VOC removal capacity and excellent recyclability show great potential for VOC controlling.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Yue Zong,Ruijun Zhang,Shanshan Gao,Jiayu Tian
Reducing the thickness of the polyamide (PA) layer has been confirmed as a feasible strategy to improve the permeability of the thin film composite (TFC) nanofiltration (NF) membrane. In this study, a novel interfacial polymerization (IP) approach assisted by the volatilization of n-hexane was proposed to promote the formation of a thinner PA layer, in which a small amount of n-hexane was added onto the substrate membrane after aqueous phase immersion and before the organic phase coating, then the temperature of the substrate membrane together with the water-soluble monomer solution would be decreased due to the volatilization of n-hexane. The infrared thermographies demonstrated that 7.8 μL cm −2 n-hexane dosage was the most efficient, which can sharply decrease the surface temperature from room temperature (25 °C) to 7.9 °C. The TFC membranes prepared at the lower temperature presented much higher permeability. When PIP concentration was 0.3% w/v, TMC concentration was 0.1% w/v and IP reaction time was 40 s, the PA layer formed at this low temperature was smoother and more hydrophilic. Its thickness was reduced from 26.97 nm to 11.98 nm and water permeability was increased by 50% to 36.7 L m −2 h −1 bar −1 while maintaining Na 2 SO 4 rejection of 96.5%.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF NON-CRYSTALLINE SOLIDS
·
2023
·
IF 3.5
Yudi Duan,Lijuan Wang,Shiyu Li,Xiaofei Liu,Jinsheng Liang,Jiachen Liu,Xinhui Duan,Hui Liu
In this work, a kind of superhydrophobic silica aerogels was prepared at ambient pressure using tetraethoxysilane (TEOS) as precursor. Particularly, N-hexane was added in the solvent to modulation pore microstructure and effect on the insulation properties of samples were analyzed. It is discovered that when the volume ratio of N-hexane to TEOS is 1:2.24 the thermal conductivity of samples can reach the lowest of 0.012 W/m·K. Compared with that of samples no addition of N-hexane, the density is decreased, the theoretical average pore size increases and the total pore volume increases. Due to N-hexane it leads cross-linking between the sol particles stronger and inhomogeneous. Thus gelation process is speeded up resulting in a change in pore structure. Low density can reduce the solid-phase heat transfer, perfect pore microstructure reduces the contribution of gas-phase heat transfer, and only when the two aspects forms a suitable combination it can exhibit optimal thermal insulation performance.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ChemistrySelect
·
2023
·Vol. 8
·期 38
·e202301288
·
IF 2.1
Lipei Fu,Houye Zhang,Wenzhe Si,Jiahui Zhu,Weiqiu Huang,Minglu Shao,Kaili Liao,Peng Xu,Bing Li,Jiang Zuo
Graphical The preparation process of composite activated carbon is mainly from stirring, then high temperature sintering to carbon, followed by a large amount of water washing to remove impurities, and finally drying to obtain composite activated carbon. During the high temperature sintering, asphalt is carbonized to form fluffy carbon material, which increases a lot of space for the loading of CNTs. Activated carbon, as the main adsorption material for treating VOCs, has been widely used. To solve the problem of safety hazards in activated carbon adsorption process due to the large amount of heat released, highly thermally conductive composite activated carbon (A-AC/CNTs) was prepared using asphalt and highly thermally conductive carbon nanotubes (CNTs) for thermal conductivity improvement. Uniform dispersion and firm loading of CNTs in the carbon production material were achieved by dispersing carbon nanotubes (CNTs) in the asphalt-in-water emulsion. Experimental results showed that the specific surface area of A-AC/CNTs reached a maximum when the loading of CNTs was 0.5 wt %. Meanwhile, the thermal conductivity increased by 1.5 times compared with the original activated carbon. The adsorption capacity of n -hexane reached the maximum of 2868 mmol ⋅ g −1 , and the adsorption capacity increased by 21.41 %. It also maintained good regeneration performance after dynamic adsorption experiments.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Nanomaterials
·
2019
·
IF 2.233
Manlin Li,Weiqiu Huang,Bo Tang,Fujiao Song,Aihua Lv,Xiang Ling
The Cu-BTC, a widely studied metal-organic framework (MOF), has been applied in various fields such as gas adsorption, separation, storage, and catalysis. However, the Cu-BTC collapses due to the replacement of the organic linker by water molecules under humid conditions, which limits its practical application in industries. In consideration of the undesirable water effect on the framework stability of Cu-BTC, a stable activated carbon (AC) was incorporated into it by the in situ method to yield a composite material AC/Cu-BTC with high water stability. XRD and SEM patterns proved that the AC7%/Cu-BTC successfully retains its crystal structure after being exposed to water molecules. The adsorption amount of n-hexane vapor of the AC7%/Cu-BTC after water vapor adsorption-thermal desorption is 307% of that of the Cu-BTC. The addition of the AC changes the adsorption active sites and reduces the strong affinity of the Cu-BTC to water molecules, resulting in the AC7%/Cu-BTC having a much lower adsorption rate for water vapor than the Cu-BTC. Therefore, the AC7%/Cu-BTC can be protected from a large amount of water molecules and avoid structural collapse caused by the disconnection between the copper center and the organic linker. The composite displays a potential value for stable applications of MOF-based materials under ambient conditions.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
FLUID PHASE EQUILIBRIA
·
2019
·
IF 2.514
Taotao Zhan,Ying Zhang,Junshuai Chen,Xiangyang Liu,Maogang He
n -Hexane is a significant component of industrial fluids. The speed of sound in supercritical n –hexane was measured by Brillouin light scattering (BLS) technique in the temperature range from (509.17–637.99) K along five isobars at p = (3.5, 4.5, 5.5, 6.5 and 7.5) MPa. The relative expanded measurement uncertainty in the speed of sound at the 95% confidence level is estimated to be 0.018. For the studied supercritical n –hexane, the change regularities of the speed of sound with increasing temperature and pressure are illustrated. Moreover, the well-known equation of state (EOS) proposed by Span and Wagner is assessed, and the absolute average deviation (AAD) between the experimental results and the calculated values is 0.89% for the whole examined p – T region.
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 THE ENERGY INSTITUTE
·
2023
·
IF 5.7
Yongdi He,Jinou Song,Jiuzhong Yang,Yuan Zhuang,Liang Qiu,Zhijun Li,Shubao Song,Yongfeng Liu,Jibiao Xie
In order to investigate the species pool and primary channels of initiated pyrolysis of n- hexane, the low-pressure (30 Torr, 4.0 kPa) flow reactor pyrolysis of n- hexane initiated by 5% 1- nitropropane ( 1- NP) was studied experimentally in a wide range of temperature from 623 K to 1223 K. Combined with synchrotron vacuum ultraviolet (SVUV) photoionization mass spectra scanned at photon energies ranging from 9.0 to 14.7 eV and near-threshold photoionization efficiency (PIE) spectra, 29 pyrolysis species, covering C 1 –C 6 hydrocarbons and several pyrolysis species containing O or N atoms, were identified. Based on the ion signal intensities of the visible peaks in the mass spectra, the mole fraction profiles of all the experimental species were evaluated. The experimental results suggested that the initial pyrolysis temperature of n- hexane was reduced by approximately 275–325 K. On the basis of the mole fraction profiles and the initial formation temperatures reported in this work and rate coefficients proposed in previous studies, the 1- NP-initiated pyrolysis mechanisms of n- hexane were discussed. It was suggested that n- hexane was dominantly consumed by the H-abstraction reactions by the attack of OH radical in this work. The 1- NP-initiated pyrolysis of n- hexane mainly proceeded via reactions to produce C 3 H 6 + C 3 H 7 , or 1- C 4 H 8 + C 2 H 5 , or 1- C 5 H 10 + CH 3 .
研究领域:
化学工程
·
物理化学
✓ 已验证
DOI
高影响因子
Petroleum Science
·
2022
·
IF 4.757
Wei-Long Zhan,Yu-Chao Lyu,Xin-Mei Liu,Lei Fan,Fu-Rang Li,Ye Yang
The Ni/SAPO-11 catalyst used for n-hexane hydroisomerization was prepared via a novel two-step crystallization strategy. It involves introduction of nickel salt into the pre-crystalized system of SAPO-11 by grinding followed by a second crystallization step. No extra solvent is introduced during the whole synthesis procedure which reduces waste liquid emissions significantly. More importantly, interaction between nickel and support is effectively regulated by the novel method to achieve a well dispersed nickel species and inhibit formation of inert nickel spinel simultaneously. Chemical environments of framework Si are tuned to enhance surface acidity of the Ni/SAPO-11 catalyst. It also shows smaller particle size which favors fast diffusion of reactants and products. Insights into the two-step crystallization indicate that accumulation of SAPO-11 precursors in the pre-crystallization stage, pH regulation by nickel salt and structural directing effect of Ni 2+ during the second crystallization period account for the rapid crystal growth and smaller particle size of the Ni/SAPO-11 catalyst. All the unique features endow the Ni/SAPO-11 catalyst higher activity and isomers selectivity than the Pt/SAPO-11 catalyst in n-hexane hydroisomerization.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2021
·
IF 5.541
Xurui Zhang,Zezhou Chen,Zhenyu Liu,Qingya Liu
Naphtha cracking for the production of olefins is extremely energy intensive, accounting for 40 % of the total energy consumption in the petrochemical industry. Since the main energy barrier of naphtha cracking is the radical initiation step, this work proposed an approach to induce the naphtha cracking by adding bibenzyl as a novel radical initiator. To verify the induction effect of bibenzyl on naphtha cracking, the conversion of naphtha model compound n -hexane with and without bibenzyl was investigated in 0.5–30 min at 400 °C and 440 °C and the products were analyzed in detail. It was found that the addition of bibenzyl increases the conversion of n -hexane from 0.39 wt.% to 5.91 wt.% at 400 °C and from 3.41 wt.% to 31.45 wt.% at 440 °C for 30 min. The gaseous products consisting of C 1 -C 4 alkanes and α-olefins showed an obviously increase after bibenzyl addition. The reaction pathways of benzyl radicals generated from the dissociation of C al -C al bonds of bibenzyl include abstracting H atoms from bibenzyl and n -hexane, and coupling with alkane radicals generated from n -hexane cracking. The incremental quantity of gaseous products is linear with the quantity of benzyl radicals. The slopes, reflecting the number of accelerated radical propagation reactions between molecules induced by per benzyl radical, increase with the decrease of bibenzyl. When the mass ratio of bibenzyl to n -hexane is 1:100, the average numbers of accelerated radical propagation reactions between molecules per benzyl radical are 185.74 and 186.38 at 400 °C and 440 °C, respectively.
研究领域:
化学工程
·
石油化工
✓ 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）