ENERGY & FUELS
·
2022
·
IF 4.654
Xiaohan Wang,Zhiqing Yu,Jinxiao Sun,Qiang Wei,Haoran Liu,Wenbin Huang,Luyuan Zhao,Meng Si,Yasong Zhou
A series of in situ dodecyl trimethyl ammonium bromide (DTAB)-modified small-crystal Y zeolites have been successfully synthesized by DTAB addition to the seed synthesis procedure, which was used to create the small crystal size Y zeolites. Compared to the Y zeolites prepared without DTAB, the Y zeolites prepared with DTAB have a uniform morphology and mesoporous structure, a larger specific surface area (up to 32.3 m2 g–1 increase), a smaller crystal size (up to 66 nm reduction), and more Brönsted acid sites (up to 55 μmol/g increase). After loading with NiW, the corresponding NiW catalysts were utilized in the hydrocracking of n-hexadecane. It is evident from the catalytic performance that the catalysts containing DTAB-modified small-crystal zeolites have a higher yield and selectivity of primary cracking products compared with the Y zeolites without DTAB modification. Moreover, the conversion of n-hexadecane is also higher due to its low mass-transfer resistance, high dispersion, and sulfation of W species. When the molar ratio of DTAB/Al2O3 is 0.15, the corresponding catalyst has the optimum balance between cracking and hydro–dehydrogenation activity. Therefore, it has the most excellent catalytic performance and a 7.3% increase in C8–C12 yield.
研究领域:
催化材料
·
石油化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2016
·
IF 2.196
Xiaojie Wang,Xiaopo Wang,Hanxiao Lang
This work reports the density and viscosity of binary mixtures for n -hexadecane with three fatty acid ethyl esters (ethyl caprylate, ethyl caprate, and ethyl laurate) in the overall composition range at temperatures from 298.15 to 323.15 K and at atmospheric pressure (0.1 MPa). Excess molar volumes and viscosity deviations have been obtained. In addition, the viscosities of the binary mixtures were correlated using a rough hard-sphere model. The average absolute relative deviations between the experimental data and the calculated values were 0.26% for n -hexadecane/ethyl caprylate, 0.30% for n -hexadecane/ethyl caprate, and 0.24% for n -hexadecane/ethyl laurate with optimized adjustable parameters. It indicates that the rough hard-sphere model is able to reproduce the viscosity behavior of the studied binary mixtures very well.
研究领域:
物理化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Particuology
·
2025
·
IF 4.3
Chengping Deng,Teng He,Liuyang Dong,Yuqiang Mao,Peilun Shen,Dianwen Liu
Dynamic pore wetting plays a major role in the flotation of porous mineral particles. However, the role of chemical properties of the liquids in dynamic pore wetting is not systematically studied. This paper studied the dynamic pore wetting process of the porous carbon particles by 10 g/L NaOL solution and n-hexadecane at different wetting times using a 1 H low-field nuclear magnetic resonance (LF-NMR). The mechanism of chemical groups of liquids affecting the pore wetting percentage and floatability of porous particles was revealed by FTIR, zeta potential, contact angle, and particle-bubble attachment tests. The results displayed that the pore wetting percentage of the particles wetted by NaOL solution was larger than that by n-hexadecane except for mesopores. Compared with the raw sample, the surface potential of the particles wetted by n-hexadecane was decreased and that by NaOL solution were negative. The NaOL, as an amphiphilic reagent contained some hydrophobic and hydrophilic functional groups, which was different from the n-hexadecane. The NaOL molecule could be easily adsorbed into the particles by electrostatic interaction compared with n-hexadecane, achieving a better surface hydrophobicity of the particles. Thus, the floatability of porous carbon particles wetted by NaOL solution was larger than that by n-hexadecane.
研究领域:
矿物加工工程
·
界面化学
✓ 已验证
产品关联
DOI
高影响因子
MINERALS ENGINEERING
·
2021
·
IF 4.765
Haoran Sun,Wanzhong Yin,Bin Yang,Keqiang Chen,Qiuyue Sheng
The flotation performances of magnesite and quartz were investigated in this work using N-hexadecyltrimethylammonium chloride (HTAC) as a collector. Micro-flotation tests were performed in a pilot study, and the results demonstrated that HTAC had high selective collection ability to quartz. Further, batch flotation results showed that HTAC could effectively remove quartz from magnesium-bearing carbonate ores. The adsorption behaviors of HTAC onto the surfaces of two minerals were analyzed through zeta-potential measurements and X-ray photoelectron spectroscopy (XPS) detection, which revealed that HTAC was mainly adsorbed on quartz rather than magnesite. Thus, HTAC could be used as a high-selectivity collector to efficiently separate magnesite from quartz.
研究领域:
矿物加工工程
·
材料科学与工程
✓ 已验证
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2021
·
IF 5.455
Jipeng Meng,Di Bai,Pahaer Zeyaodong,Chuang Li,Xiao Chen,Changhai Liang
The wirelike, rodlike and corolla-like ZSM-48 zeolites with various SiO 2 /Al 2 O 3 ratios (SARs) were successfully synthesized and exploited for the hydroisomerization of n-hexadecane (n-C 16 ). The influences of metal-acid balance, acid sites quantity, crystal morphology and textural properties on n-C 16 hydroisomerization performance were investigated primarily, via various characterization technique such as XRD , FT-IR, SEM, TEM, N 2 physisorption , NH 3 -TPD, and Py-IR. The C Pt /C A ratios of various catalysts were calculated for the quantified expression of the metal-acid balance, and the acid sites quantity was seriously crucial for the consecutive acid-catalyzed reaction after C Pt /C A ratios satisfied within an ideal range. Large external surface could accelerate the conversion rate, shorten the diffusional constraints and inhibit the cracking. The superiorities of satisfied C Pt /C A values (0.12–0.15), high concentration of acid sites (>230 μmol/g) and large external surface (>120 m 2 /g) persuaded the Pt/Z(P)80, Pt/Z(H)60 and Pt/Z(H)80 samples to demonstrate wonderful hydroisomerization performance with outstanding yield around 80 wt% and excellent i-C 16 selectivity over 91 wt%. Although Pt/Z(W)80 and Pt/Z(R)80 samples owned the relatively small crystal, the gloomy catalytic activity of them was observed due to their relatively low concentration of acid sites and external surface. Moreover, the presence of “key-lock” mechanism was verified by the observations of 7-methyl-pentadecane (7MC15) dominating in isomer products.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
THERMOCHIMICA ACTA
·
2014
·
IF 2.105
Zhenjin Fu,Lin Su,Jing Li,Ruizhuang Yang,Zhanwen Zhang,Meifang Liu,Jie Li,Bo Li
The elastic silicone/ n -hexadecyl bromide microcapsules were prepared as novel microencapsulated phase change materials by microfluidic approach with the co-flowing channels, where the double oil1-in-oil2-in-water (O1/O2/W) droplets with a core–shell geometry were fabricated. The thermal characterizations of the microcapsules were investigated using differential scanning calorimetry (DSC) and thermogravimetry analysis (TGA). The DSC results showed that the microcapsules had good energy storage capacity with melting and freezing enthalpies 76.35 J g −1 and 78.67 J g −1 , respectively. The TGA investigation showed that the microcapsules had good thermal stability. The surfaces of microcapsules were smooth and the cross sections were compact from the results of optical microscope and scanning electron microscopy (SEM). Optical microscope showed that the silicone shell can provide expansion place due to its elastic property. Therefore, the silicone/ n -hexadecyl bromide microcapsules showed good potential as thermal regulating textile and thermal insulation materials.
研究领域:
材料科学
·
热能工程
✓ 已验证
产品关联
DOI
高影响因子
ChemistrySelect
·
2022
·Vol. 7
·期 37
·e202200839
·
IF 2.307
Di Bai,Jipeng Meng,Chuang Li,Mingming Zhang,Changhai Liang
Graphical Alkali treatment and acid treatment were conducted on ZSM-23 zeolite, which achieved the acidity manipulation and improved the mesoporosity of the zeolite. The modification of the support was conducive to catalysts when used for n -hexadecane hydroisomerization, which enhanced the selectivity of isomers significantly and inhibited the cracking processes. The enhanced mesoporosity in the networks is expected to offer a potential route to surmount mass-transport constraints within one-dimensional microporous structural zeolites. Highly crystalized ZSM-23 zeolite was synthesized and subsequently post-treated with alkali-etching and acid-etching, the effects of post-treatments on the physical and chemical properties of the parent zeolite were investigated via XRD, N 2 physical adsorption, FE-SEM, TEM, 27 Al MAS NMR, Py-IR and NH 3 -TPD. The catalytic activity of various Pt supported bifunctional catalysts was investigated via n -hexadecane hydroisomerization. The post-treated process not only increased the pore volume as well as the specific surface area, which efficiently improved the diffusion efficiency, but also changed the acidity and acid distribution of zeolite: alkali treatment could increase the content of total Brönsted acid while acid treatment exhibited an opposite trend. Acid treatment effectively promoted the density of weak Brönsted acid sites and suppressed the med-strong Brönsted acid sites. With the manipulation of acidity and development of mesoporosity in zeolite, the formation of isomers and the suppression of cracked products in the n -hexadecane hydroisomerization were accomplished. The catalytic performance of catalysts showed that acid treatment could effectually promote the formation of isomeric products and inhibit cracking reactions. Especially, Pt/Z(1.0 HN) catalyst with suitable distribution of acid sites and textural properties, exhibited an outstanding n -C 16 hydroisomerization performance with the highest i -C 16 yield of 64 wt.% at 340 °C.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2020
·
IF 4.982
Haoqiang Sheng,Xiaobin Huang,Zhengchuang Zhao,Zhijia Chen,Hong Liu
Low-temperature combustion of hydrocarbons can help to increase energy efficiency and reduce the environmental pollution. In this study, an efficient homogeneous radical activation approach has been developed to improve the low-temperature combustion of n -hexadecane, which produces efficient radicals based on the dynamic inductive effect from the interaction of the adsorbed terminal methyl group . The activation ability for low-temperature combustion of n -hexadecane could be enhanced greatly by this approach. The ignition temperature of n -hexadecane on addition of 3% borane-dimethyl sulfide (Borane-DMS) was measured by droplet hot-plate impinging experiment and found to be 165 °C, which is 440 °C lower than that of pure n -hexadecane. Hence, Borane-DMS is a highly efficient activator. The interaction between Borane-DMS and n -hexadecane is mainly responsible for to the great activity enhancement of radicals. The results obtained from this study provide a new way for radical-based C H bond activation of alkanes to enhance their low-temperature ignition.
研究领域:
燃料化學
·
燃燒科學
✓ 已验证
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Tao Li,Dan Xu,Zhenye Sun,Yinghui Lv,Shuyuan Wang,Zhichao Tao,Yong Yang
A series of amorphous silica-aluminas (ASAs) were prepared by altering the initial and final calcination temperatures. Multi-characterization techniques were utilized to investigate the influence of these temperatures on the textural characteristics, coordination state, and acidity properties. The BET external surface area and pore volume showed a slight initial increase with increasing final calcination temperatures, but decreased significantly beyond 700 °C due to partial collapse and blockage of mesopores. Appropriately high calcination temperatures favored the production of metastable Al species, while ultra-high temperatures could disrupt the ASAs network, causing Al atoms to detach from their original structure. The resulting “isolated” Al IV and Al V species were inefficient in forming Brønsted acid sites (BAS), and the Al V species in them are relatively unstable, tending to convert into Al VI -enriched alumina. In contrast, the network-bound Al V species were more responsible for BAS generation, providing deeper insights into the role of Al V in BAS formation. Among all cases, SA-IC400 calcined at 700 °C with an initial calcination temperature of 400 °C, exhibited optimal physicochemical properties. The corresponding Pt/SA-IC400 catalyst demonstrated superior activity in n -hexadecane hydroisomerization, outperforming that of HBeta-based catalyst and achieving a maximum multi-branched isomer yield of 49.4%. These results are attributed to the amorphous topology and enhanced acidic properties, which play a significant role in mitigating spatial hindrance around acid sites and lowering reaction temperature. This controlled calcined treatment provides a facile method to synthesize ASAs with enhanced acidity and textural properties, providing a valuable reference for tailoring efficient hydroisomerization catalysts.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
FLUID PHASE EQUILIBRIA
·
2019
·
IF 2.514
Guanjia Zhao,Xiaona Liu,Zemin Yuan,Jianguo Yin,Suxia Ma
To facilitate the application of clean alternative fuels or fuel additives in compression ignition engines and a better understanding of the characteristics of their combustion and emission, physical biofuel surrogates are necessary to be proposed in computation and the knowledge of their thermophysical properties, such as liquid density, surface tension and viscosity, are also crucial for the design and optimization of the fuel injection system. Therefore, the surface light scattering (SLS) method was adopted for the simultaneous determination of the liquid surface tension and kinematic viscosity of the binary mixtures containing n-hexadecane, methyl butyrate and methyl decanoate in the temperature range between (353.15 and 423.15) K in the present work. Additionally, a U-tube densimeter and refractometer were used to obtain the liquid density and refractive index of the binary mixtures in the temperature range from (293.15–423.15) K and (293.15–358.15) K, respectively. Correlations for all thermophysical properties against temperature and mole fraction were also proposed. The relative deviations of liquid density, refractive index, kinematic viscosity as well as surface tension data from those calculated by the proposed equations were within ±0.3%, ±0.20%, ±2% and ±1%, respectively for the binary systems.
研究领域:
能源科学
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
PHYSICS OF FLUIDS
·
2021
·Vol. 33
·期 2
·
IF 3.521
Zhao Wenjing,Ma Hongzhi,Ji Wenjie,Li Weibin,Wang Jin,Yuan Quanzi,Wang Yuren,Lan Ding
Flows of thin fluid layers spreading, which have a distinguished history, have been studied since the days of Reynolds, who was among the early researchers to examine flows. Different from surfactant-driven spreading, which is currently the most common subject of study, we observe the spreading process of n -hexadecane driven by volatile silicone oil at the surface of the aqueous substrates and explore the influence of Marangoni flow caused by surface tension gradient on liquid-driven spreading. We find that on different substrates, the initial state of n -hexadecane is different, and there are two instability patterns during the spreading, subsequently, which are analyzed theoretically. While the n -hexadecane drop stationed on the liquid surface is small, it is driven to form a rim and then breaks up into beads, which shows the Rayleigh–Plateau instability patterns. When we put the n -hexadecane drop on the surface of the saturated sodium chloride solution, which spreads out more, it is driven to form a circular belt first and fingering instability subsequently occurs at the inner edge of the circular belt.
研究领域:
流体力学
·
物理化学
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2018
·
IF 3.141
Yujing Chen,Chuang Li,Xiao Chen,Yan Liu,Chi-Wing Tsang,Changhai Liang
A series of Fe-substituted ZSM-23 samples with different Fe/(Fe + Al) ratios were synthesized. Combined characterization by Fourier transform infrared spectroscopic, ESR, and X-ray photoelectron spectrosopic methods confirmed the presence of Fe in the ZSM-23 framework. The crystal size decreased with increasing Fe/(Fe + Al) ratio, and the Fe-substituted ZSM-23 samples exhibited large specific areas and pore volumes. The introduction of Fe in the framework reduced the acid strength compared with the Fe-free counterparts. Compared with the Pt/Fe-free ZSM-23 catalyst, the Pt/Fe-substituted catalysts showed lower activity to the hydroisomerization of n-hexadecane and higher isomerization selectivity. This is attributed to their higher ratios of weak and strong Brønsted acidic sites and smaller crystal size, which improved the product diffusion and suppressed the further product cracking. More 5M-C15 isomers were obtained over the Pt/Fe-substituted catalysts, which was different from the product distribution of Pt/Fe-free ZSM-23 where 2M-C15 isomers were the major isomer products.
研究领域:
催化化学
·
材料科学
✓ 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）