ENERGY & FUELS
·
2024
·
IF 5.2
Zhiyuan Kong,Sibao Liu,Hongwang Liu,Guozhu Liu
Endothermic hydrocarbon fuel is the most utilized coolant in regenerative cooling technology for the high-speed aircraft, but it is challenged by the limited heat sink and severe coke deposition. In this study, we propose liquid ammonia as a promising carbon-free fuel with high heat sink for advanced vehicles or aircrafts. The chemical heat sink originates from the endothermic decomposition reaction of ammonia. A series of Ru/CeO2–Al2O3 catalytic coatings were fabricated on stainless-steel tubes using the washcoating method to catalyze the ammonia decomposition reaction and enhance chemical heat sink. The catalytic performance of these Ru/CeO2–Al2O3 coatings for ammonia decomposition was evaluated using an electrically heated tubular reactor. With the Ru/CeO2–Al2O3 coatings of 19 μm, ammonia conversion reaches up to 65%, and a remarkable high heat sink of 5.9 MJ/kg was achieved at 800 °C and 5 MPa. This value is ca. 68% higher than that of the typical hydrocarbon fuel JP-7. This work shows that liquid ammonia can serve as a novel generation high heat sink fuel for advanced engines and aircrafts.
研究领域:
航空航天工程
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材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Cleaner Production
·
2023
·
IF 11.1
Hui Yang,Shuang Shao,Baozhong Ma,Yingwei Lv,Yongqiang Chen,Chengyan Wang
With the increasingly essential role of Li in new energy industry, Li extraction from ore has attracted active attention. In the prior study, a process combined thermal activation and alkali leaching was proposed to extract Li from Li concentrate. Previous research found that Li was precipitated as Li 2 SiO 3 and entered into the leach residue at the leaching temperature exceeded 100 °C. Drawing inspiration from this phenomenon, hydrothermal precipitation of Li as intermediate product Li 2 SiO 3 from the alkali leach liquor of Li concentrate was proposed. Firstly, the E–pH diagrams of Li–Si–H 2 O system were plotted to analyze the feasibility of hydrothermal precipitation Li. And the corresponding operation window was established. Subsequently, the effect of factors including Li/Si ratio, hydrothermal temperature and time, Li and NaOH concentrations on the migration behaviors of Li and Si were explored using the simulated leach liquor. The experimental results were in good consistence with the thermodynamic analysis. Ultimately, the leach liquor was used to precipitate Li at the determined optimal conditions, and the Li precipitation efficiency reached 91.0%. This study provided an innovative strategy for separating Li from the alkali leach liquor of Li concentrate without adding any reagents. An economical and sustainable route for synergistic extraction of Li, Rb, and Cs from Li concentrate was also proposed.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ENERGY
·
2025
·
IF 9.4
Hao Sun,Hui Gao,Yanhua Li,Youchang Du,Jiao Wang,Huaizhi Han,Guice Yao,Dongsheng Wen
Fully utilizing the chemical heat sink generated by hydrocarbon fuel cracking is critical for enhancing the endothermic cooling capacity of the fuel. In this study, a catalytic strategy based on oil-dispersible palladium nanoparticles (Pd NPs) is proposed for the supercritical cracking of RP-3. Pd NPs with an average size of 2.85 nm are synthesized and uniformly dispersed in RP-3, exhibiting long-term stability with a sedimentation rate below 7% after 60 days. To evaluate the catalytic performance and reveal the complex catalytic cracking mechanism of hydrocarbon fuels under supercritical conditions, a combined approach of tubular reactor experiments and reactive force field molecular dynamics (ReaxFF MD) simulations is employed. Both experimental and simulation results demonstrate that, compared to thermal cracking, Pd/RP-3 catalytic cracking exhibits significant improvements in conversion, gas yield, olefin selectivity, and heat sink. At 700 °C, 200 ppm Pd NPs increase the heat sink of RP-3 from 2.52 MJ/kg to 2.77 MJ/kg. Kinetic analysis reveals that the enhancement is ascribed to the remarkable catalytic abilities of Pd NPs to reduce the activation energies for RP-3 cracking, C-C and C-H bond cleavage by approximately 66.7%, 80.7%, and 78.7%, respectively. Pd also enhances dehydrogenation reactions, leading to higher yields of hydrogen and olefins, while effectively facilitating benzene rings decomposition within the aromatic components of RP-3. The synthesized oil-dispersible Pd NPs present great potential for enhancing the cooling capacity and the catalytic cracking mechanism proposed here may provide a theoretical foundation for designing efficient future catalysts.
研究领域:
化学工程
·
纳米技术
·
能量转换
·
催化
·
分子动力学模拟
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Ji Mi,Peilun Wang,Hongshang Wang,Chongkun Shao,Zhiyuan Yuan,Jingkai Ma,Yongsheng Guo,Xufeng Lin,Wenjun Fang
Endothermic hydrocarbon fuels (EHFs) with high heat sink have revolutionized the thermal management technology of hypersonic aircraft over the past decades. In this work, highly stable quasi-homogeneous systems as a novel type of potential EHFs are introduced by dispersing water-rich multifunctional nanospheres in hydrocarbons. Studies conducted using cryo-transmission electron microscopy, dynamic light scattering and small-angle X-ray scattering have demonstrated that nanospheres with diameter less than 100 nm can be solubilized into hydrocarbons to form semi-transparent systems. They resist phase separation, remain stable under extreme centrifugal forces (exceeding 8000 RCF), and have low freezing points (subcooling temperature below −40 °C). In these quasi-homogeneous systems, the amphiphilic macromolecules within the multifunctional nanospheres serve dual roles: they stabilize the nanospheres and initiate the thermal cracking of the fuel, while the water component mitigates coking tendencies and contributes to the high heat sink. Ultimately, this novel fuel can achieve up to 19 % improvement in heat sink (from 3.42 MJ·kg −1 to 4.05 MJ·kg −1 at 3.5 MPa) and a 96.8 % reduction in coke formation (at 700 °C) with only a 9 % loss in volumetric heat value, without the need of catalysts.
研究领域:
材料科学
·
航空工程
✓ 已验证
产品关联
DOI
高影响因子
CORROSION SCIENCE
·
2024
·
IF 7.4
Liangliang Xiong,Huaning Jiang,Mengxue Wu,Yongji Gong,Xiaoqiang Fan,Minhao Zhu
A centimeter-size carbon nitride (CN) film, with nanoscale thickness, is in situ deposited on various metals through the thermal condensation of melamine, achieving broad and uniform coverage, without any pre- and post-treatments. As the temperature rises, the nitrogen content in the film increases, leading to the part of CN to transform into g-C 3 N 4 . Benefit from higher Gibbs adsorption free energies of g-C 3 N 4 with Cl - and O 2 in aqueous environment, a 30 nm CN film deposited at 475 ℃ with large g-C 3 N 4 network, minimal segregation and low internal stress enables pure metals and alloys to achieve over 90 % protection efficiency.
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 ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Zhan Shu,MengQi Li,Lu Gan,Lijia Wan,Xiaoling Chen,Xiaohang Zhang,Weijun Gui
Highly luminescent GdVO 4 :Eu 3+ /carbon dots (CDs) nanocomposite was synthesized by hydrothermal deposition method for the first time. With the use of dialyzed CDs solution as precursor, the synthetized composite shows negligible emission intensity of CDs. On replacing the dialyzed CDs solution with the crude one, highly luminescent composite can be obtained successfully. Based on the analysis of XPS and FT-IR spectra, one can deduce that the existence of a large amount of citrate anions, ethylenediamine cations and polymer-like CDs in the crude CDs solution make it as nutrient solution of CDs, which can not only facilitate growth of CDs on the surface of GVE, but also greatly prevent nitrogen atoms from falling off the particles during the hydrothermal deposition process. For the dialyzed CDs solution, due to the ions and polymer-like CDs being thoroughly dialyzed, the coated CDs are fragile during hydrothermal deposition process. Besides, the effects of different dosages of ammonia on emission intensities of the two composites are studied. Based on the designable patterns for security application, one can think that the highly luminescent composite is one of the most promising candidates in the anti-counterfeiting field.
研究领域:
材料科学
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光学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
LUMINESCENCE
·
2023
·Vol. 38
·期 8
·1521-1528
·
IF 2.9
Zhan Shu,Mingzhe Du,Mengqi Li,Yanghui Liu,Lu Gan,Xiaohang Zhang,Weijun Gui
To obtain optimal luminescence, 0.12 g of GdVO 4 :3%Eu 3+ nanocrystals (NCs) and different volumes of nitrogen-doped carbon dots (N-CDs) crude solution were used as precursors, and the composite synthesized using the hydrothermal deposition method showed optimal luminescence when 11 ml (2.45 mmol) crude solution was used. In addition, similar composites with the same molar ratio as GVE/cCDs(11) were also prepared with the hydrothermal and physical mixing processes. Based on the test results of XRD, XPS, and PL spectra, for the composite GVE/cCDs(11), the highest (lowest) peak intensity of the C–C/C=C (C=O/C=N) bond, which was 1.18 (0.75) times that of GVE/cCDs-m, indicated most N-CDs deposition and led to their highest emission intensity under 365 nm excitation, although nitrogen atoms in the composite were shed slightly during the deposition process. Finally, as can be seen from the patterns designed for security applications that the optimally luminescent composite is one of the most promising candidates in the anti-counterfeiting field.
研究领域:
材料科学
·
化学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FUEL
·
2023
·
IF 7.4
Yu Feng,Huihang Zhang,Deming Zhang,Fuqiang Chen,Xinhai Xu,Jiang Qin,Yi Jiao
The cracking of on-board hydrocarbon fuels is a strong endothermic reaction and can provide an additional chemical heat sink in the cooling process of the hypersonic vehicle. However, the cooling capacity of current hydrocarbon fuels can hardly meet the cooling requirements of the hypersonic vehicle at higher flight speeds. Blending ethanol is an effective method to improve the chemical heat sink of hydrocarbon fuels, but the mechanism of ethanol on chemical heat sink is unclear. In this study, n-decane was selected as a model compound of hydrocarbon fuels to investigate the physical and chemical effect of ethanol on the chemical heat sink of n-decane cracking by analyzing the chemical reactions involved through experimental study and chemical dynamic simulation. The results indicate that there is an optimum ethanol blend ratio to achieve the maximum chemical heat sink. The carbon monoxide methanation reaction which is an exothermic reaction can deteriorate endothermic process at 300–375 °C. With ethanol blending ratio above 20 wt%, ethanol vaporization deteriorates chemical heat sink by reducing the residence time in the temperature range of 225–250 °C. Pressure can suppress the reduction of residence time caused by ethanol evaporation and also suppress the positive reaction of ethanol cracking. The kinetic model of ethanol and n-decane mixture cracking was established. The calculated results verify that ethanol cracking ( C 2 H 5 OH =CO+ C H 4 + H 2 ) and methane cracking ( C H 4 =C+ 2H 2 ) are dominant reactions in ethanol-assisted n-decane thermal cracking below 475 °C.
研究领域:
能源科学
·
化学工程
·
航空航天工程
✓ 已验证
DOI
高影响因子
CANADIAN METALLURGICAL QUARTERLY
·
2024
·
IF 1.3
Xiaohua Peng,Xin Jin,Yong Zhen,Bo Yang,Chang Wei,Xingbin Li,Zhigan Deng,Minting Li
Here, a hydrometallurgical process was proposed to separate nickel (Ni) and iron (Fe) from ferronickel. The effects of different factors, namely hydrothermal temperature, initial Fe2+ concentration, and Ni2+ concentration, on the hematite precipitation process, were detail investigated. Ferronickel powders were leached using a 120 g/L H2SO4 solution at 85 °C for 8 h. The final pH of the leaching solution was controlled at 3.0−4.5, and the Fe2+ concentration was maintained at 50−60 g/L. Copper from the ferronickel powder was first leached in the early stage of the leaching process, and then it was reduced by an excess of ferronickel powder, leading to its enrichment in the leaching residue. Approximately 50 g/L of Fe ions was successfully removed and precipitated as hematite containing 60% Fe, 0.3% Ni, and 1.5% S during hydrothermal precipitation at 200 °C for 3 h. Through evaporation crystallization at 90 °C for 8 h, large particles of nickel sulfate hexahydrate (NiSO4·6H2O) containing 19.4% Ni, 0.074% Fe, and 10.69% S were obtained. Moreover, through freezing crystallization at −8 °C for 1 h, smaller particles of NiSO4·6H2O product containing 20.3% Ni, 0.014% Fe, and 11.13% S were synthesised.
研究领域:
冶金学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2013
·
IF 3.357
Lei Yue,Xiaoxing Lu,Hai Chi,Yongsheng Guo,Li Xu,Wenjun Fang,Yu Li,Shenlin Hu
Three different kinds of palladium nanoparticles modified by octadecanethiol, octadecylamine, and mixture of them have been prepared, which are simply marked as Pd@S, Pd@N and Pd@S&N in turn. The nanoparticles are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and thermo-gravimetric analysis (TGA). It follows that the average diameters of the nanoparticles are 1–3 nm. Pd@S shows noncrystalline structure, while Pd@N and Pd@S&N show face-center cubic (fcc) structure. These palladium nanoparticles can be well-dispersed in decalin , and then the nanofluids composed of decalin and palladium nanoparticles are prepared, which can be regarded as pseudohomogeneous systems. The cracking of each nanofluid containing 500 ppm Pd is performed under supercritical conditions (3.5 MPa, 600–750 °C) of decalin with a mass flow rate of 1 g/s in an electrically heated tube reactor which simulates a single passage in a practical heat exchanger. The cracking results indicate that these nanoparticles exhibit catalytic activity to a certain extent, and the activity of Pd@N nanoparticles is better than that of Pd@S or Pd@S&N. At 750 °C, the conversion of decalin is raised from 70.31 wt% of thermal cracking to 73.21 wt% with the existence of Pd@S, while that raised to 80.54 wt% with Pd@S&N and even raised to 91.85 wt% with Pd@N. The heat sink of nanofluids is effectively enhanced, and the nanofluid containing Pd@N shows the highest value, which reaches 3.50 MJ/kg and is increased by 0.29 MJ/kg in comparison with the heat sink of thermal cracking at 750 °C. The cracking of aviation kerosene containing Pd nanoparticles is then performed, the results of which confirm the feasibility of practical application of Pd nanoparticles to hydrocarbon fuels.
研究领域:
化学工程
·
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
FUEL
·
2020
·
IF 5.578
Qiancheng Zheng,Zhourong Xiao,Jisheng Xu,Lun Pan,Xiangwen Zhang,Ji-Jun Zou
This work investigated the steam reforming (SR) performance of high-energy–density (HED) fuels including exo- tetrahydrodicyclopentadiene ( exo -THD), exo -tetrahydrotricyclopentadiene ( exo -THT), 1,3-dimethyladamantane (DMA) and quadricyclane (QC), aiming to provide sufficient heat sink for hypersonic flight. The fuel conversion decreases in the order of QC > DMA ≈ exo -THD > exo -THT, while the molecular-structure-dependent catalyst stability trend is DMA > exo -THD > QC ≈ exo -THT, which are related to the H/C value, carbon deposition and exposure of active Ni species after carbon deposition. Importantly, the catalytic SR reaction can significantly improve the total heat sink of HED fuels. Especially, DMA and exo -THD with higher H/C and (H/C)*M a exhibit excellent performance on activity and stability, on which high total heat sink, total heating value and coke-resistance are achieved. This work provides the molecule-SR heat sink relationship for the design of the effective cooling system for the hypersonic flight.
研究领域:
化学工程
·
航空航天工程
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2014
·
IF 2.733
Zhenjian Jia,Hongyan Huang,Weixing Zhou,Fei Qi,Meirong Zeng
The pyrolysis mechanism of fuel under supercritical conditions is an important concern for developing regenerative cooling technology of advanced aircraft using hydrocarbon fuel as the primary coolant. n-Decane as a component of some jet fuels was studied at the temperature range from 773 to 943 K in a flow reactor under the pressure of 3, 4, and 5 MPa. Gas chromatograph/mass spectrometry was used to analyze the pyrolysis products, which were mainly alkanes from C1–C9 and alkenes from C2–C9. A kinetic model containing 164 species and 842 reactions has been developed and validated by the experimental results including the distributions of products and the chemical heat sink of fuel. The decomposition pathways of n-decane were illustrated through the reaction flux analysis. It is concluded that the C4–C9 alkanes are mainly generated by the recombinations of alkyls, while the small alkanes (C1–C3) are formed by H-abstraction reactions by C1–C3 alkyl radicals. The applicability at supercritical pressure and high fuel concentration condition of previous models was discussed, and the performance of the present model in reproducing the experimental data is reasonably good.
研究领域:
化学工程
·
航空工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）