JOURNAL OF CHEMICAL THERMODYNAMICS
·
2022
·
IF 3.269
Jinkun Guo,Bo Jin,Shijin Chu,Rufang Peng
A different type of heat-flow calorimeter is developed to measure the energy of combustion. This calorimeter uses differential thermopile as the heat-flow sensor. The calorimeter and oxygen bomb have a special structure to ensure that the heat generated by combustion heat is slowly transferred to the thermopile, and the temperature of the outside interface of the thermopile is constant. The calorific coefficient is determined by chemical calibration, providing for the chemical calibration S =(64.806 ± 0.029) μV mW −1 , which means uncertainty is 0.05 % for calibration. The combustion enthalpies of anthracene and naphthalene are measured by using this calorimeter, and the results agree with the literature values or recommended values.
研究领域:
热化学
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分析化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2024
·
IF 8.4
Jiakai Chen,Hongchang Pei,Yan Zou,Huiying Ding,Zhongfang Li,Lei Zhang,Hongsen Hui,Qiang Liu,Xianhui Li,Nozipho Nonsikelelo Gumbi,Luchang Qin
In the preparation of nanofiltration (NF) membranes, the introduction of acid acceptors into the aqueous phase generates heat through their interaction with the byproduct HCl from interfacial polymerization (IP), potentially leading to the formation of bubbles. This work aims to dissect the combined influences of heat and nanobubbles on NF membrane structure and performance. Three representative alkalis (i.e., NaHCO 3 , NaOH, and Ca(OH) 2 ) were employed as acid acceptors into the aqueous phase, resulting in an increase of the consumption of PIP in the IP reaction from 10.75% to 23.65%, 19.35%, and 12.90%, respectively. The use of NaOH and Ca(OH) 2 released more heat led to a thicker polyamide layer which reduced flux. While the use of NaHCO 3 simultaneously released heat and bubbles, which promoted the development of a rougher surface polyamide layer, resulting in an increased flux from 20.3 to 28.3 L/m 2 h bar, while maintaining a salt rejection rate of 97.7%. The attendance of acid acceptors also enhanced the degree of crosslinking and resulted in a decrease in negative charge of the prepared membrane. This study advances the understanding of the impact of heat and bubbles release induced by the addition of acid acceptors on NF membrane structure and performance.
研究领域:
材料科学
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环境工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2021
·Vol. 147
·期 2
·1405-1419
·
IF 4.626
Zhao Xiao-Qiao,Wu Wen-Qian,Li Hua-bo,Chen Wang-Hua,Guo Zi-Chao,Chen Li-Ping
Adiabatic calorimetry is one of the main experimental methods to quantitatively study the thermal hazard in chemical process. There are two problems in adiabatic calorimetry: (1) identification of the reaction model is difficult; (2) the equilibrium of system and the temperature uniformity of sample will be broken under the rapid temperature rise rate, especially at lower thermal inertia. In this work, the heat-quench-heat method in adiabatic calorimetry was proposed to determine the reaction model and slow the reaction rate to evaluate kinetic parameters accurately. A criterion was proposed to identify the reaction model which states that the decomposition is an n-order reaction if T 0,stage1 < T 0,stage2 ; otherwise autocatalytic behavior was observed. Mathematical simulations have been conducted for n-order and autocatalytic decompositions. To further validate the method, it is applied to two representative substances: DTBP and CHP. The validity of this method has been verified by simulation and experiment results.
研究领域:
化学工程
·
热力学
✓ 已验证
产品关联
DOI
高影响因子
Biomass Conversion and Biorefinery
·
2025
·
IF 4.1
Li Wangliang,Fang Yi,Chang Shengqiang,Mi Shuzhen,Zhao Shengyong
Co-gasification of biomass and coal offers a strategic approach to enhance the sustainability of energy resources by exploiting the inherent synergies between various biomass components (cellulose, hemicellulose, and lignin) and coal. This study investigates the co-gasification in a downdraft fixed-bed reactor, focusing on the impacts on gas yield, calorific value, and carbon structure transformations. Thermogravimetric analysis revealed parameter-specific effects of biomass components during gasification. At a 50 wt% blending ratio, cellulose significantly enhances gasification, increasing calorific value and CO production beyond theoretical predictions. In contrast, lignin inclusion at a 70 wt% ratio decreases the calorific value and CO production by 6.44% and 11.21%, respectively. Additionally, hemicellulose is found to catalytically enhance CO 2 conversion, with a maximum increase of 45.99% at a 70 wt% ratio. The study elucidates the differential impacts of each biomass component on the co-gasification process and underscores the potential of optimizing biomass blends to maximize the efficiency and sustainability of energy production.
研究领域:
能源科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2019
·
IF 6.669
Yuan Zhang,Liping Kang,Hongmei Li,Xianzhang Huang,Xiaoyu Liu,Lanping Guo,Luqi Huang
The combustion of moxa floss was investigated by thermogravimetric/differential scanning calorimeter (TG/DSC), thermogravimetric/Fourier transform infrared spectroscopy (TG-FTIR) and an infrared radiation spectrum-detecting system. The average mass loss rate at the major stage of combustion was 1.08%/min with a peak at 7.86%/min. Moxa floss burning released the integral heat of 9188 mJ/mg from the temperature of 200 °C to 500 °C. The peak heat flow during char combustion stage was higher than those of other stages. The results indicated the combustion of moxa floss was a mild and slow process, releasing heat continuously and steadily. The infrared radiation spectra of burning moxa stick were in a range of 2.5–13.0 µm and showed double peaks at 3.75 µm and 8.75 µm. Thus, this study provided insight into why moxa floss biomass is the optimal material for thermal therapy and is beneficial for the development of electric thermal stimulation alternative.
研究领域:
热疗研究
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生物医学工程
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF NANOPARTICLE RESEARCH
·
2017
·Vol. 19
·期 9
·1-13
·
IF 2.02
Tang Huanfeng,Huang Zaiyin,Xiao Ming,Liang Min,Chen Liying,Tan XueCai
The activities, selectivities, and stabilities of nanoparticles in heterogeneous reactions are size-dependent. In order to investigate the influencing laws of particle size and temperature on kinetic parameters in heterogeneous reactions, cubic nano-Cu 2 O particles of four different sizes in the range of 40–120 nm have been controllably synthesized. In situ microcalorimetry has been used to attain thermodynamic data on the reaction of Cu 2 O with aqueous HNO 3 and, combined with thermodynamic principles and kinetic transition-state theory, the relevant reaction kinetic parameters have been evaluated. The size dependences of the kinetic parameters are discussed in terms of the established kinetic model and the experimental results. It was found that the reaction rate constants increased with decreasing particle size. Accordingly, the apparent activation energy, pre-exponential factor, activation enthalpy, activation entropy, and activation Gibbs energy decreased with decreasing particle size. The reaction rate constants and activation Gibbs energies increased with increasing temperature. Moreover, the logarithms of the apparent activation energies, pre-exponential factors, and rate constants were found to be linearly related to the reciprocal of particle size, consistent with the kinetic models. The influence of particle size on these reaction kinetic parameters may be explained as follows: the apparent activation energy is affected by the partial molar enthalpy, the pre-exponential factor is affected by the partial molar entropy, and the reaction rate constant is affected by the partial molar Gibbs energy.
In situ microcalorimetry, combined with theoretical models, was used to investigate the reaction kinetic parameters of cubic nano-Cu 2 O, and those effects of particle size and temperature were discussed systematically.
研究领域:
材料科学
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化学动力学
✓ 已验证
产品关联
DOI
高影响因子
Applied Food Research
·
2025
·
IF 6.2
Hira Ijaz,Shangde Sun,Gholamreza Abdi,Rana Muhammad Aadil
The objective of the present study was to produce one novel low-calorie structured lipids (SLs), that can be used as a healthy alternative of shortening fat. SLs were produced by the interesterification of tiger nut oil (TNO) and methyl behenate using Lipozyme RMIM at a temperature of 85 °C, an agitation speed of 300 rpm, and a reaction time of 1.25 hours. Resulting SLs characterized through a comprehensive set of advanced physicochemical analysis including AV, slip melting point, solid fat content, total fatty acid composition, x-ray diffraction, differential scanning calorimetry, and triacylglycerol composition were analyzed for both SLs and formulated blends. Results showed that novel SLs had high melting point and solid fat content, to further optimize functionality, unique blend formulations of SLs and TNO were prepared, and the best ratio was selected. This blend demonstrated reduced slip melting point and solid fat content than SLs, suggesting its potential for developing low-calorie, health-friendly shortening fats.
研究领域:
食品科学
·
生物化学
✓ 已验证
产品关联
DOI
高影响因子
THERMOCHIMICA ACTA
·
2024
·
IF 3.1
Huimin Yan,Fan Yang,Nan Yin,Yan Kou,Quan Shi
Adiabatic calorimetry is a reliable method for determining the purity of organic compounds, offering significant advantages over chromatography by eliminating the need for impurity separation. Despite its longstanding application, research in this area has been limited. This study comprehensively assessed the purity of tetradecanoic acid, n-heptadecane, and phenol using adiabatic calorimetry, comparing the results with those obtained through chromatography. The results demonstrated that tetradecanoic acid purity can be accurately measured, while n-heptadecane exhibited satisfactory repeatability in purity determination without sample separation in polycrystalline forms. Furthermore, the purity of phenol was effectively assessed using adiabatic calorimetry, where chromatography faced challenges. Overall, this study validates adiabatic calorimetry as a robust technique for organic compound purity determination and suggests avenues for further research in this domain.
研究领域:
化学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2024
·Vol. 149
·期 10
·4827-4838
·
IF 3
Li Weilong,Zhang Fengyan,Li Xiaoquan,Hu Jiwen,Gui Xuefeng,Lin Shudong
Epoxy acrylate is produced by esterifying epoxy resin and acrylic acid through a ring-opening reaction. This process is highly exothermic and can be challenging to control gel formation. The thermal hazards of epoxy acrylate preparation were evaluated in this study by investigating the ring-opening esterification reaction between acrylic acid (AA) and bisphenol A epoxy resin (E-51) catalyzed by triethylamine (TEA). The heat release during the reaction process was analyzed using a reaction calorimeter (RC1 mx ) to simulate industrial conditions. Increasing the TEA catalyst content from 0.3 to 1.0 mass% resulted in a significant rise in reaction conversion from 75.35 ± 0.10% to 98.44 ± 0.10%. Differential scanning calorimetry (DSC) and accelerating rate calorimeter (ARC) were used to examine the thermal runaway process during epoxy acrylate synthesis. Increasing the TEA content from 0.3 to 1.0 mass% decreased the initial reaction temperature from 60.16 ± 0.62 to 45.33 ± 0.40 °C and the critical temperature of side reactions from 153.71 ± 1.51 to 117.85 ± 1.19 °C. The severity of the runaway was classified as medium at process temperatures of 80–110 °C. This study highlights the importance of considering reaction conditions to prevent uncontrolled reactions during epoxy acrylate synthesis, providing valuable insights for industrial epoxy acrylate preparation.
研究领域:
化学工程
·
安全科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Food Science & Technology
·
2025
·
IF 2.8
Min Pang,Lu Xu,Ying Qian,Mengke Li,Jianglin Chen,Jieshun Cheng,Lili Cao
Cocoa butter (CB) substitution remains challenging for low-calorie chocolates due to texture and stability compromises in conventional alternatives. This study developed bigels (oleogel/hydrogel ratios = 3:7, 5:5, 7:3 w/w) from phytosterol ester oleogel and gelatin hydrogel as CB substitutes. The optimal CB substitution was screened by characterizing the bigels’ physicochemical properties. Subsequently, compound chocolates were fabricated using the selected bigel system, with the optimal substitution ratio determined through the comprehensive evaluation of their micromorphology, thermal behavior, and sensory profiles. X-ray diffraction revealed peaks at 4.151 and 3.741 nm. At 70 wt % oleogel, the bigel exhibited the highest hardness (307.34 ± 30.66 g). Subsequently, compound chocolates were produced with bigels at substitution levels of 20–100 wt %, showing melting temperatures (42.66–75.30 °C) significantly higher than CB (41.51 °C). The L* (17.43 ± 0.64) and a* (2.13 ± 0.25) values of the CB group, along with its sensory evaluation score (83.50 ± 2.31), showed no statistically significant difference (p < 0.05) when compared to 20% (16.62 ± 0.41, 2.57 ± 0.12, 83.50 ± 1.97) and 40% samples (16.19 ± 0.58, 2.66 ± 0.14, 81.14 ± 2.35). Phytosterol ester–gelatin bigels successfully replicated CB’s functional properties, demonstrating feasibility as calorie-reduced alternatives. This work provides a novel strategy for designing structured lipid systems in confectionery applications, addressing both nutritional and sustainability demands in the food industry.
研究领域:
食品科学
·
营养学
✓ 已验证
产品关联
DOI
高影响因子
THERMOCHIMICA ACTA
·
2025
·
IF 3.5
Rongkun Pan,Chensheng Wang,Qingsheng Zhang,Chenzhuo Song,Chang Lu,Ligang Zheng,Bei Pei,Lei Chen
In this paper, staged thermal characteristic experiments were conducted on commonly used powder explosion suppressants using a high-precision C600 microcalorimeter. The thermal decomposition process was divided into three stages, and a comprehensive analysis was carried out on the thermal flow curves, dHF, initial heat flow value H 0 , minimum heat flow value H min , characteristic points, and heat absorption amount Q of twelve powder explosion suppressants, including attapulgite and montmorillonite. The results indicate that carbamide has the smallest minimum heat flow value H min during powder thermal decomposition, while CaCO 3 has the largest minimum heat flow value H min . Carbamide exhibited the highest overall heat absorption amount, while NaCl showed the lowest overall heat absorption amount. The mechanism of inhibiting methane explosion with different powder suppressors was analyzed by comparing the pyrolysis experiment results. The conclusions of this study can serve as a theoretical foundation for the rational selection of powder explosion suppressors, enhancing their utilization rate, and improving their explosion suppression effectiveness.
研究领域:
化学工程
·
安全科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Cleaner Production
·
2020
·
IF 7.246
Liping Wang,Yuzhi Chang,Xuejing Zhang,Fan Yang,Yao Li,Xinran Yang,Shaogang Dong
Hydrothermal carbonization has proven to be an effective method to convert sewage sludge into solid carbon-rich hydrochar , of which the high ash content is generally regarded as limiting factor for energy-related potential application. Hydrothermal co-carbonization of sewage sludge and high concentration phenolic wastewater was firstly investigated in this study as a scenario for production of clean solid biofuel with increased calorific value and decreased ash content, by means of polycondensation reactions between phenols and highly reactive intermediates of biopolymers in sewage sludge. Results showed that addition of phenolic wastewater into sewage sludge led to a substantial increase of hydrochar yield (1.83–31.11%) and higher heating value (1.01–10.01%) and a remarkable decrease of ash content (1.39–25.68%). The reaction temperature and residence time had a complicated impact on the contribution of phenol to hydrochar production. An increase in phenol mixing ratio was beneficial to the improvement of mass yield and higher heating value but showed a less influence on the reduction of ash content. The synergistic effects between phenols and sewage sludge on the production of solid biofuel were closely related to the phenolic species, which followed the order in the aspects of hydrochar yield increase and ash content decrease: phloroglucinol > p -nitrophenol > m -cresol > phenol. The changes of phenols content in liquid phase and variations of functional groups in hydrochars implied that phenols interacted with sewage sludge and incorporated into hydrochars during the hydrothermal co-carbonization. TG-DSC confirmed the improved combustion reactivity of the phenols-sludge-derived hydrochars.
研究领域:
环境科学
·
能源工程
✓ 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）