Thermochimica Acta最新文献

英文中文

Sustainable humification of food waste slurry through thermally activated persulfate oxidation 通过热激活过硫酸盐氧化技术实现厨余泥浆的可持续腐殖化

IF 3.1 2区化学 Q2 CHEMISTRY, ANALYTICAL

Thermochimica Acta

Pub Date : 2024-11-10 DOI: 10.1016/j.tca.2024.179898

Jun Zhang , Hanbang Wang , Qinglin Zheng , Jianhui Zhi , Lianghu Su

This study introduces a thermoanalytical approach utilizing sodium persulfate (PS) to expedite the humification of food waste (FW) through advanced oxidation processes (AOPs). The method harnesses heat-induced free radicals to break down complex organic compounds into simpler forms, leading to the formation of humic substances. We conducted an analysis of changes in soluble chemical oxygen demand (SCOD), dissolved organic carbon (DOC), ammonia nitrogen, soluble proteins, and sugars, employing advanced techniques such as three-dimensional fluorescence spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, and scanning electron microscopy (SEM). The findings indicate that the activation of PS at 70 °C effectively increases SCOD and DOC levels, converts proteins into soluble forms, and enhances NH₄⁺-N content. This study, which focuses on the utilization of thermal methods, affirms that the thermal activation of persulfate (PS) significantly boosts the humification of food waste (FW), presenting a sustainable approach for waste management and resource recovery.

本研究介绍了一种利用过硫酸钠（PS）的热分析方法，通过高级氧化过程（AOPs）加速厨余垃圾（FW）的腐殖化。该方法利用热引起的自由基将复杂的有机化合物分解成更简单的形式，从而形成腐殖质。我们采用三维荧光光谱、傅立叶变换红外光谱和扫描电子显微镜等先进技术，分析了可溶性化学需氧量（SCOD）、溶解有机碳（DOC）、氨氮、可溶性蛋白质和糖类的变化。研究结果表明，在 70 °C 下活化 PS 能有效提高 SCOD 和 DOC 含量，将蛋白质转化为可溶形式，并提高 NH4+-N 含量。这项以热处理方法为重点的研究证实，过硫酸盐（PS）的热活化能显著提高食物垃圾（FW）的腐殖化程度，为垃圾管理和资源回收提供了一种可持续的方法。

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引用次数: 0

Molecular dynamics simulation of combustion reaction process and products of oxygen-containing functional groups in coal based on Machine Learning Potential 基于机器学习潜能的煤中含氧官能团燃烧反应过程及产物的分子动力学模拟

IF 3.1 2区化学 Q2 CHEMISTRY, ANALYTICAL

Thermochimica Acta

Pub Date : 2024-11-10 DOI: 10.1016/j.tca.2024.179891

Jinzhang Jia , Yumo Wu , Dan Zhao , Fengxiao Wang , Dongming Wang , Qiang Yang , Yinghuan Xing , Shan Lu

Oxygen-containing functional groups are the main heat source of coal spontaneous combustion, but their complex reaction pathways and microscopic mechanisms are still unclear. In this study, the molecular dynamics simulation of the composite combustion reaction model system with four oxygen-containing functional groups was conducted using the Machine Learning (ML) potential force field. The results showed that the stability order of these four oxygen-containing functional groups in the combustion reaction system is as follows: ‒OH < ‒COOH < ‒C‒O < ‒C = O. These simulation findings align with those obtained from in-situ FTIR experiments, thereby validating the accuracy of the ML potential force field. Notably, ‒C‒O exhibits the highest tendency for CO₂ conversion (58.57 %); ‒COOH displays the highest tendency for H₂O conversion (45.00 %); and ‒OH demonstrates the highest tendency for CO conversion (59.17 %). The essence of the oxidative combustion reaction pathway involving oxygen-containing functional groups lies in the heat accumulation resulting from the oxidative dehydrogenation effect.

含氧官能团是煤炭自燃的主要热源，但其复杂的反应途径和微观机理尚不清楚。本研究利用机器学习（ML）势力场对含有四个含氧官能团的复合燃烧反应模型体系进行了分子动力学模拟。结果表明，这四个含氧官能团在燃烧反应体系中的稳定顺序如下：-这些模拟结果与现场傅立叶变换红外实验的结果一致，从而验证了 ML 势场的准确性。值得注意的是，-C-O 对 CO2 的转化率最高（58.57%）；-COOH 对 H2O 的转化率最高（45.00%）；-OH 对 CO 的转化率最高（59.17%）。含氧官能团氧化燃烧反应途径的本质在于氧化脱氢效应产生的热量积累。

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引用次数: 0

Pyrolysis of industrial hemp biomass from contaminated soil phytoremediation: Kinetics, modelling transport phenomena and biochar-based metal reduction 受污染土壤植物修复中工业大麻生物质的热解：动力学、模拟迁移现象和基于生物炭的金属还原

IF 3.1 2区化学 Q2 CHEMISTRY, ANALYTICAL

Thermochimica Acta

Pub Date : 2024-11-09 DOI: 10.1016/j.tca.2024.179899

Jure Voglar , Anže Prašnikar , Konstantin Moser , Elisa Carlon , Manuel Schwabl , Blaž Likozar

Phytoremediation is the use of vegetation for the in situ treatment of contaminated environments. After plants have been used for phytoremediation of soils, their biomass can be used for example as value-added products or converted by thermochemical processes. Large-scale application of pyrolysis technology for phytoremediation biomass requires accurate predictive kinetic models and a characterization of the toxicity of the materials produced. The pyrolysis of industrial hemp (Cannabis sativa L.) was investigated on a laboratory scale by varying the process conditions and accurately modelled by considering four pseudo-components with first reaction order. The average value of the coefficients of determination is 0.9980. Biomass and biochar were characterized and the main components of the gas phase were monitored. We found Cd, Pb, and Zn in the roots, although in lower amounts than in the soil. Especially the leaves and stems showed negligible traces of these elements, so that these parts can be used directly, even if the hemp was grown on the polluted soil. After pyrolysis, the concentration of pollutants in the solid fraction decreased, which could be attributed to the reduction of metal oxides (or salts) to elemental form and subsequent evaporation. This pyrolysis process has the potential to treat heavy metal-rich biomass, with gas phase purification via condensation, yielding agricultural-grade biochar, CO-rich gas and a highly concentrated heavy metal stream in absorbent material.

植物修复是利用植被对受污染的环境进行就地处理。植物用于土壤植物修复后，其生物质可用作增值产品或通过热化学过程进行转化。将热解技术大规模应用于植物修复生物质需要准确的预测动力学模型和对所产生材料的毒性进行鉴定。通过改变工艺条件，在实验室规模上对工业大麻（Cannabis sativa L.）的热解过程进行了研究，并通过考虑四个具有一阶反应的假成分进行了精确建模。确定系数的平均值为 0.9980。对生物质和生物炭进行了表征，并对气相中的主要成分进行了监测。我们在根部发现了镉、铅和锌，但含量低于土壤中的含量。尤其是叶子和茎，这些元素的含量微乎其微，因此，即使大麻生长在受污染的土壤上，也可以直接使用这些部分。热解后，固体部分的污染物浓度下降，这可能是由于金属氧化物（或盐类）还原成元素形式以及随后的蒸发所致。这种热解工艺具有处理富含重金属的生物质的潜力，通过冷凝进行气相净化，产生农业级生物炭、富含一氧化碳的气体和吸收材料中高度浓缩的重金属流。

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引用次数: 0

Effects of Cu(OH)F nanoparticles on the thermal oxidation and ignition characteristics of micron-sized Al powder 纳米 Cu(OH)F 粒子对微米级铝粉热氧化和点火特性的影响

IF 3.1 2区化学 Q2 CHEMISTRY, ANALYTICAL

Thermochimica Acta

Pub Date : 2024-11-08 DOI: 10.1016/j.tca.2024.179896

Jiaming Liu , Xinwen Ma , Wenhao Wang , Weiduo Fei , Xiandie Zhang , Xiang Ke , Xiang Zhou

In this study, Cu(OH)F nanoparticles are prepared through a simple hydrothermal reaction and their effects on the thermal oxidation and ignition characteristics of micron-sized Al powder (μ-Al) are explored for the first time. Thermal analysis in air atmosphere (50∼1050 °C) shows that compared to raw μ-Al, the normalized weight gain of Al in Al-Cu(OH)F increases by about 36.9%, 64.8%, and 106.3% when the added Cu(OH)F is 1 wt%, 3 wt%, and 5 wt%, respectively. After mixed with NH₄ClO₄, electric ignition and open-air combustion tests show shortened ignition delay time (by 42.6%∼63.8%) and increased maximum light intensity (by 48.9%∼117.8%) for Al-Cu(OH)F. The effects of Cu(OH)F result from its decomposition products, namely, HF and CuO. HF reacts with alumina shell to form AlF₃, which sublimes at high temperature and thus exposes Al core instantly, while CuO can react with Al core to release heat, further facilitating the thermal oxidation and ignition processes.

本研究通过简单的水热反应制备了 Cu(OH)F 纳米粒子，并首次探讨了它们对微米级铝粉（μ-Al）的热氧化和点火特性的影响。空气气氛（50∼1050 °C）下的热分析表明，与原始μ-Al 相比，当添加的 Cu(OH)F 为 1 wt%、3 wt% 和 5 wt% 时，Al-Cu(OH)F 中 Al 的归一化增重分别增加了约 36.9%、64.8% 和 106.3%。与 NH4ClO4 混合后，电点火和露天燃烧试验表明，Al-Cu(OH)F 的点火延迟时间缩短（42.6%∼63.8%），最大光强增加（48.9%∼117.8%）。Cu(OH)F 的影响来自其分解产物，即 HF 和 CuO。HF 与氧化铝外壳反应生成 AlF3，后者在高温下发生升华，从而使铝芯瞬间暴露出来，而 CuO 可与铝芯反应释放热量，进一步促进热氧化和点火过程。

引用次数: 0

Non-isothermal kinetic analysis of phase transformations in Fe-Co-V-Mo semi-hard magnetic alloy Fe-Co-V-Mo半硬磁性合金相变的非等温动力学分析

IF 3.1 2区化学 Q2 CHEMISTRY, ANALYTICAL

Thermochimica Acta

Pub Date : 2024-11-06 DOI: 10.1016/j.tca.2024.179897

Maryam Kamali-Ardakani , Alireza Mashreghi , Saeed Hasani , Saeed Sadeghpour

In this study, the non-isothermal kinetics and phase transformations within the Fe-Co-V-Mo alloy were investigated. Four distinct transformations were identified: disorder → order (T₁), first-stage polymorphic (T₂), order → disorder (T₃), and second-stage polymorphic (T₄). The activation energy (E) for each transformation was determined using isoconversional methods. Fitting model were employed to calculate the kinetic triplets, confirming that all transformations follow the Avrami model. The Johnson-Mehl-Avrami (JMA) and Šesták-Berggren (SB) models were used to determine other kinetic parameters (n, M, and N). The findings suggest that the growth mechanisms for transformations T₃ and T₄ are interface-controlled, whereas transformation T₂ is diffusion-controlled. Consequently, the A3/2 and A3 mechanisms were identified as predominant mechanisms for transformations T₂ and T₄, respectively. Additionally, transformation T₃ follows the A3 mechanism at heating rates of 10 and 20 K/min, and the A2 mechanism at 30 K/min. Kinetic analysis revealed that the addition of Mo in Fe-Co-V alloys, acting as a ferrite (α) stabilizer, decreases the onset temperatures of transformations T₁ and T₃. Conversely, it increases those of transformations T₂ and T₄. Furthermore, Mo influences the reduction of E associated with transformation T₃.

本研究调查了铁-铜-钒-钼合金的非等温动力学和相变。确定了四种不同的转变：无序→有序（T1）、第一阶段多态（T2）、有序→无序（T3）和第二阶段多态（T4）。每种转化的活化能（E）都是用等转化法测定的。采用拟合模型计算动力学三元组，证实所有转化都遵循阿夫拉米模型。约翰逊-梅尔-阿夫拉米（JMA）和Šesták-Berggren（SB）模型用于确定其他动力学参数（n、M 和 N）。研究结果表明，转化 T3 和 T4 的生长机制由界面控制，而转化 T2 则由扩散控制。因此，A3/2 和 A3 机制分别被确定为转化 T2 和 T4 的主要机制。此外，在加热速率为 10 和 20 K/min 时，转化 T3 遵循 A3 机制，而在 30 K/min 时则遵循 A2 机制。动力学分析表明，在铁-铜-钒合金中添加钼作为铁素体（α）稳定剂，会降低转化 T1 和 T3 的起始温度。反之，则会提高 T2 和 T4 转变的起始温度。此外，钼还会影响与转变 T3 相关的 E 值的降低。

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引用次数: 0

Study of the hydrothermal stability of leather tanned with vegetable extracts using an isometric method 用等距法研究用植物提取物鞣制的皮革的水热稳定性

IF 3.1 2区化学 Q2 CHEMISTRY, ANALYTICAL

Thermochimica Acta

Pub Date : 2024-11-02 DOI: 10.1016/j.tca.2024.179893

Josep Maria Morera , Esther Bartolí , Bernat Esteban

The main objective of this research is to validate the application of a recently developed isometric method for determining the resistance to denaturation of leather tanned with different vegetable extracts. The results obtained for shrinkage temperature and denaturation temperature are similar to those obtained by methods based on ISO 3380 (traditional) and Differential Scanning Calorimetry (DSC). The isometric method also allows evaluating the evolution of hydrothermal breakdown of the different types of collagen (leather) – tannin (vegetable tanning extract) bonds as a function of the thermal increase to which the leather is subjected. It is concluded that, with the isometric method, and for leathers tanned with vegetable extracts, much more comprehensive information is obtained about the denaturation process of vegetable-tanned leather than with the traditional method, without requiring significant investments as in the case of the DSC method.

这项研究的主要目的是验证最近开发的等距法在测定用不同植物提取物鞣制的皮革的抗变性能力方面的应用。所获得的收缩温度和变性温度结果与基于 ISO 3380（传统）和差示扫描量热法（DSC）的方法所获得的结果相似。等压法还可以评估不同类型的胶原蛋白（皮革）-单宁（植物鞣制提取物）键的水热分解演变情况，并将其作为皮革所受热量增加的函数。结论是，对于使用植物提取物鞣制的皮革，使用等压法可以获得比传统方法更全面的有关植物鞣革变性过程的信息，而无需像使用 DSC 方法那样进行大量投资。

引用次数: 0

Investigation on the effect of carbon powder structural characteristics derived from ethylene decomposition on powder explosion 乙烯分解产生的碳粉结构特征对粉末爆炸影响的研究

IF 3.1 2区化学 Q2 CHEMISTRY, ANALYTICAL

Thermochimica Acta

Pub Date : 2024-11-02 DOI: 10.1016/j.tca.2024.179895

Yao Chen , Zhichen Zhang , Yunfeng Zhu , Yahui Li , Shoutao Ma , Haowen Chen , Jie Jiang , Bing Sun , Wei Xu

In LDPE production, ethylene underwent polymerization under high temperature and pressure. However, the heat generated during polymerization could cause ethylene pyrolysis, leading to safety risks. More critically, the carbon powder produced could further decompose, posing additional hazards. This study examined the pyrolysis characteristics of high-pressure, high-temperature ethylene and the explosive behavior of the resulting carbon powder. The decomposition of ethylene was carried out under 80–200 °C and 80–200 MPa with the oxygen concentration of 1000–5000 ppm using ethylene explosive device, and the explosive testing of derived carbon powder was carried out in a 20 L sphere chamber under the powder concentration of 200 g/m³. It was found that higher initial ignition pressure, temperature, and oxygen concentration intensified ethylene pyrolysis. The size of resulting carbon powder ranged from 0.5 to 500 μm and fewer structural defects, leading to stronger explosive intensity due to a larger specific surface area and longer suspension time in the air. Conversely, carbon powder with larger particle sizes and more defects tended to agglomerate, reducing suspension time and explosion intensity. This research provided a theoretical foundation for understanding powder explosions caused by ethylene decomposition.

在低密度聚乙烯生产过程中，乙烯在高温高压下进行聚合。然而，聚合过程中产生的热量会导致乙烯热解，从而引发安全风险。更重要的是，产生的碳粉可能会进一步分解，带来更多危险。本研究考察了高压高温乙烯的热解特性以及由此产生的碳粉的爆炸行为。使用乙烯爆炸装置在 80-200 ℃、80-200 MPa、氧气浓度为 1000-5000 ppm 的条件下对乙烯进行了分解，并在粉末浓度为 200 g/m3 的 20 L 球形室内对衍生碳粉进行了爆炸试验。结果发现，较高的初始点火压力、温度和氧气浓度会加剧乙烯热解。生成的碳粉粒度在 0.5 至 500 μm 之间，结构缺陷较少，由于比表面积较大，在空气中的悬浮时间较长，因此爆炸强度较强。相反，粒度较大、缺陷较多的碳粉往往会结块，从而缩短悬浮时间，降低爆炸强度。这项研究为理解乙烯分解引起的粉末爆炸提供了理论基础。

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引用次数: 0

Characterization of thermal behavior of two types of kaolin in China by ultrafast Joule heating combined with XRD, FT-IR, TG-DSC and SEM 利用超快焦耳加热结合 XRD、FT-IR、TG-DSC 和 SEM 对中国两种高岭土的热行为进行表征

IF 3.1 2区化学 Q2 CHEMISTRY, ANALYTICAL

Thermochimica Acta

Pub Date : 2024-11-02 DOI: 10.1016/j.tca.2024.179894

Jiahang Fan, Xianjie Liu, Mingyong Liu, Mengyao Yang, Yuena Jiang, Ruiyu Mi, Xin Min, Zhaohui Huang

Thermal behavior of sandy kaolin selected from Guangxi and hard kaolin from Inner Mongolia in China were characterised by ultrafast Joule heating combined with XRD, FT-IR, TG-DSC and SEM. The results indicated that the sandy kaolin was composed of kaolinite, muscovite and quartz, and hard kaolin was predominantly composed of kaolinite, with minor quantities of anatase. During ultrafast Joule heating, the layered structure of kaolinite of sand kaolin was destroyed, and all hydroxyl groups were lost at 700 °C, while dehydroxylation completion of the hard kaolin at higher temperature, accompanied by rupture of lamellar kaolinite. Muscovite disappeared completely and accompanied by the formation of mullite at 1100 °C, while quartz is relatively unaffected, resulting in the sandy kaolin consisting of quartz and mullite phases at 1200 °C. In contrast, the transformation rate and crystallinity of mullite phase of hard kaolin was significantly higher than that of sandy kaolin.

通过超快焦耳加热并结合 XRD、FT-IR、TG-DSC 和 SEM，对选自中国广西的砂质高岭土和内蒙古的硬质高岭土的热行为进行了表征。结果表明，砂质高岭土由高岭石、黝帘石和石英组成，硬质高岭土主要由高岭石组成，并含有少量锐钛矿。在超快焦耳加热过程中，砂质高岭土高岭石的层状结构遭到破坏，在 700 ℃ 时羟基全部丧失，而硬质高岭土在更高温度下脱羟基完成，并伴随着片状高岭石的破裂。在 1100 ℃ 时，绿泥石完全消失，并伴随着莫来石的形成，而石英则相对不受影响，在 1200 ℃ 时形成了由石英和莫来石相组成的砂质高岭土。相比之下，硬质高岭土莫来石相的转化率和结晶度明显高于砂质高岭土。

引用次数: 0

Extending the Transient Plane Source Scanning method for determining the specific heat capacity of low thermal conductivity materials through a numerical study 通过数值研究扩展用于确定低导热材料比热容的瞬态平面源扫描方法

IF 3.1 2区化学 Q2 CHEMISTRY, ANALYTICAL

Thermochimica Acta

Pub Date : 2024-10-28 DOI: 10.1016/j.tca.2024.179883

Zijin Zeng , Christian Müller , Besira Mihiretie

In contrast to the conventional Transient Plane Source (TPS) method, the Transient Plane Source Scanning (TPSS) technique allows for the direct determination of the specific heat capacity and requires the use of a specially designed sample holder for accurate measurements. While this method correctly determines the specific heat capacity of samples with moderate and high thermal conductivity, it tends to underestimate the values for those with low thermal conductivity. This paper demonstrates that the underestimated specific heat capacity results from heat loss during the measurement process. To precisely quantify the heat loss, a numerical model based on the finite element method was developed, with key material properties tuned based on measurement data. This model can closely describe the curve of measured thermal response, thereby enabling the precise determination of the specific heat capacity. Consequently, this study introduces a novel approach that incorporates numerical simulation to enhance TPSS measurements of poorly conducting samples, providing a reliable alternative for determining the specific heat capacity.

与传统的瞬态平面源 (TPS) 方法不同，瞬态平面源扫描 (TPSS) 技术可直接测定比热容，但需要使用专门设计的样品支架才能进行精确测量。虽然这种方法能正确测定中等和高导热系数样品的比热容，但往往会低估低导热系数样品的比热容值。本文证明，比热容被低估的原因是测量过程中的热量损失。为了精确量化热损失，我们根据测量数据调整了关键材料属性，并基于有限元法建立了一个数值模型。该模型可密切描述测量的热响应曲线，从而精确测定比热容。因此，本研究引入了一种新方法，结合数值模拟来增强导电性差样品的 TPSS 测量，为确定比热容提供了一种可靠的替代方法。

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引用次数: 0

Determination of the apparent activation energy surface from isothermal data of char combustion and gasification 根据炭燃烧和气化的等温数据确定表观活化能面

IF 3.1 2区化学 Q2 CHEMISTRY, ANALYTICAL

Thermochimica Acta

Pub Date : 2024-10-26 DOI: 10.1016/j.tca.2024.179892

Yongmyong Ri , Tokhui Ri , Hochol Rim , Hyonung Rim , Juhyon Yu , Yongho Kim , Jinhyok Ri

In this paper, the apparent activation energy (AAE) surface was determined by using isothermal data of char combustion and gasification and the apparent Arrhenius equations where the activation parameters depended on temperature and conversion. The dependence of the logarithm of the reaction rate on temperature and conversion was described by the empirical polynomial to increase the accuracy of fitting and the AAE was calculated by the isoconversional method and the fitting of reaction rate and conversion. The AAE surfaces determined for the four examples of char combustion and gasification varied considerably and differently from each other with temperature and conversion. This provides new information for a better understanding of these processes and their kinetic models.

本文利用木炭燃烧和气化的等温数据和表观阿伦尼乌斯方程确定了表观活化能（AAE）面，其中活化参数取决于温度和转化率。为了提高拟合的准确性，用经验多项式描述了反应速率对数与温度和转化率的关系，并通过等转化法和反应速率与转化率的拟合计算了 AAE。在四个炭燃烧和气化实例中测定的 AAE 面随温度和转化率的变化而有很大差异，且彼此不同。这为更好地理解这些过程及其动力学模型提供了新的信息。

引用次数: 0

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