关于城市固体废物焚烧飞灰在空气和N2大气中的动力学和热力学研究
Yegui Wang1, Weifang Chen1, Na Zhao1
1School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, China.
PloS one
|May 14, 2025
概括
这项研究分析了城市固体废物焚烧灰的热行为和反应机制. 由于碳化,空气条件在第二阶段增加了激活能量,而第三阶段的机制在空气和N2.2中相似.
科学领域:
- 环境工程 环境工程
- 材料科学 材料科学 材料科学
- 化学工程是化学工程的重要组成部分.
背景情况:
- 城市固体废物焚烧的飞灰带来了处置的挑战.
- 了解其热行为对于安全有效的治疗至关重要.
- 不同的大气条件显著影响灰分解.
研究的目的:
- 为了研究飞灰在空气和气氛下的热分解行为.
- 在热处理过程中确定反应机制和运动参数.
- 为了阐明飞灰降解的热力学特性.
主要方法:
- 热重力测量分析 (TGA) 从30°C到1100°C.
- 使用弗林-沃尔-奥扎瓦 (FWO),基辛格-阿卡希拉-苏诺斯 (KAS) 和弗里德曼方法进行动力分析.
- 通过Coats-Redfern (CR) 模型和热力学计算 (ΔH, ΔG, ΔS) 进行机械分析.
主要成果:
- 飞灰分解发生在三个阶段,主要的质量损失在500°C和1100°C之间.
- 弗林-沃尔-奥扎瓦方法提供了最适合动力学分析 (R2 > 0.99).
- 第二阶段的激活能量在空气中 (171.11 kJ/mol) 比N2 (124.52 kJ/mol) 高,归因于碳化. 第三阶段的激活能量是相似的 (~373-382 kJ/mol).
- 主要的机制是1D扩散 (第二阶段,空气),收缩球 (第二阶段,N2) 和3D扩散 (第三阶段,两大气层).
- 反应主要是内热和非自发的,在第三阶段复杂性增加.
结论:
- 该研究提供了飞灰热降解的多阶段特征.
- 对于不同的温度阶段和大气层,已经确定了不同的反应途径和机制.
- 这些发现为优化城市固体废物飞灰热处理过程提供了宝贵的见解.
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