School of Chemistry, Biology and Environment, Yuxi Normal University, Yuxi, 653100, Yunnan, China; State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering, College of Chemistry and Chemical Engineering, Ningxia University, Yinchuan, 750021, China.
School of Chemistry, Biology and Environment, Yuxi Normal University, Yuxi, 653100, Yunnan, China.
J Environ Manage. 2024 Oct;369:122388. doi: 10.1016/j.jenvman.2024.122388. Epub 2024 Sep 3.
This study explores the recycling challenges of industrial sludge, owing to its non-recyclable properties and associated environmental problems. To promote sustainable energy utilization, a novel approach combining hydrothermal carbonization and co-gasification was employed to facilitate the conversion from waste to energy. The industrial sludge was pretreated in the batch-type hydrothermal treatment unit at 180-220 °C, followed by co-gasification. The experimental results indicate that pretreating the sludge at the hydrothermal temperature of 200 °C maximized its thermal decomposition, leading to a rougher structure with obvious cracks, eventually transforming into numerous fragmented small particles. At 1100 °C with a blending mass ratio of 1:1, the sludge hydrochar at 200 °C significantly enhanced the reactivity of coal char, exhibiting the gasification reactivity index R of 1.57 times higher than that of untreated char. Using the in-situ technique with the heating stage microscope, it was first observed that the addition of pretreated sludge coal chars underwent gasification in the shrinking core mode, displaying a significant ash melt flow phenomenon. Based on the in-situ X-ray diffraction, it was discovered that more amorphous structures were formed by the reaction of Fe with other minerals in the sludge-coal blended char after hydrothermal carbonization at 200 °C. With pretreatment at the hydrothermal temperature of 200 °C, the sludge can increase the specific surface area of the blended char and facilitate the cracking of carbon crystals during co-gasification. Its specific surface area and the Raman spectroscopic ratio I/I were 1.76 and 1.17 times that of coal char, respectively. Collectively, this study highlights the potential for energy recovery from industrial sludge, contributing to sustainable waste management in the chemical industry.
本研究探讨了工业污泥的回收利用挑战，由于其不可回收的特性和相关的环境问题。为了促进可持续能源利用，采用了一种将水热碳化和共气化相结合的新方法，以促进从废物到能源的转化。在 180-220°C 的批式水热处理单元中对工业污泥进行预处理，然后进行共气化。实验结果表明，在水热温度为 200°C 下预处理污泥可最大限度地促进其热分解，导致结构更粗糙，出现明显裂缝，最终转化为众多碎片小颗粒。在 1100°C 下，混合质量比为 1:1，在 200°C 下，污泥水热炭显著提高了煤焦的反应性，表现出比未处理的炭高出 1.57 倍的气化反应性指数 R。使用原位加热阶段显微镜技术，首次观察到添加预处理污泥-煤焦的气化在收缩核模式下进行，显示出明显的灰熔流动现象。通过原位 X 射线衍射发现，在 200°C 水热碳化后，污泥与煤共混焦中的其他矿物质发生反应，形成更多的无定形结构。在水热温度为 200°C 进行预处理时，污泥可以增加共气化过程中混合焦的比表面积，促进碳晶体的破裂。其比表面积和拉曼光谱比 I/I 分别是煤焦的 1.76 倍和 1.17 倍。总之，本研究强调了从工业污泥中回收能源的潜力，为化工行业的可持续废物管理做出了贡献。
