School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China.
School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China.
J Hazard Mater. 2021 Sep 15;418:126380. doi: 10.1016/j.jhazmat.2021.126380. Epub 2021 Jun 11.
In response to the global initiative for greenhouse gas emission reduction, the co-combustion of coal and spent pot lining (SPL) may cost-effectively minimize waste streams and environmental risks. This study aimed to quantify the emission-to-ash detoxification mechanisms of the co-combustion of SPL and pulverized coal (PC) and their kinetics, gas emission, fluorine-leaching toxicity, mineral phases, and migrations. The main reaction covered the ranges of 335-540 °C and 540-870 °C while the interactions occurred at 360-780 °C. The apparent activation energy minimized (66.99 kJ/mol) with 90% PC addition. The rising PC fraction weakened the peak intensity of NaF and strengthened that of CaF, NaAlSiO, and NaAlSiO. The addition of PC enhanced the combustion efficiency of SPL and raised the melting temperature by capturing Na. PC exhibited a positive effect on solidifying water-soluble fluorine and stabilizing alkali and alkaline earth metals. The leaching fluorine concentrations of the co-combustion ashes were lower than did SPL mono-combustion. The main gases emitted were HF, NH, NO, CO, and CO. HF was largely released at above 800 °C. Multivariate Gaussian process model-based optimization of the operational conditions also verified the gas emissions results. Our study synchronizes the utilization and detoxification of SPL though co-combustion and provides insights into an eco-friendlier life-cycle control on the waste-to-energy conversion.
为响应全球温室气体减排倡议，煤与废阴极炭块（SPL）共燃可能是一种经济有效的方法，可以最大限度地减少废物流和环境风险。本研究旨在量化 SPL 与煤粉（PC）共燃的排放-灰分解毒机制及其动力学、气体排放、氟浸出毒性、矿物相和迁移。主要反应发生在 335-540°C 和 540-870°C 范围内，而相互作用发生在 360-780°C。当 PC 添加量为 90%时，表观活化能最小化（66.99 kJ/mol）。随着 PC 分数的增加，NaF 的峰值强度减弱，而 CaF、NaAlSiO 和 NaAlSiO 的峰值强度增强。PC 的添加增强了 SPL 的燃烧效率，并通过捕获 Na 提高了熔融温度。PC 对固溶态氟和稳定碱金属及碱土金属有积极作用。共燃灰的浸出氟浓度低于 SPL 单燃灰。主要排放气体为 HF、NH、NO、CO 和 CO。HF 主要在 800°C 以上释放。基于多元高斯过程模型的操作条件优化也验证了气体排放结果。本研究通过共燃实现了 SPL 的利用和解毒，为废物能源转化的更环保生命周期控制提供了思路。
