School of Optical Information and Energy Engineering, Wuhan Institute of Technology, Wuhan, 430205, China; State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
J Hazard Mater. 2019 Dec 15;380:120857. doi: 10.1016/j.jhazmat.2019.120857. Epub 2019 Jul 3.
The release and transformation mechanisms of trace elements (TEs) during biomass combustion and the environmental impact of TEs in biomass ash were evaluated in this study. Three types of biomass were selected as fuels, with a type of bituminous coal used as a comparison. The quantitative contents and chemical fractions of the TEs in the fuels, ash and char obtained after combustion and pyrolysis were analyzed. The results indicated that during the biomass combustion, the amounts of TEs released were ordered as follows: As > Cd, Pb, Zn > Cu. The TEs in the different chemical fractions both in the fuels and the solid products were shown to be in the forms of different specific compounds, and the transformation of each TE was discussed in depth. Cd, Cu and Zn were found to be released in higher quantities during pyrolysis than combustion and the reason may be that more nonvolatile TE oxides but less volatile TEs chlorides were formed during combustion. The assessment of the environmental impact of the TEs in biomass ash indicated that the environmental risks of Zn and Cu in biomass ash are higher than those in coal ash.
本研究评估了生物质燃烧过程中微量元素 (TEs) 的释放和转化机制，以及生物质灰中 TEs 的环境影响。选择了三种生物质作为燃料，以一种烟煤作为比较。分析了燃料、燃烧和热解后得到的灰和焦中 TEs 的定量含量和化学形态。结果表明，在生物质燃烧过程中，TEs 的释放量顺序为：As > Cd、Pb、Zn > Cu。燃料和固体产物中不同化学形态的 TEs 均以不同特定化合物的形式存在，并深入讨论了每种 TE 的转化。发现 Cd、Cu 和 Zn 在热解过程中的释放量高于燃烧过程，原因可能是燃烧过程中形成了更多的非挥发性 TE 氧化物，而挥发性 TEs 氯化物较少。对生物质灰中 TEs 环境影响的评估表明，生物质灰中 Zn 和 Cu 的环境风险高于煤灰。
