Role of municipal solid waste incineration fly ash components in co-pyrolysis of oily sludge: Pyrolysis products and catalytic mechanism

Di Yu; Zhiwei Li; Jie Li; Bo Li; Hao Yu; Jun He; Yin Wang

doi:10.1016/j.jhazmat.2024.134368

Role of municipal solid waste incineration fly ash components in co-pyrolysis of oily sludge: Pyrolysis products and catalytic mechanism

J Hazard Mater. 2024 Jun 5:471:134368. doi: 10.1016/j.jhazmat.2024.134368. Epub 2024 Apr 19.

Authors

Di Yu¹, Zhiwei Li², Jie Li², Bo Li³, Hao Yu², Jun He⁴, Yin Wang⁵

Affiliations

¹ Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; Department of Chemical and Environmental Engineering, University of Nottingham Ningbo China, Ningbo 315100, China; Department of Civil Engineering, University of Nottingham Ningbo China, Ningbo 315100, China.
² Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
³ Department of Civil Engineering, University of Nottingham Ningbo China, Ningbo 315100, China.
⁴ Department of Chemical and Environmental Engineering, University of Nottingham Ningbo China, Ningbo 315100, China; Nottingham Ningbo China Beacons of Excellence Research and Innovation Institute, Ningbo 315100, China. Electronic address: jun.he@nottingham.edu.cn.
⁵ Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; Zhejiang Key Laboratory of Urban Environmental Processes and Pollution Control, CAS Haixi Industrial Technology Innovation Center in Beilun, Ningbo 315830, China. Electronic address: yinwang@iue.ac.cn.

PMID: 38657512
DOI: 10.1016/j.jhazmat.2024.134368

Abstract

The co-pyrolysis of oily sludge (OS) and municipal solid waste incineration fly ash (IFA) is a promising strategy for sustainable waste management. This study delves into the distinct catalytic roles of individual IFA components during co-pyrolysis and assesses their impact on the inherent Fe species in OS, highlighting their contributions to overall catalytic activity. Notably, in comparison to IFA, CaCl₂ and KCl significantly enhance pyrolysis oil upcycling, while IFA components collectively exhibit a positive catalytic effect on pyrolysis gas and coke production. Ca(OH)₂ notably boosts H₂ yield by 137.16 %. Alkali chlorides facilitate gaseous hydrocarbon formation and convert oxygen-containing compounds to CO and CO₂ which are subsequently consumed and absorbed by CaO and Ca(OH)₂. CaCl₂ and KCl promote heavy compound decomposition and alkane aromatization, reducing coke formation and increasing light aromatic production. Conversely, NaCl increases alkane proportions. However, CaSO₄ and CaCO₃ hinder catalytic reactions, promoting carbon conversion to coke. Importantly, IFA compounds aid the dispersion of inherent Fe-based species from OS on char surface, enhancing in-situ catalytic pyrolysis. Additionally, the augmented H₂ production accelerates the reduction of Fe-based species. The findings expand waste utilization possibilities and provide insights for co-processing solid wastes.

Keywords: Co-pyrolysis mechanism; Hydrogen generation; Incineration fly ash; Oil upgrading; Oily sludge.