Co-combustion of industrial coal slurry and sewage sludge: Thermochemical and emission behavior of heavy metals

Biao Fu; Guijian Liu; Md Manik Mian; Chuncai Zhou; Mei Sun; Dun Wu; Yuan Liu

doi:10.1016/j.chemosphere.2019.05.256

Co-combustion of industrial coal slurry and sewage sludge: Thermochemical and emission behavior of heavy metals

Chemosphere. 2019 Oct:233:440-451. doi: 10.1016/j.chemosphere.2019.05.256. Epub 2019 Jun 1.

Authors

Biao Fu¹, Guijian Liu², Md Manik Mian³, Chuncai Zhou¹, Mei Sun⁴, Dun Wu⁵, Yuan Liu¹

Affiliations

¹ CAS Key Laboratory of Crust-Mantle Materials and Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui, 230026, China; State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, The Chinese Academy of Sciences, Xi'an, Shaanxi, 710075, China.
² CAS Key Laboratory of Crust-Mantle Materials and Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui, 230026, China; State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, The Chinese Academy of Sciences, Xi'an, Shaanxi, 710075, China. Electronic address: lgj@ustc.edu.cn.
³ CAS Key Laboratory of Crust-Mantle Materials and Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui, 230026, China.
⁴ CAS Key Laboratory of Crust-Mantle Materials and Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui, 230026, China; Hefei National Laboratory for Physical Sciences at the Microscale University of Science and Technology of China, Hefei, 230026, China.
⁵ CAS Key Laboratory of Crust-Mantle Materials and Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui, 230026, China; Exploration Research Institute, Anhui Provincial Bureau of Coal Geology, Hefe, Anhui 23008, China.

PMID: 31181492
DOI: 10.1016/j.chemosphere.2019.05.256

Abstract

A combination of thermogravimetric analysis and lab-scale fixed bed combustion experiments was carried out to study the thermochemical, kinetic and heavy metals emission behavior during co-combustion of industrial coal slurry (CS) and sewage sludge (SS). The results found that the blends had integrative combustion profiles which reflected both coal slurry and sewage sludge. During co-combustion, the ignition performance of CS could be significantly improved with the addition of SS. Synergetic effects of the co-combustion were observed at lower temperature, while the high-temperature char combustion of the blends was inhibited because of high ash components of SS or formation of inactive alkali metal aluminosilicates. Kinetic analysis confirmed the improve iginition behavior of blends. Both the comprehensive combustibility index S and the activation energy suggested that the blends with 20% SS may have the best promoting effects. Compared with CS, the higher concentration of Cl in SS increased the volatilization ratios of Cu, Zn, As, and Pb. When added CS into SS, the volatilization ratios of arsenic decreased during combustion. The inhibition effects for arsenic during co-combustion might be associated with the capture of arsenic vapors by the new-formed Ca/Al from CS thermal decomposition.

Keywords: Co-combustion; Coal slurry; Heavy metals; Sewage sludge; Thermogravimetric analysis.

MeSH terms

Air Pollutants / analysis*
Arsenic / analysis
Coal / analysis*
Coal Ash / analysis
Hot Temperature
Incineration / methods*
Kinetics
Metals, Heavy / analysis*
Sewage / chemistry*
Volatilization

Substances

Air Pollutants
Coal
Coal Ash
Metals, Heavy
Sewage
Arsenic