Effects of inherent components and disposal temperature on the melting behavior of petrochemical sludge char during CO2 gasification

Wenqi Zhang; Qingdong Li; Yahui He; Yinfeng Wang; Lei Wang; Yuezhao Zhu

doi:10.1016/j.jhazmat.2023.132922

Effects of inherent components and disposal temperature on the melting behavior of petrochemical sludge char during CO₂ gasification

J Hazard Mater. 2024 Feb 5:463:132922. doi: 10.1016/j.jhazmat.2023.132922. Epub 2023 Nov 4.

Authors

Wenqi Zhang¹, Qingdong Li², Yahui He¹, Yinfeng Wang³, Lei Wang⁴, Yuezhao Zhu²

Affiliations

¹ School of Mechanical and Power Engineering, Nanjing Tech University, Nanjing 211816, Jiangsu, China; Jiangsu Province Engineering Research Center of Organic Solid Wastes Deeply Treatment and Hydrogen Production, Jiangsu, China.
² School of Energy Science and Engineering, Nanjing Tech University, Nanjing 211816, Jiangsu, China; Jiangsu Province Engineering Research Center of Organic Solid Wastes Deeply Treatment and Hydrogen Production, Jiangsu, China.
³ School of Energy Science and Engineering, Nanjing Tech University, Nanjing 211816, Jiangsu, China; Jiangsu Province Engineering Research Center of Organic Solid Wastes Deeply Treatment and Hydrogen Production, Jiangsu, China. Electronic address: wangyf@njtech.edu.cn.
⁴ Jiangsu Province Engineering Research Center of Organic Solid Wastes Deeply Treatment and Hydrogen Production, Jiangsu, China; School of Environmental Science and Engineering, Nanjing Tech University, Nanjing 211816, Jiangsu, China.

PMID: 37939566
DOI: 10.1016/j.jhazmat.2023.132922

Abstract

Pyrolysis-coupled gasification-melting is a promising technology as it can dispose of the petrochemical sludge (PS) and recover the leftover energy. Unfortunately, there has been little research investigating the effects of pyrolysis degree on melting characteristics of the pyrolysis residue (PR) and the transformation properties of the heavy metal (HM). In this study, the function of inherent components and disposal temperature were elucidated. The results show that the moisture and light volatile could disperse the melting residue (MR) during gasification-melting treatment, causing different morphology and color of the MR. In addition, as pyrolysis temperature increased, the HMs speciation (e.g. Zn, Cu, and Cr) in the PR was transformed from bioavailable to a stable state, and the yield of PR decreased from 66.8% to 36.5%. The PR produced at 800 °C could decrease about 0.9 ∼ 1.9 potential ecological risk of releasing substances during the subsequent high-temperature gasification-melting owing to its stable HMs state and less char composition. Moreover, the gasification at 1250 °C could realize the safe disposal of the PR. Further increasing the gasification temperature to 1450 °C could not improve the acid-leaching resistance of the HMs, although the apparent concentration of C and the acid dissolution proportion of slag decreased by 6.3% and 1.7%, respectively.

Keywords: Gasification-melting; Heavy metals; Inherent components; Petrochemical sludge; Pyrolysis.