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Oily sludge treatment in subcritical and supercritical water: A review

Chen, Zhong1,5,6; Zheng, Zhijian2; He, Chunlan3; Liu, Jumei4; Zhang, Rui1; Chen, Qiao1,5,6
2022-07-05
摘要Oily sludge, an inherent byproduct of the petroleum industry, presents dual characteristics of petroleum resources and hazardous waste. Owing to the unique physicochemical properties of sub-/supercritical water, hydrothermal technologies have been increasingly used for oily sludge treatment. This review is the first to focus on oily sludge treatment using sub-/supercritical water. Eight hydrothermal technologies used for different purposes are summarized herein: pressurized hot water extraction (PHWE) for hydrocarbon separation, thermal hydrolysis (TH) for dewaterability improvement, hydrothermal carbonization (HTC) for hydrochar production, wet air oxidation (WAO) for biodegradability improvement, hydrothermal liquefaction (HTL) for bio-oil production, supercritical water upgrading (SCWU) for light oil production, supercritical water oxidation (SCWO) for complete degradation, and supercritical water gasification (SCWG) for H-2-rich syngas production. Moreover, a general reaction pathway for sub-/supercritical water treatment of oily sludge is presented, with a particular focus on the chemical mechanism at temperatures above 350 ?. Lastly, two reaction maps are included to illustrate the reaction pathways of two groups of identifiable model compounds in oily sludge: aliphatic and aromatic hydrocarbons. This review provides detailed information that can promote a better understanding of various hydrothermal technologies, a guideline for selecting the suitable hydrothermal process for a particular oily sludge, and recommendations for further researches.
关键词Hydrothermal technology Reaction pathways Long-chain alkanes Polycyclic aromatic hydrocarbons Fuel recovery Harmless treatment
DOI10.1016/j.jhazmat.2022.128761
发表期刊JOURNAL OF HAZARDOUS MATERIALS
ISSN0304-3894
卷号433页码:19
通讯作者Chen, Zhong(chenzhong@cigit.ac.cn) ; Chen, Qiao(chenqiao@cigit.ac.cn)
收录类别SCI
WOS记录号WOS:000791268100003
语种英语