Supercritical water pyrolysis of sewage sludge.
Municipal sewage sludge (SS) from wastewater treatment plant containing high water content (>85wt.%), lead to the difficulty of co-combustion with MSW or coal due to the high cost of drying. This study explores an alternative method by supercritical water (SCW) pyrolysis of sewage sludge (SS) in a high pressure reaction vessel. The effects of temperature and moisture content of SS on yield and composition of the products (bio-oil, bio char and non-condensable gas) were studied. A temperature of 385°C and moisture content of 85wt.% were found to be the optimum conditions for the maximum bio-oil production of 37.23wt.%, with a higher heating value of 31.08MJ/kg. In the optimum condition, the yields of aliphatic hydrocarbon and phenols were about 29.23wt.% and 12.51wt.%, respectively. The physical and chemical properties of bio-char were analyzed by using XRF and BET. Results of GC analyses of NCG showed that it has the maximum HHV of 13.39MJ/m3at 445°C and moisture content of 85wt.%. The reaction path from SS to bio-oil through SCW pyrolysis was given. Moreover, carbon balance was calculated for the optimal condition, and finding out that 64.27wt.% of the carbon content was transferred from SS to bio-oil. Finally, this work demonstrates that the SCW pyrolysis is a promising disposal method for SS.
Tianjin Engineering Center of Biomass-derived Gas/Oil Technology, Tianjin Key Laboratory of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China.
Wenchao
W
Ma
Tianjin Engineering Center of Biomass-derived Gas/Oil Technology, Tianjin Key Laboratory of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China.
Guiyue
G
Du
Tianjin Engineering Center of Biomass-derived Gas/Oil Technology, Tianjin Key Laboratory of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China.
Jian
J
Li
Tianjin Engineering Center of Biomass-derived Gas/Oil Technology, Tianjin Key Laboratory of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China.
Yuanhao
Y
Fang
Tianjin Engineering Center of Biomass-derived Gas/Oil Technology, Tianjin Key Laboratory of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China; Engineering Design and Research Institute of the Second Artillery Corps, Beijing 100011,China.
Li'an
L
Hou
Tianjin Engineering Center of Biomass-derived Gas/Oil Technology, Tianjin Key Laboratory of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China; School of Science, Tibet University, Lhasa 850012, China. Electronic address: mawc916@tju.edu.cn.
Guanyi
G
Chen
Tianjin Engineering Center of Biomass-derived Gas/Oil Technology, Tianjin Key Laboratory of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China.
Degang
D
Ma
D056804:Biofuels / Q000032:analysis*; D002606:Charcoal / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry; D005740:Gases; D006838:Hydrocarbons / Q000737:chemistry; D017745:Incineration / Q000379:methods*; D009821:Oils / Q000737:chemistry; D019800:Phenol / Q000737:chemistry; D012722:Sewage / Q000737:chemistry*; D013696:Temperature; D062065:Wastewater / Q000032:analysis*; D014867:Water / Q000032:analysis*
D056804:Biofuels; D002606:Charcoal; D005740:Gases; D006838:Hydrocarbons; D009821:Oils; D019800:Phenol; D012722:Sewage; D062065:Wastewater; D014867:Water; C540010:biochar
Bio-char; Bio-oil; Pyrolysis; Sewage sludge; Supercritical water