Open AccessSewage sludge conversion via hydrothermal liquefaction (HTL) – A preliminary study
Author(s) -
R. S. Badrolnizam,
Omar Syah Jehan Elham,
S. N. Hadzifah,
Mujahid Husain,
A. R. Hidayu,
Noor Mohammad,
Ahmad Rafizan Mohamad Daud
Publication year - 2019
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1349/1/012108
Subject(s) - sewage sludge , hydrothermal liquefaction , heat of combustion , incineration , waste management , liquefaction , environmental science , biomass (ecology) , biofuel , pulp and paper industry , sewage , chemistry , environmental chemistry , combustion , environmental engineering , geology , organic chemistry , engineering , oceanography
Sewage sludge is regarded as a residue produced from municipal waste water treatment system. This waste is often used in low-value applications such as composting and incineration or disposed in landfills. Such practices posed many potential environmental hazards due to high levels of pollutants in the sludge. Sewage sludge is also a potential energy and currently received renewed attention for potential recovery of bio-oils and biochemicals through thermochemical conversion route. Hydrothermal liquefaction is a promising green method for conversion of sewage sludge. Hydrothermal liquefaction of sewage sludge were investigated at different temperatures (250°C, 300°C, 350°C and 400°C) and 1 hour reaction time. Experiments were carried out in a 10 ml stainless steel bomb reactor. The initial calorific value of sewage sludge was 12.36 MJ/kg. It was found that significant bio-oil yield of 52.23% and 48.25% were obtained at 350°C and 400°C respectively. Overall, the bio-oil yield increases with temperature up to critical temperature of water. It was clear that synergetic effect on the yield of liquid and solid were observed due to extended biomass fragmentations and depolymerization when reaction temperature was raised.The bio-oils produced from liquefaction of sewage sludge at 350°C contained an abundant number of ester based compounds, highlighting its potential as biofuel.