Efficient renewable fuel production from sewage sludge using a supercritical fluid route. (15th July 2017)

• Record Type: Journal Article
• Authors: Prajitno, Hermawan; Zeb, Hassan; Park, Jongkeun; Ryu, Changkook; Kim, Jaehoon
• Is Part Of: Fuel. Volume 200(2017)
• Page Start: 146
• Page End: 152
• Publication Date: 2017-07-15
• Subjects: Sewage sludge -- Liquefaction -- Bio-oil -- Supercritical fluid -- Non-dry sludge; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2017.03.061
• Languages: English
• ISSNs: 0016-2361

Abstract

Graphical abstract: Highlights: Non-catalytic, non H2 sewage sludge liquefaction was held in supercritical fluids. High bio-oil yields of 87.8 wt% and HHV of 34.6 MJ kg −1 were achieved. The presence of water increases the conversion up to 96% and HHV up to 37.3 MJ kg −1 . Ester and nitrogenated compounds were the major compounds in the bio-oil. Abstract: Conversion of sewage sludge into fuel was investigated using a catalyst- and external hydrogen-free supercritical fluid route. When dried sewage sludge was treated in supercritical ethanol, an extremely high bio-oil yield of 87.8 wt% and a remarkable higher heating value (HHV) of 34.6 MJ kg −1 were obtained. The possibility of using non-dried sewage sludge as a fuel source was tested using various alcohol–water mixtures; the presence of water resulted in an almost complete (96%) conversion and high HHVs of 36.8 and 37.3 MJ kg −1 for methanol–water (3:7, v/v) and ethanol–water (3:7, v/v) mixtures, respectively. The main chemical compounds in the bio-oils were found to be esters and nitrogenated species. Plausible reaction mechanisms for sewage sludge conversion in each supercritical fluid are discussed.