title: Transesterification of activated sludge in subcritical solvent mixture.
abstract: Most previous studies reported in literature on biodiesel production from sludge were performed by acid catalyzed transesterification that required long reaction time (about 24h) and high methanol loading. The objective of this study was to investigate the in situ transesterification of sludge in subcritical mixture of methanol and acetic acid. At 250°C and a solvent (85% methanol and 15% acetic acid) to sludge ratio of 5 (mLg(-1)), a FAME yield of 30.11% can be achieved in 30min, compared to the yield of 35% obtained by the acid-catalyzed (4% H2SO4) transesterification which required 24h at 55°C and a methanol to sludge ratio of 25 (mLg(-1)). The method developed in this study avoided using mineral acid, significantly reduced reaction time and methanol loading to achieve comparable FAME yield.
authors: Department of Chemical Engineering, National Taiwan University of Science and Technology, 43, Keelung Road, Section 4, Taipei 10607, Taiwan.
authors: Phuong Lan
authors: PL
authors: Tran-Nguyen
authors: Department of Chemical Engineering, University of San Carlos - Talamban Campus, Nasipit, Talamban, Cebu City 6000, Philippines.
authors: Alchris Woo
authors: AW
authors: Go
authors: Department of Chemical Engineering, Widya Mandala Surabaya Catholic University, Kalijudan 37, Surabaya 60114, Indonesia.
authors: Suryadi
authors: S
authors: Ismadji
authors: Department of Chemical Engineering, National Taiwan University of Science and Technology, 43, Keelung Road, Section 4, Taipei 10607, Taiwan. Electronic address: yhju@mail.ntust.edu.tw.
authors: Yi-Hsu
authors: YH
authors: Ju
mesh_terms: D056804:Biofuels / Q000032:analysis*; D002384:Catalysis; D004951:Esterification; D000432:Methanol; D012722:Sewage / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry*
chemical_list: D056804:Biofuels; D012722:Sewage; D012997:Solvents; D000432:Methanol
keywords: Acetic acid; Activated sludge; Biodiesel; In situ transesterification; Subcritical solvents