Reaction kinetics, pyrolytic behavior and product characterization of dewatered solids from spent fermentation coir wastes using a fixed batch reactor

• Published in: Bioresource technology reports Vol. 22; p. 101451
• Main Authors: Sudhakaran, Ajith, Rajan, Revathy, Ravindranath, Anita, Madhavan, Anand, Kumar, Ratheesh
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2023
• Subjects: Activation energy; Bio-oil; Coir Fermentation sludge; Fixed Bed reactor; Methoxy phenols; Pyrolysis; Pyrolysis; Methoxy phenols; Fixed Bed reactor; Activation energy; Bio-oil; Coir Fermentation sludge
• ISSN: 2589-014X; 2589-014X
• DOI: 10.1016/j.biteb.2023.101451

Solid residues after pretreatment and hydrolysis of coir pith and Bit fiber waste was dewatered, dried and pyrolyzed at 300, 350, and 400 °C using a fixed bed batch pyrolyzer. The products were characterized using ultimate analysis, FTIR and GCMS. Bit fiber yielded more bio-oil (26.3 %), rich in 4-Methoxy phenol (60.94 %) and a Higher Heating Value of 27.06 MJ kg−1. Coir pith bio-oil with Higher Heating Value of 27.16 MJ kg−1, was rich in 2-Methoxy Phenol, which are principal lignin degradation products. Non condensable gases included mixture of methane, carbon dioxide and isomers of butene. Activation energy for thermal decomposition was studied using Coats and Redfern model from thermogravimetric data at heating rates of 10 and 15 k min−1, which showed two major phases of decomposition. Activation energy was higher for devolatilization phase of bit fiber waste (132 kJ/ mol) owing to higher percentage of lignin than in coir pith waste (Ea = 114 kJ/ mol). [Display omitted] •The solid residues left after pretreatment and hydrolysis of coir waste has been recovered and pyrolyzed.•These recovered solids have very high proportions of lignin (>70 %) and are good sources of bio-oil.•The lignin rich residues yielded higher amounts of bio-oil and non-condensable gases at 350 °C.•Bit fiber bio-oil was rich in 4-Methoxy Phenol and coir pith biooil was rich in 2-Methoxy Phenol.•Activation energy for the devolatilization phase of coir waste sludge was lower than for the raw coir pith.