Microwave Pyrolytic Oil from Sago Waste: Yield Optimization and Characterization

• Main Author: Syamila Aimi, Binti Yahaya
• Format: Thesis
• Language: English
• Published: Universiti Malaysia Sarawak (UNIMAS) 2019
• Subjects: Q Science (General); QD Chemistry
• Online Access: http://ir.unimas.my/id/eprint/25759/1/Syamila.pdf; http://ir.unimas.my/id/eprint/25759/

Approximately 20,000 tonnes of Metroxylon sagu (sago) bark (SB) is generated annually as agricultural waste industry. SB has high lignocellulosic content, which makes it a potential feedstock for the production of fuel material via pyrolysis. This study focuses on optimization and characterization of pyrolysis oil yield by microwave pyrolysis of SB in the presence of palm kernel shell activated carbon (POAC) as microwave absorber, and the properties of the resultant pyrolytic oil. Response surface methodology (RSM) approach via central composite rotatable design (CCRD) was used to study the effects of sample mass, POAC loading and temperature on the pyrolytic oil yield. The optimum condition for obtaining maximum pyrolytic oil yield (29.63 wt%) were 15 g sample mass, 35 wt% POAC loading, and 400 °C temperature. Characterization study revealed that the pyrolytic oil has high moisture content (56.3%), density (2 g/cm3), and oxygenated compounds (ketones and aldehydes), with calorific value, CV of 21.4 MJ/kg. Improvement on properties of the pyrolytic oil was performed via esterification with ethanol and the presence of sulfuric acid as a catalyst. The optimum operating condition using general factorial design was performed via esterification using alcohol and sulfuric acid as a catalyst. The esterified oil (EO) showed improved properties with pH (4-6) with reduced moisture content (2.95-3.45%), density (0.9-1.1 g/cm3), and acid value (39.3-123.4 mg/KOH/g), and maintained the CV (20.2-21.6 MJ/kg). GC-MS analysis of EO was sulphur free, lower in carboxylic acid and oxygenated compounds. In this study, optimal esterification which yield optimum quality biodiesel was heated at 65°C for 60 minutes with 1:1 fraction of ethanol to oil volume ratio.