One-step microwave pyrolysis of sago bark waste for rapid pyrolytic oil production: a response surface methodology approach

Purpose This study employed microwave pyrolysis using palm kernel shell activated carbon (POAC) as an absorber to maximize the output of pyrolytic oil from sago bark (SB). Design/methodology/approach Using a central composite rotatable design in response surface methodology (RSM), 17 experiments were conducted to examine the combined effects of temperature, sample mass and POAC loading. The physicochemical characteristics were thoroughly studied, and the main components of the resulting oil were identified by gas chromatography–mass spectrometry (GC–MS) analysis. Findings In the microwave pyrolysis at 400 °C, the addition of 35% POAC increased the oil output to 29.63%. The oil’s calorific value was 21 MJ/kg, density was 2 g/cm3 and the phenolic compounds accounted for 57.6% of the oil content. Practical implications The findings demonstrate an efficient way to convert sago bark waste (SBW) into pyrolytic oil through an optimized process. Pyrolytic oil’s characterization offers insights into the specific refining processes for its potential utilization as a sustainable biofuel. Originality/value This research is a distinct exploration of the application of POAC as an additive to optimize the pyrolytic oil yield. The optimized synthesis and the characterization of the oil demonstrate POAC benefits as an absorber and highlight the potential of SB as a bio-oil feedstock.