Utilization of oil palm fronds for bio-oil and bio-char production using hydrothermal liquefaction technology

Hydrothermal liquefaction technology carried out on local Malaysian oil palm fronds (OPF) in a batch autoclave reactor to produce solid bio-char as well as liquid bio-oil is reported in this study. The parameters taken in consideration for study encapsulated variable reaction temperature (160–260 °C) and reaction times (20–100 min). Observations showed that the bio-oil yield percentage increased from 27.3% at 160 °C to 41.9% at 260 °C, whereas bio-char yield percentage decreased from 65.2% at 160 °C to 43.2% at 260 °C. Similarly, higher reaction time also produces higher yield bio-oil percentage and lower bio-char yield percentage. The characterization results showed that the combustion properties of bio-char and bio-oil were improved after hydrothermal liquefaction due to decrease in percentage of oxygen of bio-oil and bio-char and an increase in percentage of carbon content. The carbon percentage increased from 42.73% for OPF to 59.42% and 60.47% for bio-char and bio-oil, respectively. Whereas, the percentage of oxygen decreased from 52.51 for OPF to 36.30% and 35.61 for bio-char and bio-oil. The main chemical compounds identified in bio-oil by GC-MS were phenolic compounds and their derivatives, alcohols, ketones, and esters.