Synergistic Effect Between Empty Fruit Bunch and HDPE on Products Yield and Functional Group Content in Bio-fuels Produced from Co-liquefaction Process Under Supercritical Methanol Condition

\nSynergism between biomass and plastic waste during co-processing reported to produce higher products yield with enhanced quality which thereby solving the problems of high oxygenated compounds and low yields with high viscosity in oil from its individual processing. However, study on synergistic effect (SE) between these feedstocks is considered lacking. In this study, the SE of co-liquefying empty fruit bunch (EFB) and high-density polyethylene (HDPE) in sc-MeOH was investigated using a high-pressure, high-temperature batch-wise reactor system at 260 °C for 30 minutes and at various EFB-HDPE ratios to determine the best ratio for bio-fuel yield and its functional group content. It was found that 25% EFB:75% HDPE (wt/wt %) provides the most significant SE (≈ 8 wt%) for bio-fuel yield and the most considerable reduction in solid residue formation under the studied conditions. The presence of hydroxyl groups from EFB and aliphatic hydrocarbons from HDPE, along with new carbonyl compounds, further highlights the SE resulting from the combined processing of these materials. The findings suggest that optimizing the ratio of biomass to plastic waste in co-liquefaction can significantly enhance the efficiency and yield of bio-fuels while minimizing waste, providing a promising approach for sustainable energy production and waste management.\n