Co-pyrolysis of oil palm empty fruit bunch and polypropylene: Synergistic effects on blending ratios and product quality

The increasing accumulation of oil palm empty fruit bunches (EFB) and polypropylene (PP) waste necessitates sustainable management solutions. This study investigates the co-pyrolysis of EFB and PP in a fixed-bed reactor at temperatures ranging from 400 to 600 °C, utilizing blending ratios of 100:0, 75:25, 50:50, 25:75, and 0:100. The results revealed notable synergistic effects, particularly at a 75:25 EFB:PP ratio, which yielded 50.35% bio-oil, the highest gas yield (28.95%), and reduced biochar formation compared to pure EFB. The bio-oil composition showed increased aliphatic compounds and reduced oxygenated compounds, making intermediate ratios such as 75:25 ideal for balancing hydrocarbons and oxygenates. The char derived from co-pyrolysis maintained adequate porosity for applications such as adsorption, catalysis, and energy storage. Gaseous products such as CO2, methane, and ethylene demonstrate a high energy potential, underlining the suitability of co-pyrolysis for industrial and energy applications. These findings confirm that co-pyrolysis is an efficient waste-to-resource strategy, optimizing bio-oil, char, and gas quality while addressing both biomass and plastic waste challenges.