Performance evaluation of pyro-diesel derived from co-pyrolysis of fresh palm fruit bunches and waste plastics in an agricultural power generator

Co-pyrolysis of biomass with waste plastics has been widely studied as a route to upgraded bio-oil; however, most previous work has focused on crude bio-oil characterization, with limited attention to distillation into engine-grade fractions and direct validation in power-generation systems. This study addresses that gap by presenting an integrated pathway from co-pyrolysis of fresh palm fruit bunches (FFB) and polypropylene (PP) waste to atmospheric distillation and engine testing of the resulting diesel-range fraction (pyro-diesel, PD) in a 2.5 kW agricultural generator. Co-pyrolysis was conducted at 450 °C using FFB:PP ratios of 100:0, 75:25, and 50:50. Increasing PP content shifted the product distribution toward lighter fractions, with pyro-gasoline yield increasing from 20.1% to 71.9% and PD yield decreasing from 26.2% to 15.5%. Despite the lower PD yield, its quality improved markedly: lower heating value increased from 41.8 to 45.2 MJ kg −1 , kinematic viscosity decreased from 2.61 to 1.81 cSt, and oxygenated compounds were substantially reduced. The liquid energy fraction also increased from 65.1% to 84.3% of total feedstock energy input. Engine tests confirmed the practical applicability of PD without engine modification: operating time increased from 2.1 to 3.6 h, electrical energy output rose from 5.2 to 8.9 kWh, and electrical generation efficiency reached 23.6–25.3%, comparable to or slightly higher than B7 diesel (22.3%) and B100 biodiesel (21.4%). Estimated brake thermal efficiency ranged from 27.2% to 29.4%, while PD (50:50) achieved the lowest estimated brake specific fuel consumption (271.1 g kWh −1 ). Indicative cost analysis showed that PD production cost decreased from 0.4 to 0.1 EUR L −1 , and electricity generation cost decreased to 0.3 EUR kWh −1 at higher PP ratios. These results demonstrate the potential of integrating biomass–plastic co-pyrolysis, fuel upgrading, and small-scale generator application for decentralized power generation.