• Higher alcohols, H 2 O 2 , and HHO enhanced the combustion of plastic-oil-based blends. • Optimized blend (M3) improved brake thermal efficiency and reduced fuel consumption. • CO, NOx, and smoke emissions were significantly reduced in the modified fuel blends. • FTIR and TGA confirmed chemical viability of WPO; SEM-EDS analyzed biochar residue. • Experimental results support WPO blends as viable, cleaner alternatives to diesel fuel. The increasing accumulation of plastic waste presents a serious environmental challenge, while rising energy demand and geopolitical uncertainties continue to intensify concerns over reliance on fossil fuels. Converting waste materials into liquid fuels offers a sustainable approach to addressing both issues simultaneously. In this context, the present study investigates the performance-oriented enhancement of diesel engine operation using pyrolysis-derived mixed plastic oil (PMPO) blended with a long-chain alcohol (n-decanol), a short-chain alcohol (isopropanol), hydrogen peroxide (H 2 O 2 ), and oxyhydrogen (HHO) as ignition-assisting additives. The investigation was conducted in two stages. First, PMPO was produced from mixed plastic waste via laboratory-scale pyrolysis at temperatures of 350–450 °C, yielding approximately 47% liquid oil. The produced oil was characterized according to ASTM standards, while thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), and GC–MS analyses confirmed thermal degradation between 100 and 350 °C and the predominance of alkanic hydrocarbons. SEM–EDS analysis of the residual biochar revealed high concentrations of calcium and titanium. In the second stage, engine combustion, performance, and emission characteristics were evaluated using three fuel blends: M1 (30% PMPO + 70% diesel), M2 (30% PMPO + 50% diesel + 10% isopropanol + 10% n-decanol), and M3 (M2 supplemented with 0.5% H 2 O 2 and 0.75 L min⁻ 1 HHO). The results showed that incorporating PMPO and long-chain alcohol significantly altered combustion behavior, resulting in higher in-cylinder pressure and heat release rate. The optimized blend (M3) demonstrated a clear improvement in engine performance, with brake thermal efficiency increasing by up to 4–6% and brake-specific fuel consumption decreasing by up to 6–9%, depending on engine load, compared with neat diesel. These performance gains were accompanied by substantial emission reductions, with carbon monoxide, nitrogen oxides, smoke opacity, and unburned hydrocarbons reduced by up to 44%, 41%, 40%, and 30%, respectively. Overall, the results confirm that the synergistic integration of long-chain alcohols with hydrogen peroxide and oxyhydrogen enhances diesel engine performance while simultaneously reducing exhaust emissions, supporting the viability of PMPO as a sustainable fuel for high-efficiency diesel engine applications.
EL‐Seesy et al. (Fri,) studied this question.