Effects of Barium Carbonate and Barium Titanate Particle Additives on the Performance and Emissions of a Diesel Engine Fueled with an Olive Pomace Oil Biodiesel–Diesel Blend

Improving fuel efficiency while controlling exhaust emissions is important for the wider use of biodiesel blends. The effects of barium carbonate and barium titanate were compared using a base fuel composed of equal volumes of diesel and biodiesel derived from olive pomace oil. Each additive was evaluated at 25, 50, and 100 ppm, with diesel, untreated BP50, and neat biodiesel serving as reference fuels. Tests used a single-cylinder diesel engine operated at 2000 rpm over a brake power range of 1.0–3.0 kW. Performance, exhaust gas concentrations, smoke opacity, exhaust temperature, and sound pressure level were measured. For neat biodiesel, the largest increases relative to diesel were 24.52% in brake specific fuel consumption and 42.86% in nitrogen oxide concentration. At 2.0 kW, the formulations containing 50 ppm BaCO3 and BaTiO3 exhibited brake specific fuel consumption values 3.80% and 3.79% below that of BP50, respectively. Both formulations raised brake thermal efficiency from approximately 22.38% to 23.27%. Relative to BP50, maximum reductions were 44.32% in carbon monoxide concentration with 50 ppm BaTiO3 at 2.5 kW, 40.00% in hydrocarbon concentration with 100 ppm BaCO3 at 2.5 kW, and 31.25% in smoke opacity with 50 ppm BaCO3 at 1.0 kW. However, NOX concentrations increased by up to 19.87% with 100 ppm BaTiO3 at 2.0 kW compared with BP50. Under the tested conditions, 50 ppm BaCO3 provided a favorable balance among fuel consumption, smoke opacity, and sound pressure level, with a smaller NOX increase than the corresponding BaTiO3 formulation.