Combustion performance and emission effects of a novel palladium thiourea additive in a diesel engine with EGR
Fuel, cilt.428, 2027 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 428
- Basım Tarihi: 2027
- Doi Numarası: 10.1016/j.fuel.2026.140494
- Dergi Adı: Fuel
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, Chimica, Compendex, INSPEC, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO)
- Anahtar Kelimeler: Benzoylthiourea, Diesel engine, Exhaust emission, Exhaust gas recirculation, Fuel additive, Palladium
- Bilecik Şeyh Edebali Üniversitesi Adresli: Evet
Özet
This study reports, for the first time, the synthesis and application of a novel palladium(II)-based thiourea derivative, Bis-((N-(2-fluoropyridine)-N′-3-nitrobenzoylthioureato))palladium(II) (PL), as a diesel fuel additive. The molecular structure of the synthesized compound was confirmed by Fourier-transform infrared spectroscopy (FT-IR), 1H NMR, and 13C NMR analyses, which verified coordination through the carbonyl oxygen and thiocarbonyl sulphur atoms. After structural characterization, PL was dissolved in chloroform (TCM) and blended with diesel fuel at 50, 100, and 200 ppm concentrations. Engine tests were performed in a single-cylinder, four-stroke, direct-injection diesel engine at a constant speed of 1800 rpm under five load conditions (0, 6, 12, 18, and 24 Nm) and four exhaust gas recirculation (EGR) ratios (0, 10, 20, and 30%). Combustion, performance, and emission parameters were evaluated by comparing neat diesel, diesel with chloroform carrier, and PL-containing blends. The results showed that increasing EGR generally weakened combustion intensity by reducing peak cylinder pressure, heat release rate, and maximum pressure rise rate because of oxygen dilution and increased charge heat capacity. However, PL-containing blends, especially the 100 ppm formulation, preserved stronger combustion development and provided the most favorable overall performance response. D + TCM + PL (100 ppm) generally improved brake thermal efficiency (BTE) and reduced brake-specific fuel consumption (BSFC) compared with neat diesel and the solvent-containing reference fuel under several operating conditions. In contrast, the 200 ppm PL blend was more effective in suppressing nitrogen oxides (NOx) emissions, particularly under EGR operation, although higher additive concentration also increased the tendency for soot and hydrocarbon formation under high-load and highly diluted conditions. Overall, the findings indicate that palladium-coordinated thiourea complexes can influence diesel combustion and emission behavior, with 100 ppm PL offering the best balance between combustion improvement and engine performance, while 200 ppm PL may be more suitable when NOx reduction is prioritized. Further studies are required to assess long-term fuel stability, spray behavior, catalyst residues, and multi-cylinder engine applicability.