Carbon Nanoparticles from <i>Psidium</i> Guava Fruit as Additives to Diesel/Butanol Blends: Their Impact on the Performance and Emissions of a Diesel Engine

Abstract Emissions from diesel engine combustion present significant challenges for climate change and public health. Recent studies have explored alternative fuels and additives, particularly carbonaceous nanomaterials (CN), which have shown effectiveness in reducing pollutants such as carbon monoxide (CO), nitrogen oxides (NO), and particulate matter (PM). This study synthesized carbon nanoparticles (CN‐GB) from Psidium guajava using a solvothermal method with butanol as the solvent. The resulting fuel composition comprised 90% diesel, 10% butanol, and 100 mg/L of CN‐GB. The modified fuel was assessed for heating value, cetane number, and emissions during operation in a compression ignition engine connected to a synchronous generator. The findings revealed that adding butanol increased CO emissions by up to 50% at 6 kW. The addition of CN‐GB resulted in a 10% reduction in carbon monoxide (CO) emissions at 12 kW compared to the diesel‐butanol blend. Additionally, nitrogen oxide (NO) emissions decreased by 42% with the diesel–butanol blend and by 38% with the diesel‐butanol‐CN‐GB blend at 6 kW compared to diesel fuel. Particulate matter (PM) emissions were reduced by 41.7% with the butanol blend, followed by an additional 18.8% decrease when CN‐GB was added at 6 kW.