Experimental Evaluation of Thermophysical Properties and Fuel Standard Compliance of 1-Propanol + Residual Biodiesel Blends

High Resolution Image Download MS PowerPoint Slide The growing dependence on fossil fuels has intensified greenhouse gas emissions, driving interest in renewable alternatives such as biodiesel. Despite its advantages, biodiesel faces limitations due to higher viscosity, lower oxidative stability, and variability in quality when compared to diesel. A promising strategy to mitigate these challenges involves blending biodiesel with short-chain alcohols, which can enhance fuel properties. In this study, experimental evaluations were conducted on blends of 1-propanol and biodiesel derived from waste cooking oil. Key fuel properties were analyzed, including density, viscosity, flash point, and distillation behavior. The addition of 1-propanol consistently decreased density and viscosity, a result attributed to structural differences between esters and alcohols. Blends with intermediate volumetric fractions (0.4–0.8) satisfied ASTM D975 specifications, indicating strong potential for practical applications. However, significant reductions in flash point were observed, emphasizing critical safety considerations for storage and handling. Correlative models demonstrated excellent agreement for density (MAPD < 0.1%) and satisfactory accuracy for viscosity. Predictive models (RAC, DSV, MCH, and NRR) estimated density with MAPDs below 2%, proving reliable for preliminary fuel screening and simulations. Additionally, the Grunberg–Nissan interaction parameter improved viscosity predictions, reducing deviations to below 1.2%. These results provide valuable insights for fuel formulation and process optimization.