Distillation analysis of diesel-biodiesel mixtures: A comparative study with ASTM norms, experimental data, and novel correlations

Abstract

This study investigates the importance of biodiesel as an alternative fuel to reduce pollutant emissions from diesel engines and mitigate the ecological impacts of fossil fuels. Biodiesel, derived from renewable sources, is notable for its environmental benefits and is produced through a transesterification reaction. This study aims to provide distillation data for biodiesel-diesel blends using grape seed, corn, and linseed biodiesel; the volumetric compositions analyzed are 20 %, 40 %, 60 %, and 80 % biodiesel in diesel. These data were obtained with an Anton Paar Diana 700 automatic distiller. Additionally, properties such as density, viscosity, refractive index, cetane index, and flashpoint were evaluated by the American Society for Testing and Materials − ASTM D975 (diesel) and ASTM D6751 (biodiesel) standards. Two correlative models based on the Riazi and Daubert were developed to calculate distillation temperatures and the distillation curves of diesel and biodiesel mixtures. A total of 207 experimental distillation points were determined. The results indicated that biodiesel addition shifts the distillation curves to higher temperatures, affecting both volatility and combustion. The pseudopure curves of biodiesels differed significantly from those of diesel because of the chemical differences between the compounds. The proposed correlations for biodiesel and diesel + biodiesel mixtures exhibited mean absolute percentage deviation (MAPD) of 3.61 %, 1.59 %, and 1.61 % for distillation temperatures at 10 %, 50 %, and 90 % of the distilled volume, respectively, for biodiesel. For the volumetric proportions of 20 %, 40 %, 60 %, and 80 % of biodiesel in the mixture, deviations of 1.46 %, 1.25 %, 1.06 %, and 0.83 % were observed without systematic deviations with increased biodiesel content. The correlations proposed for biodiesel and diesel + biodiesel mixtures demonstrated acceptable deviations, significantly contributing to the understanding and advancement of biofuels. Comparisons of the physical properties of the blends with the ASTM D975 standard confirmed compliance up to a proportion in the range of 67–76 % biodiesel by volume for viscosity and 37 % for density.