Investigation of Local Plant Extracts on Biodiesel Crystallization Temperatures Using Differential Scanning Calorimetry (DSC)

Abstract

This study investigated the natural antioxidant efficiencies of various plant extracts (Achillea millefolium L., Helichrysum arenarium L. Moench, and Rosa canina L.) on the biodiesel's oxidative stability. The Soxhlet method obtained plant extracts, and their antioxidant activities on biodiesel-diesel blends were evaluated by high-performance liquid Chromatography (HPLC) and Fourier Transform Infrared Spectroscopy (FT-IR) techniques. FT-IR spectrum of Achillea millefolium L. indicates the presence of ferrulic acid, caffeic acid, and coumaric acid in the extract, and C-H stretching vibrations detected at 2959 cm-1 and 2923 cm-1 showed the presence of catechin, taxifolin, and naringenin in the extract. Helichrysum arenarium L. Moench. and Rosa canina L. IR Spectra showed kaempherol, naringenin, chrysin, and butein. The plant extracts with 3000 ppm concentration were added to biodiesel-diesel blends consisting of 20% biodiesel and 80% diesel as natural antioxidants. The blend samples were coded as B20D80, B20D80A, B20D80H, and B20D80R. The crystallization temperatures (Tcr) were determined by Differential Scanning Calorimetry (DSC), and the results show that the crystallization onset temperatures for B20D80, B20D80A, B20D80H, and B20D80R were-8.07 degrees C, -8.16 degrees C, -8.34 degrees C, and-8.61 degrees C, respectively. Tcr values of samples with antioxidants were decreased compared to the non-antioxidant sample (B20D80). Additionally, the thermophysical properties of the samples were determined, and the results showed that the basic fuel properties were slightly affected by adding plant extracts to the base fuel sample.