This research article published by Springer Nature Switzerland AG., 2020
Biodiesel has widely been produced from common edible oils; however, food versus fuel conficts has motivated researchers to search for other less common feedstock for production of biodiesel. Thus, this study investigates the suitability
of biodiesel made from less common manketti nut oil in terms of its thermal and long-term storage stability. Also, since
biodiesel is stored in containers made of diferent metals; the infuence of metal contaminants on the storage stability
of biodiesel is also examined. Manketti Oil Methyl Ester (MOME) is synthesized by the transesterifcation process and
characterized as per biodiesel global standards. MOME is doped with antioxidants (1, 2, 3 tri-hydroxy benzene (Pyrogallol,
PY) and 3, 4, 5-tri hydroxy benzoic acid (Propyl Gallate, PG)) at diferent ratio to analyse its infuence on the stability of
MOME. Also, 2 ppm of selected metals (Co, Cu, Fe, Mn, and Ni) is doped to MOME samples with and without antioxidants
and stored for 6 months in open and closed 500 ml plastic bottles. Oxidation stability is measured once a month to
monitor stability of MOME. Thermogravimetric analysis is conducted to examine thermal stability of MOME. The results
show that freshly-synthesized MOME has oxidation stability of 4.24 h below the European EN 14214 (8 h) and South
African SANS 1935 (6 h) standards. On adding antioxidant PY and PG at 200 ppm concentration, the oxidation stability
increases to 13 h and 8.5 h respectively. The result of MOME contaminated with metals shows that Cu has the highest
damaging efects on oxidation stability during storage. Additionally, thermal stability analysis results exhibit that MOME
has excellent thermal stability of 211.33 °C.