Corrosion Properties of Biodiesel and Petroleum Diesel on Copper, Aluminium and Stainless Steel

Abstract

As the drive in research and investment in biodiesel production from non-edible sources increases, there is also increased concern in its associated challenges like the corrosion potentials on different metals. Due to the challenges caused by corrosion, it is therefore necessary to carry out a thorough evaluation of the corrosion potential of identified bio-diesel sources. This work examined the corrosion potentials of biodiesel from soapnut and rape seed oil compared with commercial petroleum diesel using metals such as copper, aluminum, and stainless steel by the non-electrochemical weight loss method. The result shows that biodiesel produced from soapnut seed oil is more corrosive than biodiesel produced from rapeseed oil. The metals corroded with variable degrees as they were immersed in the different biodiesels at room temperature for 7 weeks (1176hours). The corrosion rates of copper, aluminum, and stainless were found to be 0.0003155, 0.0000869, and 0.0000147 mm/year respectively for biodiesel from soapnut seed oil, and 0.0002319, 0.0000773, and 0.0000147 mm/year respectively for biodiesel from rapeseed oil. However, the corrosion rates of the same metals immersed in petroleum diesel were relatively lower (0.0000835, 0.0000316 and 0.0000074 respectively) under the same conditions. The corrosive effect of biodiesel on copper was found to be more pronounced than on aluminum and stainless steel.