Corrosion Potentials of Biodiesel Formulated from Soapnut Seed (Sapindusmukorossi) Oil and Rapeseed (Brassica Napus) Oil

Abstract

The aim of this study is to investigate the corrosion potentials of biodiesel
formulated from non-edible soapnut seed oil and rapeseed oil on copper, aluminum,
and stainless steel, because of their usage in transportation and storage,
and also because they are used either wholly, partially or as alloys in the
manufacture of automobile parts like fuel pumps and filters, injectors etc.
The oils were extracted from the oilseeds using mechanical engine driven
screw press. Biodiesel was produced from them using methanol and alkaline
catalyzed transesterification process. The physicochemical properties of the
produced biodiesel were determined and a comparative study on the corrosion
potentials of the produced biodiesel with commercial petroleum diesel on
copper, aluminium, and stainless steel was carried out. The corrosion rate of
copper in all the samples was more severe than those of aluminum and stainless
steel. The result obtained shows that the corrosion rate of copper is
0.0002319 mm/year for biodiesel from rapeseed oil, 0.0003155 mm/year for
biodiesel from soapnut seed oil, and 0.0000835 mm/year for petroleum diesel,
the corrosion rate of aluminium is 0.0000773 mm/year for biodiesel from
rapeseed oil, 0.0000869 mm/year for biodiesel from soapnut seed oil, and
0.0000386 mm/year for petroleum diesel, while the corrosion rate of stainless
steel is 0.0000147 mm/year for biodiesel from rapeseed oil, 0.0000147
mm/year for biodiesel from soapnut seed oil, and 0.0000074 mm/year for petroleum
diesel, respectively at room temperature. The results obtained also
shows that biodiesel from soapnut seed oil has a higher corrosion potential
than biodiesel from rapeseed oil, while petroleum diesel has the lowest corrosion
potential when compared to the produced biodiesel samples. This work
shows promise for the use of Biodiesel as an alternative to petroleum diesel.