FTIR evaluation on the fuel stability of calophyllum inophyllum biodiesel: Influence of tert-butyl hydroquinone (TBHQ) antioxidant

Abstract

‘Storage oxidation stability’ is one of the most significant criteria for appraising the biodiesel quality. Poor oxidation stability is the chief technical blockage related with the commercialization of biodiesel. The present paper investigates the effects of Tert- butyl hydroquinone (TBHQ) antioxidant additive concentrations on the long-term storage stability, thermal stability and accelerated oxidation stability of Calophyllum inophyllum biodiesel. Fourier transform infra-red (FTIR) spectroscopy was used to characterize the biodiesel oxidation variability, following the regions of C-H and O-H bonds in FTIR spectrum for different concentrations of TBHQ. Addition of TBHQ at 1000 ppm concentration (B100A3) with pure biodiesel enhances the oxidation stability by 94.67 %, storage stability by 14.47 % and thermal stability by 69.55 %; whereas further concentration of antioxidant deteriorates the formation of hydrophobic and hydrophilic clusters between biodiesel/antioxidant compounds, which is characterized by FTIR spectrum data. It is concluded that the Calophyllum inophyllum biodiesel could be accumulated for an extensive period by dosing 1000 ppm of TBHQ antioxidant.