Investigation of boiler scale deposits as heterogeneous base catalyst for biodiesel production from jatropha oil

ABSTRACT

Exploitation of non-edible oils, especially jatropha oil, for biodiesel production has been investigated extensively due to its high oil content. In this study, boiler scale deposits (BSD), an industrial waste, was calcined at 1000°C in a muffle furnace and investigated as a heterogeneous solid base catalyst for transesterification of jatropha oil to produce biodiesel. The physicochemical properties of the calcined BSD catalyst were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscope (SEM). Due to high free fatty acid (FFA) content of oil, a two-stage process, viz., acid catalyzed esterification pretreatment followed by transesterification, was employed for biodiesel production. Esterification was conducted under the following conditions: 2% (v/v) H₂SO₄, methanol to oil molar ratio 6:1, reaction time 2 h and reaction temperature 60°C and the acid value was reduced to 3.65 mg of KOH/g. Process parameters for the transesterification were 8% (w/w) catalyst,12:1 methanol to oil molar ratio, 3 h reaction time and 65°C reaction temperature and biodiesel conversion of 82.85% was reported. The biodiesel conversion was characterized by ¹H nuclear magnetic resonance spectroscopy (¹H-NMR).

KEYWORDS:

• Scale deposits
• boiler
• jatropha
• esterification
• transesterification

Disclosure statement

No potential conflict of interest was reported by the authors.