Conversion of palm oil sludge to biodiesel using sulphuric acid as catalyst

Abstract

The present study focuses on utilizing palm oil sludge (POS) as low-cost feed stock for biodiesel production. The esterification reaction was performed by varying sulphuric acid dosage (2–5% wt), methanol to palm oil sludge molar ratio (3.5:1–9.5:1), reaction time (30–120 min), temperature 60 C and stirred speed 400 rpm. The free fatty acids (FFA) considerably reduced from 17.76% to 1.34% and maximum esters yield was observed to be 91.56% at optimal conditions, 4 wt % H2SO4, methanol to palm oil sludge ratio 7.5:1 and 60 min. The biodiesel was produced by transesterification process by varying sodium hydroxide catalyst concentration from 0.25 to 1.5 wt%. The maximum biodiesel yield of 92.2% was obtained at 0.25 wt% of NaOH. The biodiesel was tested for the fuel properties as per the IS 1448 protocol and compared with normal diesel fuel with reference to ASTM D6751 standards.