Analysis and comparison of olive cooking oil and palm cooking oil properties as biodiesel feedstock

Abstract

Biodiesel was utilized as an alternative source of renewable energy to counter the shortcomings of fossil fuels. In this study, the physical and chemical properties of olive cooking oils and palm cooking oil were analysed as biodiesel feedstock based on density, specific gravity, acid value, free fatty acid content (FFA), saponification value and peroxide value. The analysis results were compared according to ASTM and EN standards. Olive cooking oil A, olive cooking oil B and palm cooking oil have densities of 895 kg/m3, 897 kg/m3 and 904 kg/m3, respectively. The specific gravities of olive cooking oil A, olive cooking oil B and palm cooking oil were 0.88, 0.88 and 0.89 respectively. Olive cooking oil A, olive cooking oil B and palm cooking oil have acid value of 0.45 mg KOH/g ± 0.02 mg KOH/g with 0.23 % ± 0.01 % FFA, 0.41 mg KOH/g ± 0.02 mg KOH/g with 0.21 % ± 0.01 % FFA and 1.08 mg KOH/g ± 0.07 mg KOH/g with 0.54 % ± 0.04 % FFA, respectively. Palm cooking oil has high acid value exceeded the standard limit; thus, it requires FFA reduction before transesterification. The saponification values of olive cooking oil A, olive cooking oil B and palm cooking oil were 187.93 mg KOH/g ± 1.40 mg KOH/g, 188.40 mg KOH/g ± 0.81 mg KOH/g and 198.22 mg KOH/g ± 0.81 mg KOH/g respectively. The peroxide values obtained for olive cooking oil A, olive cooking oil B and palm cooking oil were 8.00 meq/kg ± 2.00 meq/kg, 8.00 meq/kg ± 2.00 meq/kg and 6.00 meq/kg ± 2.00 meq/kg, respectively. Fourier Transform Infrared Spectroscopy (FTIR) analysis was done and the functional groups present in all oil samples were analysed.