Energy, Resources and Environmental TechnologySynthesis and characterization of poppy seed oil methyl esters

Response surface methodology (RSM) was used to determine the optimum conditions of the methanolysis of crude poppy seed oil using NaOCH3 as catalyst. The experiments were run according to five levels, four variable central composite rotatable design (CCRD) using RSM. The reaction variables, i.e., molar ratio of methanol/oil (3:1-9:1), catalyst concentration (0.5 wt%-1.25 wt% NaOCH3), reaction temperature (25-65 °C), and reaction time (20-90 min) were studied. We demonstrated that the molar ratio of methanol/oil, catalyst concentration, and reaction temperature were the significant parameters affecting the yield of poppy seed oil methyl esters (PSOMEs). The optimum transesterification reaction conditions, established using the RSM, which offered a 89.35% PSOME yield, were found to be 7.5:1 molar ratio of methanol/oil, 0.75% catalyst concentration, 45 °C reaction temperature, and 90 min reaction time. The proposed process provided an average biodiesel yield of more than 85%. A linear correlation was constructed between the observed and predicted values of the yield. The gas chromatography (GC) analyses have shown that PSOMEs contain linoleic-, oleic-, palmitic-, and stearic-acids as main fatty acids. The FTIR spectrum of the PSOMEs was also analyzed to confirm the completion of the transesterification reaction. The fuel properties of the PSOMEs were discussed in light of biodiesel standards (ASTM D 6751 and EN 14214).

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