Transesterification And Pretreatment Process Optimization Of Methyl Ester Production From Fish Oil Having High Free Fat Acid

Abstract

In this study, biodiesel production from fish oil which contain high levels of free fatty acids (FFA) was investigated. High FFA content causes to saponification as a result of alkali catalysts reaction and methyl ester yield decrease. Therefore, methyl ester production of fish oil was performed with two step process (pretreatment and alkali catalyzed transesterification). FFA content of fish oil was decreased with using various ratios of methanol and sulphuric acid. In methanol-oil ratio of 40 wt.% and catalyst concentration of 1 wt.%, FFA level and optimum yield was determined as 0.46% and 93%, respectively. The product obtained under these conditions was entered into alkali catalyzed transesterification reaction with different parameters such as methanol-oil ratio, catalyst concentration, reaction temperature and reaction time. Optimum yield was obtained as 89.44% in 20 wt.% methanol-oil ratio, 0.5 wt% catalyst concentration, 60 °C temperature and 120 minutes reaction time. Fuel characteristics of the methyl ester was measured at optimum conditions.