Optimization of process variables for biodiesel production by transesterification of flaxseed oil and produced biodiesel characterizations

Optimization of the operating factors to achieve the maximum yield of biodiesel through transesterification reaction was performed by using face-centered central composite design (FCCD) approach of response surface methodology. A total of 29 independent batch experiments were considered in this model to carefully observe the effect of operating factors, such as the volume ratio of methanol/oil, catalyst (KOH) weight percent, reaction temperature, and reaction time. The FCCD model predicted that a maximum yield of 99.5% biodiesel would be achieved from flaxseed oil at a reaction temperature of 59 °C, 0.51% catalyst, the reaction time of 33 min, and a molar ratio of methanol to flaxseed oil of 5.9:1. Experimental verification of the predicted yield under the optimum conditions gave a maximum yield of 98 ± 2%, which is in very good agreement with the predicted value of the model. The physicochemical properties of the flaxseed oil-derived biodiesel were compared with those of standard biodiesel to identify and verify the quality of the produced biodiesel. All observed physicochemical parameters of the flaxseed oil-derived biodiesel were closely in agreement with those of standard biodiesel. Thus, demonstrating that the production of high-quality biodiesel from flaxseed oil is a viable option.