%X 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. © 2019 %O cited By 105 %L scholars11445 %K Catalysts; Flax; Methanol; Molar ratio; Oilseeds; Physicochemical properties; Potassium hydroxide; Surface properties; Transesterification, Biodiesel production; Central composite designs; Experimental verification; Flaxseed oil; Physicochemical parameters; Reaction temperature; Response surface methodology; Transesterification reaction, Biodiesel, biofuel; catalyst; chemical reaction; design method; essential oil; experimental study; methanol; operations technology; optimization; response surface methodology; temperature effect %D 2019 %A T. Ahmad %A M. Danish %A P. Kale %A B. Geremew %A S.B. Adeloju %A M. Nizami %A M. Ayoub %P 1272-1280 %I Elsevier Ltd %R 10.1016/j.renene.2019.03.036 %V 139 %T Optimization of process variables for biodiesel production by transesterification of flaxseed oil and produced biodiesel characterizations %J Renewable Energy