3.1. Biodiesel production from corn oil
As seen in Table 1, the acid value of corn oil is below 2 mg KOH g1 which is enough to use an alkaline catalyst for transesterification reaction. The ingredient amounts used in the transesterification for the corn oil were 7.7 kg methanol, 35 kg corn oil (6:1 M ratio) and 0.35 kg KOH (1% of oil by weight). Reaction time and temperature were 2 h and 60 C, respectively. The reaction parameters were selected by considering the previous studies (Alptekin and Canakci, 2008a, 2009). Mean molecular weight of corn oil was found to be about 875 g mol1 calculated from the fatty acid composition. The fatty acid composition for each oil and methyl ester can be seen in Table 2. Ester yield is calculated by dividing the ester amount to the corn oil amount used for transesterification. After transesterification and purification process, the ester yield was found to be 91% on mass. This value is slightly lower than the value obtained in the laboratory experiments. The reason for this may be higher amount of oil and ester loss in the biodiesel pilot plant.
3.2. Biodiesel production from fleshing oil
In the previous study (Alptekin et al., 2012), optimum reaction parameters were investigated to produce biodiesel from fleshing oil in laboratory scale apparatus. Acid value of the fleshing oil used in the previous study was 24.3 mg