2.3. Oil extraction and biodiesel production
The acid values of Spirulina algae oil and pond water algae oil obtained in the present study were 9.42 mg KOH/g and 8.86 mg KOH/g respectively. The acid values were quite high and thus acid catalyzed transesterification was done in the present investigation. Acid based transesterification of algae oils also has been reported effective for biodiesel production [28].