Mass Transfer Phenomena during the Ultrasound-assisted Extraction of Algal Oil from Spirulina sp.

Abstract

Recently, microalgae is potential to be developed because it is easy to cultivate. This study investigated the effect of the solvent ratio on the mass transfer of algal oil at various residence times from 15 minutes to 60 minutes during ultrasound-assisted extraction process at 25 kHz and stirred at 150 rpm. The highest amount of the algal oil yielded was 3.01%, obtained by a ratio of isopropyl alcohol to n-hexane of 2:3 ratio at 60 minutes. A mathematical model was applied to obtain the mass transfer coefficient, diffusivity coefficient, and Henry’s constant contributing to the mass transfer rate. A GC-MS analysis was conducted to show the type of fatty acids and the fatty acid methyl ester produced by the extraction that showed the trans-esterification reaction. The lowest yield was obtained by 3:1 isopropyl alcohol to n-hexane ratio which had the lowest kca and De (4.7999×10-5 min-1 and 2.0000×10-9 cm2/min, respectively).

Keywords

• algal oil
• fatty acid
• mass transfer
• spirulina sp
• ultrasound-assisted extraction