Taguchi Optimization on the Biooil Extraction from Fresh Water Algae (Spirogyra) Using Soxhlet Apparatus

Abstract

The present investigation is aimed at maximizing the biooil yield (BOY) from the algal species Spirogyra by solvent extraction method with a nonpolar solvent n-hexane using a Soxhlet apparatus. Also, this present work is aimed at acquiring optimal physiochemical properties such as kinematic viscosity and iodine value of the biooil produced from the algae. To carry out this work, the Taguchi technique with the L9 orthogonal array (OA) was used. With the L9 OA, nine sets of experiments were directed as per the design matrix, and the results were analyzed using the Taguchi method with the help of Minitab 16 software. The results generated from this optimization process showcased that the BOY from the Spirogyra was found to be a maximum of 26.86% with the particle size (PS) being 0.462 μm, the response time (RT) of 60 minutes, the solvent ratio (SR) of 1 : 10, and the extraction temperature (ET) of 75°C. The optimal set of input parameters for the optimal output response kinematic viscosity of 1.92 mm2/s was found to be achieved with the PS being 0.462 μm, 60 minutes of RT, the SR of 1 : 15, and the ET of 75°C. Similarly, the optimal set of input parameters for the optimal output response iodine value was found to be at 0.322 μm PS, 120 minutes of RT, an SR of 1 : 5, and an ET of 75°C. The signal-to-noise ratio (SNR) for the output responses exposed that the PS exhibited a major impact on the BOY and kinematic viscosity and the contribution levels of 76.68 and 51.7%, respectively.