In situ transesterification and prediction of fuel quality parameters of biodiesel produced from Botryococcus sp. MCC31

Abstract

Microalgae are considered potential feedstocks to generate biodiesel; however, the area requires further refinement and metabolic engineering to enhance productivity along with cost reduction. Our study involved the production and quality evaluation of biodiesel from the lipids of Botryococcus sp. MCC31, after conventional and in situ transesterification. Lipids extracted fell within the range of 330 to 410 mg g⁻¹ Dry Weight (DW) (33–41% w/w) and these were identified by ¹H Nuclear Magnetic Resonance (NMR) and ¹³C NMR spectrum. After identification, the reaction conditions for indirect transesterification, in terms of catalyst type, were optimized for maximizing Fatty Acid Methyl Ester (FAME) yield. The total unsaturated and saturated fatty acids were 54% and 46%, respectively, and the results indicated higher amounts of methyl palmitate and methyl oleate, which comprised almost 65% of the total FAMEs. The biodiesel exhibited a density of 0.853 g/cc, viscosity of 3.512 mm²/s, Cetane Number (CN) of 57.57, Higher Heating Value (HHV) of 38.88, iodine value of 75.56 g I₂ /100 g, Degree of Unsaturation (DU) of 58% and a Cold Filter Plugging Point (CFPP) of 4.8 °C. The results were in accordance with the details as specified by American Society for Testing and Materials (ASTM) and European Norms (EN) standards. The study illustrates that Botryococcus sp. MCC31 can be a valuable feedstock for generation of high-quality biodiesel.

Keywords:

• Botryococcus sp.
• in situ transesterification
• prediction model
• biodiesel quality
• lipids
• nuclear magnetic resonance

Disclosure statement

No potential conflict of interest was reported by the authors.