Ferric chloride based downstream process for microalgae based biodiesel production

• Published in: Bioresource technology Vol. 181; pp. 143 - 147
• Main Authors: Seo, Yeong Hwan, Sung, Mina, Kim, Bohwa, Oh, You-Kwan, Kim, Dong Yeon, Han, Jong-In
• Format: Journal Article
• Language: English
• Published: England 01.04.2015
• Subjects: Biofuels; Biotechnology - methods; Chlorella - drug effects; Chlorella - growth & development; Chlorella - metabolism; Chlorides - pharmacology; Chromatography, Gas; Esterification; Ferric Compounds - pharmacology; Hydrogen Peroxide - pharmacology; Hydrogen-Ion Concentration; Iron - pharmacology; Lipids - isolation & purification; Microalgae - drug effects; Microalgae - growth & development; Microalgae - metabolism; Static Electricity; Lipid extraction; Ferric chloride; Fenton-like reaction; Esterification using alkaline catalyst; Harvesting
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2015.01.004

In this study, ferric chloride (FeCl3) was used to integrate downstream processes (harvesting, lipid extraction, and esterification). At concentration of 200 mg/L and at pH 3, FeCl3 exhibited an expected degree of coagulation and an increase in cell density of ten times (170 mg/10 mL). An iron-mediated oxidation reaction, Fenton-like reaction, was used to extract lipid from the harvested biomass, and efficiency of 80% was obtained with 0.5% H2O2 at 90 °C. The iron compound was also employed in the esterification step, and converted free fatty acids to fatty acid methyl esters under acidic conditions; thus, the fatal problem of saponification during esterification with alkaline catalysts was avoided, and esterification efficiency over 90% was obtained. This study clearly showed that FeCl3 in the harvesting process is beneficial in all downstream steps and have a potential to greatly reduce the production cost of microalgae-originated biodiesel.