Production of algal biodiesel from marine macroalgae Enteromorpha compressa by two step process: Optimization and kinetic study

• Published in: Bioresource technology 2013-01, Vol.128, p.392-400
• Main Authors: Suganya, Tamilarasan, Nagendra Gandhi, Nagarajan, Renganathan, Sahadevan
• Format: Article
• Language: English
• Subjects: Acid–base transesterification; Algae; Biodiesel; Biofuel production; Biofuels - analysis; Biofuels - microbiology; Biological and medical sciences; Biotechnology; Computer Simulation; Energy; Enteromorpha compressa; Fatty acids; First order kinetics; Fundamental and applied biological sciences. Psychology; Industrial applications and implications. Economical aspects; Kinetics; Marine macroalgae; Microalgae - physiology; Models, Biological; Optimization; Rate constants; Reaction kinetics; Seawater - microbiology; Transesterification
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2012.10.068

► Enteromorpha compressa is a potential source which has been used for first time. ► Maximum yield of ME 90.6% was achieved by acid–base catalyze transesterification. ► The reaction parameters were optimized and kinetic study was performed in detail. ► The activation energy was obtained as 73,154.89J/mol. ► Algal biodiesel was characterized and it was within the limits of ASTM standards. In this investigation, Enteromorpha compressa algal oil with high free fatty acids (FFA) used as a feedstock for biodiesel production. Two step process was developed and kinetic study executed to obtain reaction rate constant for the transesterification reaction. The acid esterification was carried out to reduce FFA from 6.3% to 0.34% with optimized parameters of 1.5% H2SO4, 12:1 methanol–oil ratio, 400rpm at 60°C and 90min of reaction time. The maximum biodiesel yield 90.6% was achieved from base transesterification through optimum conditions of 1% NaOH, 9:1 methanol–oil ratio, 600rpm and 60°C temperature for 70min. The algal biodiesel was characterized by GC–MS, HPLC and NIR. This transesterification follows first order reaction kinetics and the activation energy was determined as 73,154.89J/mol. The biodiesel properties were analyzed and found to be within the limits of American standards. Hence, E. compressa serves as a valuable renewable raw-material for biodiesel production.