Advances in direct transesterification of microalgal biomass for biodiesel production

• Published in: Reviews in environmental science and biotechnology Vol. 12; no. 2; pp. 179 - 199
• Main Authors: Hidalgo, P, Toro, C, Ciudad, G, Navia, R
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer-Verlag 01.06.2013; Springer Netherlands; Springer Nature B.V
• Subjects: Agricultural production; Algae; alternative fuels; Atmospheric Protection/Air Quality Control/Air Pollution; Biodiesel; Biodiesel fuels; Biofuels; Biomass; Biomass energy; Crops; Disruption; Earth and Environmental Science; Environment; Environmental Engineering/Biotechnology; environmental science; Extraction; Fatty acids; fuel production; Hydrocarbons; Industrial applications; Lipids; Mass transfer; Microalgae; Microbiology; Moisture content; Raw materials; refining; Sterols; Studies; Transesterification; Water content; Chile; Biodiesel; Microalgae; Direct transesterification
• ISSN: 1569-1705; 1572-9826
• DOI: 10.1007/s11157-013-9308-0

Microalgae biomass is becoming an interesting raw material to produce biodiesel, where several approaches in the transesterification process have been applied such as different catalysts, different acyl acceptors, incorporation of co-solvents and the different operational conditions. However there are some drawbacks that must be solved before any industrial application could be intended. The main problems are related with the high water content of the biomass (over 80 %) and the several process steps involved in biodiesel production such as: drying, cell disruption, oils extraction, transesterification and biodiesel refining. In comparison to other alternatives, the use of direct transesterification could be a suitable alternative since cell disruption, lipids extraction and transesterification are carried out in one step, with a direct reaction of oil-bearing biomass to biodiesel. This process could be applied even using biomass with high water content, and its efficiency could be improved by the incorporation of promising technologies such as microwave or ultrasonication that can enhance the mass transfer rate between immiscible phases, simultaneously diminishing the reaction time. However, it is still necessary to decrease the costs of these technologies so they can be suitable alternatives in future industrial applications.