Microalgae biomass feedstock as a smart cell factory for Biodiesel production via in situ Transesterification: A review

Abstract

The present review intends to explore role and mechanisms of the integration and application of microalgal biomass feedstock in the biodiesel production process via direct (in situ) transesterification. Such focus on microalgae – as a third-generation feedstock rather than the usual and well-known feedstock belonging to the first- and second ones derives from the emerging and growing interest in investigating such a promising bioenergy source/option able to guarantee a fast growth rate in terms of annual biomass productivity and, at the same time, microalgae don‟t compromise the food plants supply chain, since their cultivation methods and systems don‟t require as much as land area as the conventional energy crops plants. In fact, microalgae can easily and effectively grow in photobioreactors and through other cultivation systems. In addition, microalgal feedstock can even guarantee CO2 sorption. The application of this type of feedstock in the biodiesel production process has been already demonstrated as a successfully alternative option specifically via direct (or in-situ) transesterification process. In parallel, biodiesel represents an alternative and sustainable substitute (bio) fuel to the petroleum-based fuel (diesel): biofuel strictly regulated by the European standard EN14214. Therefore, the present paper aims to examine and report the emerging advances on role and mechanisms of the microalgae-biodiesel relationships in terms of biofuel production and, consequently, on some challenges as well. In this regard, some challenges were outlined in
order to place the present review in an operationally usable context and, last but not least, with a view towards ever-increasing sustainability and future improvements.