Multifunctional Nanoparticle Applications to Microalgal Biorefinery

Abstract

Microalgal feedstocks are leading candidates for application to large-scale production of sustainable biochemicals and biofuels, due to the inherent potentials of microalgae including high biomass and lipid productivities, carbon neutrality, a wide range of end products, and cultivation in nonarable lands. However, the overall process, starting from microalgae cultivation and ending in conversion to biofuels, entails complicated processes and, moreover, faces technological and economic challenges for commercialization. Recently, the application of multifunctional nanoparticles has been suggested as a potential tool to open commercialization of microalgae-based biofuels. In this context, this chapter will discuss the extensive research that has been conducted to improve process efficiency in microalgal biorefinery. Attention will be focused mainly on nanoparticle-aided microalgae harvesting, extraction, and conversion. With respect to microalgae harvesting, a diverse range of functionalized magnetic nanoparticles are utilized to enhance harvesting efficiency in a short time. Further, nanoparticles with multiple functions or recyclability are developed to reduce process costs. Aminoclay-conjugated nanoparticles are applied to increase lipid extraction yields through destabilization of cell walls or generation of hydroxyl radicals for cell disruption. Also, the various nanocatalysts for conversion yield enhancement and biodiesel upgrading are covered. It is hoped that this chapter of the current state of nanoparticle-based technology will prove a useful guide to future improvements in microalgal biorefinery.