Microalgal biovalorization: Conventional and nonconventional approach

Abstract

A tremendous amount of waste is generated across the globe in various forms as wastewater, flue gas, and polluted air in the form of NOx and SOx, and it is influencing the environment drastically. In a scenario like this, microalgae have emerged as a potential preference to harvest all the waste and convert it simultaneously in commercially viable products. The reason for selection for microalgae is the ability to grow at a higher rate than higher plants, and there is no disruption in the food supply compared to first- and second-generation biofuels. There is the ability to assimilate high concentrations of toxic compounds such as flue gas, NOx, SOx, and carbon dioxide in gases and nitrate, phosphate, arsenic, cadmium, nickel, copper, and other heavy metals from wastewater and to valorize these wastes simultaneously into commercially useful products such as biofuel and bioactive compounds. These are the conventional methods for biovalorization of microalgae. Nonconventional valorization applications such as microalgae as biosensors, and applications in nanotechnology and in green building are the technology-based aspects of microalgae. The main bottleneck is the economic feasibility and sustainability of a single process in the industry. The concept of a biorefinery similar to a petroleum refinery to obtain different products at different stages of the process was implemented in microalgae process design. This chapter discusses the production and applications of valorized products in terms of conventional and nonconventional approach and integration of all these processes in a biorefinery. © 2020 Elsevier Inc. All rights reserved.