Strategies to Produce Cost-Effective Third-Generation Biofuel From Microalgae

Nazifa Rafa,M Mofijur,Irfan Anjum Badruddin,Sarfaraz Kamangar,Shams Forruque Ahmed

doi:10.3389/fenrg.2021.749968

Abstract

Third-generation biofuel produced from microalgae is a viable solution to global energy insecurity and climate change. Despite an annual current global algal biomass production of 38 million litres, commercialization confronts significant economic challenges. However, cost minimization strategies, particularly for microalgae cultivation, have largely been excluded from recent studies. Therefore, this review provides essential insights into the technologies and economics of cost minimization strategies for large-scale applications. Cultivation of microalgae through aquafarming, in wastewater, or for biogas upgrading, and co-production of value-added products (VAPs) such as photo-bioreactors, protein, astaxanthin, and exopolysaccharides can drastically reduce biodiesel production costs. For instance, the co-production of photo-bioreactors and astaxanthin can reduce the cost of biodiesel production from $3.90 to $0.54 per litre. Though many technical challenges need to be addressed, the economic analysis reveals that incorporating such cost-effective strategies can make the biorefinery concept feasible and profitable. The cost of producing microalgal biodiesel can be lowered to $0.73kg−1dry weight when cultivated in wastewater or $0.54L−1when co-produced with VAPs. Most importantly, access to co-product markets with higher VAPs needs to be encouraged as the global market for microalgae-based VAPs is estimated to rise to $53.43 billion in 2026. Therefore, policies that incentivize research and development, as well as the production and consumption of microalgae-based biodiesel, are important to reduce the large gap in production cost that persists between biodiesel and petroleum diesel.

Highlights

Progressing industrialization coupled with the expanding world population is driving energy to become more and more important for economic growth (Ahmed et al, 2021a)
Need to use fossil fuel-based sources during cultivation High production costs for growing, harvesting, collection and transportation Pretreatment is needed to process the biomass for biofuel production Low lipid extraction efficiency High initial capital investment High biofuel production cost Nutrient-rich water or fertilisers are needed for the cultivation Commercialisation is not easy energy source after fossil-based sources, biomass and combustible renewable sources (Lam et al, 2019; Hoang et al, 2021) are promising alternatives with the capacity to address global energy needs (Azevedo et al, 2019)
Several strategies have been developed to lower the cost of microalgal biodiesel production, discussions of which have been largely excluded from the recent literature that primarily focuses on the benefits and composition of microalgal biodiesel, insights into the processes and process factors that affect yield, and efficient harvesting and extraction methods (Satpati and Pal, 2018; Shin et al, 2018; Tan et al, 2018; Deshmukh et al, 2019; Goh et al, 2019; Peng et al, 2020; Ananthi et al, 2021)

Summary

Introduction

Progressing industrialization coupled with the expanding world population is driving energy to become more and more important for economic growth (Ahmed et al, 2021a). Numerous studies have revealed the potential for oleaginous microalgal cultivation in wastewater for producing biodiesel, where microalgae have exhibited significant efficiency in removing the contaminants from wastewater (Ahmed et al, 2021b) and the capacity to collect lipid in the cell body.

Results

Conclusion