A review on the contribution of nanotechnology for biofuel production from algal biomass: A bridge to the reduction of carbon footprint

There is a rapid exhaustion of fossil fuels, so there is a huge demand to develop alternate fuels. Though algae have an excellent productivity rate with high lipid content that favours biofuel production, the downstream production cost of biofuel from the algal source is expensive. Novel techniques are required to minimise the cost involved in biofuel processing. Nanoparticles have potential advantages and are used in various stages of biofuel production from algae, such as algal harvesting, increasing biomass concentration, and separation of algal cells. Moreover, nanoparticles act as biocatalyst carriers in the transesterification process. While iron oxide nanoparticles majorly help in the growth of microalgae, nanoparticles such as carbon nanotubes and magnesium oxide aid in increasing the production of lipids. Magnesium sulphate nanoparticles increase the production of chlorophyll significantly. Though nanoparticles possess numerous benefits in increasing biofuel production, they exhibit a certain level of toxicity towards humans and our ecosystem. The toxicity mainly relies on the nature of nanoparticles, cultivation media and the type of microalgae species used for biofuel production. This review showcases algae's important features that favour biofuel production and the various sources of algae biomass. More importantly, nanotechnology's role in biofuel production and the challenges faced while using it in processing biofuel are demonstrated. Finally, opportunities for future work employing nanotechnology for sustainable biofuel production are presented. Last but not least, constant research work is required to overcome the barriers and progress the nanotechnology for their large-scale usage in increasing the algal biofuel production.