A comprehensive review of nanoadditives in Plant-based biodiesels with a special emphasis on essential oils

Biodiesel is a mixture of long-chain fatty acids derived from natural sources such as plants, animals or microbial biomass, which have long been considered as an attractive alternative to petroleum-based fuels. However, the inherent instability and corrosive properties-related challenges of biodiesels should be overcome for successful commercial use of biodiesels. Besides, production costs along with environmental issue create a crisis in world fuel production, and it forced the industrial sector to find an alternative way to conventional methods. These disadvantages could be overcome with the help of nanotechnology, which has wide applications in feedstock modification, catalytic production and esterification reaction. Nanoadditives are nanosized inclusions to biofuels, added to improve the fuel properties, emission reduction and other undesirable properties of biofuels. Metal oxides, carbon nanotubes and plant-based additives are being explored as nanoadditives to improve the liquid biofuel properties. Moreover, the use of nanocatalysts is the best option to convert essential oils into biofuel with a high yield. Overall, this review discusses the production of biofuels, especially for biodiesel, and also highlights the use of essential oil as a natural additive in biodiesel.