Nanomaterial in liquid biofuel production: applications and current status

Demand for alternative and renewable sources of energy is gaining worldwide attention due to fast depletion of fossil fuels and growing population. At present the global needs of energy are largely fulfilled by fossil fuels resulting into their depletion. However, the burning of fossil fuels contributes towards environmental issues like global warming and pollution. Biofuels like bioethanol and biodiesel are gaining popularity worldwide due to being renewable, eco-friendly and environmentally safe. Lignocellulosic biomass is available in plenty and can be transformed into bioethanol by steps including pretreatment, hydrolysis and fermentation. Various physical, chemical and biological pretreatments are used for making biomass accessible for enzymatic hydrolysis, however, these approaches are having some limitations which can be overcomes by alternative, cost-effective and environmental friendly technologies like nanotechnology. In enzymatic hydrolysis process, magnetic nanoparticles can be used for immobilization of enzymes, which makes the process more effective. The microorganisms can also be immobilized in various matrix including magnetic nanoparticles, which can enhance ethanol production. Moreover, magnetic nanomaterials can be recycled by using magnetic field and can be reused again. Nanocatalyst can also be employed in transesterification process for biodiesel production and for ameliorating the yields. Nanotechnology can play a key role in biofuel production by reducing processing cost and enhancing productivity. The present review discusses the role of nanotechnology and nanomaterials in pretreatment, enzymatic hydrolysis and fermentation steps during bioethanol production, and in transesterification for enhancing efficiency of the biodiesel production process.