Role of nanomaterials in enhanced ethanol production through biological methods – Review on operating factors and machine learning applications

Abstract

Renewable energy sources based on biomass are identified as sustainable solution to balance the carbon footprint and fuel requirements. The characteristics of bioethanol make it an ideal fuel additive due to its eco-friendliness and calorific value. Fermentation technology is used to convert carbohydrate-rich biomass into biofuel, but technical glitches and high costs have been identified as drawbacks. Nanomaterials have contributed significantly to bioethanol synthesis in terms of enhanced surface activity and selectivity. By using nanoparticles, various steps in the production of bio-alcohol can be made more efficient and cheaper. Based on the extensive review carried out, the best bioethanol yield reported were: dolomite at 121 °C (106%), methyl-functionalized cobalt ferrite– silica at 37 °C (126.9%) and calcium alginate at 37 °C (100%). Magnetic iron oxide covered cellulase yielded 60% in the temperature range of 24–96 °C and Silica-immobilized cellulase yielded 32 g/L at 25–60 °C. Methyl-functionalized cobalt ferrite–silica emerged as an efficient nano-bio catalyst as it gives highest ethanol yield at moderate temperature (37 °C) and pressure (1–2 atm). The mechanism of action of the nanoparticles is discussed in this research and the future directions of research are proposed. Machine learning applications for the prediction of bioethanol yield were discussed in detail.