Publication date: April 2019
Source: Renewable Energy, Volume 133
Author(s): Koel Saha, Pooja Verma, Jaya Sikder, Sudip Chakraborty, Stefano Curcio
Sugarcane bagasse, has been studied as lignocellulosic feedstock to derive bioethanol; a major step towards the invention of green and sustainable energy. Major cost of the whole process lies in the enzymatic digestion of bagasse, since cost of cellulase enzyme is too high. Thus recovery and reuse of cellulase can reduce the total process cost. The perspective of cellulase recycling after hydrolysis of ionic liquid pretreated sugarcane bagasse was studied by synthesizing chitosan-cellulase nanohybrid and immobilizing the nanohybrid in alginate beads. SEM and Particle size analysis confirmed the formation of variable size of nanoparticles and zeta potential denoted the tendency to form agglomerate. The performance of immobilized nanohybrid was optimized by varying different operating parameters such as pH (3–7) and temperature (30–60 °C). Immobilized nanohybrid showed higher immobilization yield and stability as compared to immobilized cellulase at the optimum condition. The maximum reducing sugar concentration of 38.87 gm/lit was achieved when immobilized nanohybrid was loaded at 20 FPU/gm of pretreated bagasse. Hydrolysate thus obtained was fermented and 0.38 g/g ethanol yield was obtained. Immobilized nanohybrid was successfully recycled up to five times which made the hydrolysis step eco-friendly and economically feasible. The contribution of the investigation leads towards the development of energy efficient enzyme recycling scheme.