Utilization of Sugarcane Field Residue (SFR) as Renewable Feedstock for Biobutanol Production

Abstract

Due to its hydrophobicity and high energy yielding, butanol emerged as an important industrial solvent and superior liquid fuel with a potential to replace gasoline. The economic production of butanol is mainly depending on raw material cost. Thus, the development of butanol production process using renewable energy sources such as lignocellulosic crop residues has gained interest. In the present study, production of butanol from sugarcane field residue (SFR) was carried using newly isolated solventogenic Clostridium beijerinckii YVU1. SFR is one of the abundant lignocellulosic potential substrate available in the tropical world. SFR contains 40.3 ± 3.5% cellulose, 28.5 ± 3.0% hemicellulose and 20.3 ± 2.6% lignin. The sequential dilute alkali and acid pretreatment was solubilized around 69% of lignin and 73% of hemicellulose. Ten percent (w/v) of pretreated substrate was subjected to enzymatic saccharification with cellulase, and it released 0.681 ± 0.041 g of glucose/g of pretreated biomass. In the batch fermentation process, 22.8 g/l ABE with 16.5 g/l of butanol, 4.8 g/l of acetone and 1.5 g/l of ethanol was obtained. The performed fermentation process yielded 0.41 g of ABE/g of hydrolysate with 0.16 g/l/h productivity. The current work presents the impact of sequential alkali and acid pretreatment on the enzymatic hydrolysis of SFR as well as its utilization for butanol production by newly isolated C. beijerinckii YVU1. The outcome of the present work could be useful for further development in utilization of various crop residues for economical butanol production.