Bio-ethanol and bio-butanol production from orange peel waste

Abstract

Orange (Citrus sinensis) peel waste was used as the substrate for bio-fuels production. It was treated with a steam explosion process to carry out its hydrolysis, and the hydrolysate was utilized as a fermentation medium. The steam explosion method variables of acid concentration, residence time and substrate concentration were optimized. Bio-ethanol and bio-butanol were produced in this study using Saccharomyces cerevisiae NCIM 3495 and Clostridium acetobutylicum NCIM 2877, respectively. The optimized parameters for the steam explosion process were 1% v/v acid concentration, 10 min residence time and 15% w/v substrate concentration. Maximum bio-ethanol yield of 4.1 g/100 mL from orange peel hydrolysate as production media was achieved with the optimized parameters such as 24 hr inoculum incubation time, 20% v/v inoculum size and 48 hr fermentation time. Orange peel waste was used as the substrate for bio-butanol production for the first time and a yield of 19.5 g/L was achieved without addition of nutritional supplements.

Keywords:

• bio-ethanol
• orange peel waste
• Gas Chromatography Mass Spectometry
• S. cerevisiae

Acknowledgments

Authors are thankful to Oils, Oleochemicals and Surfactant Technology Department, Institute of Chemical Technology, Matunga, Mumbai, and Department of Microbiology, Shivaji University, Kolhapur, for providing laboratory facilities.

Disclosure statement

No potential conflict of interest was reported by the authors.