A Novel Surfactant-assisted Transition Metal Pretreatment of Chili Post Harvest Residue for the Production of Bioethanol by Separate Hydrolysis and Fermentation

Raveendran Sindhu; Kamal Jerina; Parameswaran Binod; Anil Kuruvilla Mathew; Amith Abraham; Edgard Gnansounou; Ashok Pandey

Authors

Raveendran Sindhu Microbial Processes and Technology Division, National Institute for Interdisciplinary Science and Technology, CSIR,Trivandrum-695 019, India
Kamal Jerina Microbial Processes and Technology Division, National Institute for Interdisciplinary Science and Technology, CSIR,Trivandrum-695 019, India
Parameswaran Binod Microbial Processes and Technology Division, National Institute for Interdisciplinary Science and Technology, CSIR,Trivandrum-695 019, India
Anil Kuruvilla Mathew Microbial Processes and Technology Division, National Institute for Interdisciplinary Science and Technology, CSIR,Trivandrum-695 019, India
Amith Abraham Microbial Processes and Technology Division, National Institute for Interdisciplinary Science and Technology, CSIR,Trivandrum-695 019, India
Edgard Gnansounou Ecole Polytechnique Federale de Lausanne, Institute of Urban and Regional Sciences, GC A3, Station 18, CH-1015, Lausanne, Switzerland
Ashok Pandey Microbial Processes and Technology Division, National Institute for Interdisciplinary Science and Technology, CSIR,Trivandrum-695 019, India | Center of Innovative and Applied Bioprocessing, Mohali, Sector 81, Punjab, India

Keywords:

pretreatment, biomass, bioethanol, hydrolysis, chili, saccharification, fermentation

Abstract

In this work, a novel surfactant assisted transition metal pretreatment strategy was evaluated for the production of bioethanol from chili post harvest residue. Among the various transition metals screened surfactant assisted ferrous sulphate pretreatment was found to be more effective in terms of reducing sugar yield.Various process parameters affecting pretreatment were optimized by adopting a Taguchi design.The optimum conditions of pretreatment were (% w/w) surfactant concentration of 1, FeSO4 concentration of 2, biomass loading of 5 and pretreatment time of 20 min. Under optimized conditions 0.245g/g of reducing sugar per g of dry biomass (g/g) was obtained. The hydrolyzate is devoid of major fermentation inhibitors such as furfural, 5-hydroxymethylfurfural and organic acids such as citric acid, propionic acid and succinic acid. Fermentation of the non-detoxified hydrolyzate yielded 1.84%v/v of ethanol with a fermentation efficiency of 79%.