Comparison of different pretreatment methods for efficient conversion of bagasse into ethanol

ABSTRACT

Biofuel production is popular with biotechnologists due to the continuously increasing need for energy. One major issue is to get maximum fuel production for minimum cost. In our studies we focused on both factors and developed a method for bioethanol production by investing in low cost chemicals. We compared three chemical pretreatments (NaOH, Na₂SO₃ and H₂O₂) at 121°C temperature and 15 psi pressure for delignification to evaluate the efficacy of chemicals in pretreatment. NaOH and Na₂SO₃ showed comparable percentage delignification (81.3 and 80.17% respectively) while H₂O₂ showed 67.4% delignification. Endogenously produced cellulolytic enzyme with 30 IU/mL CMCase and 22 IU/mL FPase units was used for saccharification of exposed cellulose. An indigenously developed strain of Saccharomyces cerevisiae SC36 (developed in a peptone free high gravity media) was used to ferment saccharified sugars into ethanol at 37°C fermentation temperature. We were able to convert 27% of the total bagasse (as per dry mass basis) into ethanol with NaOH pretreatment followed by 26% bagasse (as per dry mass basis) into ethanol with Na₂SO₃ pretreatment and 1% ethanol was obtained from H₂O₂ treated bagasse.

KEYWORDS:

• Bagasse
• pretreatment
• saccharification
• fermentation
• Saccharomyces cerevisiae
• ethanol

Acknowledgement

The authors would like to thank the Ministry of Science and Technology (MoST), Islamabad, Pakistan, for providing the financial support to carry out this research work under PSDP project entitled Production of Bioenergy from Plant Biomass.

Disclosure statement

No potential conflict of interest was reported by the authors.