Delignification of cotton stalks using sodium cumene sulfonate for bioethanol production

ABSTRACT

The objective of this study was to evaluate the effect of hydrotropic delignification of cotton stalk on sugar release performance for bioethanol production. In this study, different alkyl benzene sulfonates were screened to select the best pretreatment agent, and the effectiveness of pretreatment was evaluated by enzymatic saccharification. Sodium cumene sulfonate was found to be the best hydrotropic agent in terms of reducing sugar yield. Parameters such as hydrotrope concentration, biomass loading and incubation time were optimized by adopting a central composite design. Under optimized pretreatment conditions, 0.211 g reducing sugar/g of dry biomass was obtained. Reusability of aqueous hydrotrope solution was also demonstrated.

HIGHLIGHTS*/*

• Hydrotropic delignification using alkyl benzene sulfonates was studied on cotton stalk.

• Total reducing sugar was fairly enhanced after hydrotropic pretreatment using sodium cumene sulfonate.

• Hydrotrope solution of sodium cumene sulfonate can be efficiently reused for five cycles.

• This is the first report on hydrotropic delignification of cotton stalk by statistical optimization for the efficient release of reducing sugars by enzymatic hydrolysis.

KEYWORDS:

• Cotton stalk
• delignification
• sodium cumene sulfonate
• lignin
• hydrotrope

Acknowledgements

LPD acknowledges the Department of Science and Technology (DST-SERB), Government of India, for a financial grant under the young scientist scheme (SB/YS/LS-349/2013). The authors also acknowledge Dr. Anil Mathew and Mr. Salman M. for analytical support.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Science and Engineering Research Board [grant number SB/YS/LS-349/2013].