Helically agitated mixing in dry dilute acid pretreatment enhances the bioconversion of corn stover into ethanol

Biotechnology for Biofuels

Yanqing He¹  Longping Zhang¹  Jian Zhang¹  Jie Bao¹ 

[1] State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China

关键词: Ethanol;    Corn stover;    Simultaneous saccharification and fermentation (SSF);    CFD modeling;    Helically agitated mixing;    Dry dilute acid pretreatment;   

Others  :  794211
DOI  :  10.1186/1754-6834-7-1

 received in 2013-09-04, accepted in 2013-12-20,  发布年份 2014

【 摘 要 】

Background

Dry dilute acid pretreatment at extremely high solids loading of lignocellulose materials demonstrated promising advantages of no waste water generation, less sugar loss, and low steam consumption while maintaining high hydrolysis yield. However, the routine pretreatment reactor without mixing apparatus was found not suitable for dry pretreatment operation because of poor mixing and mass transfer. In this study, helically agitated mixing was introduced into the dry dilute acid pretreatment of corn stover and its effect on pretreatment efficiency, inhibitor generation, sugar production, and bioconversion efficiency through simultaneous saccharification and ethanol fermentation (SSF) were evaluated.

Results

The overall cellulose conversion taking account of cellulose loss in pretreatment was used to evaluate the efficiency of pretreatment. The two-phase computational fluid dynamics (CFD) model on dry pretreatment was established and applied to analyze the mixing mechanism. The results showed that the pretreatment efficiency was significantly improved and the inhibitor generation was reduced by the helically agitated mixing, compared to the dry pretreatment without mixing: the ethanol titer and yield from cellulose in the SSF reached 56.20 g/L and 69.43% at the 30% solids loading and 15 FPU/DM cellulase dosage, respectively, corresponding to a 26.5% increase in ethanol titer and 17.2% increase in ethanol yield at the same fermentation conditions.

Conclusions

The advantage of helically agitated mixing may provide a prototype of dry dilute acid pretreatment processing for future commercial-scale production of cellulosic ethanol.

【 授权许可】

   
2014 He et al.; licensee BioMed Central Ltd.

【 图 表 】

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