Saccharification and ethanol fermentation from cholinium ionic liquid-pretreated bagasse with a different number of post-pretreatment washings

• Choline acetate (ChOAc) pretreated bagasse as imidazolium ionic liquid (EmimOAc).
• ChOAc showed less inhibitory effect on Ctec2 cellulase and yeast than EmimOAc.
• ChOAc remained less in ionic liquid-pretreated bagasse than EmimOAc.
• ChOAc-pretreated bagasse could be hydrolyzed with fewer wash than the case of EmimOAc.
• ChOAc-pretreated bagasse could be fermented with fewer wash than the case of EmimOAc.

Choline acetate (ChOAc), a cholinium ionic liquid (IL), was compared with 1-ethyl-3-methylimidazolium acetate (EmimOAc) with regard to biomass pretreatment, inhibition on cellulase and yeast, residuals in pretreated biomass, and saccharification and fermentation of pretreated biomass. Irrespective of ChOAc and EmimOAc, cellulose and hemicellulose saccharification of the IL-pretreated bagasse were over 90% and 60%, respectively. Median effective concentrations (EC50) based on cellulase activity were 32 wt% and 16 wt% for ChOAc and EmimOAc, respectively. The EC50 based on yeast growth were 3.1 wt% and 0.3 wt% for ChOAc and EmimOAc respectively. The residuals in IL-pretreated bagasse were 10% and 23% for ChOAc and EmimOAc, respectively, when washed 2 times after pretreatment. Ethanol yield on a bagasse basis were 60% and 24% for ChOAc and EmimOAc, respectively, in the saccharification and fermentation of IL-pretreated bagasse when washed 2 times. ChOAc-pretreated bagasse could be saccharified and fermented with fewer wash times than EmimOAc-pretreated bagasse.

Figure optionsDownload as PowerPoint slide