Economic analysis of cellulosic ethanol production from sugarcane bagasse using a sequential deacetylation, hot water and disk-refining pretreatment

Authors: CHENG, MING-HSUN - University Of Illinois; WANG, ZHAOQIN - University Of Illinois; Dien, Bruce; Slininger, Patricia - Pat; SINGH, VIJAY - University Of Illinois

Submitted to: Processes
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/17/2019
Publication Date: 9/20/2019
Citation: Cheng, M., Wang, Z., Dien, B.S., Slininger, P.J., Singh, V. 2019. Economic analysis of cellulosic ethanol production from sugarcane bagasse using a sequential deacetylation, hot water and disk-refining pretreatment. Processes. 7(10): 1-15. https://doi.org/10.3390/pr7100642.
DOI: https://doi.org/10.3390/pr7100642

Interpretive Summary: This paper is the final in a series that reports on the development of a novel pretreatment process for production of cellulosic sugars that combines hot-water and disc refining. This method affords high sugar yields without the need of an external catalyst. The former paper reported on process conditions and sugar yields. These results are used to model a full-scale commercial process and based upon this model to estimate the minimum ethanol selling price. The model is also used to examine the sensitivity of production cost to various process conditions. A notable result is that the use of higher solids during hydrolysis and fermentation reduces overall cost. Producing enzymes onsite also served to lower the cost. This paper will be of interest to processors of agricultural crops and manufacturers interested in producing advanced biofuels.

Technical Abstract: A new process for conversion of sugarcane bagasse to ethanol was analyzed for production costs and energy consumption using experimental results. The process includes a sequential three-stage deacetylation, hot water, and disk refining pretreatment and commercial glucose-xylose fermenting S. cerevisiae strain. The simultaneous saccharification and co-fermentation (SScF) step used was investigated at two solids loadings: 10% and 16% w/w. Additionally, a sensitivity analysis was conducted for the major operating parameters. The minimum ethanol selling price (MESP) varied between $4.91and $4.52/gal ethanol. The higher SScF solids loading (16%) reduced the total operating, utilities, and production costs by 9.5%, 15.6%, and 5.6%, respectively. Other important factors in determining selling price were costs for fermentation medium and enzymes (e.g. cellulases). Hence, these findings support operating at high solids and producing enzymes onsite as strategies to minimize MESP.