Abstract
Distilling and purifying ethanol and other products from second generation lignocellulosic biorefineries adds significant capital and operating costs to biofuel production. The energy usage associated with distillation negatively affects plant gate costs and causes environmental and life-cycle impacts, and the lower titers in fermentation caused by lower sugar concentrations from pretreatment and enzymatic hydrolysis increase energy and water usage and ethanol production costs. In addition, lower ethanol titers increase the volumes required for enzymatic hydrolysis and fermentation vessels increase capital expenditure (CAPEX). Therefore, increasing biofuel titers has been a research focus in renewable biofuel production for several decades. In this work, we achieved approximately 230 g L-1 of monomeric sugars after high solid enzymatic hydrolysis using deacetylation and mechanical refining (DMR) processed corn stover substrates produced at the 100 kg per day scale. The high sugar concentrations and low chemical inhibitor concentrations achieved by the DMR process allowed fermentation to ethanol with titers as high as 86 g L-1, which translates into approximately 10.9% v/v ethanol. To our knowledge, this is the first time that titers greater than 10% v/v ethanol in fermentations derived from corn stover without any sugar concentration or purification steps have been reported. The potential cost savings from high sugar and ethanol titers achieved by the DMR process are also reported using TEA analysis.
Original language | American English |
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Pages (from-to) | 1237-1245 |
Number of pages | 9 |
Journal | Energy and Environmental Science |
Volume | 9 |
Issue number | 4 |
DOIs | |
State | Published - Apr 2016 |
Bibliographical note
Publisher Copyright:© 2016 The Royal Society of Chemistry.
NREL Publication Number
- NREL/JA-5100-64078
Keywords
- biofuels
- cellulosic ethanol
- deacetylation and mechanical refining
- pretreatment