Title: DMR (deacetylation and mechanical refining) processing of corn stover achieves high monomeric sugar concentrations (230 g L^-1) during enzymatic hydrolysis and high ethanol concentrations (>10% v/v) during fermentation without hydrolysate purification or concentration

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. As a result,more » the potential cost savings from high sugar and ethanol titers achieved by the DMR process are also reported using TEA analysis.« less

Authors:

Chen, Xiaowen ^[1]; Kuhn, Erik ^[1]; Jennings, Edward W. ^[1]; Nelson, Robert ^[1]; Tao, Ling ^[1]; Zhang, Min ^[1]; Tucker, Melvin P. ^[1]

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+ Show Author Affiliations

1. National Renewable Energy Lab. (NREL), Golden, CO (United States)

Publication Date:

Fri Apr 01 00:00:00 EDT 2016

Research Org.:

National Renewable Energy Lab. (NREL), Golden, CO (United States)

Sponsoring Org.:

USDOE Office of Energy Efficiency and Renewable Energy (EERE), Sustainable Transportation Office. Bioenergy Technologies Office

OSTI Identifier:

1248075

Report Number(s):

NREL/JA-5100-64078
Journal ID: ISSN 1754-5692

Grant/Contract Number:  

AC36-08GO28308

Resource Type:

Accepted Manuscript

Journal Name:

Energy & Environmental Science

Additional Journal Information:

Journal Volume: 9; Journal Issue: 4; Related Information: Energy and Environmental Science; Journal ID: ISSN 1754-5692

Publisher:

Royal Society of Chemistry

Country of Publication:

United States

Language:

English

Subject:

09 BIOMASS FUELS; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANAYLYTICAL CHEMISTRY; pretreatment; deacetylation and mechanical refining; biofuels; cellulosic ethanol