Title: Ternary ionic liquid–water pretreatment systems of an agave bagasse and municipal solid waste blend

Abstract

Pretreatment is necessary to reduce biomass recalcitrance and enhance the efficiency of enzymatic saccharification for biofuel production. Ionic liquid (IL) pretreatment has gained a significant interest as a pretreatment process that can reduce cellulose crystallinity and remove lignin, key factors that govern enzyme accessibility. There are several challenges that need to be addressed for IL pretreatment to become viable for commercialization, including IL cost and recyclability. In addition, it is unclear whether ILs can maintain process performance when utilizing low-cost, low-quality biomass feedstocks such as the paper fraction of municipal solid waste (MSW), which are readily available in high quantities. One approach to potentially reduce IL cost is to use a blend of ILs at different concentrations in aqueous mixtures. Herein, we describe 14 IL-water systems with mixtures of 1-ethyl-3-ethylimidazolium acetate ([C 2 C 1 Im][OAc] ), 1-butyl-3-ethylimidazolium acetate ([C 4 C 1 Im][OAc] ), and water that were used to pretreat MSW blended with agave bagasse (AGB). The detailed analysis of IL recycling in terms of sugar yields of pretreated biomass and IL stability was examined. Results: Both biomass types (AGB and MSW) were efficiently disrupted by IL pretreatment. The pretreatment efficiency of [C 2 C 1 Im][OAc] andmore » [C 4 C 1 Im][OAc] decreased when mixed with water above 40%. The AGB/MSW (1:1) blend demonstrated a glucan conversion of 94.1 and 83.0% using IL systems with ~10 and ~40% water content, respectively. Chemical structures of fresh ILs and recycle ILs presented strong similarities observed by FTIR and 1 H-NMR spectroscopy. The glucan and xylan hydrolysis yields obtained from recycled IL exhibited a slight decrease in pretreatment efficiency (less than 10% in terms of hydrolysis yields compared to that of fresh IL), and a decrease in cellulose crystallinity was observed. Conclusions: Our results demonstrated that mixing ILs such as [C 2 C 1 Im][OAc] and [C 4 C 1 Im][OAc] and blending the paper fraction of MSW with agricultural residues, such as AGB, may contribute to lower the production costs while maintaining high sugar yields. Recycled IL-water mixtures provided comparable results to that of fresh ILs. Both of these results offer the potential of reducing the production costs of sugars and biofuels at biorefineries as compared to more conventional IL conversion technologies. Graphical abstract Schematic of ionic liquid (IL) pretreatment of agave bagasse (AB) and paper-rich fraction of municipal solid waste (MSW).« less

Authors:

Perez-Pimienta, Jose A.; Sathitsuksanoh, Noppadon; Thompson, Vicki S.; Tran, Kim; Ponce-Noyola, Teresa; Stavila, Vitalie; Singh, Seema; Simmons, Blake A.

Publication Date:

Tue Mar 21 00:00:00 EDT 2017

Research Org.:

Idaho National Laboratory (INL), Idaho Falls, ID (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Biological and Environmental Research (BER)

OSTI Identifier:

1618673

Alternate Identifier(s):

OSTI ID: 1357758; OSTI ID: 1409430

Report Number(s):

INL/JOU-16-39088
Journal ID: ISSN 1754-6834; 72; PII: 758

Grant/Contract Number:  

AC02-05CH11231; AC07-05ID14517

Resource Type:

Published Article

Journal Name:

Biotechnology for Biofuels

Additional Journal Information:

Journal Name: Biotechnology for Biofuels Journal Volume: 10 Journal Issue: 1; Journal ID: ISSN 1754-6834

Publisher:

Springer Science + Business Media

Country of Publication:

Netherlands

Language:

English

Subject:

09 BIOMASS FUELS; agave biomass; biomass blend; biomass pretreatment; IL recycling; ionic liquid; municipal solid waste; ternary system; 12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES