One-pot integrated biofuel production using low-cost biocompatible protic ionic liquids. Issue 13 (5th June 2017)

• Record Type: Journal Article
• Authors: Sun, Jian; Konda, N. V. S. N. Murthy; Parthasarathi, Ramakrishnan; Dutta, Tanmoy; Valiev, Marat; Xu, Feng; Simmons, Blake A.; Singh, Seema
• Is Part Of: Green chemistry. Volume 19:Issue 13(2017)
• Page Start: 3152
• Page End: 3163
• Publication Date: 2017-06-05
• Subjects: Environmental chemistry -- Industrial applications -- Periodicals; Environmental management -- Periodicals; 660
• DOI: 10.1039/c7gc01179b
• Languages: English
• ISSNs: 1463-9262

Abstract

Abstract : We present an inexpensive and biocompatible protic ionic liquid that enables one-pot integrated cellulosic ethanol production without any pH adjustments and without water-wash or solid–liquid separations. Abstract : The transformation of biomass into liquid fuels is of great importance. Previous work has demonstrated the capability of specific ionic liquids (ILs), such as 1-ethyl-3-methylimidazolium acetate ([C2 C1 Im][OAc]) and cholinium lysinate ([Ch][Lys]), to be effective biomass pretreatment solvents. Using these ILs for an integrated biomass-to-biofuel configuration is still challenging due to a significant water-wash related to the high toxicity of [C2 C1 Im][OAc] and pH adjustment prior to saccharification for the highly basic [Ch][Lys]. In this work, we demonstrate, for the first time, that a one-pot integrated biofuel production is enabled by a low cost (∼$1 per kg) and biocompatible protic IL (PIL), ethanolamine acetate, without pH adjustments, water-wash and solid–liquid separations. After pretreatment, the whole slurry is directly used for simultaneous saccharification and fermentation (SSF) with commercial enzyme cocktails and wild type yeast strains, generating 70% of the theoretical ethanol yield (based on switchgrass). The structure–performance relationships of PILs in terms of lignin removal, net basicity, and pH value are systematically studied. A technoeconomic analysis (TEA) revealed that an integrated biorefinery concept based on this PIL process could potentially reduce the minimum ethanol selling price by more than 40% compared to scenarios that require pH adjustment prior to SSF. Improvement of the economic performance will be made by reducing the dilution and enzyme loading during SSF as identified by TEA. This study demonstrates the impact of a biocompatible IL in terms of process optimization and conversion efficiency, and opens up avenues for realizing an IL based efficiently integrated biomass conversion technology.