Life-Cycle Greenhouse Gas and Water Intensity of Cellulosic Biofuel Production Using Cholinium Lysinate Ionic Liquid Pretreatment

TitleLife-Cycle Greenhouse Gas and Water Intensity of Cellulosic Biofuel Production Using Cholinium Lysinate Ionic Liquid Pretreatment
Publication TypeJournal Article
Year of Publication2017
AuthorsBinod Neupane, N. V. S. N. Murthy Konda, Seema Singh, Blake A. Simmons, Corinne Scown
JournalACS Sustainable Chemistry & Engineering
Date PublishedMay-09-2019
ISSN2168-0485
KeywordsBiomass pretreatment, Cholinium lysinate, Ionic liquid, life-cycle assessment, Water intensity
Abstract

Cellulosic biofuels present an opportunity to meet a significant fraction of liquid transportation fuel demand with renewable, low-carbon alternatives. Certain ionic liquids (ILs) have proven effective at facilitating hydrolysis of lignocellulose to produce fermentable sugars with high yields. Although their negligible vapor pressure and low flammability make ILs attractive solvents at the point of use, their life-cycle environmental impacts have not been investigated in the context of cellulosic biorefineries. This study provides the first life-cycle greenhouse gas (GHG) and water use inventory for biofuels produced using IL pretreatment. We explore two corn stover-to-ethanol process configurations: the conventional water-wash (WW) route and the more recently developed integrated high gravity (iHG) route, which eliminates washing steps after pretreatment. Our results are based on the use of a representative IL, cholinium lysinate ([Ch][Lys]). We find that the WW process results in unacceptably high GHG emissions. The iHG process has the potential to reduce GHG emissions per megajoule of fuel by ∼45% relative to gasoline if [Ch][Lys] is used. Use of a protic IL with comparable performance to [Ch][Lys] could achieve GHG reductions up to 70–85%. The water intensities of the WW and iHG processes are both comparable to those of other cellulosic biofuel technologies.

DOI10.1021/acssuschemeng.7b02116
Short TitleACS Sustainable Chem. Eng.