1 research outputs found
Life-Cycle Greenhouse Gas and Water Intensity of Cellulosic Biofuel Production Using Cholinium Lysinate Ionic Liquid Pretreatment
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]Â[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]Â[Lys] is used.
Use of a protic IL with comparable performance to [Ch]Â[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