Guiding Optimal Biofuels: A Comparative Analysis of the Biochemical Production of Ethanol and Fatty Acid Ethyl Esters from Switchgrass

Technical Report · Mon Dec 31 23:00:00 EST 2012

DOI:https://doi.org/10.2172/1088082· OSTI ID:1088082

Paap, Scott M. ^[1]; West, Todd H. ^[1]; Manley, Dawn Kataoka ^[1]; Dibble, Dean C. ^[1]; Simmons, Blake Alexander ^[1]; Steen, Eric J. ^[2]; Beller, Harry R. ^[3]; Keasling, Jay D. ^[3]; Chang, Shiyan ^[4]

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1. Sandia National Lab. (SNL-CA), Livermore, CA (United States)
2. Joint BioEnergy Institute (JBEI), Emeryville, CA (United States)
3. Joint BioEnergy Institute (JBEI), Emeryville, CA (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
4. Tsinghua Univ., Beijing (China)

In the current study, processes to produce either ethanol or a representative fatty acid ethyl ester (FAEE) via the fermentation of sugars liberated from lignocellulosic materials pretreated in acid or alkaline environments are analyzed in terms of economic and environmental metrics. Simplified process models are introduced and employed to estimate process performance, and Monte Carlo analyses were carried out to identify key sources of uncertainty and variability. We find that the near-term performance of processes to produce FAEE is significantly worse than that of ethanol production processes for all metrics considered, primarily due to poor fermentation yields and higher electricity demands for aerobic fermentation. In the longer term, the reduced cost and energy requirements of FAEE separation processes will be at least partially offset by inherent limitations in the relevant metabolic pathways that constrain the maximum yield potential of FAEE from biomass-derived sugars.

• Research Organization: Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA); USDOE Laboratory Directed Research and Development (LDRD) Program; USDOE Office of Science (SC), Biological and Environmental Research (BER)
• DOE Contract Number: AC04-94AL85000; AC02-05CH11231
• OSTI ID: 1088082
• Report Number(s): SAND--2013-0208; 452408
• Country of Publication: United States
• Language: English