Techno-economic Analysis for the Thermochemical Conversion of Lignocellulosic Biomass to Ethanol via Acetic Acid Synthesis

Technical Report · Wed Apr 01 04:00:00 EDT 2009

DOI:https://doi.org/10.2172/962851· OSTI ID:962851

Zhu, Yunhua; Jones, Susanne B

Biomass is a renewable energy resource that can be converted into liquid fuel suitable for transportation applications. As a widely available biomass form, lignocellulosic biomass can have a major impact on domestic transportation fuel supplies and thus help meet the Energy Independence and Security Act renewable energy goals (U.S. Congress 2007). This study performs a techno-economic analysis of the thermo chemical conversion of biomass to ethanol, through methanol and acetic acid, followed by hydrogenation of acetic acid to ethanol. The conversion of syngas to methanol and methanol to acetic acid are well-proven technologies with high conversions and yields. This study was undertaken to determine if this highly selective route to ethanol could provide an already established economically attractive route to ethanol. The feedstock was assumed to be wood chips at 2000 metric ton/day (dry basis). Two types of gasification technologies were evaluated: an indirectly-heated gasifier and a directly-heated oxygen-blown gasifier. Process models were developed and a cost analysis was performed. The carbon monoxide used for acetic acid synthesis from methanol and the hydrogen used for hydrogenation were assumed to be purchased and not derived from the gasifier. Analysis results show that ethanol selling prices are estimated to be $2.79/gallon and $2.81/gallon for the indirectly-heated gasifier and the directly-heated gasifier systems, respectively (1stQ 2008$, 10% ROI). These costs are above the ethanol market price for during the same time period ($1.50 - $2.50/gal). The co-production of acetic acid greatly improves the process economics as shown in the figure below. Here, 20% of the acetic acid is diverted from ethanol production and assumed to be sold as a co-product at the prevailing market prices ($0.40 - $0.60/lb acetic acid), resulting in competitive ethanol production costs.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 962851
• Report Number(s): PNNL-18483; BM0101010
• Country of Publication: United States
• Language: English

Related Subjects

08 HYDROGEN
09 BIOMASS FUELS
10 SYNTHETIC FUELS
ACETIC ACID
BIOMASS
Biomass
CARBON MONOXIDE
ECONOMICS
ETHANOL
FUEL SUPPLIES
GASIFICATION
HYDROGEN
HYDROGENATION
LIQUID FUELS
MARKET
METHANOL
METRICS
PRICES
SECURITY
SYNTHESIS
WOOD
acetic acid
economics
ethanol
gasification
hydrogenation