Low Temperature and Long Residence Time AFEX Pretreatment of Corn Stover
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Low temperature and long residence time pretreatments have been proposed as an alternative to conventional pretreatments within a centralized biorefinery, allowing for a decentralized pretreatment without high energy costs. Ammonia fiber expansion (AFEX™) pretreatment may be uniquely suitable for decentralized pretreatment, and this study considers the possibility of decreasing the temperature in AFEX pretreatment of corn stover. AFEX pretreatment at 40°C and 8 h produced comparable sugar and ethanol yields as conventional AFEX pretreatment at high temperatures and short residence time during subsequent hydrolysis and fermentation. Increasing the ammonia loading at these temperatures tends to increase digestibility, although the moisture content of the reaction has little effect. This study suggests a greater flexibility in AFEX pretreatment conditions than previously thought, allowing for an alternative approach for decentralized facilities if the economic conditions are appropriate.
KeywordsAFEX Biofuel Corn stover Pretreatment Ammonia Regional processing
Ammonia fiber expansion
National Renewable Energy Laboratory
Low temperature/long residence time
This project was funded in part by the Michigan Agricultural Experiment Station. Additional funding was provided by DOE Great Lakes Bioenergy Research Center (www.greatlakesbioenergy.org) supported by the US Department of Energy, Office of Science, Office of Biological and Environmental Research, through Cooperative Agreement DEFC02-07ER64494. AFEX is a trademark of MBI International. The corn stover used in this project was provided by the National Renewable Energy Laboratory, and the Spezyme CP, Multifect Xylanase, and Multifect Pectinase were donated by Genencor International. We would like to thank Christa Gunawan and Heather Hodge for providing the HPLC analysis, as well as Janette Moore for her help in performing enzymatic hydrolysis.
- 4.Carolan JE, Joshi SV, Dale BE (2007) Technical and financial feasibility analysis of distributed bioprocessing using regional biomass pre-processing centers. J Agric Food Ind Org 5:10Google Scholar
- 7.Garlock RJ, Balan V, Dale BE, Pallapolu VR, Lee YY et al (2011) Comparative material balances around pretreatment technologies for the conversion of switchgrass to soluble sugars. Bioresour Technol. doi: 10.1016/j.biortech.2011.04.002
- 13.Leboreiro J, Hilaly AK (2010) Biomass transportation model and optimum plant size for the production of ethanol. Bioresour Technol. doi: 10.1016/j.biortech.2010.10.144
- 16.Selig M, Weiss N, Ji Y (2008) Enzymatic saccharification of lignocellulosic biomass. US Dept of Energy Technical Report NREL/TP-510-42629Google Scholar
- 17.Sluiter A, Hames B, Ruiz R, Scarlata C, Sluiter J, Templeton D (2006) Determination of sugars, byproducts, and degradation products in liquid fraction process samples. US Dept of Energy Technical Report NREL/TP-510-42623Google Scholar
- 18.Sluiter A, Hames B, Ruiz R, Scarlata C, Sluiter J, Templeton D et al (2008) Determination of structural carbohydrates and lignin in biomass. US Dept of Energy Technical Report NREL/TP-510-42618Google Scholar