Agricultural and Biosystems Engineering Publications
Campus Units
Agricultural and Biosystems Engineering
Document Type
Article
Publication Version
Published Version
Publication Date
2010
Journal or Book Title
Transactions of the ASABE
Volume
53
Issue
6
First Page
1921
Last Page
1927
DOI
10.13031/2013.35791
Abstract
This article presents the biochemical methane potential (BMP) results from the anaerobic digestion (AD) of switchgrass. Triplicate BMP assays were performed on: untreated switchgrass, aqueous ammonia soaking (AAS) pretreated switchgrass (soaked in 29.5% reagent-grade aqueous ammonia at 5 L kg-1 switchgrass for 5 d), and AAS-pretreated switchgrass plus cellulytic enzymes at 12.5, 25, 62.5, and 125 filter paper units (FPU) enzyme g-1 volatile solids (VS). Biogas production and biogas methane content were measured daily in all treatments for 21 d. Both biogas and corrected methane production varied significantly among treatments, especially during the first 7 d of the BMP period. Total methane production at 21 d was corrected for enzyme degradation, and methane yields ranged from 0.15 to 0.36 m3 CH4 kg-1 VS. We compared the corrected energy yield of biogas from switchgrass to prior reports of the energy yield of ethanol from switchgrass via simultaneous saccharification and fermentation (SSF). The AD of AAS-pretreated switchgrass at the highest enzyme loading rates resulted in a 120% increase in energy extracted as compared to AAS-pretreated switchgrass converted to ethanol via SSF. Overall, the addition of enzymes to AAS-pretreated switchgrass greatly accelerated the rate of methane production over the untreated switchgrass and AAS-pretreated switchgrass without enzymes. However, the process economics are not clear, and additional work is needed to determine whether pretreating switchgrass with aqueous ammonia and/or enzymes before AD is economically advantageous.
Access
Open
Copyright Owner
American Society of Agricultural and Biological Engineers
Copyright Date
2010
Language
en
File Format
application/pdf
Recommended Citation
Himmelsbach, Jennifer Nicole; Raman, D. Raj; Anex, Robert P.; Burns, Robert T.; and Faulhaber, Carol Rose, "Effect of Ammonia Soaking Pretreatment and Enzyme Addition on Biochemical Methane Potential of Switchgrass" (2010). Agricultural and Biosystems Engineering Publications. 55.
https://lib.dr.iastate.edu/abe_eng_pubs/55
Comments
This article is from Transactions of the ASABE, 53, no. 6 (2010): 1921–1927.