Abstract
Stillage of American whiskey (e.g., bourbon) manufacturing is an abundant byproduct that is distinguished from fuel ethanol and malt whisky stillage materials by its highly inconsistent nature due to variability in mash bill composition. The impact of stillage physicochemical characteristics on biomethane production through anaerobic digestion was assessed by characterizing American whiskey stillage samples before batch biochemical methane potential tests of whole stillage. A maximum methane yield of 419 Nml CH4/g VS was obtained under food to microbe ratio (F: M) of 0.5 and organic loading rate (OLR) of 10 g VS/L while digester instability was noted under F: M ratios exceeding 0.5 under batch production. Methane production was significantly influenced by the mash bill composition with lowest methane yields obtained with higher rye content (rye whiskey) and highest methane yields obtained with higher corn content (bourbon or corn whiskey). A multiple linear regression model including C, P, N, and Na was able to accurately describe the methane yield (R2 = 0.93). This study provides valuable insights to aid the design of anaerobic digesters generating renewable natural gas from heterogeneous American whiskey stillage.
Original language | English |
---|---|
Article number | 121975 |
Journal | Journal of Environmental Management |
Volume | 367 |
DOIs | |
State | Published - Sep 2024 |
Bibliographical note
Publisher Copyright:© 2024
Funding
This work was supported by the National Institute of Food and Agriculture, U.S. Department of Agriculture, Hatch-Multistate project under accession number 1018315.The authors extend their gratitude to Jim Nelson for his assistance with biomass characterization, Zachary Byrd and Ashlyn Lippert for their assistance running the biochemical methane potential tests, and the University of Kentucky Martin-Gatton College of Agriculture, Food and Environment Division of Regulatory Services for material characterization. The authors would lastly like to thank the distilleries that graciously supplied stillage samples for this study.
Funders | Funder number |
---|---|
National Institute of Food and Agriculture | |
University of Kentucky Martin-Gatton College of Agriculture, Food and Environment Division of Regulatory Services | |
U.S. Department of Agriculture | 1018315 |
U.S. Department of Agriculture |
Keywords
- Biochemical methane potential
- Corn
- Distillers' spent grains
- Distillery
- Mash bill
- Rye
ASJC Scopus subject areas
- Environmental Engineering
- Waste Management and Disposal
- Management, Monitoring, Policy and Law