Anaerobic digestion produced biogas is an environmentally friendly, renewable fuel. Before use, it is important to clean or upgrade the gas to increase its heating value and to make it functional in some gas appliances such as engines and boilers.
Biogas includes methane, carbon dioxide, and other trace gases. The production of biogas happens when manure is kept in an anaerobic environment. The produced methane can be utilized right away to create heat or electricity, or go through a cleanup process to create renewable natural gas for the grid or fuel.
- A Technical Reference Guide for Dairy-Derived Biogas Production, Treatment, and Utilization - Tim Shelford, Curt Gooch, Abhinav Choudhury, and Stephanie Lansing, January 2019
- Characterization of Dairy-Derived Biogas and Biogas Processing - Norm Scott, Steven Zicari, Kelly Saikkonen, and Kimberly Bothi, July 2006
Biogas production relies on anaerobic bacteria to transform manure and other organic material into biogas and liquid effluent. There are three stages to the process of biogas production.
Liquefying bacteria convert insoluble, fibrous materials such as carbohydrates, fats, and proteins into soluble substances. Water, some fibrous material, and other inorganic material also can accumulate in the digester or pass through the digester unchanged. Undigested materials make up the low-odor, liquefied effluent.
- Acid Production
Acid-forming bacteria convert the soluble organic matter into volatile acids--the organic acids that can cause odor production from stored liquid manure.
- Biogas Production
Methane-forming bacteria convert those volatile acids into biogas--a gas composed of about 60 percent methane, 40 percent carbon dioxide, and trace amounts of water vapor, hydrogen sulfide, and ammonia. Not all volatile acids and soluble organic compounds are converted to biogas; some become part of the effluent.
- Energy Crops and Residuals
- Methods for Kinetic Analysis of Methane Fermentation in High Solids Biomass Digesters - Brian Richards, Robert Cummings, Thomas White, and William Jewell, 1991
- Biogas Processing and Utilization - Norm Scott, Kim Bothi, Bruce Roloson, 2004
- A Model of Solar Energy Utilization in the Anaerobic Digestion of Cattle Manure - Hamed M. El-mashad, Wilko K.P. Van Loon, and Grietje Zeeman, 2005
- Part 1: Absorption chilling process, types, and comparison to compression chilling
- Part 2: Applications and practical considerations of absorption chilling for dairy farms
- Part 3: Technical feasibility of dairy farm applications of absorption chillers
- Part 4: Economic feasibility of milk cooling with lithium bromide absorption chiller
- Part 1: What are the potential emissions from engine-generation sets?
- Part 2: What are the current emission regulations for New York State?
- Part 3: Greenhouse gas reduction and other benefits of biogas upgrading?
- Part 4: How do operators of engine-generation sets meet applicable emission regulations?
- Obtaining Utility Interconnection of On-site Generation - Curt Gooch (August 2009)
- Feasibility of Fuel Cells for Biogas Energy Conversion on Dairy Farms - Brian Aldrich, Stefan Minott, Norman Scott (2005)
Hydrogen Sulfide Removal from Biogas
- Performance and Economic Results for Two Full-Scale Biotrickling Filters to Remove H2S from Dairy Manure-Derived Biogas - T. J. Shelford, C. A. Gooch, S. A. Lansing, 2019
- Part 1A: Hydrogen sulfide and biogas - Basics - Timothy Shelford and Curt Gooch, 2017
- Part 1B: Measuring hydrogen sulfide - Timothy Shelford and Curt Gooch, 2017
- Part 1C: Available technologies for hydrogen sulfide removal from biogas - Jason Oliver and Curt Gooch, 2016
- Part 1D: Partial budget analysisTimothy Shelford and Curt Gooch, 2017
- Part 1E: Hydrogen sulfide and sulfur emissions - Timothy Shelford and Curt Gooch, 2017
- Part 2A: Microbial underpinnings of hydrogen sulfide biological filtration - Jason Oliver and Curt Gooch, 2016
- Part 2B: Biotrickling filters for hydrogen sulfide - Overview of configuration and design - Jason Oliver and Curt Gooch, 2016
- Part 2C: Biotrickling filters for hydrogen sulfide - Improvement opportunities - Jason Oliver and Curt Gooch, 2016
- Part 3A: Iron sponge basics - Timothy Shelford and Curt Gooch, 2017
- Part 3B: Iron sponge design considerations: vessel sizing - Timothy Shelford and Curt Gooch, 2017
- Part 1: What are the available technologies for biogas desulfurization? - Jason Oliver and Curt Gooch, June 2016
- Part 2: Microbial underpinnings of H2S biological filtration - Jason Oliver and Curt Gooch, June 2016
- Part 3: Biotrickling filters for H2S - Overview of configuration and design - Jason Oliver and Curt Gooch, June 2016
- Part 4: Biotrickling filters for H2S - Process control options - Jason Oliver and Curt Gooch, June 2016