|Cole, Noel - Andy|
Submitted to: ASABE Annual International Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 4/1/2002
Publication Date: 7/28/2002
Citation: Parker, D.B., Williams, D.L., Cole, N.A., Auvermann, B.W., Rogers, W.J. 2002. Dry nonheated anaerobic biogas fermentation using aged beef cattle manure. In: Proceedings of ASABE Annual International Meeting, July 28-31, 2002, Chicago, Illinois. Paper No. 024142. Interpretive Summary:
Technical Abstract: Biogas production at beef cattle feedlots is hard to justify because of the large amounts of dilution water required and the high cost to design and operate conventional water-based digestion systems. Laboratory and field experiments were conducted to determine the feasibility of producing biogas using "dry" aged beef cattle manure scraped from open-lot feedyards. Biogas production rates were measured at 21°C in the laboratory at four total solids contents using a water displacement technique. Biogas yields were 0.180, 0.210, 0.190 and 0.005 L per gram volatile solids (VS) at solids contents of 20, 30, 40 and 50%, respectively. Biogas was produced steadily for 300 days before declining and eventually ceasing after 450 days. The biogas contained 52 to 60% methane. A field demonstration project was conducted to produce biogas using geomembrane-lined digesters. Two 90 m**3 digesters excavated in native soil to a depth of 1.8 m were lined on top and bottom with ethylene propylene diene monomer (EPDM) geomembranes. Digester 1 was loaded with manure (solids content 40%) in February, 1999. Biogas was produced during the first summer for 12 weeks beginning August 1, 1999, and during the second summer for 13 weeks beginning July 14, 2000. Digester 1 produced 1,510 m**3 of biogas the first summer and 920 m**3 the second summer, with a typical methane concentration of 52%. Total biogas yield over the two summers was 0.16 L/g VS in digester 1. Digester 2 was loaded with manure (solids content 50%) in January, 2000, and produced less than 5 m**3 of biogas. This research demonstrates that biogas can be produced in below-ground digesters using aged beef cattle manure if the solids content is less than or equal to 40 percent. Year-round biogas production may not be feasible unless the digesters are heated or insulated.