Title: Evaluation of Methane Potential from Swine Slurry with Poultry Litter Amendments Authors
Submitted to: ASABE Annual International Meeting
Publication Type: Proceedings
Publication Acceptance Date: June 18, 2008
Publication Date: June 30, 2008
Citation: Lovanh, N.C., Loughrin, J.H., Ruiz-Aguilar, G., Sistani, K.R. 2008. Evaluation of Methane Potential from Swine Slurry with Poultry Litter Amendments. ASABE Annual International Meeting. Technical Abstract: Millions of tons of animal wastes from livestock operations are generated in the U.S. each year. Animal manure has been traditionally used as natural fertilizer for crop production. However, land application of manure is limited due to problems associated with potential groundwater contamination, air quality, and limited immediate availability of agricultural land. Thus, alternative waste management and treatment are sought. Animal wastes can serve as the feedstock for biogas production (mainly methane) that could be used as alternative energy source. The green energy derived from animal wastes is considered to be carbon neutral and offsetting those generated from fossil fuels. In this study, an evaluation of methane production from swine slurry amended with poultry litter was carried out. Anaerobic batch reactors (250 mL) containing different mixtures of swine and poultry litter (10% by mass) were set up to evaluate methane potential from each scenario. Five scenarios were set up as follows: (1) sterile swine waste and sterile poultry litter; (2) sterile swine waste and non-sterile poultry litter; (3) non-sterile swine waste and sterile poultry litter; (4) non-sterile swine waste and non-sterile poultry litter; and (5) non-sterile swine waste only. Sterilization was carried out by autoclaving and nitrogen gas was used to purge the headspace of the reactors to obtain anaerobic conditions. Biogas production was monitored by photoacoustic gas analyzer and gas chromatography. The results showed that methane production is the greatest when non-sterile swine waste was used (scenarios 3 and 4). Methane production is more than several times greater from reactors with swine waste amended with poultry litter (scenarios 3 and 4) than the ones with swine waste only (scenario 5) and sterile swine waste (scenario 2). There is no methane production in the sterile control (scenario 1). Thus, it appears that poultry litter is necessary to increase methane production from swine waste anaerobic digester. Poultry litter appears to provide an additional substrate and microbes for methanogenesis in an otherwise diluted swine waste for optimum methane production.