The aim of this research is to evaluate the co-digestion of cow and llama manure combined with sheep manure, in psychrophilic conditions and real field low cost tubular digesters adapted to cold climate. Four digesters were monitored in cold climate conditions; one fed with cow manure, a second one with llama manure, the third one with co-digestion of cow-sheep manure and the fourth one was fed with llama-sheep manure. The slurry had a mean temperature of 16.6°C, the organic load rate was 0.44kgvsm-3d-1 and the hydraulic retention time was 80days. After one hundred days biogas production was stable, as was the methane content and the pH of the effluent. The co-digestion of cow-sheep manure results in a biogas production increase of 100% compared to the mono-digestion of cow manure, while co-digestion of llama-sheep manure results in a decrease of 50% in biogas production with respect to mono-digestion of llama manure.
Bibliographical noteFunding Information:
Financial support to carry out this research was provided by Hivos and the Endev-Bolivia Program of the GIZ , as well as the collaboration of the Caribbean and Latin American Biodigesters Net (RedBioLAC). Jaime Martí-Herrero is thankful to the Prometeo Project of the Secretariat for Higher Education, Science, Technology and Innovation of the Republic of Ecuador that funded part of his work. The authors wish to acknowledge the revision of the document by Mike Baker and Samay Schütt.
© 2015 Elsevier Ltd.
- Anaerobic digestion
- Low temperature