Abstract
Temperature is a critical factor affecting anaerobic digestion because it influences both system heating requirements and methane production. Temperatures of 35-37°C are typically suggested for manure digestion. In temperate climates, digesters require a considerable amount of additional heat energy to maintain temperatures at these levels. In this study, the effects of lower digestion temperatures (22 and 28°C), on the methane production from dairy digesters were evaluated and compared with 35°C using duplicate replicates of field-scale (FS) digesters with a 17-day hydraulic retention time. After acclimation, the FS digesters were operated for 12weeks using solids-separated manure at an organic loading rate (OLR) of 1.4kgVSm-3d-1 and then for 8weeks using separated manure amended with manure solids at an OLR of 2.6kgVSm-3d-1. Methane production values of the FS digesters at 22 and 28°C were about 70% and 87%, respectively, of the values from FS digesters at 35°C. The results suggest that anaerobic digesters treating dairy manure at 28°C were nearly as efficient as digesters operated at 35°C, with 70% of total methane achievable at 22°C. These results are relevant to small farms interested in anaerobic digestion for methane reduction without heat recovery from generators or for methane recovery from covered lagoon digesters.
Original language | English |
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Pages (from-to) | 108-113 |
Number of pages | 6 |
Journal | Waste Management |
Volume | 43 |
DOIs | |
Publication status | Published - 1 Sept 2015 |
Bibliographical note
Publisher Copyright:© 2015 Elsevier Ltd.
Keywords
- Anaerobic digestion
- Dairy manure
- Methane
- Psychrophilic
- Temperature