Effects of Mixing Duration on Biogas and Methanogen Distribution in Dairy Manure Digesters
Channel: Livestock & Poultry Environ. Learning Community
Date: 2015-04-30

Full proceedings at: http://www.extension.org/pages/72955 Mixing is an important parameter for anaerobic digesters for both design and operation. This is especially true for digesters that treat diary manure, which is a mixture of feces, urine, blood, food wastes, and bedding. Many of the solids fed to the digester have no or low degradability, and some of the large fibers can clog pumps or pipes in the transfer system. Mixing also plays an important role in maintaining a uniform environment for biological processes. However, the energy input for operating mechanical mixers requires a large part of the total energy for a biogas plant. Previous studies have suggested that optimum biogas production does not require continuous active mixing. It is essential to evaluate the mixing duration in order to balance energy inputs and biogas production rates.