Material Characterization and Substrate Suitability Assessment of Chicken Manure for Dry Batch Anaerobic Digestion Processes

Chicken manure is an agricultural residue material with a high biomass potential. The energetical utilization of this feedstock via anaerobic digestion is an interesting waste treatment option. One waste treatment technology most appropriate for the treatment of stackable (non-free-flowing) dry organic waste materials is the dry batch anaerobic digestion process. The aim of this study was to evaluate the substrate suitability of chicken manure from various sources as feedstock for percolation processes. Chicken manure samples from different housing forms were investigated for their chemical and physical material properties, such as feedstock composition, permeability under compaction and material compressibility. The permeability under compaction of chicken manure ranged from impermeable to sufficiently permeable depending on the type of chicken housing, manure age and bedding material used. Porous materials, such as straw and woodchips, were successfully tested as substrate additives with the ability to enhance material mixture properties to yield superior permeability and allow sufficient percolation. In dry anaerobic batch digestion trials at lab scale, the biogas generation of chicken manure with and without any structure material addition was investigated. Digestion trials were carried out without solid inoculum addition and secondary methanization of volatile components. The specific methane yield of dry chicken manure was measured and found to be 120 to 145 mL/g volatile solids (VS) and 70 to 75 mL/g fresh matter (FM), which represents approximately 70% of the methane potential based on fresh mass of common energy crops, such as corn silage

Effects of Two Manure Additives on Methane Emissions from Dairy Manure

Liquid manure is a significant source of methane (CH4), a greenhouse gas. Many livestock farms use manure additives for practical and agronomic purposes, but the effect on CH4 emissions is unknown. To address this gap, two lab studies were conducted, evaluating the CH4 produced from liquid dairy manure with Penergetic-g® (12 mg/L, 42 mg/L, and 420 mg/L) or AgrimestMix® (30.3 mL/L). In the first study, cellulose produced 378 mL CH4/g volatile solids (VS) at 38 °C and there was no significant difference with Penergetic-g® at 12 mg/L or 42 mg/L. At the same temperature, dairy manure produced 254 mL CH4/g VS and was not significantly different from 42 mg/L Penergetic-g®. In the second lab study, the dairy manure control produced 187 mL CH4/g VS at 37 °C and 164 mL CH4/g VS at 20 °C, and there was no significant difference with AgrimestMix (30.3 mL/L) or Penergetic-g® (420 mg/L) at either temperature. Comparisons of manure composition before and after incubation indicated that the additives had no effect on pH or VS, and small and inconsistent effects on other constituents. Overall, neither additive affected CH4 production in the lab. The results suggest that farms using these additives are likely to have normal CH4 emissions from stored manure