BIOGAS GENERATION FROM ANAEROBIC FERMENTATION OF ANIMAL MANURES AND THE NUTRIENT DYNAMICS IN THE RESIDUES

Biogas technology helps to generate energy from waste treatment, reduce global warming, and earn carbon credits. The biogas residues (BRs), which contain all available plant nutrients, would be good sources of organic fertilizer for crop production. A Chinese fixed dome biogas digester has been successfully adopted in Asian countries recently but not in Thailand. The objectives of this study were to compare biogas generated from domestic animal manures (pig, chicken, and cow) in the Chinese fixed dome digesters and to determine the nutrient dynamics in both biogas liquid residues (BLRs) and biogas solid residues (BSRs). The results showed that from 1000 kg dry matter, the duration of biogas production from pig, chicken, and cow manures was 150, 90, and 90 days, and gas volume was 250, 150, and 70 m 3 with maximum CH4 compositions of 76.1, 79.9, and 62.0%, respectively. Nutrient dynamics were analyzed regularly and it was found that all manures had similar nutrient dynamics but cow manure BLR had a lower N content. Most of the N in all the BRs was in NH 4 + form. NH 4 +