Enhancing renewable energy production from water hyacinth (Eichhornia crassipes) by a biogas-aerating recirculation system: A case study in the Vietnamese Mekong Delta

The study aims to examine biogas-aerating recirculation on biomethanation in a farm-scale digester with water hyacinth substrate. The experiment was conducted with the difference in biogas-aerating times and frequencies. Methane yield considerably improved by 27.44–52.12%, 50.19–62.30% and 63.11−71.46% for aerating biogas from 15 to 60 minutes at once, twice and four-time d−1, respectively. Maximum biogas yields were estimated for biogas-aerating at once, twice, and four daily repetitions at 47.8, 78.0, and 145 minutes. Biogas-aerating 30 minutes at twice d−1 and 15–60 minutes at four-time d−1 displayed great potential for biogas production augmentation.