2024/10/08 by Gamta Sagni, Mulissa Jida, Girmaye Kenasa
Engineering · Environmental Science · Medicine · #Anaerobic Digestion and Biogas Production #Biogas #Coffee research and impacts #Municipal Solid Waste Management #coffee husk #cow dung #fermentation #poultry manure
paper · doi:10.20372/star.v13.i3.05
openalex publication_date 2024/10/08 · openalex created_date 2025/11/18 · openalex updated_date 2026/07/01
Coffee is one of the important cash crops globally, consumed with various food products and beverages. Dry coffee processing generates husk as solid waste, often disposed-off untreated in surrounding areas. This experiment is to assess the potential of coffee husk for biogas production when anaerobically co-digested with poultry manure or cow dung. Nine treatment mixtures of coffee husk, poultry manure, and cow dung were evaluated in batch-type anaerobic digesters over 30 days under mesophilic conditions (38°C). Physico-chemical characteristics of the feedstock before and after the digestion were analyzed using standard procedures. Biogas production was monitored for 30 days, revealing significant variations among treatments. The highest cumulative biogas yield was observed in the co-digestion of coffee husk and cow dung in a 1:1 ratio, followed by coffee husk and poultry manure in a 1:1 ratio, with the lowest yield from 100% poultry manure. Additionally, the 1:1 ratio of coffee husk and cow dung exhibited the highest reduction in total solids, volatile solids, and organic carbon. These findings suggest that anaerobic co-digestion of coffee husk and cow dung in equal proportions is optimal for biogas production and warrants further investigation at a pilot scale.