Production of biogas from banana and plantain peels.

Abstract

The rising cost of fossil oil, potentially diminishing supplies, attendant pollution problems associated with petroleum and allied products as well as desert encroachment have provided the impetus to consider alternative sources of energy. An investigation was launched to produce biogas from agricultural wastes including banana and plantain peels. The experiment was carried out using a 10-liter laboratory scale anaerobic digester for a period of 35 weeks. The volume of gas generated from banana and plantain peel feedstocks were respectively 8,800 cm and 2,409 cm . However, the highest volume of gas (13,356 cm ) was obtained in the digester 3 3 3 containing equal proportions of banana and plantain peels in combination as feedstocks. The physico-chemistry of respective feedstocks in the digesters revealed an initial drop in pH to acidic range and a steady increase 7.2 – 7.4. The temperature remained relatively constant at mesophilic range: 32 – 35 C throughout the study o period. The C/N ratio was within 26:1.1 and 30:1.2. Population distributions of the microflora show that aerobic and anaerobic bacteria were the active community members although with latter higher than the former. Among the widely distributed are Micrococcus luteus, Bacillus subtilis, Escherichia coli and Clostridium perfringens. Methanogens identified belong to the genera Methanobacterium, Methanococcus and Desulfovibrio. In developing countries and especially in the rural areas where electricity and heat are sparse and biological waste is profuse, the anaerobic digestion process could be the light at the end of the tunnel.