Biogas from Different Parts of a Banana Plant: A Case Study of the Banana Plant from Kisii County

Abstract

Bananas are the main source of stable food among the Kisii people in Kenya. Apart from the banana fruit, the other parts are usually thrown to waste although can be used in a useful manner like to generate biogas. This research sought to investigate biogas production potential from different parts of a banana plant in Kisii County, Kenya. In the study, 2 kg of banana leaves, pseudo-stem, fruit bunch stalk (FBS) and peels were collected as feed-stocks for a laboratory-scale anaerobic digester to produce biogas. The experiment was carried out in a multi-stage anaerobic digestion system operated under mesophilic temperature (30-35°C). Various process parameters were measured including total solid, volatile solid and volume of biogas produced. After completion of 21-day digestion at an average temperature of 33°C, specific Biogas yields reached were about 16.5 litres/kg (leaves), 13.5 litres/kg (pseudo-stem), 12.7 litres/kg (fruit bunch stalk) and 15.1 litres/kg (peels). The optimum daily production of biogas was between the 13th-15th day. Cumulatively, it was observed that after the 15th day, almost all of the biogas had been released from the digester. By doing a simple computation based on energy calculation, it was found that 61% of the energy expected from a similar quantity by other researchers. The study showed that banana leaves have highest potential for biogas as compared to the other parts.