Electricity Generation by Using Water Hyacinth

Water hyacinth, E. crassipes, an invasive water weed thrives in fresh water bodies, causing serious environmental problems. Currently, the weed is harvested from the Lake and left in the open to rot and decay leading to loss of aesthetics, land and air pollution. There is therefore need for development of value addition and economic exploitation strategies. The aim of the study is to assess the potential for utilization of the weed as a renewable energy resource for biogas production. Samples were collected from Lake Victoria, pulped and blend with cow dung at a ratio of 3:1 as inoculum. The resultant mixture was mixed with water at a ratio of 1:1 and fed into a 6 m3 tubular digester. The digester was recharged with 20 kg after every three days. The temperature, pH variations, gas compositions, upgrading and gas yields were studied. The temperature ranged between 22.8 C - 36.6 C and pH 7.4 - 8.5. Biogas was found to contain 49% - 53% methane (CH4), 30% - 33% carbon dioxide (CO2), 5% - 6% nitrogen (N2) and traces of hydrogen sulfide (H2S).