Comparative Study of Biogas Generation Using Locally Constructed Bioreactor

This research work is focused on the construction of bioreactor for the production of biogas. This is due to the fact that Nigeria is facing energy problem. Biogas generation is an alternative area of research work and an alternative method for waste management. In this research work, two bioreactors were constructed using locally sourced materials and feed them with substrates, they are cow dung and kitchen waste in the ratio 1:2 (i.e. substrate to water) to form slurry. The slurry was transferred into the bioreactors for fermentation to generate biogas. The parameters such as temperature within and outside the bioreactors were observed and recorded weekly, the cumulative volume of biogas generated by each bioreactor were observed and recorded daily. The biogas generated was analyzed using gas chromatography. the result revealed that the average daily temperature in the bioreactors and ambient per day for the first week, for kitchen waste and cow dung and ambient were 32.2240C, 32.2120C, 28.7890C, second week, 32.760C, 32.0720C, 28.4410C,the third week, 30.8820C,31.0360C and 28.6120C and the fourth week,30.0950C, 30.5090C and 28,7440C respectively. It was observed that the biogas analysis using gas chromatography showed that kitchen waste had the gas component as follows CH4, NH3,CO,H2S and CO2, 70.29%, 0.58%, 1.62%, 0.75% and 26.76% whereas cow dung had 68.26%, 0.49%, 1.18%, 0.15% and 29.92% respectively. Daily cumulative volume of biogas generated indicates that the first twenty hours had no gas generated, due to the fact that the organisms are trying to adapt to the new environment. The total volume of biogas generated from cow dung and kitchen waste after twenty eight days of fermentation were 167.4cm3 and 192.7cm3 respectively. It was revealed from this research work that the two subtracts used in this locally constructed bioreactors are excellent materials for biogas generation.