Low Cost, Energy Efficient Production of Bio-Methane from Landfill Gas

Abstract

As the world is currently moving fast towards globalization, industrial and technological advancement; sufficient generation and utilization of energy sources have become important issues. Presently, the main energy source is fossil fuel which is non-renewable. However, Renewable energy sources (RES) supply about 14% of the total world energy demand. The aim of this research work is to generate and study the quality of gases produced from municipal solid waste. Landfill simulating vessels, with associated piping, fitting and treatment unit, were to generate the required gas samples for the study. The test rig is intended to receive, treat and convert bio-degradable non-hazardous solid waste into pure bio-methane which is a useful renewable energy resource. The objectives of this study are to;(1) To ensure maintenance of high sanitary standards for the disposal of waste in Niger Delta University and its environs;(2) To develop waste prevention scheme via recycling and conversion of waste into bio-methane;(3) To reduce cost for the disposal of waste. A total of three gas samples were simulated; one gas sample in each of the three vessels and subjected to five different treatment resulting to fifteen gas samples (5 treatment by 3 replication experiment =15 samples) which were collected using 0.5L capacity Swagelok gas bottles and stored in large plastic coolers containing iced blocks so as to retain the quality & composition of gas samples, while in transit to laboratory for analysis. The experimental gas samples were designated as samples; A₁, A₂, A₃, A₄, A₅, B₁, B₂, B₃, B₄, B₅, C₁, C₂, C₃, C₄ and C₅ respectively. Analysis of collected gas samples was carried out at Niger Delta University central Research laboratory with support from Geospectra Engineering services & consultancy laboratory, using gas chromatograph and other hi-tech equipment. Results show that; sample A1 had the highest methane content of 78.87 %. The methane contents got here are higher than those reported in some past researches. For example Polprasert (1996), reported that landfills gas is basically composed of methane (CH₄, 55 to 65%). While, Larry (2011), Reported in his research on landfills gas that he recorded Methane content of between 45 – 60%. Sample A5 had the highest amount of carbon dioxide of 10.53%. While sample C2 yielded the smallest amount of CO₂ of 3.94% out of the 15 gas samples that were used for this experiment. Sample A1 had the lowest moisture content of 0.5 ppm. Sample A1 also yielded the highest Gross heating value of 48.67 KJ/kg and Net heating value of 44.16 KJ/kg. From the findings of this research the following recommendations were made; That the renewable energy solutions got in this research should be commercialized by the Niger Delta University management, the federal government of Nigeria and agencies of government like; Petroleum Technology Development Fund, Tertiary Education Trust fund & Nigeria content Development Board.