| Popis: |
In this study, an engineered landfill prototype was designed and constructed as an alternative system for landfill gas production which can offset Nigeria’s increasing demand for energy and dependence on fossil fuels. To design a landfill system for landfill gas production which is the primary aim of this study, Computer Aided Design (CAD) model of 1.2m depth, base area of 1.44m2, top area of 5.06m2, volume of 3.68m3 (3680 litres) with side walls slope of 45o was developed. The modelled design was practically replicated in the field, with the field construction consisting of prepared subgrade, compacted clay, geomembrane liner, geotextile mat, leachate collection system, gas extraction system, landfill cover etc. Food-based organic waste of about 1763kg was measured and deposited in the system prior to closure, and landfill gas evolved after six months of intense chemical reaction and biological degradation within the anaerobically confined system. Raw and purified landfill gas samples of 1kg were collected and analyzed to determine their percentage compositions. CH4, CO2, O2, H2, N2 and H2O (moisture) were the primary constituents in the raw landfill gas. However, CH4 and CO2 were dominant in both samples with 55.40% CH4 and 43.60% CO2 contents in the raw landfill gas and 99.60% CH4 and 0.20% CO2 contents in the purified landfill gas. O2, H2, N2 and H2O in the purified landfill gas were observed in trace quantities. While the raw landfill gas during combustion burned with yellow flame due to impurities, the purified landfill gas was observed to burn with blue flame that was odorless, indicating high concentration of methane gas. |
