Design and Construction of an Energy Specific Landfill Gas Production System for use in Nigeria

Abstract

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.