Harnessing Abuja's Municipal Solid Waste as a Renewable Energy Source: Scanning Electron Microscopy Analysis

Abstract

A study of Abuja’s municipal solid waste (MSW) samples using the scanning electron microscopy analysis was undertaken in this work. In  the face of the severe energy poverty being experienced in Nigeria which largely depends on diminishing fossil fuel resources coupled  with the associated problem of greenhouse gas emission, the energy potential available in municipal solid wastes needs to be  investigated. Using MSW as a fuel source for electric energy production will also positively impact on Abuja’s waste management. This  present study requires the analysis of the MSW with aim of confirming that products of its incineration will not be hazardous to the  environment. ASTM E 1508 procedures for utilizing the scanning electron microscope (SEM) were followed to identify elements that  would be contained in the bottom ash of the incineration process of samples of Abuja’s municipal solid wastes obtained from selected  districts of the city. Elemental composition of the bottom ash that will be formed from incineration of Abuja’s MSW was obtained by the  use of energy dispersive x-ray analysis. The micrographs plotted indicate that silicon and iron are the principal elements present in the  samples with values for silicon and iron being highest at 49.5 and 19.55%, respectively, for the sample from Dutse-Alhaji. The tests also  show the presence of silver in the organic wastes generated in Abuja, while presence of sulphur is very minimal. The silicon levels present  in Abuja’s municipal solid waste compare well with values for Nigerian coals which have percent silicon contents ranging from  39.0 – 49.4% (Enugu coal – 39.0%; Okaba – 44.8%; Maiganga – 49.4%). The test results also show that Abuja’s MSW samples had grain  sizes ranging from 3.5 mm 16 mm. The results indicate Abuja’s MSW combustion rate will be lower than for pulverised coal which is  known to have much lower grain size in the range of 75 μm to 106 μm and will need shredding before firing since grain size is a very  critical determinant factor in solid fuel combustion rate and burn-out time. The tests conclusively show that Abuja’s MSW will be a more  environmentally friendly fuel than coal because of its lower sulphur content.