Title: Faecal sludge as a solid industrial fuel: a pilot-scale study

Moritz Gold, Daniel Isaac Waya Ddiba, Alsane Seck, Patrick Sekigongo,
Alassane Diene, Serigne Diaw, Seydou Niang, Charles Niwagaba
and Linda Strande

Keywords: co-combustion, fecal sludge management, heavy metals, resource recovery, sanitation, waste-to-energy
Published: 2017
Abstract: Revenues from faecal sludge (FS) treatment end products could offset treatment costs and contribute to fi nancially viable sanitation. In urban sub-Saharan Africa, energy-producing resource recovery has the potential to generate greater revenue than use as soil conditioner. In contrast to wastewater sludge, the technical feasibility of using dried FS as solid fuel in industries has not been investigated. This study evaluated it through characterization of dried FS from drying beds and by assessing the combustion performance in two pilot-scale kilns; in Kampala and Dakar. Results from the fuel characterization demonstrate that dried FS had comparable fuel characteristics as wastewater sludge considering calorifi c value and ash content. The calorifi c values and ash contents were 10.9–13.4 MJ/kg dry matter (DM) and 47.0–58.7%, respectively. Results from pilot-scale experiments suggest that dried FS can be effective in providing energy for industries. Temperatures in pilot-scale kilns fueled by FS were 800 WC, sufficient for curing of clay bricks, and 437 WC, sufficient for waste oil regeneration. In Kampala and Dakar, an estimated 20,000 tons of FS DM per year accumulate. Tapping the industrial fuel market and financial benefits could be realized through optimization of onsite sanitation and treatment technologies.
Published in: Journal of Water, Sanitation and Hygiene for Development, 2017


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Faecal sludge as a solid industrial fuel: a pilot-scale study