Municipal Dewatered Sewage Sludge for Sustainable Solid Fuel Production

The study concludes that municipal dewatered sewage sludge can be effectively converted into granulated solid fuel when blended with sawmill dust and fly ash in suitable proportions. The research demonstrates a practical waste-to-energy approach that reduces the environmental burden of sewage sludge disposal while producing a usable alternative fuel. The experimental results show that sawmill dust plays a major role in improving the calorific value and volatile matter content of the fuel, whereas fly ash supports stabilisation of the mixture. Among all tested combinations, Mix III was found to be the most suitable composition because it achieved the highest calorific value of 14,431 kJ/kg, lowest moisture content of 34.80%, and comparatively lower ash content of 21.70%. These values indicate that the prepared granulated fuel has potential for co-firing applications in cement plants and energy generation units. The fuel may help reduce fossil fuel dependency and support circular economy practices by converting waste materials into useful energy resources. However, further research is required on combustion behaviour, emission analysis, long-term storage stability, and large-scale industrial application before commercial adoption.  

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