Oduro, et al (2024) Production of sustainable fuel briquettes from the co-carbonization of sewage sludge derived from wastewater treatment and wood shavings as a sustainable solid fuel for heating energy. South African Journal of Chemical Engineering. https://doi.org/10.1016/j.sajce.2024.09.011

This study explores the production of biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More briquettes using co-carbonization of sewage sludge and wood shavings, targeting sustainable and eco-friendly heating energy solutions. By converting sewage sludge, a byproduct of wastewater treatment, into biochar, the research seeks to create a renewable fuel alternative to traditional wood-based charcoalCharcoal is a black, brittle, and porous material produced by heating wood or other organic substances in a low-oxygen environment. It is primarily used as a fuel source for cooking and heating.   More, widely used for cooking in regions like Ghana.

The biochar was produced through a controlled carbonization process at 600°C, with varying ratios of sewage sludge and wood shavings. The best-performing biochar composite (1:1 sludge to wood shavings) showed superior burning characteristics, including a burning rate of 10.51 g/min and lower emission levels of carbon monoxide (59.64 g/kg) and fine particulate matter (PM2.5) (4.76 g/kg), which are within acceptable limits for human health and environmental safety.

The study also assessed the ecological impact, particularly regarding heavy metal content in the residual ashAsh is the non-combustible inorganic residue that remains after organic matter, like wood or biomass, is completely burned. It consists mainly of minerals and is different from biochar, which is produced through incomplete combustion.   Ash Ash is the residue that remains after the complete More. Though the ash contained trace amounts of metals like copper and zinc, the overall potential ecological risk was low, making the fuel safe for disposal and land application.

Furthermore, the energy balance analysis revealed a net energy gain of 2.35 MJ/kg, indicating the process’s efficiency and potential for reducing carbon emissions. The biochar briquettes performed well compared to traditional biomassBiomass is a complex biological organic or non-organic solid product derived from living or recently living organism and available naturally. Various types of wastes such as animal manure, waste paper, sludge and many industrial wastes are also treated as biomass because like natural biomass these More fuels, offering a promising solution for sustainable energy in regions with high wood fuel dependence.