Transforming Fecal Sludge into an Affordable Biofuel Alternative: A Sustainable Solution for Developing Countries

Abstract

Developing countries are facing challenges due to rapid urbanization and insufficient sanitation facilities. However, valorizing treated fecal sludge as a fuel source presents an opportunity to recover energy and mitigate environmental impacts. This experimental study aimed to produce low-cost biofuel from dried fecal sludge and enhance its energy efficiency by incorporating locally available organic matters. Various organic materials like rice husk, cow dung, sawdust, and coal were carbonized and mixed with the sludge to enhance calorific value. Eight sludge and organic matter mixtures were formed into briquettes. The blend of 50% sludge and 50% coal yielded the highest calorific value of 14618 KJ/kg and a boiling time of 14 minutes. The second-highest result was for 50% sludge and 50% cow dung, with a calorific value of 14427 KJ/kg and a boiling time of 23 minutes. The study found that blending sludge with organic materials enhances energy output. Briquettes with 50% sludge and 50% coal cost 19.87 BDT/kg, while those with 50% sludge and 50% cow dung cost 14.37 BDT/kg, proving more economical. The latter blend emerged as the most efficient and cost-effective biofuel, offering a sustainable eco-friendly solution for Bangladesh's rural energy market.