Research Information System
FUEL, vol.413, 2026 (SCI-Expanded, Scopus)
Hazardous sludge generated from various industrial, agricultural and municipal activities poses serious environmental challenges due to its heavy metal content, complex composition and processing difficulties. Pyrolysis is a promising solution for converting sludge into valuable energy products. The review covers a wide range of sludge types, including sewage sludge, industrial sludge, and textile sludge for analyzing their pyrolysis behaviour, product yields, and energy recovery potential. Fundamental principles of sludge pyrolysis, including process parameters such as temperature, heating rate and residence time were discussed in detail, along with their influence on the pyrolysis performance and product composition. The review also highlights the importance of process optimization, including the catalysts usage, innovative reactor designs to mitigate the challenges to enhance the overall efficiency and sustainability of sludge pyrolysis. Due to inherently low organic content of sludge, its pyrolysis typically requires high activation energy. This limitation can be effectively mitigated through use of catalytic additives or by implementing co-pyrolysis with complementary feedstocks. Elevated oxygen levels in sludge adversely affect the quality of pyrolysis products by promoting the formation of oxygenated compounds and reducing energy density. However, the incorporation of metal oxide catalysts significantly enhances product quality by facilitating deoxygenation and improving conversion efficiency. Despite certain drawbacks in product distribution and energy yield, pyrolysis remains a viable and environmentally sound strategy for the treatment and disposal of hazardous sludge waste. Its ability to adapt to different feedstock compositions and its potential for resource recovery make it a key player in sustainable waste management frameworks.