Comparative assessment of municipal sewage sludge incineration, gasification and pyrolysis for a sustainable sludge-to-energy management in Greece

•The high output of MSS highlights the need for alternative routes of valorization.•Evaluation of 3 sludge-to-energy valorisation methods through SWOT analysis.•Pyrolysis is an energy and material recovery process resulting to 'zero waste'.•Identification of challenges and barriers for MSS pyrolysis in Greece was investigated.•Adopters of pyrolysis systems face the challenge of finding new product markets.

For a sustainable municipal sewage sludge management, not only the available technology, but also other parameters, such as policy regulations and socio-economic issues should be taken in account. In this study, the current status of both European and Greek Legislation on waste management, with a special insight in municipal sewage sludge, is presented. A SWOT analysis was further developed for comparison of pyrolysis with incineration and gasification and results are presented. Pyrolysis seems to be the optimal thermochemical treatment option compared to incineration and gasification. Sewage sludge pyrolysis is favorable for energy savings, material recovery and high added materials production, providing a 'zero waste' solution. Finally, identification of challenges and barriers for sewage sludge pyrolysis deployment in Greece was investigated.