Title:
Comparative Life Cycle Assessment of Pyrolysis and Hydrothermal Carbonization for Sewage Sludge Valorization
Author(s):
Fonseca Castro, S., Gomez, A., Rincón Prat, S.
Document(s):
Paper
Poster
Abstract:
This study presents a life cycle assessment (LCA) of two emerging sewage sludge (SS) thermal treatment technologies—pyrolysis in a rotary kiln (E1) and hydrothermal carbonization (E2)—compared to conventional incineration (E0). The evaluation used experimental data, process simulations in Aspen Plus V10, and literature values for SS from the Salitre WWTP in Bogotá, Colombia. Environmental impacts were quantified across 13 midpoint categories using the ILCD method in EASETECH. E0 shows moderate impacts in most categories, mainly due to emissions from gas cleaning. E1 shows high impacts in eutrophication (freshwater and marine) and non-carcinogenic toxicity due to nutrient release and drying energy. E2 presents the highest impacts in freshwater ecotoxicity, carcinogenic and non-carcinogenic toxicity, associated with the potential mobilization of Zn and Cr in soil applications. However, E2 achieves the lowest impacts in climate change, particulate matter formation, ionizing radiation, and acidification, driven by carbon storage and nutrient recovery. Sensitivity analysis identified sludge composition, process conditions, and fertilizer substitution rate as key drivers. Discernibility analysis shows that E2 performs best in 9 of 13 categories, E1 in 3, and E0 in 1. Hydrothermal carbonization demonstrates the best overall environmental performance, although its application may be limited by heavy metal mobility risks under specific reuse conditions.
Keywords:
pyrolysis, sewage sludge, life cycle assessment (LCA), hydrothermal carbonization
Topic:
Sustainability, Impacts, Policies and Systems Analysis
Subtopic:
Environmental impacts
Event:
33rd European Biomass Conference and Exhibition
Session:
2AV.3.13
Pages:
313 - 316
ISBN:
978-88-89407-25-7
Paper DOI:
10.5071/33rdEUBCE2025-2AV.3.13
Price:
FREE
