(2018) Energy_Effects of calcium carbonate on pyrolysis of sewage sludge

Kwon E.E., Lee T., Ok Y.S., Tsang D.C.W., Park C., Lee J.

(Elsevier Ltd) Energy ISSN: 3605442 Vol.153 Issue. Article No. DOI: 10.1016/j.energy.2018.04.100

This study demonstrates that calcium carbonate (CaCO₃) allows not only enhancement of the production of CO as syngas, but also reduction of the content of polycyclic aromatic hydrocarbons (PAHs) in the pyrolytic products from sewage sludge. CO₂ was formed by the decomposition of CaCO₃ in pyrolysis. The CO₂ derived from CaCO₃ enhanced thermal cracking of volatile organic carbons (VOCs) generated during the pyrolysis of sewage sludge and provided an additional source of C and O, likely enhancing the production of CO at 650 °C. In addition, more solid product was converted into gaseous and liquid products by the addition of CaCO₃ in the pyrolysis of sewage sludge. This work suggests that CaCO₃ can be used as an inexpensive source of CO₂ that increases thermal efficiency of the pyrolysis process and reduces the evolution of harmful chemical species such as PAHs during thermal treatment of the byproduct during processing at municipal and industrial wastewater treatment facilities (i.e., sewage sludge). © 2018 Elsevier Ltd

This work was supported by a National Research Foundation of Korea (NRF) Grant funded by the Korean Government (the Ministry of Education) (No. NRF-2016R1D1A1B03933027 ).