(2020) Journal of Hazardous Materials_Use of steel slag as a catalyst in CO₂-cofeeding pyrolysis of pine sawdust

Lee S., Kim S.-H., Jung S., Park Y.-K., Tsang Y.F., Kwon E.E.

(Elsevier B.V.) Journal of Hazardous Materials ISSN: 3043894 Vol.392 Issue. Article No.122275 DOI: 10.1016/j.jhazmat.2020.122275

To seek an innovative way for simultaneous waste management and energy recovery, two waste materials (pine sawdust: PSD and steel slag: SS) were used in the pyrolysis process. PSD was used as a carbonaceous material for pyrolysis, and SS was used as a catalyst. Also, to achieve a more sustainable conversion system, a viable use of carbon dioxide (CO₂) as a raw material in the non-catalytic/catalytic pyrolysis process was evaluated. Hence, the present study laid great stress on the CO₂ effects. The present study pointed the optimistic technical features in line with the use of CO₂ in the pyrolysis process. Exploiting CO₂ in pyrolysis of PSD offered a strategic way to control carbon reallocation from liquid to gaseous pyrolysates by the gas phase reactions (GPRs). The reactions of CO₂ and volatile pyrolysates led to CO enhancement, which was only observed at ≥ 600 °C due to the slow reaction kinetics of the GPRs of volatile pyrolysates and CO₂. Such the slow reaction kinetics was expedited remarkably when SS was acted as a catalyst. Moreover, CO₂ expedited thermal cracking of volatile pyrolysates including dehydrogenation, which led to the enhanced formation of CH₄ and H₂. © 2020 Elsevier B.V.

This study was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea Government (MSIT) (No. NRF-2017R1D1A1B03028176 ).