(2018) Journal of CO₂ Utilization_Enhanced accessibility of carbon in pyrolysis of brown coal using carbon dioxide

Choi D., Kim H., Lee S.S., Nam I.-H., Lee J., Kim K.-H., Kwon E.E.

(Elsevier Ltd) Journal of CO₂ Utilization ISSN: 22129820 Vol.27 Issue. Article No. DOI: 10.1016/j.jcou.2018.08.022

This work investigates the effect of CO₂ in pyrolysis of brown coal (also referred to as lignite). CO₂ changes the distribution of pyrolytic products of brown coal. More CO is generated for the pyrolysis of brown coal in CO₂ than that in N₂. Differential scanning calorimeter (DSC) experiments show that the pyrolysis of brown coal in CO₂ is more exothermic than that in N₂. This may indicate that the enhanced generation of CO is attributed to an enhanced thermal cracking induced by CO₂. The more generation of CO for the reaction in CO₂ (4.2 mol.% at 700 °C) than in N₂ (0.5 mol.% at 700 °C) is a result of shifting carbon distribution from condensable hydrocarbons (e.g., tar) to CO. In addition, more CO is generated from the pyrolysis of brown coal in CO₂ than pyrolysis of sub-bituminous coal. This study signifies that low-rank coal can be effectively used as an energy source when CO₂ is employed during pyrolysis process. © 2018 Elsevier Ltd.

This study was supported by Korea Institute of Geoscience and Mineral Resources (KIGAM) Basic Research Project (No. 18-3413 ). Appendix A