(2020) Journal of CO₂ Utilization_Study on carbon rearrangements of CO₂co-feeding pyrolysis of corn stover and oak wood

Choi D., Jung S., Jeon Y.J., Moon D.H., Kwon E.E.

(Elsevier Ltd) Journal of CO2 Utilization ISSN: 22129820 Vol.42 Issue. Article No.101320 DOI: 10.1016/j.jcou.2020.101320

Pyrolysis has been broadly applied to biomass valorization process to convert solid biomass waste into three phase value-added products such as biochar, pyrolytic oil, and pyrolytic gas. The carbon rearrangement process is highly affected by contents of cellulose, hemicellulose, and lignin due to their different structures. In this respect, this study laid great emphasis on the thermolytic behaviors of cellulosic corn stover (CS) and lignin-rich oak wood (OW) to understand carbon reallocations of them as a case study. In addition, CO₂ was employed as a reaction medium for biomass pyrolysis to control the carbon redistribution between CO₂ and CS/OW in line with the achievement of sustainable thermo-chemical conversion of biomass consuming a greenhouse gas (i.e., CO₂). Lignin-rich OW showed higher tolerance to thermal degradation, thereby resulting in more biochar and less pyrolytic oil formations. During the CO₂-assisted pyrolysis, carbon redistribution was appeared between liquid and gas phase products. This showed the gas phase reactions (GPRs) between volatilized liquid pyrolysates and CO₂ with additional CO formation. To expedite the GPRs, Ni/SiO₂ catalyst was employed. The CO₂-assisted catalytic pyrolysis of CS and OW significantly improved dehydrogenation and deoxygenation, showing more than one order of magnitude higher production of H₂ and CO. © 2020 Elsevier Ltd.

This study was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea Government (MSIT) (No. NRF-2019R1A4A1027795 ).