Journal: Bioresource Technology

Author: Dong-Wan Cho, Seong-Heon Cho, Hocheol Song, Eilhann E. Kwon

Abstract: 

This work mainly presents the influence of CO₂ as a reaction medium in the thermo-chemical process (pyrolysis) of waste biomass. Our experimental work mechanistically validated two key roles of CO₂ in pyrolysis of biomass. For example, CO₂ expedited the thermal cracking of volatile organic compounds (VOCs) evolved from the thermal degradation of spent coffee ground (SCG) and reacted with VOCs. This enhanced thermal cracking behavior and reaction triggered by CO₂ directly led to the enhanced generation of CO (∼3000%) in the presence of CO₂. As a result, this identified influence of CO₂ also directly led to the substantial decrease (∼40–60%) of the condensable hydrocarbons (tar). Finally, the morphologic change of biochar was distinctive in the presence of CO₂. Therefore, a series of the adsorption experiments with dye were conducted to preliminary explore the physico-chemical properties of biochar induced by CO₂.

Keywords: CO₂, Thermo-chemical process, Pyrolysis, Spent coffee ground (SCG), Biomass waste

DOI:  https://doi.org/10.1016/j.biortech.2015.04.002