Catalytic thermolysis of oak sawdust using Fe-based catalyst and CO2

To achieve the more sustainable thermolytic energy conversion platform for biomass, this study particularly employed CO₂ as reactive gas medium. Thus, this study laid great emphasis on elucidating the mechanistic role of CO₂ during the thermolysis of biomass. As a case study, sawdust was used as the carbon substrate in this study. Lab-scale pyrolysis of sawdust in the CO₂ environment revealed that the homogenous reactions between volatile organic carbons (VOCs) from the thermolysis of sawdust and CO₂. In detail, two mechanistic pathways arising from CO₂ were identified. First, CO₂ played a role for an oxygen-donor and reacted with VOCs, thereby resulting in CO formation. Second, CO₂ expedite thermal cracking of VOCs. In an effort to enhance the identified mechanistic role of CO₂, industrial waste, namely red mud, was mixed with sawdust to fabricate the Fe-carbon composite, and the Fe-carbon composite was further used as a catalyst. In the presence of the Fe-carbon composite, the identified mechanistic roles of CO₂ were further reinforced.