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

Abstract

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.