2025/08/18 by Schmitt, Marian, Lindmüller, Lennard, Fritzler, Alexander +1
Chemical Engineering · #Biomass conversion #Chemical Engineering #Chemical looping #Devolatilization behavior #Energy and Environment #Oxygen carrier #Social Sciences::333: Economics of Land and Energy::333.7: Natural Resources #Spouted bed #Technology::621: Applied Physics #Technology::660: Chemistry
paper · doi:10.15480/882.15777
In the course of efforts to reduce emissions of carbon dioxide and to meet the global climate targets, the chemical looping combustion process (CLC) has increasingly received more attention over the years. In CLC the contact of the gasified solid fuel with the oxygen carrier is of great importance. Especially when combusting biomasses which include high amounts of volatiles, there is a risk of incomplete conversion of said volatiles. To tackle this challenge of volatile bypasses, the installation of a spouted bed is proposed to increase the mixing of solid fuel and oxygen carrier and thereby increase the conversion. Furthermore, the higher mechanical stress in a spouted bed can lead to fuel particle breakage which can result in higher fuel conversions. In this work biomass pellets were compared under spouted bed and bubbling bed conditions in a lab-scale hot plant. The influence of pellet size was studied and concentration profiles were tracked using online gas analytics. Stable operating conditions were found for the spouted bed setup and compared regarding conventional combustion and oxygen carrier aided devolatilization. Under spouted bed conditions higher carbon conversion, higher conversion rates and a higher degree of conversion were achieved. This increase was attributed to the better mixing and higher gas-solid contact in the spouted bed and the breakage of pellets and subsequent increase of specific surface area due to higher forces.