In the CLC-process the combustion chamber of a power plant is substituted by two interconnected fluidized bed reactors. In the first fluidized bed reactor the fuel reacts with a solid oxygen carrier (e.g. metal oxide). The chemically reduced oxygen carrier is re-oxidized in a second fluidized bed reactor with air. Employing this technology, it is possible to achieve an almost pure stream of CO2 – after water condensation – as off gas from the fuel reactor. This results in the significant advantage of an inherent CO2 separation.
At the SPE chemical-looping combustion of coal is experimentally investigated in a pilot-scale coupled fluidized bed system. The fluid-mechanical behavior of the system is studied in a cold-model. Reaction kinetics are measured in a laboratory scale fluidized bed reactor. Furthermore, the process is modeled under consideration of reactions attrition and particle size distribution.
Pyrolysis of Biomass
As partner in the joint research cluster BIOREFINERY2021 of academia and industry, the expertise of the institute in particle and energy technology contributes to the overall goal to enhance the state of the art bio-refinery with processes for value added production from waste products. In this context the use of lignin as a waste product can be used for the production of chemicals with high value instead of combusting it for energy production, as practiced today investigated. Pyrolysis of the waste products in a stationary fluidized or circulating bed reactor is a promising technology in achieving this goal.
At the institute the pyrolysis research is focused on the investigation of a system of coupled fluidized beds. The pyrolysis takes place in a circulating fluidized bed, producing pyrolysis oil, which is containing the desired products. The by-products of the process are coke, tar and permanent gases. For the supply of the endothermic pyrolysis reaction heat, the by-products are combusted in a stationary fluidized bed. The heat is transported via the circulation bed material. Both reactions shall be integrated in one process to avoid heat loss. Furthermore it is presumable that the yield of desired chemicals will be increased by reduction of the coke loading on the bed material.