Development of a process model for coal chemical looping combustion and validation against 100Â kWth tests

Chemical looping combustion is a very efficient CO2 capture technology utilizing two interconnected circulating fluidized beds. Despite promising results in basic research on chemical looping combustion at laboratory scale, the technical process has to be further developed, especially toward a potential industrial application. In order to accelerate this development, it is essential to simulate chemical looping combustion with process simulation software. In this study a process simulation model is validated using experimental data obtained from a 100 kWth pilot plant at Chalmers University of Technology (Sweden). The targeted configuration of the process is created and all substances and boundary conditions are defined. The solids distribution and also the chemical conversion of gases and solids are simulated by a user defined model. This model is based on mathematical equations for fluidized beds and kinetic data of the chemical reactions is taken into consideration. The one-dimensional solids distribution is validated with experimental measurements using empirical correlations according to Kunii and Levenspiel. Conversions in the dense and the lean zone of the fluidized bed are determined using kinetic data from literature. The elaborated model is validated against the concentrations of gases at the fuel reactor exit. The calculated results are in very good agreement with experimental data. Sensitivity analyses are performed to optimize the operational conditions of the pilot plant.