(380s) Design of Fluidized Bed Combustor Reactor in Chemical Looping Combustion: Hydrodynamic and Heat Transfer Properties
The chemical looping combustion (CLC) technology is one of the most promising CO2 capture technologies for fossil fuel power generation applications. CLC utilizes a metal oxide as an oxygen carrier (OC) to supply oxygen from air to the fuel through a reduction and oxidation reaction pathways of the OC, thus avoiding contact between fuel and air to allow effective separation of O2/N2, CO2, and H2O. In the CLC process developed by The Ohio State University (OSU), an iron-based OC is circulated between a counter-current moving bed reducer reactor for full combustion of fossil fuel and a fluidized bed combustor reactor for OC regeneration by air. High quality heat can be extracted from reducer flue gas, combustor flue gas and combustor for power generation. While heat recovery from flue gas has been extensively studied and employed in existing power plants, the properties of the granular flow in the fluidized combustor is the key aspect remain unresolved in the design of CLC power plant. Two-fluid model (TFM) was adopted in the present work for its high efficiency in large-scale simulation when compared with CFD-DEM method. Experiments in the fluidized bed were conducted as a baseline to calibrate the hydrodynamic and heat transfer coefficients of the TFM. Specifically, the validated TFM model was applied to the fluidized combustor of a coal-based CLC power plant. We can then configure the design of combustor itself and heat transfer surface in combustor based on the hydrodynamic and heat transfer properties and information of energy and material balance from process modeling by Aspen Plus.