Modeling of Carbon Dioxide Capture in Fluidized Bed.

Emad, Shady; Hegazi, Ahmed Abd-Elsalam; El-Emam, Salah H.; Okasha, Farouk M.

doi:10.21608/bfemu.2020.103977

Modeling of Carbon Dioxide Capture in Fluidized Bed.

Document Type : Research Studies

Authors

¹ Mechanical Power Engineering Department, Faculty of Engineering, Mansoura University, El-Mansoura, 35516, Egypt

² Mechanical Engineering Department, University of Mansoura, CO 35516, Egypt

10.21608/bfemu.2020.103977

Abstract

Carbon capture and storage (CCS) has been globally gaining popularity as a viable greenhouse gases mitigation strategy throughout the last decade. Calcium looping (CaL) is an emerging technology to capture carbon dioxide from flue gases of fossil fueled power plants exploiting the reversible gas-solid reaction between the carbon dioxide (CO2) and calcium oxide (CaO) to form calcium carbonate (CaCO3) in a fluidized bed. In this work, a dynamic model of a bubbling bed carbonator, the key reactor in the capture process, has been presented. The model incorporate both hydrodynamics and chemical kinetics to provide more reliable predictions. The model has been validated with experimental data obtained at combustion lab, Mansoura University using a fluidized bed carbonator of 10.5 cm inner diameter as well as a mathematical model found in literature. The key parameters have been investigated to check for system sensitivity. Bed temperature has a non-monotonic effect on CO2 capture efficiency. Maximum CO2 capture efficiency was found to occur around a temperature of 675 °C. Capture efficiency increases with either decreasing fluidization velocity or increasing bed particle size due to enhanced mass transfer and increased residence time. These findings almost accord with published data. Also, the average CO2 capture efficiency was found to increase with increasing static bed height up to a certain limit. Further increase in bed height doesn’t considerably affect the capture efficiency. The proposed model can be used as a design tool that would enable the optimization and commercialization of calcium looping.

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