Chemical Engineering Science, Vol.201, 157-166, 2019
Kinetic study of SO2 adsorption on microfibrous entrapped sorbents for solid oxide fuel cell cathode protection
The kinetics of the non-catalytic gas-solid reaction between MnOx/gamma-Al(2)O(3 )and SO2 were investigated. A mathematical model based on axial dispersion, external and internal diffusion resistance, as well as a depletion mechanism for the sorbent has been established in this study. It predicted the breakthrough curves of packed bed (PB) and microfibrous entrapped sorbent (MFES) with acceptable deviations. This model consists of two predetermined parameters: the initial sorption rate constant (k(o)) and the depletion rate constant (k(d)), which can be determined by fitting the model to experimental data at various temperatures. Due to the uniform flow pattern and minimized bed channeling, MFES outperformed conventional PB consisting of the same sorbent particle size in terms of the reduction in SO2 concentration. The MFES surpassed PB significantly during the in situ regeneration in anode exhaust gas (AEG). Furthermore, MFES maintained its high breakthrough capacity up to five adsorption/regeneration cycles. Therefore, the MFES is a superior approach to remove the potential SO2 from the fuel cell cathode air stream for practical applications. (C) 2019 Elsevier Ltd. All rights reserved.
Keywords:Breakthrough curve;Sulfur dioxide;Axial dispersion;Microfibrous entrapped sorbent;Mathematical model;SOFC power system