Development for Three-Phase Fluidized Bed Fuel Cell System

传统的燃料电池设计采用板状电极，因此电流密度自然是有限制的。细胞卡的结构相当复杂，而且没有放大的优点。为了克服传统燃料电池系统的这些缺点，我们将流化床电极应用于燃料电池。流化床电极具有更大的电极面积，并且可以方便地按比例放大。本文研究了流化床氢电极和流化床氧电极在碱性燃料电池中的性能。在三相流化床中考察了气速、KOH浓度、电极颗粒类型和集电极尺寸对电池电流的影响。此外，还进行了体积气液传质系数的测定实验。综上所述：1)流化床氢电极性能接近理想。另一方面，由于过氧离子的催化分解，流态化坏氧电极的性能不理想。2)欧姆极化是由集电极与电极颗粒之间的接触电阻决定的。3)粒径和固体浓度对传质系数的影响在三种反应器中表现出不同程度的差异，并按固体浓度分布进行分类。

The conventional fuel cell design employs electrodes in the shape of plates, so that there is naturally a limit of current density. The structure of cell stuck is quite complex, and furthermore there is no scale-up merit. To overcome these disadvantages of conventional fuel cell systems, we applied a fluidized bed electrode to the fuel cell. The fluidized bed electrode has a larger electrode area per volume and can conveniently be scaled-up.In this study, the performance of a fluidized-bed hydrogen electrode and a fluidized-bed oxygen electrode was investigated for an alkaline fuel cell. The effects of gas velocity, KOH concentration, type of electrode particles and size of collector electrode on the cell current were examined in the three-phase fluidized beds. In addition, the experiments were carried out to measure volumetric gas-liquid mass transfer coefficient.In conclusion :1) The fluidized-bed hydrogen electrode behaves nearly ideally. On the other hand, the fluidized-bad oxygen electrode does not behave ideally because of the catalytic decomposition of peroxyl ions.2) The ohmic polarization is governed by the contact resistance between the collector electrode and the electrode particles.3) The effects of particle size and solid concentration on mass transfer coefficients appeared differently in three types of reactors, which are classified by solid concentration profiles.