Development for Three-Phase Fluidized Bed Fuel Cell System

传统的燃料电池设计采用极板形状的电极，因此自然会有电流密度的限制。细胞粘连的结构比较复杂，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，我们将沸腾床电极应用到燃料电池中。沸腾床电极具有更大的单位体积电极面积，可以方便地放大，本研究以碱性燃料电池为例，研究了沸腾床氢电极和床氧电极的性能。考察了气速、氢氧化钾浓度、电极颗粒类型和集电极尺寸对三相流态化过程中电池电流的影响。此外，还进行了体积气液传质系数的测量实验。结论：1)沸腾床氢电极的性能接近理想状态。另一方面，由于过氧化氢离子的催化分解，流态化-坏氧电极的性能并不理想。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)颗粒尺寸和固体浓度对传质系数的影响在三种类型的反应器中表现不同，根据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.