Visualization of electrolyte volatile phenomenon in DIR-MCFC
Visualization of electrolyte volatile phenomenon in DIR-MCFC
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DOI：
10.1016/j.jpowsour.2006.01.007
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发表时间：
2006-07
影响因子：
9.2
通讯作者：
K. Sugiura;Tadakatsu Yodo;M. Yamauchi;K. Tanimoto
中科院分区：
文献类型：
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作者：
K. Sugiura;Tadakatsu Yodo;M. Yamauchi;K. Tanimoto
熔盐的挥发是影响熔融碳酸盐燃料电池（MCFC）性能的因素之一。熔盐的挥发促进了金属部件的交叉泄漏和腐蚀。此外，管道堵塞是由挥发性物质的固化引起的。在直接内重整熔融碳酸盐燃料电池（DIR-MCFC）中，填充阳极通道的重整催化剂会受到熔盐挥发物的污染，熔盐挥发是一个特别严重的问题。然而，迄今为止，熔融盐挥发物的行为和挥发量均未得到阐明，因为具有强碱性的熔融盐挥发物不能直接供给至分析仪，所以其挥发量小，并且分析精度差。因此，试图通过使用非接触式图像测量技术来阐明MCFC中的电解质挥发现象。16 cm 2 MCFC单电池框架具有观察窗和照射窗。通过从照射窗口向阳极通道中照射2 mm厚的YAG激光片，并使用高空间分辨率摄像机（12位）从观察窗口进行测量，来显示挥发现象的图像。结果，虽然在OCV下在阳极通道中没有观察到挥发性物质，但是挥发性物质在150 mAcm-2的电流密度下以带状方式从电极附近的入口侧朝向出口流动。此外，在阳极电极的常规厚度下难以观察到挥发性物质。因为这些挥发物的组成通过离子色谱分析为15 Li 2CO 3/85 K2 CO 3（转化为熔融盐的结果），所以它不是电解质（62 Li 2CO 3/38 K2 CO 3），而是钾的挥发物，例如KOH。因此，应当理解，挥发性物质K2 CO 3在与CO2的反应中作为KOH产生，其包括通过与电解质的细胞反应产生的水。相反，挥发性物质流到阴极电极的表面，而不考虑电流密度的变化。此外，挥发性物质存在于电极表面上，尽管其随着阴极电极的常规厚度而或多或少地减少。因此，应当理解，为了使挥发性物质不与细胞反应相关，挥发性物质不包括熔融盐的分散体。
Volatilization of molten salt is one of the factors that control the performance of molten carbonate fuel cells (MCFC). Volatilization of molten salt promotes cross-leakage and the corrosion of metallic components. Moreover, piping blockage is caused by the solidification of volatile matter. Because reforming catalysts filling the anode channel are polluted by molten salt volatile matter in direct internal reforming molten carbonate fuel cells (DIR-MCFC), the volatilization of molten salt is an especially serious subject. However, neither the behaviour nor the volatilization volume of molten salt volatile matter has heretofore been elucidated on. Because molten salt volatile matter that has strong alkalinity cannot be supplied directly to an analyzer, its volatilization volume is small, and analytical accuracy is poor. Therefore, an attempt has been made to elucidate about the electrolyte volatile phenomenon in an MCFC by using a non-contact image measurement technique. A 16cm2MCFC single cell frame has an observation window and an irradiation window. The image of the volatile phenomenon is shown by irradiating a YAG laser light sheet 2mm thick from an irradiation window into the anode channel, and taking measurements from an observation window with a high spatial resolution video camera (12bit). As a result, though the volatile matter is not observed in an anode channel at OCV, the volatile matter flows in a belt-like manner from the inlet side near the electrode toward the outlet at a current density of 150mAcm−2. In addition, volatile matter is difficult to observe with the conventional thickness of an anode electrode. Because the composition of these volatile matters is 15Li2CO3/85K2CO3(the result of conversion into molten salt) by ion chromatography analysis, it is not an electrolyte (62Li2CO3/38K2CO3) but rather the volatile matter of potassium, such as KOH. Therefore, it is understood that the volatile matter K2CO3is generated as KOH, comprising the water generated by the cellular reaction with an electrolyte, in a reaction with CO2. Conversely, the volatile matter flows to the surface of the cathode electrode without regard to changes in current density. In addition, the volatile matter exists on the electrode surface, although it decreases more or less with the conventional thickness of the cathode electrode. Therefore, it is understood that the volatile matter, in order for it not to be related to the cellular reaction, does not comprise the dispersion of molten salt.