Evaluation of volatile behavior and the volatilization volume of molten salt in DIR-MCFC by the image measurement technique

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构件的交叉泄漏和腐蚀。此外，管道堵塞是由挥发性物质凝固引起的。特别是在直接内重整碳酸盐熔盐燃料电池（DIR-MCFC）中，由于填充阳极通道的重整催化剂受到熔盐挥发物的污染，熔盐的挥发成为一个重要的课题。然而，熔盐挥发物的行为和挥发量都没有得到阐明，因为具有强碱度的熔盐挥发物不能直接提供给分析仪，其挥发量小，分析精度差。因此，尝试用非接触式图像测量技术来阐明汽化氢氧化碱的行为。DIR-MCFC电解液一般为62Li_2CO_3/38K_2CO_3。考虑了DIR-MCFC催化剂的污染机理。熔盐挥发性物质是电池与电解质反应时产生的水所产生的KOH。在CO_2浓度高的区域，生成的KOH再次返回到K_2CO_3， K_2CO_3附着在催化剂上造成催化剂污染。此外，当生成的水成为粘结材料并堵塞管道时，K_2CO_3粒子相互凝聚。本文利用图像测量技术，对KOH的挥发量，即KOH向K_2CO_3转变的行为，K_2CO_3的颗粒生长进行了实验测定。测定KOH挥发量时，KOH挥发后在电炉坩埚中加热与CO_2反应生成K_2CO_3，然后注入反应管中。通过YAG激光和CCD相机测量K_2CO_3颗粒的图像来测量K_2CO_3的量，从而通过K_2CO_3量的化学计量计算得到KOH的挥发量。从KOH到K_2CO_3的变化过程中，K_2CO_3颗粒的生长过程可以通过KOH和CO_2作用较长时间后形成的K_2CO_3颗粒的照片来说明。由此产生大颗粒与小颗粒相互粘附，颗粒生长积聚，造成管道堵塞。少

The volatilization of molten salt is one of factors that control the performance of Molten Carbonate Fuel Cells (MCFC). Volatilization of molten salt promotes the cross-leakage and corrosion of metallic components. Moreover, piping blockage is caused by the solidification of volatile matter. Especially, because reforming catalysts filling the anode channel are polluted by molten salt volatile matter in Direct Internal Reforming Molten Carbonate Fuel Cells (DIR-MCFC), volatilizing of the molten salt is a weighty subject. However, neither the behavior nor the volatilization volume of molten salt volatile matter has been elucidated upon, 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 was made to elucidate about the behavior of vaporized alkali hydroxide by using a non-contact image measurement technique. The DIR-MCFC electrolyte is generall … More y 62Li_2CO_3/38K_2CO_3. Consideration was given to the DIR-MCFC catalyst pollution mechanism of as follows. Molten salt volatile matter is KOH generated as water is generated when the cell reacts with electrolytes. Generated KOH returns to K_2CO_3 again in high CO_2 concentration regions, catalyst pollution being caused by the adherence of the K_2CO_3 to the catalyst. Moreover, the K_2CO_3 particle mutually coheres when generated water becomes bonding material and blockades the piping. The present report experimentally evaluates the volatilization volume of KOH, which is the behavior which changes from KOH to the K_2CO_3, particulate growth of K_2CO_3, using the image measurement technique. In measuring the KOH volatilization volume, K_2CO_3 is generated as KOH volatilized by heating it in a crucible in an electric furnace reacts with CO_2, and is then injected into a reaction tube. The amount of K_2CO_3 is measured by measuring the image of the K_2CO_3 particle with a YAG laser and CCD camera, thereby obtaining the KOH volatilization volume from the calculation of the stoichiometry of the amount of K_2CO_3. In behavior that changes from KOH to K_2CO_3, the particulate growth of K_2CO_3 can be clarified by taking a picture of a K_2CO_3 particle generated with KOH and CO_2 for an extended period. As a result, a large particle is generated with the mutual adhesion small particles, which particulate growth is accumulated, causing piping blockage. Less