污泥微波热解气为燃料的SOFC积碳控制研究

发布时间：2018-01-02 07:23

本文关键词：污泥微波热解气为燃料的SOFC积碳控制研究　出处：《哈尔滨工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：针对日益紧张的能源形势,为解决污水污泥处理处置效率低下等问题,实现生物质的高效利用,本文基于污水污泥微波热解生物质气,开展以生物质气为燃料的固体氧化物燃料电池的产电研究。固体氧化物燃料电池(Solid Oxide Fuel Cell,SOFC)是一类将化学能直接转化为电能的高效发电装置,目前阻碍SOFC推广应用的一大难题是,以碳基燃料气(CH4、CO、C2H4等)运行电池时,电池阳极产生的碳沉积,会破坏电池结构、阻碍气体传输,影响电池放电稳定性,以致缩短电池使用寿命。本文利用Ni-YSZ阳极支撑SOFC,基于运行条件及电极材料性能两大影响因素,开展了操作状态优化、燃料气改进、阳极材料改性等方面研究,探讨了电池恒流运行的积碳问题,提高了电池运行稳定性,使以污泥微波热解气为燃料时电池抗积碳性能得到改善。以模拟生物质气为燃料时,较高的操作温度与工作电流密度有利于电池减少积碳、提高电池恒流运行稳定性;在低温、低电流密度下,电池运行的稳定性较差,此时电池的积碳现象严重。同时考察了以氢气和模拟生物气为燃料时电池的放电性能,结果表明操作温度对电池的放电性能影响显著,电池的最大功率密度随温度升高而提高。在燃料气改进研究中,首先考察了CO2气体的消碳作用。以CO2/CH4混合气体为燃料时,探讨了不同比例混合气的放电性能及积碳行为,结果表明向CH4气体中添加CO2有助于电池稳定运行,在CO2/CH4比例为2时,电池的运行最平稳。以模拟生物气为燃料,提高CO2浓度进行燃料气改进后,电池的放电性能有所下降,恒流放电稳定性得到提升。当模拟生物气中CO2浓度达到20%时,恒流放电时电池的输出电压最稳定。向燃料气中添加水蒸气后,电池的放电功率有小幅上升,且运行稳定性提高,结果表明当水蒸气比例达到7%时,电池的恒流放电性能优于3%的水蒸气添加比。通过溶胶-凝胶自蔓延燃烧法制备尖晶石型Mn Fe2O4粉体,以丝网印刷技术在电池阳极制备Mn Fe2O4阻挡层,经扫描电子显微镜观测并考察阻挡层电池的电化学性能。结果表明,以模拟生物气为燃料时,较无阻挡层的空白电池,阳极阻挡层电池的放电性能虽有小幅下降,但电池恒流运行稳定性得到提升。24小时测试显示16 wt%石墨阻挡层电池恒流运行表现最佳,恒流后电池放电性能衰减量最小。
[Abstract]:In order to solve the problem of low efficiency of sewage sludge treatment and realize the efficient utilization of biomass, this paper is based on microwave pyrolysis of biomass gas from sewage sludge. The research of solid oxide fuel cell based on biomass gas was carried out. Solid Oxide Fuel Cell was used in solid oxide fuel cell. SOF C) is a kind of high efficiency power generation device which converts chemical energy directly into electric energy. At present, one of the major problems that hinder the popularization and application of SOFC is to use carbon based fuel gas to produce CH4CO. C _ 2H _ 4) when running the battery, the carbon deposition produced by the anode of the battery will destroy the structure of the battery, hinder the gas transfer, and affect the stability of the battery discharge. In this paper, the Ni-YSZ anode is used to support the SOFC, based on the operation conditions and the performance of the electrode material, the operation state optimization and fuel gas improvement are carried out. The carbon deposition in the constant current operation of the battery is discussed, and the stability of the battery is improved. The anti-carbon performance of the cell is improved when the sludge is used as fuel by microwave pyrolysis gas, and the high operating temperature and working current density are favorable to reduce the carbon deposition of the battery when the simulated biomass gas is used as the fuel. Improving the stability of battery constant current operation; At low temperature and low current density, the stability of the cell is poor, and the carbon deposition of the battery is serious. The discharge performance of the cell is also investigated when hydrogen and simulated biogas are used as fuel. The results show that the operating temperature has a significant effect on the discharge performance of the battery, and the maximum power density of the battery increases with the increase of temperature. Firstly, the carbon removal of CO2 gas was investigated. The discharge performance and carbon deposition behavior of different ratios of mixed gases were discussed when CO2/CH4 mixture was used as fuel. The results show that the addition of CO2 to CH4 gas is helpful to the stable operation of the battery, and the most stable operation of the battery is at 2:00 of CO2/CH4. The simulated biogas is used as fuel. After improving the fuel gas concentration of CO2, the discharge performance of the battery decreased, and the stability of constant current discharge was improved. When the concentration of CO2 in the simulated biogas reached 20. After adding water vapor to the fuel gas, the discharge power of the battery increased slightly, and the stability of the battery was improved. The results showed that when the ratio of water vapor reached 7%, the output voltage of the battery was the most stable. The constant current discharge performance of the battery is better than the water vapor addition ratio of 3%. Spinel mn Fe2O4 powders are prepared by sol-gel self-propagating combustion method. The mn Fe2O4 barrier layer was prepared on the anode of the battery by screen printing technique. The electrochemical performance of the barrier layer battery was observed by scanning electron microscope. The results showed that the simulated biogas was used as fuel. Compared with the blank cell without barrier layer, the discharge performance of anode barrier layer battery decreased slightly. However, the constant current running stability of the battery was improved. 24 hours test showed that the 16 wt% graphite barrier layer battery had the best constant current operation, and the cell discharge performance attenuation was the least after constant current operation.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM911.4

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