堆叠型微生物燃料电池的放大试验研究

发布时间：2018-03-17 07:26

本文选题：堆叠型微生物燃料电池　切入点：欧姆阻力　出处：《武汉科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：微生物燃料电池（Microbial Fuel Cell，MFC）能够利用微生物的催化作用，将污水中有机物的化学能直接转化为电能，是一种集污水处理和能源回收为一体的创新性技术。本研究以放大的填料电极微生物燃料电池（L-MFC）的欧姆阻力分析和内部流态分析为基础，设计出堆叠型填料电极MFC的放大装置（总净容积72L），并对其各方面性能进行研究和分析，旨在促进微生物燃料电池的工程化放大应用。研究结果表明：（1）钛网由于表面氧化膜的影响会导致其导电性下降；0.45mm×20目的钛网与电极的接触面积最小，接触电阻最小；并联集电时的L-MFC的产电效果最好，最大功率密度达到了34.62W/m3；L-MFC的欧姆阻力中，电子传导阻力一般大于离子迁移阻力，其主要来源是集电材料与电极的接触阻力。（2）L-MFC的实际水力停留时间普遍大于理论停留时间，，二者之间的差异是由于理论值采用定值孔隙率得到，而L-MFC电极孔隙间的传质并不是均匀分布的；L-MFC的内部流态属于介于平推流和完全混合流之间的多孔介质的非均匀流态，并且进水流量越大，水流的混合流动程度越小，流态越接近平推流。（3）堆叠型L-MFC启动阶段的总内阻约为0.19；并联供电、三电阻单独供电和五电阻单独供电时的最大功率密度分别为47.25W/m3、30.55W/m3和50.45W/m3，每个MFC单元独立供电时堆叠型L-MFC的产电效率最高。并联供电时，各阴极或阳极之间易出现“内电流”，导致MFC单元的极性反转，并且外阻越大，越容易出现反极现象。（4）堆叠型L-MFC的最大功率密度随着进水COD浓度的提高而增大，在处理高浓度或低浓度COD污水时，独立供电时的产电性能优势更明显。在连续流运行模式下，独立供电时MFC的库仑效率普遍高于并联供电的，而COD去除负荷相差不大。此外，通过测试每个腔体水头损失的方法可以得知各极室的电极堵塞状况，及时疏通换水能够使MFC的输出电压得到恢复。
[Abstract]:Microbial Fuel cell (MFCs) can directly convert the chemical energy of organic matter into electric energy by using the catalytic action of microorganisms. It is an innovative technology which integrates wastewater treatment and energy recovery. Based on the ohmic resistance analysis and internal flow state analysis of packed electrode microorganism fuel cell (L-MFC), a MFC amplification device with stacked packed electrode (total net volume 72L ~ (-1)) was designed, and its various properties were studied and analyzed. The purpose of this paper is to promote the engineering application of microbial fuel cells. The results show that:. (1) because of the influence of oxide film on the surface of titanium mesh, the electric conductivity of titanium mesh will decrease by 0.45mm 脳 20. The contact area between titanium mesh and electrode is the smallest and the contact resistance is the smallest. The L-MFC with parallel current collection has the best power generation effect, and the maximum power density reaches 34.62W / m ~ (3) m ~ (3) L 路M ~ (-1) of ohmic resistance of L-MFC. The resistance of electron conduction is generally greater than that of ion migration, and the main source is the contact resistance between the collector and the electrode. The actual hydraulic retention time of L-MFC is generally larger than that of theoretical residence time, and the difference between them is due to the fact that the theoretical value is obtained by using constant porosity. However, the mass transfer between the pores of L-MFC electrode is not uniformly distributed. The internal flow state of L-MFC belongs to the non-uniform flow state of porous media between flat push flow and complete mixed flow, and the greater the influent flow is, the smaller the mixing flow degree of water flow is. The flow pattern is closer to the flat thrust flow. The total internal resistance of stacked L-MFC at startup stage is about 0.19. The maximum power density of three resistors and five resistors are 47.25 W / m ~ 3 and 50.45 W / m ~ 3, respectively. When each MFC unit is supplied independently, the power generation efficiency of stacked L-MFC is the highest. The "internal current" between the cathodes and anodes is easy to appear, which leads to the reversal of the polarity of the MFC cells, and the larger the external resistance, the more prone is the reverse pole phenomenon. (4) the maximum power density of stacked L-MFC increases with the increase of influent COD concentration, and the advantages of independent power supply in the treatment of high concentration or low concentration COD wastewater are more obvious. In continuous flow operation mode, the maximum power density of stacked L-MFC increases with the increase of influent COD concentration. The Coulomb efficiency of MFC with independent power supply is generally higher than that of parallel power supply, but the removal load of COD is not different. In addition, the electrode clogging of each electrode chamber can be obtained by measuring the head loss of each cavity. Timely dredging and changing water can restore the output voltage of MFC.
【学位授予单位】：武汉科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703;TM911.45

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