微生物燃料電池與儲電系統效能之探討

Abstract

生物燃料電池兼具產生電能與處理廢水的兩種功能，若將其運用於豬場可達到處理豬糞尿水並獲得電能以回饋豬場的雙重優點，但微生物燃料電池所產生的能量並不足以直接啟動電子零件。 為增加MFC的輸出電壓，串聯兩個MFC為一系統，本實驗以豬場厭氧污泥作為菌種，將其製作為固定化細胞放置於陽極槽內。利用人工廢水操作在兩種不同的HRT條件下對菌種馴養(短時間馴養: HRT 1天;長時間馴養: HRT 3天)，接著以豬糞尿水做為進流並操作於HRT 3天、1天以及0.5天下，觀察不同操作條件對於MFC系統產電效能的影響。結果顯示在相同HRT下，菌種經過長時間的馴養有利於COD去除率的提升以及內電阻的下降。而HRT的縮短將不利於COD的去除率，對於電壓以及電流的表現並沒有顯著差異。串聯MFC會導致庫倫效率的下降，不利於電子回收。 以超級電容、開關與升壓轉換器製作一儲電系統，將MFC系統產生的能量儲存於不同容量的超級電容中(1 F、6.6 F及10 F)。儲電至電容電壓達0.5 V計算儲電效能，最後利用升壓轉換器穩定輸出3.3 V，用以啟動紅光LED。兩種馴化條件皆在連接1 F超級電容時可獲得最大的平均儲存速率，但1 F的超級電容電壓達1.4 V僅提供不到1 W的電量，在實際運用上略嫌不足。儲電效能隨電容容量的增大而下降，但大容量的電容可儲存較多的電量，因此可依實際的負載需求選擇合適的電容。MFC系統將能量儲存至10 F的超級電容達充電電壓0.7 V時，可提供一顆紅色LED燈點亮約10秒。

Microbial fuel cell could produce electricity and treat wastewater at same time. If MFC applied to farms to reach the dual advantages, the deal with swine waste water and electricity to feedback of the pig farms. But energy generated by the microbial fuel cell not enough to start the electronic components directly. To increase the output voltage of the MFC, two air-cathode MFCs were connected in series.In this study, immobilized cells with anaerobic bacteria which was acquire from a three-stage swine wastewater treatment system were packed into the anodic compartment. The artificial wastewater operations bacteria acclimated in two different HRT conditions (short period of acclimation: HRT 1; long period of acclimation: the HRT 3 days), followed by swine waste water as substrate and operating at HRT 3 days,1 day, and 0.5 day. To investigate the performance impact of different operating conditions for the electricity production of the MFC system. The results show that under the same HRT, the bacteria after a long period of acclimation is conducive to the enhancement of COD removal efficiency and to reduce the internal resistance. HRT shortening will be decreased the COD removal, voltage and current performance and no significant difference. Series MFC will lead to a decline in the coulomb efficiency is not conducive to electronic recycling. Eelectrical storage system contained super capacitors, switches, and the boost converter. The energy generated by the MFC system is stored in a different capacity super capacitor (1 F, 6.6 F and 10 F). The electrical storage capacitor voltage of 0.5 V to calculate the electrical storage performance, and finally the stability of the boost converter output 3.3 V, to start the red LED. The maximum average storage rate of the two acclimation condition would appear in the super capacitor of 1 F connection. However, if the capacitor voltage up to 1.4 V, the super capacitor of 1 F only provide less than 1 W of power, a bit less than in actual use. Electrical storage efficiency decreased with the increase of the capacitance, but large-capacity capacitor can store more power, so according to the actual load demand to choose the right capacitor. MFC system would store the energy to super capacitor of 10 F, and when the charging voltage reached 0.7 V, a red LED lights for approximately 10 seconds.