以動力學分析與比較光合微生物燃料電池效能

Kinetic analysis and comparison with photosynthetic microbial fuel cell performance

黃鈞懋(Chun-Mao Huang)

指導教授 ： 藍祺偉

元智大學/工程學院/化學工程與材料科學學系/碩士(2011年)

摘要

現今世界各地都存在兩個重要問題，一個是環保，另一個則能源危機。為了解決問題，發展綠色能源似乎是一個可行的解決方案。最近幾年很多研究學者都廣泛地討論微藻，因為它可以應用於生物能源的來源上。光合燃料電池是利用光合作用的微生物（如光合菌或藻類）將光能或化學能轉換成電能。大多數生物燃料電池研究重點著重於改善電池效率，然而，利用動力學方程式對光合微生物燃料電池（Photosynthetic microbial fuel cell, PMFC）的探討上目前並不完善。因此，本研究目的主要為利用動力學分析與比較光合微生物燃料電池。
　　本研究發現R. palustris PMFC在不同碳源濃度中，不管是在照光或是黑暗，內電阻會隨著碳源增加而增加；但與C. reinhadtii PMFC在25 mM醋酸為碳源下的表現不同，照光下內電阻最大（149.4 kΩ），黑暗下則是最小（64.9 kΩ）。本研究顯示，經轉殖後的C. reinhadtii P1-10，因為提高硫鐵化蛋白表現量，使得細胞能從光的能量轉換更多電子釋放出來，所以輸出功率（2.0x10-3 mW m-2）比原生種的高（0.5x10-3 mW m-2）。且發現讓細胞在傳遞電子至電極板的過程中，電壓並無損失。此外實驗結果指出細胞於不同生長階段，會影響電池的效率，C. reinhadtii原生種在延滯期時細胞活性最大，電池功率也最高（9.18x10-2 mW m-2），而轉殖株P-10則是在指數期時效率最高（2.01x10-1 mW m-2），而利用不同細胞濃度從7.5x108 CFU mL-1增加至2.4x1010 CFU mL-1時，會將電池的效率由6.78x10-3 mW m-2提升至2.73x10-2 mW m-2。本研究成功利用動力學分析光合微生物燃料電池內電子的傳遞機制，且呼應了文獻上所報導的電池效能實驗結果，雖然目前功率較低，但是對未來的綠色能源發展是有可行性的。

關鍵字

紅假單胞菌 ； 衣藻 ； 光合微生物燃料電池 ； 動力學模組 ； 極化曲線

並列摘要

There are two important issues around the world including environmental protection and energy crisis. In order to solve those challenges, the development of green energy seems to be a promising solution. The potential of microalgae applied as bioenergy source has been widely discussed in recent years. Photomicrobial fuel cells is use of photosynthesis microbial (such as photosynthesis bacteria or microalgae) to convert photo or chemical energy into electrical energy. Most bio-fuel cell researches are focusing upon improvement of the battery efficiency; however, the mechanism of microbial fuel cell in terms of relation between each operating factors and kinetic of fuel cell is not well illustrated. Therefore, this study is purposed to use kinetic equation to demonstrate the kinetic interaction while perform the photosynthetic microbial fuel cells.
　　It was found the internal resistance increased corresponded to increasing concentration of acetic acid addition from 0 mM to 75 mM in R. palustris PMFC either under light or dark condition. However it presented a different patent for C. reinhadtii PMFC. The maximum and minimal internal resistance（149.4 kΩ and 64.9 kΩ）were obtained when PMFC was operated in 25 mM addition of acetic acid under light and dark, respectively. This study found transgenic strain, C. reinhadtii P1-10, displayed higher power density than wild type at identical conditions （2.0x10-3 mW m-2 vs 0.5x10-3 mW m-2）.Such results demonstrated the improvement of ferredoxin expression can enhance the performance of PMFC under light circumstance. From the investigation of impact of cell activity upon PMFC performance indicated a better power density was shown for cells at lag or exponential phase（2.01x10-1 mW m-2 and 9.18x10-2 mW m-2）.
　　In addition, the power density derived from PMFC was increased as cell is much concentrated in anode of PMFC. From kinetic analysis, we found the β and η was improved when the carbon source increase or under light condition. In the present study, we successfully employed kinetic analysis to describe the mechanism of electron transfer inside of PMFC.

並列關鍵字

Rhodopseudomonas palustris ； Chlamydomonas reinhadtii ； Photomicrobial fuel cells ； Kinetic model ； Tafel plot ； Polarization curve

參考文獻

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