能源問題是人類在本世紀面臨的重要議題之一。人們亟需尋求綠色可再生能源來滿足巨額的能源消耗，並且擺脫對於化石燃料的依賴。厭氧發酵技術可以利用微生物將農業廢棄物轉化為沼氣，這使得其不單具有經濟價值，更有環保方面的效用，將農業廢棄物轉化為甲烷既能得到清潔環保的可燃氣體，又可以解決原有的廢棄物處理問題，因此目前世界各國都在積極發展厭氧發酵技術。 目前台灣的厭氧發酵工廠大多使用單階段厭氧發酵反應，即在一個反應器內同時進行全部的厭氧發酵反應。但厭氧發酵反應實際上具有多個步驟，並且由不同的微生物群完成。如果可以從微生物群的角度將用於產酸水解的微生物與用於產甲烷的微生物分離，則將有機會找到它們各自適合的發酵參數，使得每個步驟都有最適化的可能。除此之外還可以避免因過度產酸而抑制產甲烷菌活性的情況。因此本研究，將水解產酸菌與產甲烷菌做分離構成獨立的水解產酸階段和產甲烷階段，再使用兩階段厭氧發酵最終生成甲烷。對每個階段進行的最適化討論，以達到提升產率的目的。 本研究使用熱處理的方式對厭氧微生物做處理，得到可用於水解產酸，但不會產生甲烷的厭氧污泥。之後使用該污泥做兩階段厭氧發酵與單階段厭氧發酵做對比，甲烷產量提升21%。最後探討碳氮比，一階段溫度，二階段溫度對厭氧發酵之影響。當一階段溫度為35℃，二階段溫度為50℃，碳氮比為10時甲烷產量最大，達到每克揮發性固體84毫升甲烷氣體。 ;Abstract The energy issue is one of the important topics in this century. With the growing demand for energy, there is an urgent need to develop clean, renewable energy to get rid of dependence on fossil fuels. Anaerobic fermentation technology converts agricultural waste into biomethane, and at the same time generates clean and environmentally friendly biogas and solves the problem of waste disposal. Therefore, countries around the world actively developing anaerobic fermentation technology. Most of the anaerobic fermentation plants in Taiwan use a single-stage anaerobic fermentation reaction, that is, the entire anaerobic fermentation process is performed simultaneously in one reactor. But the anaerobic fermentation actually has multiple steps and is completed by the different microorganism. If the microorganisms used for acidogenic hydrolysis are separated from the microorganisms used for methanogenesis, there will be an opportunity to find their respective optimized operating parameters. If volatile fatty acid-producing microorganisms are separated from methanogens, the respective optimized operating parameters will be found. This study uses a two-stage operation for anaerobic fermentation and optimizes it for higher yields. When the first stage temperature is 35 degrees, the second stage temperature is 50 degrees, and the carbon-nitrogen ratio is 10, the methane production is the best, reaching 84 (ml) of methane gas per gram of volatile solids.
