本研究利用模擬都市有機固體廢棄物採批次固態厭氧消化產甲烷，以模擬一般廢棄物為基質，下水污泥為植種菌，利用幫浦將淋滲液迴流至消化槽，取代在過去液態厭氧消化研究所需的機械攪拌裝置。原物料含水量於85%以下，符合固態厭氧消化之條件。本研究參考過去液態厭氧消化產甲烷之文獻設計兩個不同因子之實驗：溫度與滲漉量。在不同的溫度(35℃、55℃)下，顯示消化槽溫度在55℃的兩個不同滲漉量之批次時，有最佳的累積產甲烷量，分別為43.32 L/kg VS與39.42 L/kg VS，且在此溫度條件下所需反應時間最短，分別為28及26天即達到反應終點；其次為35℃，甲烷產量分別為35.65 L/kg VS與38.83 L/kg VS，所需反應時間為52天及56天。在不同滲漉量(0.38 ml/cm2/min與0.76 ml/cm2/min)下對於甲烷產量則無明顯之趨勢，但在反應初期，溫度55℃，滲漉量0.38 ml/cm2/min有氫氣之產生，產氣量為1.91 L/kg VS。在四個不同批次實驗中揮發性脂肪酸與總有機碳被厭氧微生物所利用轉化成甲烷，顯示利用固態厭氧消化處理高固體物含量之有機廢棄物不僅可去除有機物質，亦可產生再生能源甲烷。This study investigated the feasibility of solid-state anaerobic digestion for methane production, using simulated municipal solid waste as substrate and sewage sludge as inocula. Unlike the conventional wet anaerobic digestion process, mechanical stirring was not adopted in the digesters of this study. Instead, passive-mixing was achieved by pumping and spraying the liquid residues (i.e., leachate) back to the system, thus gradually rinsing the digesting materials. Initial moisture contents of the feedstock were all below 85%, conforming that the system was always initiated as a solid-state digestion. The effect of temperature on methane production was examined by performing the digestion process at 35℃and 55℃. Results showed that under thermophilic conditions (i.e., 55℃), 43.32 and 39.42 L/kg VS of maximum methane yields were obtained on Day 28 and 26, respectively. In comparison, mesophilic (35℃) processes only resulted in 35.65 and 38.83 L/kg VS of maximum methane yields, and required a longer period of incubation process (52 and 56 days, respectively). No significant differences in methane production were observed between the circulation rate at 0.38 ml/cm2/min and 0.76 ml/cm2/min. However, when the system was conducted at 0.38 ml/cm2/min circulation rate under mesophilic conditions, production of hydrogen (up to 1.91 L/kg VS) appeared at the early stage of incubation. These results indicated that using this solid-state anaerobic digestion system to treat municipal solid waste not only can help the degradation of organic substances but can also promote the formation of methane.
