摘要 學號:N9731021 論文題目:有機廢棄物厭氧消化之氣相資源化再利用研究 總頁數:104 學校名稱:國立屏東科技大學 系(所)別:環境工程與科學 畢業年月:2012年 6月 學位別:碩士學位 研究生:王肇源 指導教授:郭文健 博士 論文摘要內容: 為了瞭解厭氧消化系統放大為模廠规模的效果,以3,000L酸化槽及12,000L醱酵槽進行兩相式半連續厭氧試驗。系統以單一廚餘進料並維持系統穩定,進料濃度為(90 g COD/ L)、體積負荷(4.5 kg TCOD/ m3-day)。並探討經由厭氧消化後其有機物之去除率與產氣率。此外,透過自行組裝之鹼液洗滌塔進行沼氣純化測試。藉由探討沼氣成份中甲烷濃度之提升、二氧化碳及硫化氫之去除率、循環水之處理,並對純化後之沼氣進行發電機發電測試。 在厭氧消化系統中,TCOD及SS去除率方面分別為77.30±3.41 %及86.9±3.7 %。產氣量約為6.95±2.63 (m3/day),平均產氣回收率則為61.4±14.9 %。沼氣中甲烷及二氧化碳濃度百分比分別為65.8 ± 3.6 %及28.3 ± 3.8 %,而硫化氫平均濃度則為13,387±3420 ppm。 在沼氣純化方面,以濕式洗滌塔並添加NaOH進行沼氣淋洗測試。在氣液比30:60 (L/min) 、pH值=9、30℃、1大氣壓時,甲烷含量百分率為97.7±0.85%,熱值約為9,301 Kcal/m3,經換算約為38,896.8 KJ/m3。二氧化碳之平均濃度約為1.7±0.6 %,去除率為94.3 %。硫化氫之平均濃度約為90±30 ppm,去除率達99%以上。而沼氣洗滌後之呈現飽和狀態之循環水,經曝氣試驗之結果,pH值從7.79上升至9.0,H2S則在第25分鐘時已無法檢出。符合高鹼度、低H2S濃度,可利用其繼續作為循環水使用或作為醱酵槽鹼度添加使用。 以純化後沼氣作為發電機發電測試,經試驗結果為平均每發1度電使用沼氣量為0.656 m3。 關鍵字:廚餘、厭氧消化、洗滌塔、沼氣純化與發電
Abstract Student ID: N9731021 Title of Thesis: Anaerobic digestion of organic wastes for biogas resource recovery Total Pages: 104 Name of Institute: National Pingtung University of Science and Technology Name of Department: Department of Environmental Engineering and Science Date of Graduation: June, 2012 Degree Conferred: Master Name of Student: Jau-Yuan Wang Adviser: Dr. Wen-Chien Kuo The Contents of Abstract in this Thesis: To understand the performance of a pilot scale anaerobic digestion system, a two-phased semi-CSTR system with a volume of 3000 L acidogenesis tank and a 12,000 L methanogenesis tank was investigated. In the system, kitchen waste was the only substrate. The influent concentration and volumetric loading rate (VLR) were set at 90 g COD/L-d and 4.5 Kg COD/ m3-day, respectively. Performance of this system was evaluated and gas by-product was investigated for resource recovery. In addition, biogas purification test was conduced using self-assembled wet scrubber system. Through study of the upgraded biogas, carbon dioxide and hydrogen sulfide removal, recycling of water from the scrubber, and purified of biogas was used for electricity generation test. In the anaerobic digestion system, TCOD and SS removal efficiencies were 77.3 ± 3.4 % and 86.9 ± 3.7 %, respectively. Biogas production was 6.95 ± 2.63 m3/day, with the recovery of 61.4 ± 14.9%. The CH4 and CO2 percentages wree 65.8 ± 3.6 % and 28.3 ± 3.8 % , respectively. A wet scrubber system was used to purify the biogas by adding NaOH in the water. At the water temperature of 30 ℃and pH = 9, under the gas/liquid ratio of 30:60 (L/min), the percentage of methane in the biogas can be upgraded to 97.7 ± 0.85 %. This concentration of the biogas has a calorific value of about 9,301 Kcal/m3, which is equivalent to approximately 38,896.8 KJ/m3. The average concentration of carbon dioxide after the scrubber is about 1.7 ± 0.6 %, with the removal percentage of 94.3 %. The average concentration of hydrogen sulfide is about 90 ± 30 ppm in the effluent of the scrubber, with the removal percentage of 99 %. The pH of recirculateion water from scrubber was found to increase from 7.79 to 9.0, and the H2S comcentration was below detection limit after 25 minutes’ aertion. This water’s characteristics meet the high alkalinity, low concentration of H2S criteria and can be reused as the dilution water in the feed or to supply alkalinity to the methanogenesis tank. In the electricity generation test, it was found to consume 0.656 m3 of purified biogas for 1 KWH. Key words: kitchen waste, anaerobic digestion, wet scrubber, biogas purification and electricity generation.