有鑑於台灣地區垃圾焚化底渣產出量逐漸增加且再利用比率極低,其中底渣所散發出之臭味將造成再利用過程上之困擾,因此利用流體化床高熱傳之特性進行底渣除臭之處理,並藉由操作流體化床過程中選定兩大操作參數,分別為時間及溫度,最後藉由官能判定法選定除臭效果最佳之操作參數。 因為底渣之物、化性質深受進料端垃圾組成之影響,故本研究針對北部某大型垃圾焚化爐,進行每月之生垃圾及底渣之採樣、分析工作,生垃圾之分析項目包含基本物量組成、單位容積重、三成份分析、元素分析、熱值分析,而底渣部份則有灼燒減量、三成份分析、氧化物分析、總量分析及TCLP試驗,由生垃圾之基本物理組成試驗中得知,廚餘類及木竹類佔相對大量,而三成份分析方面,生垃圾含有約50%之水份、10%之灰份、40%之可燃份,而底渣水份含量約為25%、灰分70%、可燃份5%,而灼燒減量方面經實驗結果得知平均僅為3%左右,而灼燒減量為評估焚化爐燃燒效率高低指標之一,由此得知底渣中含有許多未燃燒完之垃圾,當然也含有較大比例之廚餘,造成底渣散發出腐敗之臭味。 經過流體化床最佳化處理(即溫度200℃,時間150min)之底渣其臭味濃度指數,由原先之1,000降至30,其去除率可高達97%,經由統計軟體SPSS將實驗結果回歸整理後得方程式 ,利用此方程式可推估不同操作條件下之臭味濃度指數,另外流體化床脫臭相較於其他脫臭方法例如生物脫臭或化學脫臭,流體化床脫臭法具有高去除率,節省處理時間及可直接再利用等三大優點,在處理成本分析方面,模擬建造一處理量20噸/小時處理場之處理成本,其年攤提之建造成本為9,396,989元,年操作成本為20,253,764元,年利息為2,012,083元,若扣除底渣販售之金額200元/噸,故每噸處理成本為1,799元。
Because of the bottom ash gradually increase and ratio of recycle very low from waste incinerator, the odour will be influence recycle process. Adorpting the high heat transfer efficiency treatment the bottom ash by fluidized bed, the studies selection two operation parameter that the temperature and time, use the Triangular Odor Bag Method to selection the best operating parameters. Due to physics and chemistry characteristic of the bottom ash by waste composition influence, the sampling and analyzing of waste and bottom ash at waste incinerator in Taiwan. The analyzing item of waste has physics composition analysis, specific weight, element analysis, heat value and three component analysis. The analyzing item of bottom ash has three component analysis, ignition loss, toxic characteristic leaching process, total mass and oxide of analysis. The results of waste physics component analyzing the kitchen waste and wood waste for the majority, the water content of 50%,ash test of 10%, combustibility content of 40%. The results of bottom ash analyzing the water content of 25%,ash test of 70%, combustibility content of 5%, ignition loss approximately 3%.The ignition loss was a index of combustion efficiency. Therefore, will be generated odour in bottom ash when containing a large proportion of the kitchen waste. After the fluidized bed treatment, the odour index will reduce from 1,000 to 30 and removal efficiency approximately 97% at 200℃ and 150min.The paper also proposes a statistical regression relationship between the operation conditions and odour. The correlation is a Y=-2.771t-4.306T+1344.626(Y:odour index, t:time , T:temperature). Therefore, can obtain an optimal condition to reduce the odour emitted from bottom ash by fluidized bed. The treatment cost approximately 1,799 NT for one ton.