| Abstract: | 本研究分別利用固定床熱裂解、旋轉窯熱裂解及旋轉窯氣化反應系統，評估含鋁塑膠包裝廢棄物能源轉換效率及鋁回收之可行性。試驗條件主要包括熱裂解溫度450、500、550及600℃，以及旋轉窯傾斜斜率0.052與0.067；此外，氣化反應溫度控制為600℃及當量比(Equivalence ratio, ER)為0.1、0.2、0.3之條件。為進一步釐清含鋁塑膠包裝廢棄物之資能源再利用特性，研究將探討產物產率、產物特性、鋁回收效率與產能效率等項目。
研究結果顯示，固定床熱裂解產油率最高，約為43.09 wt.%，而旋轉窯熱裂解產油率，隨著熱裂解溫度增加而減少，約介於2.17至26.18 wt.%。至於旋轉窯氣化反應之裂解油產率，則隨著當量比(ER)增加而增加，產率約介於0.41至0.62 wt.%。根據裂解油之化合物組成分析結果顯示，固定床熱裂解反應產生之裂解油組成，以脂肪族化合物為主；而旋轉窯熱裂解產生之裂解油，則以含氧化合物為主。至於旋轉窯氣化反應所衍生之裂解油，主要化合物亦為含氧化合物，且隨ER值增加，而轉變為芳香族化合物為主。
經由熱裂解反應後回收鋁之分析結果顯示，以溫度450℃及500℃之鋁回收率最佳，其中旋轉窯熱裂解反應系統之鋁回收率最高，可達到93.29 wt.%。若改以旋轉窯氣化反應系統，不論ER值為0.1至0.3，鋁回收率均較熱裂解系統為低，約介於49.24 wt.%至54.53 wt.%。至於回收鋁的純度分析結果顯示，以旋轉窯熱裂解反應系統而言，回收鋁之純度最高可達86.03~92.79%，至於旋轉窯氣化反應系統，則由於供氧氣之影響，致使回收鋁之純度降低至16.68~33.21%。根據XRD及SEM/EDS分析結果可知，回收鋁除為金屬鋁成分外，亦發現金屬鋁之氧化物等物種存在，致使回收鋁之純度降低。整體而言，本研究不僅建立含鋁塑膠包裝廢棄物之基本特性分析，同時應用固定床與旋轉窯反應系統，進行熱裂解及氣化反應，研究成果已成功驗證旋轉窯熱裂解反應系統，有助於提升鋁回收及能源應用之效率，後續若能進一步驗證規模放大之可行性，將有助於含鋁塑膠包裝廢棄物之回收與再利用處理技術選擇之參考。
;This research investigates the energy conversion efficiency and aluminum recovery of aluminum-containing plastic packaging waste by the fixed-bed pyrolysis, rotary kiln pyrolysis, and rotary kiln gasification systems. The experimental conditions mainly included pyrolysis temperatures of 450, 500, 550, and 600℃ and rotary kiln slopes of 0.052 and 0.067. In addition, the gasification temperature is controlled at 600°C, and the equivalence ratio (ER) is 0.1, 0.2, and 0.3, respectively. The conversion products yield, products characteristics, aluminum recovery efficiency, and energy yield are evaluated for understanding the feasibility of aluminum-containing plastic packaging waste recycling and energy recovery.
The experimental results indicated that the higher pyrolytic oil yield was approximately 43.09 wt% by the fixed bed pyrolysis. In the case of the rotary kiln pyrolysis, pyrolytic oil yield was decreased with an increase in the temperature as well the oil yield ranged between 2.17 wt% and 26.18 wt.%. However, the pyrolytic oil is also significantly reduced with the equivalence ratio (ER) increasing as well the range between 0.41 wt% to 0.62 wt% by rotary kiln gasification. According to the results of pyrolysis oil speciation, the oil speciation produced by the fixed-bed pyrolysis is mainly aliphatic compounds as well the oil-containing oxygen compounds produced by the rotary kiln pyrolysis and gasification. However, the oil containing oxygen compounds will significantly convert to the aromatic compounds as the ER value increases during the rotary kiln gasification.
The aluminum recovery results indicated that the highest aluminum recovery rate is approximately 93.29 wt % by rotary kiln pyrolysis operated at the temperature of 450℃ and 500℃. However, the aluminum recovery rate will decrease to 49.24-54.53 wt.% resulted in the rotary kiln gasification application. The recovered aluminum purity ranged between 86.03% and 92.79% using the rotary kiln pyrolysis system. In the rotary kiln gasification system, the recovered aluminum purity decreased significantly to 16.68-33.21%, resulting in the aluminum oxide derived by oxygen supply. Based on the XRD and SEM/EDS analysis results, it can confirm that the aluminum speciation as well aluminum oxide also presented in the recovered aluminum.
In summary, this research establishes the characteristics of aluminum-containing plastic packaging waste and studies the feasibility of aluminum and energy recovery by the pyrolysis and gasification using the fixed bed and rotary kiln system. The research has successfully verified the enhancement of aluminum recovery and energy production by pyrolysis using the rotary kiln system. Further research can successfully confirm the scale-up tests in the future. It will be helpful for the selection of recycling and reuse treatment technology for aluminum-containing plastic packaging waste. |
