| dc.description.abstract | 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. | en_US |