Methodology Comparison of Life Cycle Assessment － Case Studies of High-Density Polyethylene(HDPE) Products

• Main Authors: Zhi-Kai Yang, 楊智凱
• Other Authors: Sue-Jane Lin
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/71855242030758981037

碩士 === 國立成功大學 === 環境工程學系碩博士班 === 93 === 　　This study used SimaPro 5.1 program and three models of life cycle assessment (LCA) including Eco-indicator 95, Eco-indicator 99 and EPS 2000 to analyze the environmental impacts of the manufacturing of plastic bags and to compare the distinctions among those models of LCA. 　　The system boundary of this study combined the production of high-density polyethylene (HDPE) and the manufacturing of plastic bags. Therefore, the general processes for production of HDPE in Taiwan, Ziegler Slurry and Gas Phase Fluidized bed, were combined with the manufacturing of plastic bags, and set to A factory(Ziegler Slurry plus blowing bags) and B factory(Gas Phase Fluidized bed plus blowing bags) for further comparison, respectively. 　　Results of this study indicate that the environmental impacts of A factory is similar to B factory, and both are major in environmental impact categories of “resource depletion”, “greenhouse”, “acidification”, “winter smog”, and “summer smog”. In order to decrease the environmental impacts of A or B, we must improve the energy efficiency in the reaction of polymerization process, decrease the energy intensity, replace a new reactor or apply a high-efficiency catalyst, etc. 　　The distinctions among Eco-indicator 95, Eco-indicator 99 and EPS 2000 are major in the subjective steps, weighting and single point, besides the differences of characterization, for instance, the weight of “resource depletion” in the weighting step of Eco-indicator 95 is set to zero. Therefore, the environmental impacts of the reaction of polymerization process in single point step of Eco-indicator 95 is only 40.44% for all, less than the 75.49% in single point step of Eco-indicator 99.