半導體業超純水系統之生命週期評估及生態效益分析研究

Abstract

半導體業超純水系統提供產品製造之清洗用水，其重要性與技術性是相當高。本研究藉由生命週期評估技術，及生態效益指標來量化超純水的製造所需相關設備的耗能、產生的廢水、廢棄物對生態環境衝擊影響，並比較分屬兩廠的兩套不同超純水系統對環境的衝擊之差異，最後加入生命週期成本分析，以經濟角度與環境衝擊上研究分析。 研究結¬¬果顯示系統製程所衍生之衝擊，在Eco-indicator 99之三大類損害類別中，頗具一致性，A廠以Polish系統為主要衝擊來源，B廠以Make up系統為主要衝擊來源，其中以生態系統品質、資源耗用等衝擊較明顯。生態效益分析差異性主要是設備之泵動力(A廠)以變頻控制明顯優於以全載(100%)供應(B廠)，及採用熱泵為熱交換與傳統使用鍋爐為熱交換比較，採用熱泵的超純水系統(A廠)節能效益明顯比較好。兩套超純水系統為不同系統商設計，生命週期成本分析比較；兩廠之初設及操作成本費用差異不大，主要是維護費用及能源消耗費用則A廠明顯比B廠優異，生命週期成本上， A廠比B廠表現好。

Ultrapure water system provides clean water products manufacturing in semiconductor industry, the purpose of this study is the application of life cycle assessment and eco-efficiency to analyze environmental impacts of two different sets of ultrapure water system. In addition, the use of life cycle cost method to analyze their economy and environmental impact is also included. According to the classifications in the Eco-indicator 99, the results shows there are similar impacts caused by two sets of ultrapure water system. The source of major impact is from the polishing and make up process in ultrapure water systems. Among them, the most significant impact is energy consumption. Eco-efficiency ratios of indicator have shown that factory A has a better performance on energy efficiency, it is because pump in the factory A is controlled by frequency, not in full run like factory B. Moreover, the result of cost analysis on life cycle shows that factory A is better than factory B.