| 摘要: | 海水淡化技術是一種非常耗費能資源取得淡水的方式，而利用太陽能做為驅動海水淡化系統之能量來源是希望藉此能減少海水淡化技術之能資源消耗，本研究是對於太陽能驅動薄膜蒸餾海水淡化廠進行生命週期評估，研究範圍設定於生命週期-使用階段，評估海淡廠在使用階段時各個程序之環境衝擊，將評估結果提供給設計團隊以達到預先改善之效果。
本研究之生命週期評估主要是針對前處理製程、中心薄膜蒸餾製程以及末端處理製程進行評估，主要研究的項目為設備所消耗之能資源、海水淡化過程中所投入之藥劑及藥量，而評估之方法是根據國際ISO 14040、ISO 14044的生命週期規範，然後藉由德國PE公司研發的LCA運算軟體-GaBi 5來計算Eco-indicator 99衝擊指標，找出各個製程之衝擊值。
結果顯示，太陽能驅動薄膜海水淡化廠每日生產1,000噸淡水所消耗電量為5,662 kWh，各個部份分別為前處理2,350 kWh/day、中心薄膜過濾2,805 kWh/day、末端處理508 kWh/day。藥劑使用部份：次氯酸鈣用量為129.9 kg；HCl用量為6.1 kg；氫氧化鈉用量為0.11kg。以各個製程對環境衝擊高低為：中心薄膜蒸餾製程>前處理製程>末端處理製程。以每日生產1,000噸淡水對環境衝擊主要三項，分別為可吸入性無機物〔Respiratory (inorganic)〕181 Pt，接著為化石燃料〔Fossil fuels〕80.1 Pt，其次為氣候變遷〔Climate Change〕26.2 Pt。
Desalination system can get fresh water from seawater, but it is extremely energy consumption. However, use of solar energy driven desalination system can decrease the energy consumption. The aim of this study is to assess the life cycle assessment (LCA) of the solar-driven membrane distillation desalination plant. The scope of the LCA was set in the operation stage of the plant. The environmental impact of the every stages in the plant were assessed, the results will be offered to the research group of the solar-driven membrane distillation desalination system.
In this study, desalination system was separated into three divisons. There were pre-treatment process, centre membrane filtration process, end-of-pipe treatment process. The main items of this study included the energy consumption of the equipment, and the quantity of chemicals usage during the treatment process. The assessment method is based on ISO 14040 and ISO 14044 environmental management guideline. GaBi 5 software was used to calculate the environmental impact at each stage.
The results indicated that producing 1,000 ton/day of fresh water needs total power consumption of 5,662 kWh which included pre-treatment 2,350 kWh/day, centre membrane filtration 2,805 kWh/day, and end-of-pipe treatment 508 kWh/day. Chemicals consumption were Calcium hypochlorite (Ca(OCl)2) 129.9 kg, Hydrochloric acid (HCl) 6.1 kg, Sodium hydroxide (NaOH) 0.11 kg. The order of environmental impact were：centre membrane filtration process> pre-treatment process> end-of-pipe treatment process. The major three environmental impacts were respiratory (inorganic) 181 Pt, fossil fuels 80.1 Pt, climate change 26.2 Pt respectively. |
