| 摘要: | 隨著民眾環保意識抬頭，企業紛紛開始追求永續發展。永續發展定義為「人類的發展能夠滿足當代的需求，且不致危及到子孫滿足其需要的能力」，而談永續發展，須對產品的整個生命週期對於環境的衝擊，作全盤考量。
本研究對太陽能薄膜蒸餾海水淡化廠做生命週期評估，分析在建造階段原料之使用與淡化過程對環境的衝擊，並找出各單元中對環境負擔較大者，提供研發團隊修正之參考。
本研究使用生命週期評估軟體GaBi 6 來計算Eco-indicator 99的衝擊指標，模擬全太陽能薄膜蒸餾海水淡化系統(SE)、傳統逆滲透海水淡化系統(RO)以及混和能源薄膜蒸餾海水淡化系統(HE系統)三種情境，以生產100m3/day之淡水為功能單位，評估建廠階段所需原料與營運階段所造成的環境衝擊。
結果顯示在建廠階段使用原料方面三種系統衝擊大小順序為SE系統最大、HE系統次之而RO系統最小，主要原因為海水轉換效率，SE與HE系統為10%，而RO系統為30%，因此SE與HE系統所需設備及廠房皆較RO系統為大，且SE與HE系統所需使用之太陽能史特靈碟型盤需要極大的土地面積。在營運階段方面以RO系統衝擊最高、HE系統次之、SE系統最小，主要原因為能源使用，台灣目前電力來源以燃煤發電為主，由於開採煤礦在化石燃料因子的衝擊有顯著影響，發電過程排放硫、氮等氧化物，導致可吸入無機物增加。
太陽能碟型盤使用原鋁製作，整體衝擊以SE系統最大、HE系統次之、而RO系統最小，其原因為RO系統在營運階段之衝擊雖遠大於SE、與HE系統兩廠，但SE系統與HE系統在建廠階段碟型盤引擎與廠房大小以及桶槽需求量使用原料皆大於RO系統(約3倍)，導致SE與HE兩系統整體衝擊大增，其中以可吸入性無機物、化石燃料以及氣候變遷最為明顯。
如使用回收鋁製作碟型盤，SE系統與HE系統之衝擊將大幅下降，在整體衝擊上RO系統衝擊最高為、HE系統次之，SE系統最低，主要原因為RO系統整廠能源來自台電所提供之電力，造成人體健康衝擊項目極大所導致。
關鍵字:太陽能、海水淡化系統、Gabi、生命週期評估
Owing to the rising awareness of environmental protection, sustainable development is being required and meets the needs of enterprises. Sustainable development is the development that meets the needs of the present without compromising the ability of future generations to meet their own needs. All impacts to environment should be considered comprehensively into the life cycle assessment of one product.
The aims of this study: (1) evaluate the life cycle assessment of thin film solar distillation desalination plant, (2) explore the environmental impacts of raw material use during the construction procedure and the impacts to desalination process, and (3) provide more useful environmental loading analyses to further studies.
The software, GaBi6, was used to calculate the impacts of Eco- indicator 99. GaBi6 provided modules to model these three cases: whole solar thin film distillation desalination systems (SE), reverse osmosis desalination systems (RO), and thin film distillation desalination systems mixing energy (HE). Each of cases was hypothesized that 100 m3 of fresh water produced per day to evaluate impacts on construction procedure and operating procedure.
The results showed the impacts in orders on entire construction procedure were following: SE > RO > HE, which reflected the differences of seawater transfer efficiencies. The transfer efficiencies of SE and HE were the same as 10%, while that of RO was 30%. In other words, larger instruments, plants, and land-use were required in SE and HE rather to RO. On the operating procedure, the impacts in orders were RO > HE > SE, owing to the “energy use”. In Taiwan, most generations of electric powers were by coal-fired. As a result, fossil fuels increased the emission of sulfur and nitrogen oxides, and raised the risk of inorganic substance-intake.
Besides, solar disks were manufactured by Aluminum, so the total environmental impacts were in sequence of SE > HE > RO. In the case of operating procedure, the impacts of RO were far more than these of SE, or HE.
In the case of construction procedure, the solar disks, plant-size, and tankages of SE, or HE were about three times than these of RO. The contributions of inorganic respiratory, fossil fuels, and climate change were the most significant impact items to environment.
Once the Recycling aluminum applied in the solar disks of SE or HE, total impacts decreased significantly. The total environmental impacts were in sequence of RO > HE > SE. The risks of human health were raising by means of the electric power produced . |
