以殘餘生質物料替代燃煤之生命週期與健康風險評估

Life Cycle and Health Risk Assessment of Residue-based Bioenergy

劉恩廷(En-Ting Liu)

指導教授 ： 闕蓓德

國立臺灣大學/工學院/環境工程學研究所/碩士(2018年)

https://doi.org/10.6342/NTU201803525

摘要

能源使用造成環境污染並危害人體健康，成為現今國際社會必須面對的重要議題。以殘餘生物質為原料的固態生質燃料可取代高污染的燃煤，不僅可滿足能源需求、減少環境污染，亦可解決生質廢棄物過多的環境問題。然而，由於生質原料分布分散、品質不穩定且加工與使用方式多元，各個階段的差異皆會影響整體環境表現，使得生質能的永續性具有不確定性。必須確認整體生產過程符合環境永續，發展生質能才能確實降低環境衝擊，達到環境永續目標。
本研究評估生質燃料替代燃煤之環境影響。首先以生命週期評估方法，評估桃園市工業鍋爐產熱之環境衝擊，分析棕櫚殼、木顆粒及稻稈顆粒三種生質燃料使用情境，並與使用煤之基線情境比較。再以健康風險評估方法，分析工廠使用煤以及木顆粒燃料兩種情境下，桃園市污染物質NOX、SOX、PM10及PM2.5之年平均濃度，並進一步比較桃園市民眾之吸入性健康風險差異，將健康風險貨幣化。
生命週期評估結果顯示，使用生質燃料可減少46～76%的環境衝擊，可降低人體健康、氣候變遷及資源等類別衝擊，在生態品質的衝擊則增加。在四種燃料中棕櫚殼的衝擊最低，顯示燃料熱值是整體環境表現中影響最大的因子。健康風險評估結果顯示，使用生質能可大幅降低SOX濃度，進而降低民眾的吸入性健康風險。貨幣化結果顯示，健康成本較燃煤情境少926.79百萬元，與增加的生質燃料成本132.28百萬元比較，使用生質燃料可降低整體社會成本。綜合兩種評估結果，使用生質能取代煤對於整體環境、健康及社會都是有益的。

關鍵字

環境衝擊 ； 空氣污染 ； 固態生質燃料 ； 健康風險 ； 乾淨能源

並列摘要

Residue-to-energy is a sustainable way to simultaneously produce energy and reuse bio-waste. Industrial and agriculture residues are potential alternatives to fossil fuels for Taiwan. However, it is worth noting that not all biofuels are sustainable. There are some disadvantages of residue-based biofuels, such as containing low heat value, requiring energy-intensive pretreatment, requiring long distance transportation, as well as generation of airborne pollutants from bioenergy combustion.
In this study, life cycle assessment is used to evaluate the life-cycle environmental impact of four energy scenarios for industrial heating boilers in Taoyuan City: (a) palm kernel shells; (b) wood pellets; (c) rice straw pellets; and (d) coal (business as usual). Similarly, health risk assessment is used to evaluate the potential reduction in inhalation health risk and monetary valuation from using biofuel as an alternative to coal.
The LCA results showed that the environmental impacts of three biofuel scenarios had 46-76% lower impacts than those of coal scenario. The palm kernel shells scenario had the lowest environmental impacts, suggesting that the heat value of a bioenergy product was the most important factor in life cycle environmental performance. For the health risk assessment, the results indicated a significant reduction in sulfur dioxide emissions from biofuels scenarios, which consequently decreased the health risk for the local population. The monetary valuation was 926.79 million NTD lower than coal scenario, comparing to fuel cost 132.28 million, biofuel was shown to be a better fuel for Social cost. In conclusion, using biofuel to replace coal is beneficial to the environment, human health and society.

並列關鍵字

Environmental impact ； Air pollution ； Solid biofuel ； Health risk ； Clean energy

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