利用生命週期評估探討廚餘處理模式對環境衝擊之研究

The Environmental Impact of Food Waste Processing by Using Life Cycle Assessment

呂從英(Tsung-Ying Lu)

指導教授 ： 羅煌木

朝陽科技大學/理工學院/環境工程與管理系/碩士(2014年)

摘要

中文摘要
經濟活動型態的改變，廢棄物日益增加，憑藉著民眾的自律性，大多數的回收類達到了不錯的回收成效，但較難回收的廚餘，則成效不彰，導致廚餘佔垃圾總量的36.28 %，廚餘具有高水分高有機物之特性，因此掩埋易導致惡臭產生，焚燒造成效率降低等問題，且廚餘中含有鹽分，會產生戴奧辛等問題，因此廚餘的資源化能源化將顯得格外重要。生命週期評估，係用於分析各種環境衝擊如(Life Cycle Assessmen; LCA)，主要分析各產品生命週期的各種環境衝擊如致癌性、呼吸性有機物、呼吸性非有機物、氣候變化、輻射、臭氧層、毒性、酸化、土地利用、礦物、石化燃料等，又將以上11項劃分為人類健康、生態系統、資源耗用三個指標。近年來也被廣泛運用在廢棄物管理方面。
本研究將各種廚餘處理模式進行生命週期評估，探討各處理方式對環境的衝擊，並探討在清運方式與廚餘的處理過程中，找尋不同的規劃下，可能發揮的最佳效益。本研究利用生命週期評估軟體SimaPro 7.1，探討台北市廚餘飼料處理、堆肥處理、焚燒處理及廚餘絞碎機處理等技術對環境的衝擊評估，藉以找對環境衝較為友善的處理技術。尋找廚餘最佳化處理模式，提供政府施政機關參考，在環境與成本考量下，依據現有處理機構探討興建技術廠址的必要性。研究結果顯示，在人體健康危害的部分，焚燒處理因污染排放較大衝擊相對提升，其造成之影響為四項處理方案之冠，廚餘絞碎機處理係藉由厭氧則因發酵中造成部份污染排放及污泥餅之滲出水，因此衝擊屬次之方案，因此衝擊屬次之技術，其次養豬和堆肥；生態系統品質的部分焚燒處理，因為排放污染物產生較大之衝擊，其次為廚餘絞碎機處理，因厭氧發酵過程中部分沼氣洩漏以及沼氣純化所釋放之CO2 ，因此衝擊屬次之方案，飼料養豬及堆肥則不明顯；能資源耗用以養豬所造成的影響最大，因為廚餘蒸煮殺菌過程中，大量使用柴油所致。在三項指標中均顯示堆肥處理方案對環境衝擊最小，養豬的部分則為耗用資源為主，但兩項處理方案均架構在民眾的自主性上，因此回收率一直停滯餘在約30%，造成回收成效不彰，導致仍然多數廚餘進入焚燒系統進行處理。目前廚餘回收成效不彰，因此建議採用多元化的廚餘回收方案進行廚餘回收。由於廚餘絞碎機處理方案，在台灣尚未推廣，因此建議可以針對厭氧消化對增加廚餘絞碎機處理後對環境之衝擊影響。

關鍵字

生命週期評估 ； 環境衝擊 ； 廚餘絞碎機 ； 廚餘處理方案

並列摘要

Abstract
Due to changes in the nature of economic activities, amounts of waste are increasing even as the majority of recycled goods have, through public discipline, reached a decent level of recycling efficiency. However, food waste recycling is more difficult to implement and thus shows poorer results, such that food waste accounts for 36.28% of the total volume of waste. Food waste is high in water content and organic matter, and therefore is likely to produce a stench if buried. Meanwhile, efficiency will be reduced if such waste is burned. Moreover, food waste has a high degree of salinity, which causes problems such as the production of dioxins. Therefore, the waste of resources and waste of energy resulting from food waste have become especially important. Life cycle assessment (LCA) is method mainly used to analyze the various environmental impacts of the life cycles of different products, including carcinogenic and respiratory organic matter, respiratory non-organic matter, climate change, radiation, the ozone layer, toxicity, acidification, land use, minerals, and fossil fuels. The aforementioned 11 impacts can be categorized in terms of their effects on 3 indicators: human health, the ecosystem, and resource consumption. LCA has also been widely used in waste management in recent years.
This study conducted LCA on various food waste treatment models to investigate the impact of each treatment on the environment as well as the optimal efficiency that may be reached in the cleaning and delivery method and the treatment process of food waste under different plans. This study used the LCA software program SimaPro 7.1 to explore the impact that techniques such as food waste animal feed treatment, compost treatment, incineration treatment, and food waste disposer treatment have on the environment in order to find an environmentally friendly treatment technique. The purpose of finding an optimal treatment model for food waste is to provide governmental organizations with a reference for exploring the necessity of establishing technical factories based on existing treatment institutions and considering environmental and cost factors. The research results showed that, in terms of human health hazards, incineration treatment has a greater impact due to its higher discharge of pollutants, with its effects being the greatest among the four types of treatment methods. Food waste disposers release a portion of the pollutants and sludge cake leachate through anaerobic fermentation; the impact of this method and technique is therefore the second greatest, followed by the effects of pig breeding and composting. In terms of ecosystem quality, incineration treatment causes the greatest impact due to the resulting discharge of pollutants. The next greatest impact is again from food waste disposer treatment due to landfill gas leaks and the CO2 released during the landfill gas purification process of anaerobic fermentation. This impact was therefore the second greatest, while the impacts of pig breeding and composting were not evident. In terms of energy and resource consumption, pig breeding has the greatest impact due to the large amount of diesel used during the cooking and sterilization process for the food waste. The three indicators all showed that composting treatment has the smallest impact on the environment, while the impacts of pig breeding are mainly focused on resource consumption. However, these two treatment methods are both dependent on public discipline, and therefore the recycling rate has continued to stagnate at approximately 30%. This indicates a poor recycling efficiency, and leads to the majority of food waste being incinerated. The current recycling efficiency of food waste is poor, and so it is suggested that diversified food waste recycling methods be adopted. Because food waste disposer treatment has not yet been promoted in Taiwan, it is suggested that a focus can be placed on the influence that anaerobic digestion has on increasing the impact that food waste disposers have on the environment.

並列關鍵字

life cycle Assessment ； food waste treatment ； environmental impact ； food waste disposer

參考文獻

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