本研究以生命週期評估探討臺灣塑木產品之環境衝擊與生態效益，並研究產品如何導向綠色產品。以木材、傳統塑膠(HDPE)及塑木為個案，探討三者之環境衝擊與生態效益，其環境衝擊包括能源投入、碳足跡、生態毒性與其他環境衝擊類別。研究結果主要包括四大部分，第一部分為個案產品生命週期評估環境衝擊結果；第二部分為個案之能源投入、碳足跡與生態毒性；第三部分為產品生態效益比較；第四部分為環境改善方案模擬。每公斤之功能單位之結果顯示： (1)產品生命週期評估，以HDPE能源投入較高(118.04MJ)，其次為塑木產品為(70.45MJ)，能源投入較低產品為木材(23.12MJ)；(2)產品碳足跡以塑木最低為8.10kgCO2-eq.其次為木材8.27kgCO2-eq.；(3)產品生態效益以HDPE較優5.62NT$/kgCO2-eq.，其次為塑木3.85NT$/kgCO2-eq.；(4)以熱泵替代傳統窯乾法改善方案，可減少2.35MJ能源投入，並可減少碳足跡5.73kgCO2-eq.；在防腐處理減量方案之生態毒性比較，添加木材防腐劑可增加產品使用年限，然將增加產品之生態毒性。 The study focused on environmental impact and eco-efficiency for wood of Taiwan by Life Cycle Assessment (LCA), and guide for the green products. Compare with environmental impacts and eco-efficiency among the wood, high density polyethylene (HDPE) and wood plastic composites (WPC) according to the energy inputs, carbon footprint, ecological toxicity and other environmental impact categories. The results contain four parts, the first part was LCA results and interpretation; the second part was the energy consumption, carbon footprint and eco-toxicity among three materials; the third part of eco-efficiency results; and the last was environmental improvement simulations. The results indicated, (1)About LCA results, the HDPE energy was with 118.04MJ, the next was WPC with 70.45MJ, and the least was the wood with 23.12MJ, respectively; (2)The carbon footprint of WPC was less with 8.10 KgCO2-eq., the next was wood with 8.27kgCO2-eq.; (3)The HDPE eco-efficiency was better than the WPC, the value was 5.62NT$/kgCO2-eq. and 3.85NT$/kgCO2-eq.; (4)The heat pump alternation decreased by 2.35MJ energy input compared with the dry kiln process, and the carbon footprint benefit with 5.73kgCO2-eq.; Compare with the wood preservation and free preservation scenarios, the benefit indicate increasing the using lifetime but increasing the eco-toxicity value span the life time.
