台灣利用短輪伐期木質作物生產生質酒精之成本效益分析

Abstract

生質酒精為可再生性資源，能作為汽油的替代燃料，成為有效舒緩能源、環境問題之對策。本文旨在擬定並評估以短輪伐期木質作物製造生質酒精的經營計畫。首先，分別根據銀合歡、孟宗竹與相思樹三樹種之特性，擬定林農木竹材生產供作廠商製造生質酒精之經營方案。並以成本效益分析將經營方案之投入成本與產出效益貨幣化，藉以評估三經營方案之淨效益現值、益本比、內部報酬率，再就重要變數行敏感度分析，最後參照評估結果擬定政府能源政策措施。 本研究顯示三經營方案於人力與資本等投入集約程度依序為銀合歡、孟宗竹與相思樹；單位面積土地酒精之產出效率依序為孟宗竹6.12公秉/公頃/年、銀合歡4.77公秉/公頃/年與相思樹4.10公秉/公頃/年；三種木竹製造酒精之投資成本效益淨現值依序為銀合歡130.3百萬元、孟宗竹7.5百萬元與相思樹-514.2百萬元。本研究顯示，擬在台灣利用短輪伐期木質作物發展氣化合成生質酒精，以有限土地生產最多國內生質酒精為目標時，孟宗竹經營方案較為適合；而在以投資效益最大為目標時，銀合歡經營方案則較為合適。就敏感度分析可知，木竹材產量與酒精價格對經營利潤影響顯著，其中又以銀合歡經營方案較孟宗竹經營方案能承受更高的風險。在比較能源政策措施上，政策目標為酒精添加3% 時，以補貼政府需負擔25.28億元的國庫支出，以強制添加汽油消費者需增加負擔21.12億元。

Bioethanol is a renewable resource as petroleum substitution, relieving the energy and environmental problems effectively. The purpose of the thesis is devising and assessing the management plan which is using short rotation woody crops on gasification and catalyst of bioethanol in Taiwan. At first, according to the characteristics of White Popinac (Leucaena leucocephala), Mosochiku (Phyllostachys pubescens) and Taiwan Acacia (Acacia confuse), and to draw up the business plan for forestry farms produce timber and bamboo for bioethanol manufacturers to produce bioethanol. Second, Using cost benefit analysis turns input cost and output benefit into price, then assess net present value, benefit-cost ratio, internal rent to these three business plans; furthermore, choose the important parameters to perform sensitivity analysis. In the end, consult assessment result to draft government energy policy. This research shows the gradation of these three business plans in intensive farming is White Popinac, Mosochiku and Taiwan Acacia; the gradation of Ethanol production in unit area is Mosochiku 6.12 kl/ha/y, White Popinac 4.77 kl/ha/y, Taiwan Acacia 4.10 kl/ha/y. The gradation of cost benefit analysis in net present value is White Popinac 130.3 million dollars, Mosochiku 7.5 million dollars, Taiwan Acacia -514.2 million dollars. By sensitive analysis, timber, bamboo production and bioethanol price both are important parameters. In addition, White Popinac business plan with better risk endurance than Mosochiku. According to energy policy, when the goal of policy is adding 3% ethanol to gasoline, government need to spend 25.28 billion dollars on subsidies and gasoline and consumers of gasoline have to increase 21.12 billion dollars.