水泥業替代燃料減碳效益之綜合評估

Abstract

隨著全球節能減碳與能源轉型趨勢加速推動，我國環境部於113年頒布「碳費徵收辦法」，促使年排放量超過2.5 萬噸二氧化碳當量的企業積極尋求低碳轉型策略。在工業部門之中，水泥業因高度仰賴化石燃料進行熟料煅燒，不僅為全球第三大工業能源消耗者，其碳排放亦佔全球總量約7%。水泥製程中約有40%的碳排來自燃燒煤炭、石油焦與天然氣，為當前水泥業環境衝擊熱點，為因應全球減碳趨勢，水泥業有尋求替代能源之急迫性。 本研究整合環境與經濟層面，探討水泥業在未來能源轉型以及碳費徵收情境下，最佳替代燃料配比策略。採用生命週期評估方法，分析各種類替代燃料應用於水泥製程對各項環境衝擊類別之相對表現，並進一步透過多目標線性規劃模型，優化燃料配比以同時最小化環境衝擊與燃料成本。模型情境考量熱值替代率、燃料許可條件、碳費費率與技術限制等多重參數，並以110年為基線，模擬包含水泥廠自主減量目標與碳費政策導入等多種未來情境。 研究結果釐清不同替代燃料種類衝擊熱點來源，在熱值替代率分別為25%、35%、50%之情境下，固體再生燃料綜合效益最佳；而污泥與廢輪胎燃料則受限於前處理衝擊與成本負擔。木材雖為現行主要替代燃料，惟因熱值偏低，未來競爭力可能受限。儘管研究結果顯示，透過減少產能可協助企業達成碳費優惠門檻 ，並最高可達86.05%熱值替代率，但此一策略可能降低水泥營收，為提升企業之低碳轉型韌性，建議企業於推動替代燃料應用時，應同步導入其他減碳技術措施，以兼顧環境永續目標與營運穩定性。本研究釐清水泥業替代燃料導入下之衝擊關鍵，亦可作為其他碳密集型產業採納替代燃策略之政策建議，研究成果有助於提升企業在碳費制度下的適應能力，並加速實現減碳目標與循環經濟之推動。

With the global acceleration of energy transition and decarbonization efforts, Taiwan's Ministry of Environment announced Regulations Governing the Collection of Carbon Fees in 2024, mandating enterprises emitting over 25,000 metric tons of CO₂-equivalent annually to actively pursue low-carbon transition strategies. Within the industrial sector, the cement industry remains highly dependent on fossil fuels for clinker production, making it the third-largest industrial energy consumer globally and contributing approximately 7% of total global CO₂ emissions. Notably, about 40% of emissions from cement production originate from the combustion of coal, petroleum coke, and natural gas, underscoring the urgency for the industry to adopt alternative energy sources in response to international decarbonization trends. This study integrates environmental and economic considerations to investigate optimal alternative fuel blending strategies for the cement industry under future energy transition scenarios and carbon fee policies. A life cycle assessment (LCA) approach is employed to evaluate the relative environmental performance of various alternative fuels used in cement production, followed by the application of a multi-objective linear programming model to optimize fuel composition with the dual objectives of minimizing environmental impacts and fuel costs. The optimization model incorporates multiple parameters, including thermal substitution rate (TSR), fuel permit constraints, carbon fee rates, and technological limitations, using the year 2021 as the baseline. Multiple future scenarios are simulated, including voluntary emission reduction targets and carbon fee implementation. The results identify the environmental hotspots associated with different types of alternative fuels. Among the scenarios with TSR levels set at 25%, 35%, and 50%, solid recovered fuel (SRF) demonstrates the most favorable overall performance. In contrast, sludge and tire-derived fuel (TDF) face limitations due to high pre-treatment impacts and cost burdens. Although waste wood is currently the most widely used alternative fuel, its relatively low calorific value may hinder its future competitiveness. While reducing production can help enterprises qualify for carbon fee discounts—achieving up to 86.05% TSR—this strategy may also introduce financial risks. To enhance the resilience of low-carbon transitions, it is recommended that the adoption of alternative fuels be complemented by additional decarbonization measures, such as improving energy efficiency and implementing carbon capture, utilization, and storage (CCUS) technologies, thereby ensuring both environmental sustainability and operational stability. This study elucidates the key environmental impacts associated with the use of alternative fuels in cement production and provides policy implications for other carbon-intensive industries. The findings contribute to enhancing industry adaptability under carbon pricing mechanisms and accelerating progress toward decarbonization and circular economy goals.