本研究以廢棄煉鋼爐渣作為矽源，並以碳酸鋰（Li2CO3）為鋰源，透過固相反應法製備鋰矽酸鹽非均相鹼性催化劑，並應用於生質柴油轉酯化反應。研究中分別探討起始物莫耳比、煅燒溫度及煅燒時間等製備條件對催化劑晶相組成、鹼性特性及催化效能之影響，並藉由XRD分析、Hammett 指示劑法及轉酯化反應測試進行綜合評估，以建立催化劑結構與催化活性間之關聯性。研究結果顯示，起始物比例、煅燒溫度及煅燒時間皆會影響鋰矽酸鹽晶相之生成，其中以碳酸鋰與相當於一莫耳二氧化矽（SiO2）之矽源莫耳比 2：1、煅燒溫度 800 ℃及煅燒時間 4 小時之條件下所製備之催化劑具有最佳表現。XRD 分析結果顯示，最佳化催化劑主要由正矽酸鋰（Li4SiO4）及偏矽酸鋰（Li2SiO3）所組成，其中正矽酸鋰被認為是催化劑系統中最主要之活性相。綜合分析結果顯示，催化劑之催化效能與晶相組成之關聯性較鹼強度更為顯著。在最佳反應條件下，以大豆油進行轉酯化反應時，其轉酯率可達 96.67%。此外，將催化劑應用於不同油品系統，除蓖麻油及廢食用油之轉酯率低於 80% 外，其餘油品之轉酯率皆可達 86% 以上，顯示該催化劑具有一定之原料適用性。催化劑暴露於空氣中 72 小時後，其轉酯率仍可維持 91.47%；重複使用 10 次後，轉酯率仍可維持約 86%，顯示其具有良好之環境穩定性及再利用能力。整體而言，本研究成功利用廢棄煉鋼爐渣合成鋰矽酸鹽非均相鹼性催化劑，並建立起始物比例、煅燒溫度及煅燒時間對催化劑生成與催化效能之影響趨勢。研究成果除驗證廢棄煉鋼爐渣資源化利用之可行性外，亦顯示其於生質柴油製程及非均相催化劑開發方面具有良好之應用潛力。;In this study， waste steelmaking slag was utilized as the silica source， and lithium carbonate (Li2CO3) was employed as the lithium precursor to prepare lithium silicate heterogeneous basic catalysts through a solid-state reaction method for biodiesel production via transesterification. The effects of synthesis parameters， including the molar ratio of reactants， calcination temperature， and calcination time， on the crystal phase composition， basic properties， and catalytic performance of the catalysts were investigated. XRD analysis， Hammett indicator method， and transesterification tests were employed to establish the relationship between catalyst structure and catalytic activity. The results indicated that the crystal phases of lithium silicates were significantly affected by the reactant ratio， calcination temperature， and calcination time. The optimum catalyst was obtained at a molar ratio of Li2CO3 to silica source equivalent to one mole of SiO2 of 2:1， a calcination temperature of 800 ℃， and a calcination time of 4 h. XRD analysis revealed that the optimized catalyst mainly consisted of lithium orthosilicate (Li4SiO4) and lithium metasilicate (Li2SiO3)， among which Li4SiO4 was considered the major active phase in the catalyst system. The comprehensive results further demonstrated that the catalytic performance was more closely related to the crystal phase composition than to the basic strength. Under the optimum reaction conditions， the maximum transesterification yield reached 96.67% when soybean oil was used as the feedstock. In addition， except for castor oil and waste cooking oil， the transesterification yields of the other feedstocks were all above 86%， indicating that the catalyst possessed satisfactory applicability to various feedstocks. After exposure to air for 72 h， the catalyst still maintained a transesterification yield of 91.47%， while approximately 86% conversion could still be achieved after ten consecutive reuse cycles， demonstrating its excellent environmental stability and iv reusability. Overall， this study successfully synthesized lithium silicate heterogeneous basic catalysts using waste steelmaking slag and established the effects of reactant ratio， calcination temperature， and calcination time on catalyst formation and catalytic performance. The results not only verified the feasibility of recycling waste steelmaking slag as a valuable resource but also demonstrated its potential applications in biodiesel production and the development of heterogeneous catalysts.
