磁性固體鹼觸媒之合成及其應用於生質柴油製造

Synthesis of Magnetic Solid Base Catalysts and Their Application for Biodiesel Manufacturing

涂培琳(Pei-lin Tu)

指導教授 ： 張慶源

國立臺灣大學/工學院/環境工程學研究所/碩士(2017年)

https://doi.org/10.6342/NTU201703667

摘要

本研究應用磁性固態鹼觸媒(CaO-MgO-SiO2-Fe3O4, CM-SM)進行轉酯化反應製備生質柴油。利用新型可回收磁性固態觸媒，可增加觸媒的回收率並能重複使用，減少材料浪費及降低廢液處理成本。藉由磁性固態鹼觸媒對大豆油轉酯化反應找出最適條件，再進行痲瘋樹油兩階段轉酯化反應，並透過分析反應後所得生質柴油性質包括酸價、碘價、動黏度、密度及熱值等性質進行討論。
鈣鎂質量比為9:1之磁性固體鹼觸媒(CM9-SM)為次微米顆粒(100~200 nm)，飽和磁化量為7.76 emu/g，具有高比表面積(16.14 m2/g)，能和反應物有較大的接觸機會，觸媒表面披覆之鈣含量高(17.69 wt %)，具有一定之催化活性。結果顯示對大豆油進行轉酯化反應所得最適條件為甲醇與油莫耳比(M:O)為12:1、轉酯化溫度(TT)為363 K、轉酯化時間(tT)為3 h、觸媒添加量(MC)為3 wt%及觸媒鈣濃度(CCa)為17.9 wt%，其轉酯率(YF)為98.46 %。但觸媒之重複使用性不佳，主要原因為Mg的溶出、觸媒表面活性位置減少等造成催化活性之損失。於上述條件當tT為3小時時，使用第一次時轉酯率為98.3~99.74%，但重複使用第一次之轉酯率僅12.04~12.80%。在對痲瘋樹油轉酯化反應中，轉酯率達97.77%。
大豆油生質柴油及痲瘋樹油生質柴油之含水率高，且皆高於標準規範，可透過硫酸鎂脫水或蒸餾等方式去除水分，其餘性質如酸價及密度已符合法規標準(CNS 15072)。大豆油生質柴油的碘價及痲瘋樹油生質柴油的動黏度皆略高於法規，此可藉由摻配方式改善。

關鍵字

生質柴油 ； 大豆油 ； 痲瘋樹油 ； 磁性固體觸媒 ； 轉酯化反應 ； 氧化鈣 ； 氧化鎂

並列摘要

In this study, transesterifications of soybean oil and jatropha oil to biodiesel using magnetic solid alkali catalysts (CaO-MgO-SiO2-Fe3O4, CM-SM) were examined. The use of recyclable magnetic solid catalysts can increase the catalyst recovery efficiency and reusability, also can decrease the waste of materials and reduce the cost of wastewater retreatment. The mesoporous CM-SM catalyst was prepared by impregnant method. The characteristic analyses of biodiesel include acid value, iodine value, kinetic viscosity, density and heating value.
The CM9-SM particles are submicron particles size of 100~200 nm. It posses magnetic susceptibility of 7.76 emu/g and has high specific surface area with BET surface area of 16.14 m2/g and thus can be recovered by magnetic separation and easily contact with the reactant. The Ca concentration (CCa) in CM9-SM catalysts is as high as 17.69wt% which offers promising catalysis acitivity in transesterification process. The results of soybean-oil biodiesel (SOB) show that the proper operating conditions are 12:1 molar ratio of methanol to oil (M:O), 3 wt% of catalyst loading (MC) and 17.9 wt% Ca concentration in catalyst at 363 K (TT) for 3 hours (tT). Under the operating conditions, the yield of fatty acid methyl ester (YF) can reach 98.46 %. However, CM9-SM reusability was not good with yield declined from 98.3 ~ 99.74% to 12.04 ~ 12.80% for the second reuse. The main cause may be due to the dissolution of calcium and magnesium and deposition of organic matter on catalyst surface. Jatropha-oil biodiesel (JOB) with yield of 97.77% was producted by using a two-stage transesterification process.
Properties of SOB and JOB of acid value and density comply with standards (CNS 15072). However, the water contents are higher than the standard. The water in oil can be removed by distillation or magnesium sulfate. Furthermore, the iodine value of SOB and kimetic viscosity of JOB are slightly higher than the standards and can be improved by blending with other biodiesel.

並列關鍵字

Biodiesel ； soybean oil ； jatropha oil ； magnetic solid catalysts ； transesterification ； calcium oxide ； magnesium oxide

參考文獻

35.田偲穎，2015，「以超音波輔助半連續式痲瘋油轉酯化程序產製生質柴油」，國立臺灣大學環境工程研究所碩士論文。

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