Enhancement of Production Technology for Biodiesel Using Solid Super Acidic/Basic Catalysts

• Main Authors: Chia-Wei Shu, 許嘉威
• Other Authors: Kuen-Song Lin
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/60524958990124519870

碩士 === 元智大學 === 化學工程與材料科學學系 === 101 === The global warming has gained increased concerns, so the transformation of vegetable oils to biodiesel as bioenergy becomes more important. Biodiesel can mix with petro-diesel at any ratio and has lower amounts of NOx and SOx polluting emissions than fossil fuel. It has advantages such as low emissions, biodegradable, non-toxic, and better lubricity. In this research, the purpose is the synthesis of complete solid super-acidic SO42-/ZrO2/Al2O3, solid super-basic Na/NaOH/Al2O3, and solid super-basic KF/CaO–Fe3O4 catalysts in optimal condition. In addition, this research investigates the efficiency of esterification and transesterification. In the instrumental analysis, several experimental techniques were used; such as XRD, TGA, FE-SEM, HR-TEM, N2 adsorption, FTIR, ESCA and XAS. XRD patterns indicate that solid super-acidic SO42-/ZrO2/Al2O3 catalysts main structure has tetragonal phase. The XRD pattern of solid super-basic KF/CaO–Fe3O4 catalyst shows KCaCO3F peak, the newly formed crystal phase is favorable for weakening the catalytic activity and stability of the catalyst. The XRD pattern of solid super-basic Na/NaOH/Al2O3 catalysts shows NaAlO2 and NaOH peaks. This result makes the catalyst increased hygroscopic properties. TGA displays the thermal stability of solid super-acidic SO42-/ZrO2/Al2O3, solid super-basic KF/CaO–Fe3O4 and solid super-basic Na/NaOH/Al2O3 catalysts. We also analyzed appearance and microstructure by FE-SEM and HR-TEM. Solid super-acidic SO42-/ZrO2/Al2O3 catalysts are mainly composed of tetragonal columnar structure, solid super-basic KF/CaO–Fe3O4 catalysts have a ferromagnetic center, and solid super-basic Na/NaOH/Al2O3 catalysts have cluster structure. From N2 adsorption analysis it can be seen that solid super-acidic SO42-/ZrO2/Al2O3 and solid super-basic Na/NaOH/Al2O3 catalysts have non-porous structure, but solid super-basic KF/CaO–Fe3O4 catalysts have meso–porous structure. In FTIR analysis, we have focused on Lewis acid and Br#westeur057#nsted acid distribution on solid super-acidic SO42-/ZrO2/Al2O3, moreover, we also have investigated the solid super-basic Na/NaOH/Al2O3 and KF/CaO–Fe3O4 catalyst’s hygroscopicity. From ESCA and XPS analysis, we have confirmed that Zr valence in the solid super-acidic SO42-/ZrO2/Al2O3 catalysts are Zr4+ and Zr2+, and Fe3O4 also can be exprseeed as Fe2O3‧FeO. In this research, we have performed the esterification of methanol and soybean oil to synthesize biodiesel by packing solid super-acidic SO42-/ZrO2/Al2O3 catalysts in a self-designed reactor. The reaction was carried out under atmospheric pressure and room temperature. After esterification reaction, we also performed the esterification of methanol and soybean oil to synthesis biodiesel by packing solid super-basic Na/NaOH/Al2O3 and KF/CaO–Fe3O4 catalysts in the same reactor. The esterification experiment results showed that SO42-/ZrO2/Al2O3 catalyst has higher removal efficiency of free fatty acid than Amberlyst IR120 catalyst. The results of biodiesel yield testing, solid super-basic Na/NaOH/Al2O3 catalyst has higher biodiesel yield than solid super-basic KF/CaO–Fe3O4 catalyst. This is helpful to shorten the process time. According to the removal efficiency and biodiesel yield testing, we found that 1.5M sulfuric acid and 329℃ calcination temperature was the optimum condition for solid super-acidic SO42-/ZrO2/Al2O3 catalyst, and the 600℃ calcination temperature and 25 wt% KF were the optimum condition for solid super-basic KF/CaO–Fe3O4 catalyst.