Biodiesel synthesis using K2CO3/Al-O-Si aerogel catalysts

Abstract

In this study, catalysts for fatty acid methyl esters (FAME or biodiesel) synthesis with K2CO3 as the active component on an alumina/silica support were synthesized using the sol-gel method, which was followed by drying the 'dense' wet gels with supercritical carbon dioxide to obtain the aerogels. The prepared catalysts were characterized by XRD analysis, FTIR spectroscopy and N2 physisorption at 77 K, and tested in the methanolysis of sunflower oil. The effects of reaction variables, such as reaction time, temperature and methanol to oil molar ratio, on the yield of FAME were investigated. The aerogel catalysts with K2CO3 as the active component on an alumina/silica support exhibited good activity in the methanolysis of sunflower oil. The leaching of potassium when the catalyst was in contact with pure methanol under the working conditions of methanolysis was also tested in this study, indicating that it occurred only at higher temperatures, while at lower ones, it was negligible.

U ovom radu katalizator za sintezu metil estara masnih kiselina (MEMK ili biodizel) sa K2CO3 kao aktivnom komponentom na alumosilikatnom nosaču sintetizovan je sol-gel metodom nakon čega je dobijeni gel sušen uz prisustvo natkritičnog ugljen dioksida da bi se dobio aerogel. Za karakterizaciju sintetizovanih katalizatora korišćene su metode XRD, FTIR i N2 fizisorpcija na 77 K i katalizatori su testirani u reakciji metanolize suncokretovog ulja. Katalizator je testiran u reakciji metanolize suncekrotovog ulja i sintezi MEMK. Ispitan je uticaj različitih parametara kao što su vreme, temperatura i molarni odnos metanol : ulje na prinos MEMK. Aerogel katalizator sa K2CO3 kao aktivnom komponentom na alumosilikatnom nosaču pokazao je dobru katalitičku aktivnost u reakciji metanolize suncokretovog ulja. Izluživanje kalijuma u kontaktu sa metanolom na radnim uslovima metanolize takođe je testirano u ovom radu, pokazujući da ono postoji na višim temperaturama, dok je na nižim zanemarljivo.