Investigation of Lauric Acid Conversion with the STA Incorporated Heterogeneous Catalysts in the Liquid Phase Reaction

Abstract

In this study, firstly the synthesis of acidic catalysts was carried out by loading the active compoundsilicotungstic acid(STA) with dry (W/Si:10-50%) and wet (W/Si:10%) impregnation methods into MCM-41support material. These synthesized catalysts were used in the production of mono-di and tri laurin. Theamount of active substance in the synthesized catalysts was determined by the ratios of tungsten in STA and silicon inMCM-41 structure. Moreover, W/Si: 10% by weight of STA was applied to the support material after the calcinationprocess was loaded by dry impregnation method. Brønsted acid (BA) and Lewis acid (LA) regions of synthesizedcatalysts were determined by DRIFT analysis. The catalytic activities of the catalysts were determined by a glycerollauric acid esterification reaction in a batch reactor. The effect of calcination and active compound ratio with reactiontemperature on the lauric acid conversion and mono-di and tri laurin selectivity was investigated. Furthermore, theesterification reaction of glycerol with lauric acid was carried out under the same conditions in the presence of acommercial catalyst Amberlyst-21. The experimental results of the synthesized catalysts and Amberlyst-21catalystwere compared. The synthesized catalysts after comparison were observed that have high catalytic activity. Lauricacid conversion and monolaurin selectivity have been obtained with W/Si: 10% catalyst (dry impregnation method)3/3/1 molar ratio at383K after 6 hours 95% and 88%, respectively. XRD analysis was conducted on calcineduncalcined MCM-41support material. Moreover, the structural properties of synthesized catalysts after theesterification reaction were determined by SEM-MAPPING analysis methods.