Cholada Komintarachat

A KCr/calcium oxide (CaO) bifunctional catalyst was synthesized from CaO from eggshells and impregnated with K₂Cr₂O₇ (KCr). The catalysts were assessed in a transesterification reaction between waste cooking oil and ethanol (EtOH) for the biodiesel production. The properties of the KCr/CaO catalyst were investigated by using scanning electron microscopy, X-ray diffraction, ATR/FTIR, TGA, and FESEM-EDS. The results show that Cr₂O₇ ^2– can be reduced by trace elements (Mg, Si, and C) in CaO and converted to Cr₂O₃, which facilitates catalytic activity. The reactions were optimized using a Box-Behnken design and response surface methodology (RSM), and the results were analyzed by analysis of variance. According to the RSM, the consequences showed that an EtOH-to-WCO molar ratio of 12, KCr/CaO of 4.0% w/w, and 180 min produced an 89.32% biodiesel yield. Reaction catalysts and time were key factors influencing the biodiesel synthesis. The biodiesel under these conditions was found to be substantially consistent with the parameters given in ASTM D6751 and EN 14214.

A conventional biofuel production via transesterification of fatty acids and alcohols in presence of a basic or acidic catalyst produces glycerol by-product that lowers the biofuel yield. Alternatively, interesterification reaction has been gained further attention to substitute the conventional reaction due to no glycerol formation. Furthermore, the interesterification produces a value-added by-product of triacetin, a good bio-additive as anti-knocking agent and cetane number improver. The aim of this work is to investigate the interesterification of fatty acids in waste cooking oil (WCO) and ethyl acetate (ETA) under solid catalyst calcium oxide (CaO) catalyst derived from eggshells for biofuel production. The eggshell catalyst not only reduces environmental problem, but also reduces the cost of biofuel raw material. In this study, eggshell waste was grounded after cleaning up and the powder produced was calcined at 900 C for 4 hours in a furnace. The catalyst was characterized using the Fourier transform-infrared spectroscopy and the biofuel yield was determined by the gas chromatography. A certain amount of 4.0 wt% of catalyst was consumed throughout the experiment with varied parameters such as molar ratio of WCO and ETA, reaction time and temperature. The subsequent results indicate that the CaO derived from eggshell can convert the fatty acids in WCO to biofuel with high quality according to ASTM specifications.

Density of Ethyl Acetate-Palm Oil Mixture in Supercritical Condition

Problem statement: Waste used Cooking Oil (WCO) harmfully affected to environment and human’s health can be a feedstock for producing biodiesel. Approach: The conversion of Fatty Acid and Free Fatty Acid (FFA) of WCO with 15.0% w/w FFA content to biodiesel was studied through transesterification reactions. This work investigated the effects of alcohol and catalyst quantity, reaction time and temperature on the FFA conversion and biodiesel production and also determines the optimum condition. Results: The optimum use of 5% w/w potassium hydroxide (KOH) catalyst at 70°C for 2 h yielded 88.20% FFA conversion and 50% biodiesel recovery of WCO. For the reaction rate analysis, based on Arrhenius equation, the activation energy of 47.07 kJ.mo1-1 and the pre-exponential factor of 7.58×1010 min-1 were obtained using pseudo first-order model. In addition, the produced biodiesel was blended with diesel in the volumetric proportions of 5:95 (ExB5), 20:80 (ExB20) and 50:50 (ExB50) and characterized by FT-IR, in order to compare to biodiesel blend sold in local gas station (B5). It was observed that the ExB5 has exhibited the same functional group as of the B5. Conclusion: The produced biodiesel may be used in diesel engines if other properties are tested for compatibility. This provides one more choice for alternative energy and commercialization.