Uticaj kosolvenata na etanolizu suncokretovog ulja katalizovanoj kalcijum-oksidom: doktorske disertacije

Abstract

In this dissertation, the influence of different organic solvents (triethanolamine, diethanolamine, ethylene glycol, methyl ethyl ketone, n-hexane, triethylamine, ethylene glycol dimethyl ether, glycerol, tetrahydrofuran and dioxane) as cosolventethanolysis of sunflower oil catalyzed by calcinated CaO. Ethanolysis was performed as a heterogeneous base-catalyzed process in which calcinated CaO in a stirred batch reactor was used as a catalyst. The reaction conditions were: temperature 70 °C, ethanol:oil molar ratio 12:1, catalyst concentration 1.374 mol·dm-3 and cosolvent amount 20% by weight of oil. Without cosolvent, the reaction is relatively slow, because the EEMK content of 89.7 ± 1.73% was obtained only after 4 h of reaction. Of the cosolvents used, only diethanolamine, triethanolamine and ethylene glycol had a positive effect on the rate of ethanolysis reaction, with the use of triethanolamine and ethylene glycol achieved the highest EEMK content of 93.1±2.1 and 94.1± 1.5%, respectively, after 0,5 h reaction. Based on the experimental results, triethanolamine and the cosolvent that had the greatest positive effect on the rate of the transesterification reaction of the safety profile were selected, triethanolamine was selected as the best cosolvent of the reaction ethanolysis reaction catalyzed by CaO. The reaction with triethanolamine was optimized with respect to temperature (61,6-78,4 °C), ethanol:oil molar ratio (7:1-17:1) and cosolvent amount (3-36%, by weight of oil) using a central composite rotatable experimental design (RCCD) in combination with a response surface methodology (RSM). The optimal reaction conditions are: molar ratio ethanol:oil 9:1, temperature 75 °C and cosolvent amount 30% ( to the mass of oil), where the predicted value of EEMK content after only 20 min of reaction was 98,8%, while the experimentally obtained value was 97,9 ± 1,3%. High EEMK contents were also obtained during the application of expired sunflower oil, hemp oil and waste lard. X-ray diffraction analysis (XRD) was used to understand the structural changes of CaO catalysts. The CaO catalyst could be used without any additional treatment in two consecutive cycles. Due to the leaching of calcium into the product, an additional purification process must be included in the entire production process.