Supplementary data for article: Đokić-Stojanović, D. R.; Todorović, Z. B.; Troter, D. Z.; Stamenković, O. S.; Veselinović, L. M.; Zdujić, M. V.; Manojlović, D. D.; Veljković, V. B. Triethanolamine as an Efficient Cosolvent for Biodiesel Production by Cao-Catalyzed Sunflower Oil Ethanolysis: An Optimization Study. Hemijska Industrija 2019, 73 (6), 351–362. https://doi.org/10.2298/HEMIND190822033D

Supplementary material for: [https://doi.org/10.2298/HEMIND190822033D]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/3797

Triethanolamine as an efficient cosolvent for biodiesel production by cao-catalyzed sunflower oil ethanolysis: An optimization study

Triethanolamine was applied as an efficient „green“ cosolvent for biodiesel production by CaO-catalyzed ethanolysis of sunflower oil. The reaction was conducted in a batch stirred reactor and optimized with respect to the reaction temperature (61.6-78.4 °C), the ethanol-to-oil molar ratio (7:1-17:1) and the cosolvent loading (3-36 % of the oil weight) by using a rotatable central composite design (RCCD) combined with the response surface methodology (RSM). The optimal reaction conditions were found to be: the ethanol-to-oil molar ratio of 9:1, the reaction temperature of 75 °C and the cosolvent loading of 30 % to oil weight, which resulted in the predicted and actual fatty acid ethyl ester (FAEE) contents of 98.8 % and 97.9±1.3 %, respectively, achieved within only 20 min of the reaction. Also, high FAEE contents were obtained with expired sunflower oil, hempseed oil and waste lard. X-ray diffraction analysis (XRD) was used to understand the changes in the CaO phase. The CaO catalyst can be used without any treatment in two consecutive cycles. Due to the calcium leaching into the product, an additional purification stage must be included in the overall process.Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3798

Supplementary data for article: Đokić-Stojanović, D. R.; Todorović, Z. B.; Troter, D. Z.; Stamenković, O. S.; Veselinović, L. M.; Zdujić, M. V.; Manojlović, D. D.; Veljković, V. B. Triethanolamine as an Efficient Cosolvent for Biodiesel Production by Cao-Catalyzed Sunflower Oil Ethanolysis: An Optimization Study. Hemijska Industrija 2019, 73 (6), 351–362. https://doi.org/10.2298/HEMIND190822033D

Supplementary material for: [https://doi.org/10.2298/HEMIND190822033D]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/3797

Influence of various cosolvents on the calcium oxide-catalyzed ethanolysis of sunflower oil

Ten organic solvents (triethanolamine, diethanolamine, ethylene glycol, methyl ethyl ketone, n-hexane, triethylamine, ethylene glycol dimethyl ether, glycerol, tetrahydrofuran and dioxane) were applied as cosolvents in the CaO-catalyzed ethanolysis of sunflower oil performed in a batch stirred reactor under the following reaction conditions: temperature 70 °C, ethanol-to-oil mole ratio 12:1, initial catalyst concentration 1.374 mol·L -1 and amount of cosolvent 20 % based on the oil amount. The main goals were to assess the effect of the used cosolvents on the synthesis of fatty acid ethyl esters (FAEE) and to select the most efficient one with respect to the final FAEE content, reaction duration and safety profile. In the absence of any cosolvent, the reaction was rather slow, providing a FAEE content of only 89.7±1.7 % after 4 h. Of the tested cosolvents, diethanolamine, triethanolamine and ethylene glycol significantly accelerated the ethanolysis reaction, whereby the last two provided a final FAEE content of 93.1±2.1 and 94.1±1.5 %, respectively, within 0.5 h. However, because of its safety profile, triethanolamine was selected as the best cosolvent for the ethanolysis of sunflower oil catalyzed by calcined CaO

Preparation of Molybdenum Powders by Rotating Electrode Process

Molybdenum powders were produced by the rotating electrode process in helium atmosphere. The electrode diameter was 0.01 m and the angular velocity was 524 and 2094 rad/s, respectively. The increase of the angular velocity was followed by the decrease of mean particle size, which was 690 and 193 μm for the indicated angular velocities, respectively. The particles obtained were spherical, and their flow rate and apparent density was high. Theoretical cooling rates were calculated and were in the range 104–106 K/sec for particle diameters 800 μm — 50 μm. Typical powder solidification structure consisted of equiaxed grains and dendrites whose sizes were related to particle size

Kinetic properties of the Ti-Ni intermetallic phases and alloys for hydrogen evolution

The kinetics and mechanism of hydrogen evolution at Ti-Ni alloy electrodes prepared by are-melting and mechanical alloying methods has been studied by means of AC impedance spectrum measurements. The electrode, prepared by mechanical alloying (porous electrode), after activation in a 10% HF solution, is very active despite its large Tafel slope. The SEM studies show a formation of deep pores on the electrode surface. The rate constants of the forward and backward reactions of the corresponding steps were estimated by a nonlinear fitting method. It has been found that the overall reaction proceeds through a Volmer-Heyrovsky mechanism

Mechanochemical synthesis of gamma-Bi2O3

A series of gamma-Bi2O3 phases doped with Zn, Si, Pb and Fe was prepared by mechanochemical treatment of corresponding oxide mixtures with a nominal composition 6Bi(2)O(3) (.) MOx (MOx = ZnO, SiO2, PbO) and 12Bi(2)O(3) (.) Fe2O3 using high-energy ball mill. The products are characterized by X-ray powder diffraction technique. Influence of milling conditions: milling time from 5 min to 10 h, milling medium (steel or ZrO2) and injected mechanical power on unit-cell parameters and crystallinity of products, as well as on reaction kinetics are investigated and discussed

Catalytic combustion of methane over Pd containing perovskite type oxides

The mixed perovskite type oxides with nominal formula LaTi0.5Mg0.5-xPdxO3, (0 LT = x LT = 0.10) were prepared by anneling the ethanol solution of precursor in nitrogen flow at 1200 degrees C. X-ray powder diffraction (XRPD) analysis shows that the orthorhombic perovskite structure was found in all investigated samples. However, at least a part of palladium is not incorporated into perovskite structure and remains as separate phase, which is reduced to Pd-0 at 1200 degrees C. X-ray photoelectron spectroscopy (XPS) reveled the presence of Pd2+, which indicate a reoxidation of Pd-0 in the surface layers during cooling. The Pd content in the samples has a small influence on the methane oxidation activity below the temperature of 500 degrees C. At temperatures higher than 500 C, the methane oxidation activity of the sample with x = 0.05 exceeds the activity of the sample with x = 0.10. The sharp increase of methane oxidation activity over the sample with lower content of palladium at about 500 degrees C was ascribed to the higher dispersion of PdO and Pd-0 phases. Thus, the higher contribution of lattice oxygen and possible local change in oxidation state of palladium can be a reason for the enhanced activity. Contrary to the supported Pd/Al2O3 catalyst, the incorporation of palladium into perovskite matrix and interaction of PdO-Pd-0 benefits the activity of smaller particles at higher reaction temperatures

LaMO3 (M = Mg, Ti, Fe) perovskite type oxides: Preparation, characterization and catalytic properties in methane deep oxidation

Two new series of perovskite-type oxides LaMO3 (M = Mg, Ti, Fe) with different ratio Mg/Fe (MF) and Ti/Fe (TF) in the B cation site were prepared by annealing the precursor, obtained by the mechanochemical activation (MCA) of constituent metal oxides, at 1000 degrees C in air. In addition, two closely related perovskites LaFeO3 (LF) and LaTi0.5Mg0.5O3 (TM (50:50)) were synthesized in the similar way. Using MCA method, perovskites were obtained in rather short time and at room temperature. The samples were characterized by X-ray powder diffraction (XRPD), Xray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS), temperature programmed desorption of oxygen (TPD), Mossbauer spectroscopy, BET surface area measurements and tested in methane deep oxidation. According to XRPD analysis all synthesized samples are almost single perovskite phase, with trace amounts of La2O3 phase. Data of Mossbauer spectroscopy identify Fe 31 in octahedral coordination. The activity of perovskite in methane deep oxidation increases in the order TM (50:50) LT MF series LT TF series. Higher activity of TF samples in respect to MF with similar Fe content can be related to the structural characteristic., mainly to the presence of predominantly most labile oxygen species evidenced by TPD at lowest temperature of oxygen evaluation. In used experimental conditions, the Fe substituted perovskite are thermal stable up to the temperature of 850 degrees C. The stability of Fe active sites is probably the most important parameter responsible for thermal stability of perovskite, but the atomic surface composition also should be taken into account

Valorization of walnut shell ash as a catalyst for biodiesel production

The catalytic activity of the walnut shell ash was investigated in the biodiesel production by the sunflower oil methanolysis. The catalyst was characterized by the TG-DTA, XRD, Hg porosimetry, Ny physisorption, SEM, and Hammett method. In addition, the effects of the catalyst loading and the methanolto-oil molar ratio on the methyl esters synthesis were tested at the reaction temperature of 60 degrees C. The walnut shell ash provided a very fast reaction and a high FAME content (over 98%). As the reaction occurred in the absence of triacylglycerols mass transfer limitation, the pseudo-first-order model was employed for describing the kinetics of the reaction. The catalyst was successfully reused four times after the regeneration of the catalytic activity by recalcination at 800 degrees C