Effect of Calcination Temperature on Catalytic Activity of Synthesis SrO/S-ZrO2 by Solvent-free Method in Esterification of Oleic Acid

Currently, the major concern in production of biodiesel fuel is to exploit new catalysts with the optimal conditions. In this study, the effect of calcination temperature on the synthesis of 20 mol % SrO/S-ZrO2 was examined by solvent-free method. Moreover, the ability of the catalyst for esterification reaction of oleic acid with methanol was also assessed. To obtain this objective, X-ray diffraction and infra-red spectroscopy method was employed to characterize the structure of the catalysts. The results of this study reveal that the calcined strontium oxide promoted sulfated zirconia at 500 °C has the highest percentage of tetragonal phases of zirconia. It has also been demonstrated that owing to the high percentage of the tetragonal phases of zirconia and the acidity of the catalyst, conversion of oleic acid to fatty acids methyl esters (i.e., FAME) could be enhanced from 88.36 % to 91.13 %. Moreover, it has also been shown that 20 mol % SrO/S-ZrO2 exhibits higher activity in comparison with S-ZrO2 at 500 °C in esterification reaction due to the presence more sulfate ions and higher activity of strontium ions

Preparation of Nano-Size Al-Promoted Sulfated Zirconia and the Impact of Calcination Temperature on Its Catalytic Activity

Solvent-free technique was employed in this work in order to assess the influence of the calcination temperature on the activity of Al-promoted sulfated zirconia. The catalyst was analyzed by XRD and IR-spectrum method, and catalytic activity was examined by esterification reaction of oleic acid. XRD analysis revealed that a decline in the percentage of tetragonal phases of zirconia was observed by increasing the calcination temperature from 500 to 900 °C. In addition, a reduction of sulfate groups as SO42– on zirconia surface was observed. As a consequence, a decline in Brønsted sites with calcinationtemperature enhancement also prevailed. Therefore, the size of Al-promoted sulfated zirconia particles was increased accordingly. On the other hand, with the aluminum sulfate loading, the amount of sulfate ions on Al-promoted sulfated zirconia surface was enhanced and a reduction in particle size of Al2O3/S-ZrO2 was also observed, as compared to non-promoted. The result of this study revealed that an increase of sulfate and alumina groups causes a raise in the acidity of catalyst. Furthermore, the calcined Al-promoted and non-promoted sulfated zirconia would convert 96.10 % and 89.36 % of oleic acid to biodiesel, respectively. Therefore, Al2O3/S-ZrO2 as a catalyst exhibits a higher activity than S-ZrO2

Preparation of Supported Nanosized Sulfated Zirconia by Strontia and Assessment of Its Activities in the Esterification of Oleic Acid

The aim of this study was to examine a new nanocatalyst of SrO/S-ZrO2 in esterification reaction and the optimum value of strontia loading over the sulfated zirconia. The sulfated zirconia was supported with different molar ratios of strontia in the range of 0.0–0.30, using the solvent-free method. The samples were characterized using XRD, FT-IR, BET and TEM analysis and their activity were investigated in esterification reaction of oleic acid. The findings of this study revealed that 25 mol % SrO/S-ZrO2 had the highest yield in the esterification reaction. It was also concluded that strontia-supported sulfated zirconia could improve the low reusability of the catalyst. Furthermore, 95 % conversion was also obtained at optimized conditions (i.e., 100 °C, 2 wt. % of catalyst, 6:1 molar ratio of methanol/oleic acid and for a period of 30 minutes)

Immunization of Arabian sheep with whole gut homogenate of Haemonchus contortus

Summary Ten female lambs of 7-month-old were divided into two equal groups and raised under a helminth-free conditions. Animals in group 1 were immunized two times by whole gut homogenate (WGH) of Haemonchus contortus emulsified in Freund's adjuvant. In group 2 (control), animals were injected by phosphate buffered saline emulsified in the same adjuvant. Animals were challenged by 10000 third-stage larvae (L3) of Haemonchus contortus on day 33 after the first immunization and then humanely killed on day 42. Animals were tested for serum antibody and eggs per gram of faeces (EPG) throughout the study and nematodes in their abomasom were counted after necropsy. The results indicated that animals immunized with WGH showed a higher level of serum antibodies. A significant difference was observed in mean optical density of sera in ELISA between the two groups (P<0.05) and a 77 and 78% reduction in EPG and nematode counts at necropsy, respectively (P<0.05)

Effect of Calcination Temperature on Catalytic Activity of Synthesis SrO/S-ZrO2 by Solvent-free Method in Esterification of Oleic Acid

Currently, the major concern in production of biodiesel fuel is to exploit new catalysts with the optimal conditions. In this study, the effect of calcination temperature on the synthesis of 20 mol % SrO/S-ZrO2 was examined by solvent-free method. Moreover, the ability of the catalyst for esterification reaction of oleic acid with methanol was also assessed. To obtain this objective, X-ray diffraction and infra-red spectroscopy method was employed to characterize the structure of the catalysts. The results of this study reveal that the calcined strontium oxide promoted sulfated zirconia at 500 °C has the highest percentage of tetragonal phases of zirconia. It has also been demonstrated that owing to the high percentage of the tetragonal phases of zirconia and the acidity of the catalyst, conversion of oleic acid to fatty acids methyl esters (i.e., FAME) could be enhanced from 88.36 % to 91.13 %. Moreover, it has also been shown that 20 mol % SrO/S-ZrO2 exhibits higher activity in comparison with S-ZrO2 at 500 °C in esterification reaction due to the presence more sulfate ions and higher activity of strontium ions