scholarly journals Kinetic Study of Epoxidation of Rubber Seed Oil Using Tungstate-based Catalyst

Author(s):  
Nguyễn Thị Thủy

By performing the reaction for one hour at three different temperatures, the thermodynamic properties of the epoxidation reaction using tungstate-based catalyst of RSO and eRSO were determined. The rate constant of these epoxidation reactions were varied from 0.57.10-2 to 1.01.10-2 l.mol-1.s-1 with RSO and 0.97.10-2 to 1.76.10-2 l.mol-1.s-1 with eRSO. The activated energies of reaction were 6.2 and 6.6 kcal.mol-1, respectively. The enthalpy ΔH was positive indicating that the epoxidation process was a endothermic reaction, but the free-energy ΔF was also positive, so there was a specific temperature at which the epoxidation process was the most effective. Experimental results showed that 60oC was the most suitable temperature for epoxidation reaction of both RSO and eRSO with the conversion of 91.37% (RSO) and 94.87% (eRSO), the yield of 75.06% (RSO) and 89.56% (eRSO) and the selectivity was 0.82 (RSO) and 0.94 (eRSO), respectively.

2021 ◽  
Vol 50 (8) ◽  
pp. 2407-2417
Author(s):  
R.A. Hambali ◽  
M.A. Faiza ◽  
A. Zuliahani

Epoxidised rubber seed oil (ERSO) was successfully synthesized into non-isocyanate polyurethane via carboxylation method whereas peroxoformic acid was formed by in-situ reaction for epoxidation. The effects of temperature and ratio of hydrogen peroxide and formic acid to rubber seed oil carboxylation were studied. The optimum temperature for the epoxidation reaction was found at 50 °C to avoid ring opening reaction of epoxy whilst the optimum ratio of hydrogen peroxide and formic acid is equal molar of double bond: formic acid at 1:2 and 1:1, respectively. At a lower concentration of hydrogen peroxide and formic acid, the oxirane ring was stable due to the lower hydrolysis (oxirane cleavage) of an epoxide. The effect of using low content of formic acid tends to minimize unwanted epoxide ring opening to occur and make the epoxidation rate increased with increasing of oxirane number. Fourier transform infrared (FTIR) spectral displayed the presence of an epoxy functional group at 822 cm-1 and the disappearance of double bond peak at 3011 cm-1 corresponding to epoxidised oil and carbonyl group confirmed the epoxidation reaction had taken place. 1H-NMR was used to confirm the formation of carboxylate functionality after the reaction of epoxy at δ 4.83 and 4.61 ppm. In conclusion, ERSO has great potential to be used as a precursor in producing environmentally friendly non-isocyanate polyurethane.


Author(s):  
Nguyễn Thị Thủy

The selectivity of tungstate-based catalyst in the epoxidation reaction of rubber seed oil and modified rubber seed oil was studied in two ways. The titration method was performed according to the ASTM standard and the H-NMR method was based on the peaks of the three different standard groups. The catalyst selectivity of the epoxidation reaction of modified rubber seed oil was much higher than that of non-modified rubber seed oil for both methods. The average catalyst selectivity obtained by using H-NMR method of the modified rubber seed oil epoxidation reaction was equal, while of the rubber seed oil epoxidation reaction was 11% lower than that of the titrimetric method. For both types of oils, the difference between the catalytic selectivity obtained by using titration method and by using protons in group α-CH2-(C=O)-O- as the standard peak was the smallest and was the biggest when the protons in group -CH3 was used as the standard peak.


2018 ◽  
Author(s):  
Jilse Sebastian ◽  
Vishnu Vardhan Reddy Mugi ◽  
C. Muraleedharan ◽  
Santhiagu A
Keyword(s):  
Seed Oil ◽  

Author(s):  
Vishal V Patil ◽  
Ranjit S Patil

In this study, different characteristics of sustainable renewable biodiesels (those have a high potential of their production worldwide and in India) were compared with the characteristics of neat diesel to determine optimistic biodiesel for the diesel engine at 250 bar spray pressure. Optimistic fuel gives a comparatively lower level of emissions and better performance than other selected fuels in the study. Rubber seed oil methyl ester was investigated as an optimistic fuel among the other selected fuels such as sunflower oil methyl ester, neem seed oil methyl ester, and neat diesel. To enhance the performance characteristics and to further decrease the level of emission characteristics of fuel ROME, further experiments were conducted at higher spray (injection) pressures of 500 bar, 625 bar, and 750 bar with varying ignition delay period via varying its spray timings such as 8°, 13°, 18°, 23°, 28°, and 33° before top dead center. Spray pressure 250 bar at 23° before top dead center was investigated as an optimistic operating condition where fuel rubber seed oil methyl ester gives negligible hydrocarbon emissions (0.019 g/kW h) while its nitrogen oxide (NOX) emissions were about 70% lesser than those observed with neat diesel, respectively.


Author(s):  
Hellismar W. da Silva ◽  
Renato S. Rodovalho ◽  
Marya F. Velasco ◽  
Camila F. Silva ◽  
Luís S. R. Vale

ABSTRACT The objective of this study was to determine and model the drying kinetics of 'Cabacinha' pepper fruits at different temperatures of the drying air, as well as obtain the thermodynamic properties involved in the drying process of the product. Drying was carried out under controlled conductions of temperature (60, 70, 80, 90 and 100 °C) using three samples of 130 g of fruit, which were weighed periodically until constant mass. The experimental data were adjusted to different mathematical models often used in the representation of fruit drying. Effective diffusion coefficients, calculated from the mathematical model of liquid diffusion, were used to obtain activation energy, enthalpy, entropy and Gibbs free energy. The Midilli model showed the best fit to the experimental data of drying of 'Cabacinha' pepper fruits. The increase in drying temperature promoted an increase in water removal rate, effective diffusion coefficient and Gibbs free energy, besides a reduction in fruit drying time and in the values of entropy and enthalpy. The activation energy for the drying of pepper fruits was 36.09 kJ mol-1.


2016 ◽  
Vol 66 (1) ◽  
pp. 126-132 ◽  
Author(s):  
Jian Hong ◽  
Xiao-Qin Yang ◽  
Xianmei Wan ◽  
Zhifeng Zheng ◽  
Zoran S Petrović
Keyword(s):  
Seed Oil ◽  

Author(s):  
Elena Gotlib ◽  
Elena Cherezova ◽  
Anh Nguyen Thi Lan ◽  
Alla Sokolova

2019 ◽  
Vol 12 (8) ◽  
pp. 2028-2036 ◽  
Author(s):  
Chanatip Samart ◽  
Surachai Karnjanakom ◽  
Chaiyan Chaiya ◽  
Prasert Reubroycharoen ◽  
Ruengwit Sawangkeaw ◽  
...  

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