with the collaboration of Iranian Society of Mechanical Engineers (ISME)

Document Type : Research Article

Authors

1 Department of mechanics of Biosystems Engineering, Shahrekord University, Shahrekord, Iran

2 Department of mechanics of Biosystems Engineering, Tarbiat Modares University, Tehran, Iran

Abstract

Introduction
Biodiesel is a promising renewable substitute source of fuel produced from tree born oils, vegetable based oils, fats of animals and even waste cooking oil, has been identified as one of the key solutions for the alarming global twin problems of fossil fuel depletion and environmental degradation. One of the sources for biodiesel production is mastic which is often grown in mountains. Its kernel contains 55% oil which makes it as a valuable renewable resource for biodiesel production. The objective of this research was to study of the feasibility of biodiesel production from Atlas mastic oil using ultrasonic system and optimization of the process using Response surface methodology.
Materials and Methods
In order to supply the required oil for the biodiesel production process, the oil should be prepared before the reaction. Hence, the purified oil was methylated using Metcalf et al (1996) method, and the prepared sample was injected into Gas Chromatography device to determine fatty acids profile and molecular weight of the used oil. An ultrasonic processor (Hielscher Model UP400S, USA.) was used to perform the transesterification reaction.
All the experiments were replicated three times to determine the variability of the results and to assess the experimental errors. The reported values are the average of the individual runs. The different operating parameters used in the present work, to optimize the extent of conversion of Atlas pistache oil, include methanol to oil molar ratio (4:1, 5:1 ,6:1), amplitude (24.1, 62.5 100%), pulse (24.1, 62.5 100%), reaction time (3, 6, 9 min).
Results and Discussion
Results of analyses showed that the independent variables, namely molar ratio, vibration amplitude, pulse and reaction time had significant effects on the amount of produced methyl ester.
By increasing the amplitude and pulse, the methyl ester content increased. Increase in amplitude and pulse cause to increase the mixing effect and physical interface. Increasing the ratio of ultrasonic working time to its idling time caused to an increase in the conversion percent. Because the treating time of the samples by ultrasound in limit time durations is increased, while this increase becomes lower at higher ratios. This is due to the fact that the initial vibrative shock acted on the samples after ultrasonic restarting, finds an identical effect with uniform wave. However, the idling phase of ultrasound caused a decrease in the amount of consumed energy. Similar results have been reported by Chand et al. (2010) for the effect of pulse on conversion percent of methyl ester. Trend of reaction time and molar ratio were different with trend of amplitude and molar ratio on methyl ester content so that they were divided to two sections. It should be mentioned that the increase in biodiesel yield because of molar ratio has some limitations. If the ratio is increased more than a certain extent, biodiesel conversion percent will decrease. The main reason for this result can be related to the amount of methanol increase in the mixture, which leads to more dissolution of glycerin and alcohol in biodiesel which considerably influences its purity.
Optimization was carried out based on Response Surface Methodology (RSM) using Design Experts software. The obtained results from optimization were as follow: 5.45 molar ratio, 0.89 amplitude, 0.71 pulse and 5.99 minutes of time. The conversion percentage obtained as 94.96. It is worthy to note that the experiment was iterated at suggested point by the optimization software and the conversion percent was 94.02. As well as 34792.37 J at the obtained point to be acceptable (1%) difference from the model.
Conclusions
The increase in the ultrasound amplitude resulted in an increase in the conversion percentage which tends to ascend. Also, the increase of reaction time by 5 to 7 minutes increased the conversion percentage, following which is the descend trend. The obtained results from optimization were as follow: 5.45 molar ratio, 0.89 amplitude, 0.71 pulse and 5.99 minutes of time. The conversion percentage and consumed energy obtained as 94.96 and 32421.5 J, respectively. It is worthy to note that the experiment was iterated at suggested point by the optimization software and the conversion percent was 94.02.

Keywords

1. Anwar, F., and U. Rashid. 2007. Production of biodiesel through optimized alkaline-catalyzed transesterification of rapeseed oil. Journal of Fuel ISSN 0016-2361.
2. Bagherpour, H., B. Ghobadian, T. Tavkoli Hashjin, A. Mohammadi, M. FeizolahNejad, and A. Zonozi. 2010. Optimization of the parameters affecting the biodiesel production using transesterification method. Journal of Biosystem Engineering of Iran 41 (1): 37-43.
3. Chand, P., V. R. Chintareddy, J. G. Verkade, and D. Grewell. 2010. Enhancing biodiesel production from soybean oil using ultrasonics. Energy & fuels 24: 2010-2015.
4. Demirbas, A. 2003. Biodiesel fuels from vegetable oils via catalytic and non-catalytic supercritical alcohol transesterifications and other methods: a survey. Energy Conversion and Management 44: 2093-2109.
5. Fayyazi, E. 2012. Biodiesel production using ultrasonic. M.Sc thesis, Department of Mechanics of Agricultural Machinery, Tarbiat Modares University.
6. Gerpen, J. V. 2004. Biodiesel Production Technology, National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden.
7. Guan, G., and K. Kusakabe. 2009. Synthesis of biodiesel fuel using an electrolysis method. Chemical Engineering Journal 153: 159-163.
8. Hingu, S. M., P. R. Gogate, and V. K. Rathod. 2010. Synthesis of biodiesel from waste cooking oil using sonochemical reactors. Ultrasonicssonochemistry 17: 827-832.
9. Kalva, A., T. Sivasankar, and V. S. Moholkar. 2008. Physical mechanism of ultrasound-assisted synthesis of biodiesel. Industrial & Engineering Chemistry Research 48: 534-544.
10. Kelkar, M. A. 2008. Intensification of esterification of acids for synthesis of biodiesel using acoustic and hydrodynamic cavitation. Ultrasonic Sonochemistry 15: 188-194.
11. Khatamifar, M. 2005. Design, development and testing of biodiesel process. M.Sc thesis, Department of Mechanics of Agricultural Machinery, Tarbiat Modares University.
12. Kim, H. J., B. S. Kang, M. J. Kim, Y. M. Park, D. K. Kim, J. S. Lee, and K. Y. Lee. 2004. Transesterification of vegetable oil to biodiesel using heterogeneous base catalyst. Catalysis Today 93-95: 315-320.
13. Koc, A. B. 2009. Ultrasonic monitoring of glycerol settling during transesterification of soybean oil, Bioresour. Technol 100: 19-24.
14. Koc, A. B., and M. Vatandas. 2006. Ultrasonic velocity measurements on some liquids under thermal cycle: Ultrasonic velocity hysteresis. Food Research International 39: 1076-1083.
15. Kumar, D., G. Kumar, and C. Singh. 2010. Fast, easy ethanolysis of coconut oil for biodiesel production assisted by ultrasonication. Ultrasonicssonochemistry 17: 555-559.
16. Kusdiana, D., and S. Saka. 2001. Kinetics of transesterification in rapeseed oil to biodiesel fuel as treated in supercritical methanol. Fuel 80: 693-698.
17. Manzarian, V. 2010. Trees and shrubs ofIran.Farhang-e-Moaser, Tehran, Third edition.
18. Mason, T. J. 1999. Sonochemistry, Oxford University Press New York. PP: 564-587.
19. Mason, T. J., and J. P. Lorimer. 2002. Applied sonochemistry, Wiley Online Library.
20. Meher, L. C., D. V. Sagar, and S. N. Naik. 2006. Technical aspects of biodiesel production by transesterification – a review, Renewable and Sustainable Energy Reviews 10: 248-268.
21. SafieddinArdebili, M., B. Ghobadian, G. Najafi, and A. Chegeni. 2011. Biodiesel production potential from edible oil seeds in Iran. Renewable and Sustainable Energy Reviews 15: 3041-3044.
22. Stavarache, C., M. Vinatoru, Y. Maeda, and H. Bandow. 2007b.Ultrasonically driven continuous process for vegetable oil transesterification. Ultrasonicssonochemistry 14: 413-417.
23. Teixeira, L. S. G., and J. C. R. Assis. 2009. Comparison between conventional and ultrasonic preparation of beef tallow biodiesel. Fuel Processing Technology 90: 1164-1166.
24. Thanh, L.T., K. Okitsu, Y. Sadanaga, N. Takenaka, Y. Maeda, and H. Bandow. 2010. A two-step continuous ultrasound assisted production of biodiesel fuel from waste cooking oils: A practical and economical approach to produce high quality biodiesel fuel. Bioresource Technology101: 5394-5401.
25. Wang, J., Y. Li, Y. Yu, and Z. Xu. 2006. Preparation of biodiesel with the help of ultrasonic and hydrodynamic cavitation. Ultrasonic 44: 411-414.
26. Xue J., E. Tony, A. Grift, and C. Hansen. 2011. Effect of biodiesel on engine performances and emissions. Renewable and Sustainable Energy Reviews 15: 1098-1116.
CAPTCHA Image