Optimization of pretreatment of Jatropha oil with high free fatty acids for biodiesel production

Abstract

A central composite rotatable design and response surface methodology were used in order to investigate the individual and combined effects of the ethanol-to-oil ratio, H₂SO₄ concentration, temperature and time of reaction on the reduction of free fatty acid (FFA) in jatropha oil. A quadratic polynomial model relating the reaction variables with FFA reduction was developed, presenting a good coefficient of determination (R²= 0.893). For reducing FFA to less than 1%, the optimal combination was found to be 0.62 v·v^-1 ethanol-to-oil ratio (14.9 v·v^-1 ethanol-to-FFA ratio), 1.7% v·v^-1 H₂SO₄ concentration, and 79 min reaction time at a reaction temperature of 54°C. These results are of great relevance to maximize methyl esters formation by transesterification using an alkaline catalyst.

Keywords

biodiesel / biofuel / esterification / free fatty acids / jatropha curcas oil

References

[1] Veljkovic V B, Lakicevic S H, Stamenkovic O S, Todorovic Z B, Lazic M L. Biodiesel production from tobacco (Nicotiana tabacum L.) seed oil with a high content of free fatty acids. Fuel, 2006, 85(17–18): 2671–2675

[2] Deng X, Fang Z, Liu Y. Liu Y H. Ultrasonic transesterification of Jatropha curcas L. oil to biodiesel by a two-step process. Energy Conversion and Management, 2010, 51(12): 2802–2807

[3] Vicente G, Coteron A, Martinez M, Aracil J. Application of the factorial design of experiments and response surface methodology to optimize biodiesel production. Industrial Crops and Products, 1998, 8(1): 29–35

[4] Çetinkaya M, Karaosmanoglu F. Optimization of base-catalyzed transesterification reaction of used cooking oil. Energy & Fuels, 2004, 18(6): 1888–1895

[5] Berchmans H J, Hirata S. Biodiesel production from crude Jatropha curcas L. seed oil with a high content of free fatty acids. Bioresource Technology, 2008, 99(6): 1716–1721

[6] Syam A, Yunus R, Ghazi T, Yaw T. Methanolysis of jatropha oil in the presence of potassium hydroxide catalyst. Journal of Applied Sciences, 2009, 9(17): 3161–3165

[7] Kumar Tiwari A, Kumar A, Raheman H. Biodiesel production from jatropha oil (Jatropha curcas) with high free fatty acids: an optimized process. Biomass and Bioenergy, 2007, 31(8): 569–575

[8] Ghadge S V, Raheman H. Biodiesel production from mahua (Madhuca indica) oil having high free fatty acids. Biomass and Bioenergy, 2005, 28(6): 601–605

[9] Jena P C, Raheman H, Prasanna Kumar G V, Machavaram R. Biodiesel production from mixture of mahua and simarouba oils with high free fatty acids. Biomass and Bioenergy, 2010, 34(8): 1108–1116

[10] Dorado M, Ballesteros E, de Almeida J, Schellert C, Lohrlein H, Krause R. An alkali-catalyzed transesterification process for high free fatty acid waste oils. Transactions-American Society Of Agricultural Engineers, 2002, 45(3): 525–530

[11] Lu H, Liu Y, Zhou H, Yang Y, Chen M, Liang B. Production of biodiesel from Jatropha curcas L. oil. Computers & Chemical Engineering, 2009, 33(5): 1091–1096

[12] ASTM. American Standards for Testing of Materials. D 189–01 D, D 4052–96, D 445–03, D 482–74, D 5555–95, D 6751–02, D 93–02, D 95–990, D 97–02. 2003

[13] Canakci M, Gerpen J V. Biodiesel production from oils and fats with high free fatty acids. Transactions of the ASAE. American Society of Agricultural Engineers, 2001, 44(6): 1429–1436

[14] Azhari M, Faiz M, Yunus R, Ghazi T, Yaw T. Reduction of free fatty acids in crude Jatropha curcas oil via an esterification process. International Journal of Engineering and Technology, 2008, 5(2): 92–98

[15] Marchetti J M, Errazu A F. Esterification of free fatty acids using sulfuric acid as catalyst in the presence of triglycerides. Biomass and Bioenergy, 2008, 32(9): 892–895

[16] Zhang J, Jiang L. Acid-catalyzed esterification of Zanthoxylum bungeanum seed oil with high free fatty acids for biodiesel production. Bioresource Technology, 2008, 99(18): 8995–8998

[17] Yuan X, Liu J, Zeng G, Shi J, Tong J, Huang G. Optimization of conversion of waste rapeseed oil with high FFA to biodiesel using response surface methodology. Renewable Energy, 2008, 33(7): 1678–1684

Acknowledgements

This work was supported by Fundação para a Ciência Technology through G. Dragone grant SFRH/BPD/44935/2008. The authors acknowledge financial support from project INNOVALGAE (PTDC/AAC-AMB/108511/2008).

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2014 Higher Education Press and Springer-Verlag Berlin Heidelberg