Production of Biodiesel with Seed Soybean and Supercritical Ethanol


This paper presents a study of biodiesel production by a non-catalytical process. The innovation in this study is the use of novel materials for production: seed soybean (Glycine Max) “in natura” and ethanol in a supercritical state. To conduct the experiments, a bench reactor with a capacity of 150 mL, resistant to pressure of up to 300 bar and temperature of 350°C was developed. The fractional factorial experimental design () was used to evaluate the temperature, seed granulometry, molar ratio ethanol/oil and water percent of the mixture. The best yield observed was that of 94.07%, 10 minutes after the reactor entered a supercritical condition. Significant effects on seed granulometry, molar ratio ethanol, oil and temperature were verified. From the proposed process, biodiesel and toasted soybean seed were obtained. To purify the biodiesel sample it was necessary to use ultra-centrifugation to separate seed particles, and rotoevaporation to separate the fatty acid ethyl ester and unreacted ethanol. The chemical analyses were conducted directly by gas chromatography. The yield was calculated in accordance with concentrations obtained in the chromatographic analysis and seed mass of the experiment. Also checked was the presence of palmitate esters, stearate, oleate, linoleate and linolenate. By analyzing the ester composition it was possible to assess whether a good quality biodiesel was available. The roasted soybean seeds obtained after the reaction showed a calorific potential of 2203.17 kcal/kg and also be used as fuel.

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Mariano, G. , Lopes, T. , Dias, R. , Bastos Quadri, M. and Bolzan, A. (2014) Production of Biodiesel with Seed Soybean and Supercritical Ethanol. Journal of Sustainable Bioenergy Systems, 4, 128-135. doi: 10.4236/jsbs.2014.42012.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] 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, 93-109.
[2] Bala, B.K. (2005) Studies on Biodiesels from Transformation of Vegetable Oils for Diesel Engines. Energy Education Science Technology, 15, 1-43.
[3] Kusdiana, D. and Saka, S. (2004) Effects of Water on Biodiesel Fuel Production by Supercritical Methanol Treatment. Bioresource Technology, 91, 289-295.
[4] Demirbas, A. (2006) Biodiesel Production via Non-Catalytic SCF Method and Biodiesel Fuel Characteristics. Energy Conversion and Management, 47, 2271-2282.
[5] Pinto, A.C., Guarieiro, L.L.N., Rezende, M.J.C., Ribeiro, N.M., Torres, E.A., Lopes, W.A., Pereira, P.A.P. and Andrade, J.B. (2005) Biodiesel: An Overview. Journal of the Brazilian Chemical Society, 16, 1313-1330.
[6] Silva, C. (2007) Produção de ésteres Etílicos por Transesterificação não catalítica de óleo de Soja. Dissertação de Mestrado, Departamento de Ciências Agrárias, URI Campus Erechim, 132 p.
[7] Vieitez, I., Silva, C., Borges, G.R., Corazza, F.C., Oliveira, J.V., Grompone, M.A. and Jachmanián, I. (2008) Continuous Production of Soybean Biodiesel in Supercritical Ethanol—Water Mixtures. Energy & Fuels, 22, 2805-2809.
[8] Kusdiana, D. and Saka, S. (2001) Biodiesel Fuel from Rapeseed Oil as Prepared in Supercritical Methanol. Fuel, 80, 225-230.
[9] Anitescu, G. and Tavlarides, L.L. (2009) Integrated Multistage Supercritical Technology to Produce High Quality Vegetable Oils and Biofuels. Syracuse University, Intl. Patent Appl. WO 2008101200 A2 20080821, Sept.18.
[10] Tan, K.T., Lee, K.T., Mohamed, A.R. and Bhatia, S. (2009) Palm Oil: Addressing Issues and towards Sustainable Development. Renewable & Sustainable Energy Reviews, 13, 420-427.
[11] Knothe, G., Gerpen, J.V., Krahl, J. and Ramos, L.P. (2006) Manual Do Biodiesel. Edgard Blucher, São Paulo, 340 p.
[12] Neff, W.E., Selke, E., Mounts, T.L., Rinsch, W., Frankel, E.N. and Zeitoun, M.A.M. (1992) Effect of Triacylglycerol Composition and Structures on Oxidative Stability of Oils from Selected Soybean Germplasm. Journal of the American Oil Chemists’ Society, 69, 111-118.
[13] Vieitez, I., Silva, C., Alckmin, I., Castilhos, F., Oliveira, J.V., Grompone, M.A. and Jachmanián, I. (2011) Stability of Ethyl Esters from Soybean Oil Exposed to High Temperatures in Supercritical Ethanol. Journal of Supercritical Fluids, 56, 265-270.

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