Sains Malaysiana 44(2)(2015): 281–290

An Optimization Study for Transesterification of Palm Oil using Response Surface Methodology (RSM)

(Suatu Kajian Pengoptimuman bagi Transesterifikasi Minyak Sawit Menggunakan Kaedah Gerak Balas Permukaan (RSM))

Y.C. WONG, Y.P. TAN*, Y.H. TAUFIQ-YAP & I. RAMLI

Centre of Excellence for Catalysis Science and Technology, Universiti Putra Malaysia

43400 UPM Serdang, Selangor Darul Ehsan, Malaysia

Department of Chemistry, Faculty of Science, Universiti Putra Malaysia

43400 UPM Serdang, Selangor Darul Ehsan, Malaysia

Diserahkan: 22 November 2013/Diterima: 8 Ogos 2014

ABSTRACT

Biodiesel was produced via transesterification of palm oil with methanol in the presence of CaO-Nb₂O₅ mixed oxide catalyst. Response surface methodology (RSM) with central composite design (CCD) was performed to determine the optimum operating conditions and to optimize the biodiesel yield. In this study, the reaction variables being optimized were reaction time, catalyst loading and methanol to oil molar ratio. From the analysis of variance (ANOVA), the most influential parameter on biodiesel production was reaction time. The predicted yield was found in good agreement with the experimental value, with R2= 0.9902. The optimum biodiesel yield of 97.67% was achieved at 2.67 h reaction time, with 3.60 wt. % of catalyst and with methanol to oil molar ratio of 13.04. The high biodiesel yield can be correlated to the synergic effect of basicity between the metallic ions of CaO-Nb₂O₅ shown in the physicochemical analysis.

Keywords: Biodiesel; optimization; palm oil; RSM; transesterification

ABSTRAK

Biodiesel telah dihasilkan melalui transesterifikasi minyak sawit dengan metanol dan kehadiran pemangkin oksida bercampur CaO-Nb₂O₅. Kaedah gerak balas permukaan (RSM) dengan pusat reka bentuk komposit (CCD) telah dijalankan untuk menentukan keadaan operasi optimum dan mengoptimumkan hasil biodiesel. Dalam kajian ini, pemboleh ubah tindak balas yang dioptimumkan ialah masa tindak balas, pembebanan pemangkin dan nisbah molar metanol kepada minyak. Daripada analisis varians (ANOVA), parameter yang paling berpengaruh dalam penghasilan biodiesel adalah masa tindak balas. Hasil yang diramalkan adalah bersamaan dengan nilai eksperimen, dengan R2= 0.9902. Hasil optimum biodiesel sebanyak 97.67% dicapai pada masa tindak balas 2.67 h dengan 3.60 wt. % pemangkin dan nisbah molar metanol kepada minyak 13.04. Hasil biodiesel yang tinggi boleh dikaitkan dengan kesan sinergi kebesan antara ion logam CaO-Nb₂O₅ seperti yang ditunjukkan dalam analisis fisikokimia.

Kata kunci: Biodiesel; minyak sawit; pengoptimuman; RSM; transesterikasi

RUJUKAN

Alamu, O.J., Waheed, M.A. & Jekayinfa, S.O. 2008. Effect of ethanol-palm kernel oil ratio on alkali-catalyzed biodiesel yields. Fuel 87: 1529-1533.

Antunes, W.M., Veloso, C.O. & Henriques, C.A. 2008. Transesterification of soybean oil with methanol catalyzed by basic solids. Catalysis Today 133-135: 548-554.

Arzamendi, G., Campoa, I., Arguinarena, E., Sanchez, M., Montes, M. & Gandia, L.M. 2007. Synthesis of biodiesel with heterogeneous NaOH/alumina catalysts: Comparison with homogeneous NaOH. Chem. Eng. J. 134: 123-130.

Bas, D. & Boyacl, I.H. 2007. Modeling and optimization I: Usability of response surface methodology. Journal of Food Engineering 78: 836-845.

Bezerra, M.A., Santelli, R.E., Oliveira, E.P., Villar, L.S. & Escaleira, L.A. 2008. Response surface methodology (RSM) as a tool for optimization in analytical chemistry. Talanta 76: 965-977.

Chen, X., Du, W. & Liu, D. 2008. Response surface optimization of biocatalytic biodiesel production with acid oil. Biochemical Engineering Journal 40: 423-429.

Dmytryshyn, S.L., Dalai, A.K. & Chaudhari, S.T. 2004. Synthesis and characterization of vegetable oil derived esters: Evaluation for their diesel additive properties. Bioresource Technology 98: 1724-1733.

Dorado, M.P., Ballesteros, E., Arnal, J.M., Gómez, J. & López, F.J. 2003. Exhaust emissions from a diesel engine fueled with transesterifiedwaste olive oil. Fuel 82: 1311-1315.

Dennis Leung, Y.C., Wu, X. & Leung, M.K.H. 2010. A review on biodiesel production using catalyzed transesterification. Applied Energy 87: 1083-1095.

Fukuda, H., Kondo, A. & Noda, H. 2001. Biodiesel fuel production by transesterification of oils. Journal of Bioscience Bioengineering 92: 405-416.

Gryglewicz, S. 1999. Rapeseed oil methyl esters preparation using heterogeneous catalysts. Bioresource Technology 70: 249-253.

Helwani, Z., Othman, M.R., Aziz, N., Fernando, W.J.N. & Kim, J. 2009. Technologies for production of biodiesel focusing on green catalytic techniques: A review. Fuel Processing Technology 90: 1502-1514.

Kouzu, M., Yamasaka, S., Hidaka, J. & Tsunomori, M. 2009. Heterogeneous catalysis of calcium oxide used for tranesterification of soybean oil with refluxing methanol. Applied Catalysis A: General 355: 94-99.

Lin, C.Y., Lin, H.A. & Hung, L.B. 2006. Fuel structure and properties of biodiesel produced by peroxidation process. Fuel 85: 1743-1749.

Lin, L., Ying, D., Chaitep, S. & Vittayapadung, S. 2009. Biodiesel production from crude rice bran oil and properties as fuel. Applied Energy 86: 681-688.

Liu, X., He, H., Wang, Y., Zhu, S. & Piao, X. 2008. Transesterification of soybean oil to biodiesel using CaO as a solid base catalyst. Fuel 87: 216-221.

Montgomery, D.C. 2001. Design and Analysis of Experiments. 5th ed. New York: John Willy and Sons.

Mootabadi, H., Salamatinia, B., Bhatia, S. & Abdullah, A.Z. 2010. Ultrasonic-assisted biodiesel production process from palm oil using alkaline earth metal oxides as the heterogeneous catalysts. Fuel 89: 1818-1825.

Ngamcharussrivichai, C., Totarat, P. & Bunyakiat, K. 2008. Ca and Zn mixed oxide as a heterogeneous base catalyst for transesterification of palm kernel oil. Applied Catalysis A: General 341: 77-85.

Sharma, Y.C., Singh, B. & Korstad, J. 2011. Latest development on application of heterogeneous basic catalysts for an efficient and eco-friendly synthesis of biodiesel: A review. Fuel 90: 1309-1324.

Sharma, Y.C., Singh, B. & Upadhyay, S.N. 2008. Advancement in development and characterization of biodiesel: A review. Fuel 87: 2355-2373.

Shuit, S.H., Lee, K.T., Kamaruddin, A.H. & Yusup, S. 2010. Reactive extraction of jatropha curcasL. seed for production of biodiesel: Process optimization study. Environmental Science & Technology 44: 4361-4367.

Sohn, J. & Park, E. 1997. Acidic properties of CaO-SiO2 binary oxide catalyst and activity for acid catalysis. Korean Journal of Chemical Engineering 14: 192-197.

Vujicic, Dj., Comic, D., Zarubica, A., Micic, R. & Boskovic, G. 2010. Kinetics of biodiesel synthesis from sunflower oil over CaO heterogeneous catalyst. Fuel 89(8): 2054-2061.

West, A.R. 1999. Basic Solid State Chemistry. 2nd ed. Chichester: John and Sons.

Wong, Y.C., Tan, Y.P., Taufiq-Yap, Y.H. & Ramli, I. 2014. Effect of calcination temperatures of CaO/Nb₂O₅ mixed oxide catalysts on biodiesel production. Sains Malaysiana 43(5): 783-790.

*Pengarang untuk surat-menyurat; email: typ@upm.edu.my