Reaction kinetics of isopropyl palmitate synthesis

doi:10.1016/j.cjche.2015.05.004

Abstract

Abstract: In this study, the kinetics of isopropyl palmitate synthesis including the reaction mechanism was studied based on the two-step noncatalyticmethod. The liquid-phase diffusion effect on the reaction process was eliminated by adjusting the stirring rate. The results showed that the two-step reaction followed a tetrahedral mechanism and conformed to second-order reaction kinetics. Nucleophilic attack on the carbonyl carbon afforded an intermediate, containing a tetrahedral carbon center. The intermediate ultimately decomposed by elimination of the leaving group, affording isopropyl palmitate. The experimental data were analyzed at different temperatures by the integral method. The kinetic equations of the each step were deduced, and the activation energy and frequency factor were obtained. Experiments were performed to verify the feasibility of kinetic equations, and the result showed that the kinetic equations were reliable. This study could be very significant to both industrial application and determining the continuous production of isopropyl palmitate.

Key words: Isopropyl palmitate, Reaction kinetics, Chemical reaction, Preparation, Chloridization, Palmitic acid

摘要： In this study, the kinetics of isopropyl palmitate synthesis including the reaction mechanism was studied based on the two-step noncatalyticmethod. The liquid-phase diffusion effect on the reaction process was eliminated by adjusting the stirring rate. The results showed that the two-step reaction followed a tetrahedral mechanism and conformed to second-order reaction kinetics. Nucleophilic attack on the carbonyl carbon afforded an intermediate, containing a tetrahedral carbon center. The intermediate ultimately decomposed by elimination of the leaving group, affording isopropyl palmitate. The experimental data were analyzed at different temperatures by the integral method. The kinetic equations of the each step were deduced, and the activation energy and frequency factor were obtained. Experiments were performed to verify the feasibility of kinetic equations, and the result showed that the kinetic equations were reliable. This study could be very significant to both industrial application and determining the continuous production of isopropyl palmitate.

关键词: Isopropyl palmitate, Reaction kinetics, Chemical reaction, Preparation, Chloridization, Palmitic acid

Lili Fu, Yinge Bai, Gaozhi Lü, Denggao Jiang. Reaction kinetics of isopropyl palmitate synthesis[J]. Chin.J.Chem.Eng., 2015, 23(8): 1335-1339.

Lili Fu, Yinge Bai, Gaozhi Lü, Denggao Jiang. Reaction kinetics of isopropyl palmitate synthesis[J]. Chinese Journal of Chemical Engineering, 2015, 23(8): 1335-1339.

References

[1] I. Lee, L.A. Johnson, E.G. Hammond, Use of branched-chain esters to reduce the crystallization temperature of biodiesel, J. Am. Oil Chem. Soc. 72(10) (1995) 1155-1160.

[2] Shun-yu Chen,Wen-hui Tian, Zhen-zhen Xie, Preparation and effect of fatty acid isopropyl ester used as pour point depressant of biodiesel, J. Fujian Norm. Univ. (Nat. Sci. Ed.) 04(2009) 62-66.

[3] Qing Shu, Jixian Gao, Yuhui Liao, Jinfu Wang, Reaction kinetics of biodiesel synthesis from waste oil using a carbon-based solid acid catalyst, Chin. J. Chem. Eng. 19(1) (2011) 163-168.

[4] Zai-xin Geng, Miao-juan Zhang, Li-li Fu, Deng-gao Jiang, Study on the new synthetic technology of the branched-chain alcohol biodiesel with low-freezing point, J. Chem. Eng. Chin. Univ. 26(6) (2012) 1073-1076.

[5] Hui-liang Jiang, Li-qiang Zhu, Study on the continuous esterification of fatty acids under normal pressure, Speciality Chem. 4(1996) 40-42.

[6] Liu Xuemin, Synthesis of isopropyl palmitate, Flavour Fragrance Cosmet. 6(2004) 14-16.

[7] S.Y. Chin, A.L. Ahmad, A.R. Mohamed, S. Bhatia, Characterization and activity of zinc acetate complex supported over functionalized silica as a catalyst for the production of isopropyl palmitate, Appl. Catal. A Gen. 297(2006) 8-17.

[8] L.Weizhong,Weiping Tu, Zhuoru Yang, Study on the synthesis of non-ion surfactant isopropyl palmitate, Chem. Reagents 22(6) (2000) 360-361.

[9] Shuangfei Cai, LishengWang, Epoxidation of unsaturated fatty acid methyl esters in the presence of SO₃H-functional bronsted acidic ionic liquid as catalyst, Chin. J. Chem. Eng. 19(1) (2011) 57-63.

[10] Yixin Qu, Shaojun Peng, Shui Wang, Zhiqiang Zhang, Jidong Wang, Kinetic study of esterification of lactic acid with isobutanol and n-butanol catalyzed by ion-exchange resins, Chin. J. Chem. Eng. 17(5) (2009) 773-780.

[11] S. Bhatia, A.L. Ahmad, A.R. Mohamed, S.Y. Chin, Production of isopropyl palmitate in a catalytic distillation column:experimental studies, Chem. Eng. Sci. 61(2006) 7436-7447.

[12] Zai-xin Geng,Miao-juan Zhang, Li-li Fu, Deng-gao Jiang, A novel non-catalyticmethod for synthesizing bio-diesel at ordinary temperature, Chem. World 53(4) (2012) 236-238.

[13] Z.X. Geng, M.J. Zhang, D.G. Jang, A method for synthesis biodiesel, China Pat., 200910064763.1(2009). (in Chinese).

[14] You-lin Li, Mi-fen Cui, Xu Qiao, Ji-hai Tang, Study on the formation kinetics of isopropyl acetate synthesized from acetic and propylene, J. Chem. Eng. Chin. Univ. 25((3) (2011) 430-436.

[15] Joseph M. Fox, Olga Dmitrenko, Lian-an Liao, Robert D. Bach, Computational studies of nucleophilic substitution at carbonyl carbon:the SN2 mechanism versus the tetrahedral intermediate in organic synthesis, J. Org. Chem. 69(2004) 7317-7328.

[16] T. William Bentley, Gareth Llewellyn, J. Anthony McAlister, SN2 mechanism for alcoholysis, aminolysis and hydrolysis of acetyl chloride, J. Org. Chem. 61(22) (1996) 7927-7932.

[17] Mallaiah Mekala, Venkat Reddy Goli, Kinetics of esterification of methanol and acetic acid with mineral homogeneous acid catalyst, Chin. J. Chem. Eng. 23(2015) 100-105.

[18] M.B. Smith, J.March, March's Advanced Organic Chemistry:Reactions, Mechanisms, and Structure, Sisth edition John Wiley & Sons, Inc., Hoboken, 2007. 1254-1260.

[19] P. Vollhardt, N. Schore, Organic Chemistry:Structure and Function, Sixth edition W. H. Freeman and Company, New York, 2011. 886-889.

[20] L.G. Wade, Organic Chemistry, Eighth edition Pearson Education, Inc., New York, 2011. 971.

[21] Clayden, Greeves, Warren, Wothers, Organic Chemistry, Oxford University Press, 2000.

[22] Yin-ge Bai, Li-li Fu, Deng-gao Jiang, Reaction kinetics of methyl oleate synthesis, Chem. Eng. (China) 42(5) (2014) 56-60.