Kinetic and thermodynamic parameters of biodiesel oxidation with synthetic antioxidants: simplex centroid mixture design

Journal of the Brazilian Chemical Society

Dionisio Borsato¹  Diego Galvan¹  Jaqueline L. Pereira¹  Juliane R. Orives¹  Karina G. Angilelli¹  Rodolfo L. Coppo¹ 

[1] ,State University of Londrina Chemistry Department Fuels Analyses and Research LaboratoryLondrina PR ,Brazil

关键词: activated complex;    synthetic antioxidants;    oxidation stability;    mixture design;   

DOI  :  10.5935/0103-5053.20140182

来源: SciELO

【 摘 要 】

Temperature's influence on biodiesel oxidation was evaluated by kinetic and thermodynamic data in biofuel from soybean oil and lard with synthetic antioxidants: butylatedhydroxyanisol (BHA), butylatedhydroxytoluene (BHT), tert-butylhydroquinone (TBHQ), and propylgallate (PG) by simplex centroid mixture design. The kinetic parameters ware obtained by Arrhenius equation and showed that addition of antioxidants in all tests increased activation energy (Ea) and that TBHQ and PG were more efficient and presented synergistic effect. BHT and BHA were the least efficient, as well as their mixtures. The thermodynamic activation parameters of the reactions, evaluated by the Eyring equation and based on the theory of the activated complex (ACT), indicated no spontaneous processes (∆G‡ > 0) with positive ∆H‡ values and positive and negative ∆S‡ values. The application of simplex centroid mixture design, using Ea as response, showed the optimised value of 174.46 kJ mol-1 for a mixture containing 33.33 and 66.67% of TBHQ and PG, respectively.

【 授权许可】

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