Abstract

A novel macrokinetic model is proposed for the hydrogenation purifying of terephthalic acid (HPTA), which is catalyzed by Pd/C in an industrial trickle-bed reactor (TBR). First, the reaction orders of HPTA are estimated by the mass transfer-free experiment data in the laboratory stirred batch reactor (SBR). The hydrogenation reaction kinetics is assumed to be first-order with respect to 4-carboxybenzaldehyde (4-CBA), which is the most important contamination of terephthalic acid and hydrogenated to produce p-toluic acid. Second, due to the fact that the reaction factors of HPTA have a high-nonlinear and complex effect on the reaction rate constant of HPTA, the nonlinear partial least squares regression method was used to model the influence of the reaction factors on the rate constant based on the transfer-free experiment data of HPTA in the laboratory SBR. Thus, the macrokinetic model of HPTA in the laboratory SBR is developed. Third, to indicate the difference between HPTA in the industrial TBR and that in the laboratory SBR, the correction coefficients were proposed and introduced into the obtained rate constant model to describe the influence of the reaction factors on HPTA in the industrial TBR. Based on the macrokinetic model with the unknown correction coefficients and the data obtained in the industrial TBR, differential evolution (DE) algorithm was used to obtain the optimum correction coefficients according to the fitting performance of the macrokinetic model, and the macrokinetic model for HPTA in the industrial TBR was developed. Further, the reliability of the model was investigated and satisfactory results were obtained.

Recommended Citation

Hu, Chunping and Yan, Xuefeng (2008) "Novel Macrokinetic Model for Industrial Hydrogenation Purifying of Terephthalic Acid," Chemical Product and Process Modeling: Vol. 3 : Iss. 1, Article 37.
Available at: http://www.bepress.com/cppm/vol3/iss1/37