SEARCH

SEARCH BY CITATION

Keywords:

  • lumped kinetic model;
  • oxidation;
  • p-xylene;
  • terephthalic acid;
  • continuous stirred-tank reactor;
  • semibatch reactor;
  • radial basis functions;
  • partial least squares;
  • chaos-genetic;
  • algorithms

Abstract

A novel lumped kinetic model for the liquid-phase oxidation of p-xylene to terephthalic acid (OXTA) catalyzed by cobaltic, manganic, and bromide salts in industrial continuous stirred-tank reactor (CSTR) was proposed. First, the radial basis functions (RBF) coupled with partial least squares (PLS) approach was used to model the influence of the reaction factors on the rate constants of the lumped kinetic scheme for OXTA in the laboratory semibatch reactor (SBR). Second, to indicate the difference between OXTA in the industrial CSTR and that in the laboratory SBR, the correction coefficients were proposed and introduced into the obtained rate constants models to describe the influence of the reaction factors on OXTA in the industrial CSTR. Third, the kinetics of each of the lumped reactions is assumed to be zeroth-order with respect to gaseous reactants, 0.65-order with respect to p-xylene, and first-order with respect to the other liquid reactants, respectively. Based on the lumped kinetic model with unknown correction coefficients and the data obtained in the industrial CSTR, a modified genetic algorithm containing a chaotic variable, designated chaos-genetic algorithm (CGA), was used to obtain the optimum correction coefficients, and the lumped kinetic model for OXTA in the industrial CSTR was developed. Further, the reliability of the model was investigated and the satisfactory results were obtained. © 2004 American Institute of Chemical Engineers AIChE J, 50: 1169–1176, 2004