Kinetic Model of Toluene Alkylation with Methanol to para-Xylene
1. Technology Research Institute of Shanghai Huayi Group, Shanghai 200241, China;
2. Chemical Engineering Institute, East China University of Science and Technology, Shanghai 200237, China;
3. Computational Chemistry and Chemical Engineering Technology Research Center of Shanghai, Shanghai 200241, China
Abstract The intrinsic kinetics of toluene alkylation with methanol over homemade zeolite catalyst was studied in a fixed bed reactor. Excluding internal and external diffusion, kinetic data was obtained under the conditions of 480-560 ℃, the total mass space velocity of toluene and methanol 2 h-1, the molar ratio of toluene to methanol 1-6, the molar ratio of water to toluene 2-6, the molar ratio of hydrogen to toluene 2-8. A complete reaction network was established including seven reactions of toluene alkylation with methanol to para-xylene, xylene isomerization, xylene depth alkylation with methanol to trimethylbenzene and methanol to olefins. The kinetic model parameters were estimated using the nonlinear optimization method, and the applicability of the model was verified by residual analysis and statistical test. The results showed that the addition of methanol to olefins reaction made the kinetic model have a better reflection of the effect of the molar ratio of toluene to methanol on reaction results. And the activation energy of toluene alkylation with methanol to para-xylene was 76.66 kJ/mol. The residual analysis and statistical tests showed that the proposed kinetic model was reliable and adequate.
