甲苯甲醇烷基化制对二甲苯动力学模型

采用固定床反应器,在消除内外扩散影响的基础上,在反应温度480~560℃、甲苯甲醇总质量进料空速2 h-1、甲苯甲醇物质的量之比为1~6、水与甲苯物质的量之比为2~6和氢气与甲苯物质的量之比为2~8的条件下,研究了在自制沸石分子筛催化剂上甲苯甲醇烷基化反应的本征动力学,建立了包括甲苯甲醇烷基化制对二甲苯、二甲苯间异构化、二甲苯深度烷基化生成三甲苯和甲醇生成烯烃等7个反应的完整反应网络。采用非线性优化方法进行参数估算,并对模型的适用性进行了误差分析和统计检验。结果表明,甲醇生成烯烃反应的加入使模型能较好地反映出甲苯甲醇物质的量比对反应结果的影响,甲苯甲醇烷基化制对二甲苯的表观活化能为76.66 k J/mol,通过误差分析和统计检验表明,动力学模型是适用的。

Kinetic Model of Toluene Alkylation with Methanol topara-Xylene

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 topara-xylene was 76.66 kJ/mol. The residual analysis and statistical tests showed that the proposed kinetic model was reliable and adequate.