关键词: 乙醇, 水, 水合反应, 醚化反应, &beta, 分子筛, 宏观动力学, 混合进化算法

Abstract: A new method of removing water from the ethanol and water mixture near azeotropic concentration was proposed based on isobutylene (IB) hydration-etherification catalyzed by β molecular sieve. The macro-kinetic study of IB hydration-etherification was investigated under the reaction conditions of 2.0 MPa and 313～363 K. The influence of the stirring speed, initial content of water in ethanol, IB/water ratio, and reaction temperature on IB hydration-etherification was investigated. The results indicated that the presence of ethanol favored IB hydration at first, but then it inhibited the reaction. Water had little effect on the etherification between ethanol and IB. The water conversion increased with the IB/water molar ratio and decreased with the initial water content in ethanol; and it increased with the increase of temperature in lower temperature range, but decreased when the temperature was higher than 353 K. The selectivity of IB hydration increased with the initial content of water in ethanol. Under the conditions of 353 K, IB/water molar ratio of 7, and initial water content in ethanol of 10%, the water conversion reached as high as 92.58%. The macro-kinetic model was developed according to the Langmuir-Hinshelwood-Hougen-Watson theory and the experimental results using the Wilson liquid-phase activity to describe the non-ideality of the reactants. The calculated results using the parameters obtained from the hybrid evolutionary algorithm with multi-pattern evolution were in good agreement with the experimental data.

Key words: ethanol, water, hydration, etherification, &beta, molecular sieve, macro-kinetics, hybrid evolutionary algorithm