TS-1催化丙烯环氧化反应本征动力学

INTRINSIC KINETICS OF TS-1 CATALYZED EPOXIDATIONOF PROPYLENE

研究了甲醇 /水溶剂中TS - 1催化剂上丙烯与H2 O2 反应生成环氧丙烷的本征动力学 .根据推测的反应机理建立了 4种动力学模型 ,经参数估值及模型筛选 ,假设反应符合Eley -Rideal机理 ,H2 O2 吸附、表面反应为控制步骤时 ,所导出的模型最为满意 ,该模型的计算值与实验值吻合很好 ,对反应速率的平均偏差为 1 2 5% .

In this paper the intrinsic kinetics of TS-1 catalyzed epoxidation of propylene with hydrogen peroxide inmethanol/water is studied. The kinetic reaction is carried out in a semi-batch stirred-tank reactor at T=303.15～333.15 K,p=0.4～0.7 MPa.Four models from proposed mechanisms are regressed.The results obtainedshow that the Eley-Rideal mechanism fits the experimental data best.The Eley-Rideal mechanism Supported by the National Natural Science Foundation of China(No.29792070). To whom correspondence should be addressed.proposes that hydrogen peroxide molecule adsorbs on the catalytic sites and reacts with dissociated propylene molecule, and surface reaction is the rate-controlling step.Propylene oxide and propylene can also adsorb on the catalytic sites and compete with hydrogen peroxide, which hindes the epoxidation.Then, it is advisable to take propylene oxide out of the reactor to improve the reaction rate of epoxidation and prevent the side reaction of propylene oxide with the solvent(methanol).The adsorption of solvent methanol and water on the catalytic sites is complete under the reaction condition, so it does not affect the epoxidation rate.After parameter estimation and model discrimination, a rational model, which gives a good agreement with the experimental data, is obtained.The average relative deviation between experimental and calculated reaction rates is 12.5 %.roposesthathydrogenperox