Modified Zeolite Shape-selective Catalytic Synthesis Of 2,6 - Isopropyl Naphthalene

In recent years, shape-selective alkylation of polynuclear aromatics has begun to receive increasing attention. 2,6-diisopropylnaphthalene(2,6-DIPN) is a potentially useful raw material for production of polyethylene naphthalate (PEN), polybutylene naphalate(PBN) and liquid crystalline polymers (LCP) with superior properties. Investigation of the reaction and the catalyst for conversion of polynuclear aromatics is needed both from fundamental and practical viewpoint.In this paper, the process for preparing 2,6-DIPN by isopropanol and naphthalene over modified molecular sieves catalysts was employed. The effects of reactions conditions on isopropylation of naphthalene were studied. The researching contents were as follows:1. At refluence temperature, modified molecular sieves catalysts were prepared by immobilization of Lewis acids through ion-exchanging methods.2. At refluence temperature, modified molecular sieves catalysts were prepared by modification of rare earths and alkali earths through ion-exchanging methods.3. At ambient temperature, modified molecular sieves catalysts were prepared by impregnation of phosphotungstic acid (PW) through impregnating methods.4. At ambient temperature, modified molecular sieves catalysts including Si/NH₄M, PDMS/NH₄M, HMx were prepared by liquid deposition or dealuminated with acids methods.5. The structure of the modified molecular sieves catalysts were characterized by XRD,SEM/EDS, BET,FT-IR. Based on the characterizations, the catalytic behavior was tested in isopropylation of naphthalene with isopropanol, and the correlation of the properties of the catalysts and their performance has been discussed in detail.6. The estimating of their performance were carried out in a fixed-bed down-flow microreactor. The optimum reaction conditions were determined at the same time. The optimum reaction conditions are the reactant molar ratio(naphthalene: isopropanol: cyclohexane=1 :2:10),catalyst charge(2g),weight space velocity(3h^-1), reaction temperature(280℃).