The Research on Properties of the Catalyst in Preparation of Epichlorohydrin from Allyl Chloride by Epoxidation Method
|Keywords||Titanium-silicon molecular sieve deactivation reactivation characterization epoxidation method|
There are two ways for the production of epoxy chloropropane: high temperature chlorination of chloropropene and allyl alcohol method. But all these two methods have environmental harassment that large numbers of wastewater and waste residue are produced. The exploitation of new cleanly technics with high efficiency is much important.However, the epoxidation of chloropropene with hydrogen peroxide catalyzed by TS-1 possess the merits as mild reaction conditions, rapid reaction rate and no pollution. In this paper, a distillation-deactivation method was used. The effects of chloropropene, impurities in hydrogen peroxide, and reaction promoter on the TS-1 stability were also studied. The newly, deactived and reactivated catalysts were characterized and analyzed by methods of physical adsorption of nitrogen gas, thermogravimetric analyses, X-ray resonance diffraction method, infrared analyses, element analyzer and fluorescent analyzed method. The reactivations of deactivated catalysts were done by acid treatments, stoving method and high temperature roasting.1. Superabundant solvent would accelerate the side reaction, and the byproduct macromolecule affected the catalyst stability;2. The iron ion would affect the stability of TS-1 when it was deposited on TS-1;3. The adsorption of macromolecules on catalysts was the major reason for deactivation of the catalysts in epoxidation of chloropropene;4. The method as acid treatments, stoving method and high temperature roasting could make the deactivated catalysts in distillation reach the catalysis level as newly catalyst;5. The membrane separation experiments in the epoxidation of chloropropene showed that the epoxy chloropropane product was ideal and it could satisfy the invert ration of hydrogen peroxide, yield and selection of epoxy chloropropane.