Abstract:

The fixed bed process of epoxidation of 1-pentene to epoxypentane catalyzed by formed titanium silicalite（TS-1） was studied by using TS-1 as catalyst and hydrogen peroxide（H₂O₂） as oxidant.The effects of reaction temperature，reaction pressure，hydrogen peroxide space velocity，solvent type，the molar ratio of methanol to hydrogen peroxide，the molar ratio of 1-pentene to hydrogen peroxide，and hydrogen peroxide space velocity on the catalytic activity and selectivity of TS-1 catalyst were investigated.The experimental results showed that the fixed bed process of TS-1 had good catalytic activity and product selectivity for the epoxidation of 1-pentene.The reaction temperature had great influence on the stability of the catalyst，and the activity of the catalyst was decreased rapidly at high temperature.The reaction pressure had little effect on the reaction performance of the catalyst，and methanol was the suitable solvent for the epoxidation of 1-pentene catalyzed by TS-1.Under the optimized process conditions（35 ℃，1.5 MPa，hydrogen peroxide space velocity 0.08 h^-1，methanol to hydrogen peroxide mass ratio of 19.9，1-pentene to hydrogen peroxide mass ratio of 1.5~2.0），the catalyst was continuously operated for 132 h，and the hydrogen peroxide conversion rate and epoxypentane selectivity remained above 95%.Through the analysis of the catalyst after use，it was found that the main reason for the reduction of its activity was the blockage of the catalyst micropores in the process of 1-pentene epoxidation.The catalyst activity could be restored by in-situ regeneration due to non-permanent deactivation.

Key words: TS-1, 1-pentene, epoxidation, fixed-bed reactor, 1,2-epoxypentane