Synthesis And Application Of TS-1 For Ammonia Cyclohexanone Oximation Reaction

Titanium silicon molecular sieve TS-1 owns good catalytic oxidation properties,which has important application in industrial processes.This thesis investigated application and synthesis of TS-1 in ammonia cyclohexanone oximation reaction.Further more,the deactivation and regeneration of the catalyst were in-depth examined.The details are as follows:1.Titanium silicon molecular sieve TS–1 was synthesized by hydrothermal crystallization,and the obtained TS–1 was characterized by SEM,XRD,FT-IR,icp-ms.The effect of crystallization time and silica-titania ratio on properties of TS-1 were examined.In a range of crystallization time 24 h¹20 h,with the increasing of the crystallization time,the relative crystallinity of TS-1 increased firstly,then reduced to stabilization,Ti content in TS-1 increased firstly,then reduced,the suitable crystallization time was 48 h.In a range of Silica-titania ratio 20⁶0,with the increasing of the silica-titania ratio,Ti content of TS-1 reduced,and TS-1 particle size increased,relative crystallinity of TS-1 increased firstly,then reduced and its surface topography also changed.2.The catalytic activity and selectivity and stability of TS-1 for cyclohexanone oximation ammonia reaction were evaluated by using the experimental rig set up in our Lab,and,the effects of the reaction temperature,feed ratio and physical quality space velocity the reaction were also examined.The results indicate that with the increase of reaction temperature,cyclohexanone conversion rate increased slightly,the suitable reaction temperature was 351k.Excess ammonia could inhibit the occurrence of side reaction,and increased the selectivity of desired product,the suitable ammonia-cyclohexanone molar ratio was 1.76.With the increasing of water-cyclohexanone molar ratio,the amount of ammonia dissolved in the system increased,the shade of the reaction products gradually reduce,and the catalyst deactivation was accelerated with the increasing of water,the suitable water-cyclohexanone molar ratio was 5.12.When H₂O₂-cyclohexanone molar ratio was low,TS-1 would rapid deactivated,when H2O2-cyclohexanone ratio was too high,H2O2 was invalid decomposition,to cause depth of oxidation reaction products,the suitable H₂O₂-cyclohexanone molar ratio was 1.05.Cyclohexanone WHSV has significant effects on TS-1 life,unit mass TS-1 could product more cyclohexanone-oxime under a lower WHSV.3.The results of deactivation and regeneration TS-1 indicate that the deactivation of TS-1 was due to the pores blockaged by by-products and the framework dissolved of TS-1zeolite.The activity of deactivated TS-1 could be recover by high-temperature calcination and acid pickling,but the life of it could not match the that of fresh TS-1 because of its pore structures and framework dissolved were could not recover.