Preparation And Study Of The Catalyst Used In Preparation Of Piperazine From Ethanolamine

The paper has reviewed physical and chemical properties,production status and related uses of piperazine.At present,the application fields of piperazine have been expanded to the environmental protection except the traditional pharmaceutical chemical industry.Based on consulting the domestic and international reference documents,deamination of ethanolamine on normal pressure was determined by a comparison of synthesis routes.HZSM-5 zeolite was chosen as catalyst by comparison of TS-1 molecular sieve,MOR molecular sieve,HZSM-5 molecular sieve.Modified P/HZSM-5 zeolite catalysts were prepared with the method of ion-exchange.The effect of preparation conditions was discussed in this paper.The modified HZSM-5 zeolite catalysts were prepared with ion-exchange.The catalysts were characterized by the method of XRD,SEM,N2 adsorption-desorption,XRF,NH3-TPD to analysis the crystal structure,appearance shape,BET surface area,pore volume,bore diameter,the components and acidity of the catalysts.The following has been obtained through lots of experiments.1.Higher activity and selectivity of P/HZSM-5 catalyst prepared by the method of ion-exchange was obtained.The optimum conditions for preparing condition:HZSM-5 zeolite with the ratio of silicon to aluminum 38;infused for 24 h at 20? in 0.5 mol/L;activated for 3h at 500 ?.The result of stability experiment indicates that the activity of P/HZSM-5 catalyst was fine in 50 h.2.The effect of modifiers on catalyst performance was discussed.Phosphorus ion as the best modifier,the suitable addtion amount was 2.0%.Potassium and zinc can reduce the selection of TED A.3.The content of phosphorus,potassium,zinc was optimized through orthogonal experiments.The catalysts were characterized.The result indicated that skeleton structure of catalysts had no differences,and no new diffraction peaks were observed.The results indicated that P 2%,K 0.2%,Zn 0.005%was the suitable content.4.The optimum processing conditions:reaction temperature 310?,mass space velocity 0.3554 h-1,n(NH3):n(MEA)=0.5:1,moisture content 50%.In these conditions,the conversition of MEA is 76.59%.the selection of PIP 61.71%and TEDA 8.27%.