Studies On The Preparation And Operation Conditions Of New Alkane Dehydrogenation Catalyst

In this paper,Pt-Sn-Li/Al₂O₃ catalysts for the preparation of Dodecene by long-chain paraffin dehydrogenation and Pt-X-K/A1203 for the dehydrogenation of Isobutane were prepared by vacuum impregnation?X=Sn,Fe?.The performance was evaluated on a fixed bed continuous flow reactor.And the influence of the addition of coking inhibitor on the catalyst performance was investigated.In this study,the carrier of Pt-Sn-Li/Al₂O₃ catalyst was screened firstly.And the carrier which can be applied to make long-chain alkane Dodecane dehydrogenate for the preparation of Pt-Sn-Li/Al₂O₃ was determined.On the basis of this,the amount of the active components of the catalyst were optimized.The amount of the active components of the catalyst was determined as follows:the Pt content was 0.3%,the Sn content was 0.35%and the Li content was 0.5%.The experimental results show that the conversion of dodecane decreased from 16.35%to 11.5%during the long period of 420 h,while the selectivity of dodecene was stable at about 72.4%.In this paper,the preparation method and composition of Pt-X-K/Al₂O₃?X=Sn,Fe?catalysts for the preparation of isobutylene by isobutane dehydrogenation were optimized.The effect of the type of competitive adsorbent used in the preparation of Pt-Fe-K/Al₂O₃ catalyst for isobutane dehydrogenation on the catalyst performance was studied.The activity of the catalyst prepared using hydrochloric acid as a competitive adsorbent is higher than that of using trichloroacetic acid as a competitive adsorbent,but the selectivity of isobutylene is higher than that of the former.Addition of adjuvant K will lead to reduced activity of the catalyst but contribute to the selectivity of isobutene,the appropriate amount of K 0.5%.In the process of Isobutane dehydrogenation preparation of isobutylene,coking reaction system is an important factor affecting the normal operation of industrial devices.The use of coke inhibitors can inhibit coking,but the effect on the catalyst performance needs to be carefully evaluated.Therefore,the effect of coking inhibitor on the performance of Isobutane dehydrogenation catalyst was studied in detail.The experimental results show that the activity of the Pt-Fe-K/Al₂O₃ catalyst is decreased with the use of coking inhibitor,but the selectivity of isobutylene is obviously improved.For the Pt-Sn-K/Al₂O₃ catalyst,an appropriate amount of coking inhibitor do not have any significant effect on its activity and selectivity.