Rsearch on Catalysts Synthesis from 2,2’-Diaminodibenzyl to Iminodibenzyl
|School||East China University of Science and Technology|
|Keywords||Iminodibenzyl 2,2’-Diaminodibenzyl P/γ-Al2O3 Gas phase catalytic NH3 removing reaction|
Iminodibenzyl is an important drug intermediate,which can be used for the medicine synthesis as a tristimania and epilepsia. Many available methods can be used to prepare iminodibenzyl. The main method is by removal NH3 from 2,2’-Diaminodibenzyl over solid acid catalysts, with the advantages of simple process, high quality products and low requirements for equipments. However, this process has not been applied in chemical production yet, as the reported catalysts are still in low activity and short life span.In this work, acidic catalyst carrier comparisons and catalyst impregnation methods investigation were carried out respectively. The catalysts deactivation behaviors in different positions of the reactor were studied using small size catalyst particles to analyses the carbon depositting mechanism and regeneration method. Meanwhile, the large size catalyst particles’ reaction performance were also investigated to explain the phosphoric acid dipping mechanism and to compare the catalysts’reaction performance with different P-diepersion, and the preferred catalyst preparation process was obtained at last.The results show that, during the 1000-hour activity experiment, the small particle P/γ-Al2O3 selectivity and conversion can achieve above 97% respectively. The deactivated catalysts can be recovered in steam atmosphere at high temperature. The novel multiple-impregnation method can improve P-loading amount and increase P-dispersion with different concentrations of phosphoric acid. When the P-loading amount reached 2.2%, the catalytic activity was found to have the most excellent performance,yield achieve 94%.