The Research Of Hydrogenation Of Isophthalonitrile To M-xylylenediamine

The catalytic hydrogenation of nitriles is an important process to produce the corresponding amines,especially primary amines,which have a high value of industrial application.M-xylylenediamine is an excellent epoxy resin curing agent and an important fine chemical intermediates to synthesis polyurethane,xylene nylon resin,aromatic polyamide and isocyanate.Recently,with the growing demand for M-xylylenediamine,the research on the hydrogenation of Isophthalonitrile is gradually penetrating.The key point to improve the yield of primary amines is the control of selectivity of primary amines by catalyst tailoring to suppress the formation of secondary and tertiary amines.At present,M-xylylenediamine is mainly synthesized by hydrogenation of Isophthalonitrile over Raney-Ni catalyst in industry.However,Raney Ni is easy to be inactivatied due to mechanical damage during hydrogenation.In the present thesis,on the basis of Ni-based catalysts,the effects of the additives（Ru,Pd,Pt,Co,and Fe,etc）on the catalyst performance were investigated,and then further researches were carried out.The results showed that Ni-Ru bimetallic catalyst has positive hydrogenation reactivity of Isophthalonitrile to M-xylenediamine and excellent stability.H2-TPR revealed that the addition of Ru improved the reducing ability of Ni.The TEM characterization demonstrated that the alloy of Ni and Ru exists in the catalyst.Secondly,after the determination of the catalyst,the influence of the diffusion effect on the continuous hydrogenation of Isophthalonitrile has been studied.The experimental results indicated the diffusion effect plays an important role on the distribution of the hydrogenation products.The selection of pore size and particle size of catalyst is based on this result.In addition,effects of the kinds of the supports and the reaction conditions have also been discussed in the paper.Respectively,the effects of Al₂O₃,HZSM-5,SiO₂ and SBA-15,MCM-41 as the carriers on the hydrogenation of Isophthalonitrile were studied.