Study On Non-noble Metal Catalyst For Light Paraffine Isomerization At Low Temperature

The paper presents the preparation of non-noble metal catalyst for Light paraffine isomerization at low temperature.Select n-pentane as reaction medium to evaluate catalyst .It has evaluated on the experiment set-up composed of high pressure microreactor used 10 ml continous flow fixed-bed and of chromatography unit.Frist ,for isomerization of n-pentane over mordenite,Ni/HM catalyst was prepared with Ni as active component. The effects of acid washing .the number of ammine exchanged,addition of competitive absorbate,temperature for calcinations ammonia , content of Ni. temperature of calcinations Ni. temperature of catalyst reduction.and reaction conditions on catalyst are respectively investigated.The result of experiment show that the more the content of nickel is,the more the catalyst behave is.But the catalyst behave increased slow and slow after the content of nickel reached a fix point. It shows that add-doff hydrogen function of metal is no longer control procedure to the reaction. Then,improved isomerization function of Ni/HM catalyst with ammonium fluorosilicate, ammonium fluorinate. potassii nitras. magnesium nitrate,phosphoric acid.aluminium chloride. The results show that the isomerization activity of Ni-F/HM catalyst improved obviously with the content of fluorine increased,the temperature of reaction declined evidently(even more 50 ).It shows abundantly that n-pentane isomerization adhered to the representative bifunctional catalytic reaction mechanism. The well match between metal and acid function is the key to the research of light paraffine isomerization catalyst.According to the evaluate and the sift through light paraffine isomerization catalyst.It shows that preparated Ni-F/HM catalyst achieved superior activity under the condition that the content of nickel is 4% and that of fluorine is 5%.At this time.the specific surface area of catalyst is 327.63(square meter per gram).all the Specific orifice volume is 0.2382(ml per gram),plane orifice radius is 1.0884(nm).The selected prepared catalyst for isomerization of light oil is used under the reaction conditions of 250 ,2.0Mpa,WHSV=1.0h-1. H2/Hydrocarbon molar ration 4.0,n-pentane conversion rate is 70.49%, isopentane yield is 68.27%,isopentane selectivity is 96.85%.liquid product yield is 97.78%.It has exceeded the the results of the same isomerization catalyst research and apply.