The Use Of A Selective Hydrogenation Catalyst In A Carbon Nine Hydrogenation Unit

Carbon nine fraction born from ethylene pyrolysis has been used for fuel,which is not only waste of resources but also harmful to environment because of containing sulfur and nitrogen.In order to better use this portion of the resources,carbon nine hydrogenation and carbon nine resin was developed.Pyrolysis carbon nine contains large amounts of aromatic hydrocarbons and alkenyl aromatics,good dissolving capacity and higher octane number,after modification can be used as aromatic solvent oil,and the harmonic components of high octane number gasoline.But having pyrolysis carbon contains a small amount of dienes unsaturated hydrocarbons,such as for the subsequent processing trouble,dienes unsaturated hydrocarbons,such as easy on the acidic catalyst polymerization raw rubber,glue once deposited adsorption on the catalyst,will cause the catalyst pore jams,active center are covered,causing the catalyst deactivation.In addition,carbon 9 as heavy oil containing iron,metal impurities,such as lead,copper and arsenic can cause catalyst poisoning.Dedicated to carbon nine hydrogenation catalyst,therefore,become an important topic in the field of petrochemical industry.Selective hydrogenation is the removal of carbon in nine dienes,sulfur,a kind of effective means such as nitrogen,oxygen,carbon in nine hydrogenation unit two reactors in series,in the design of the first reactor loading nickel-based(or Pd-based)catalysts,the dienes monoene selective hydrogenation formation;In the second reactor loading molybdenum-nickel catalyst,the carbon nine impurities such as nitrogen,oxygen and sulfur removal,guarantee the octane value of the product.In selective hydrogenation technology is the most critical of the catalyst selection and preparation.Commonly used catalyst active component is a transition metal,a catalyst with noble metal palladium nickel catalysts and non-noble metal catalysts used most commonly,the paper will be two kinds of catalysts in the device usage is a reaction in the comparison,select more suitable for the carbon nine fraction of selective hydrogenation catalyst.In the preparation of a new nickel-based catalyst active component in the form of nickel oxide,before use must be after the reduction treatment,the nickel oxide reduction for the hydrogenation activity of nickel.But at the beginning of new reduction catalyst has strong activity center,sulfide has a strong adsorption ability ofraw materials,the reaction catalyst adsorption sulfide first,and then the adsorption dienes and monoene.Sulfide will cover at the center of the activity of catalysts,reduce its activity,for the selective hydrogenation of dienes have much impact,in order to prevent the catalyst strong active center,before the reaction was carried out on the catalyst passivation treatment.New preparation of the second paragraph of molybdenum-nickel catalyst in the form of nickel oxide and molybdenum oxide,before the reaction must obtain the vulcanization process,make the production of nickel sulfide and molybdenum sulfide with hydrogenation activity.