Study On Ultrafine Ni-based Catalysts For Benzene Hydrogenation

It has made the good progress of laboratory research in earlier stage of this subject, the result show that, the catalyst(NiO/SiO2-TiO2) prepared by Sol-Gel, is a kind of new-type fine hydro-catalysts . It is being enlarged and studies that carrying on pilot scale industry at present. In industry enlarges and tests, the form of the catalyst is a bottleneck question. At present, we have not found about the pilot scale shaping of ultrafine nickel base catalyst in document reportsSo, based on the laboratory research, the main work of this subject is get technological conditions of the pilot scale shaping process conditions of catalyst. This work, have very important meanings to use to the industrialization of this catalyst Around this central issue, we have done the researches of the following aspectsFirst, adopt by the methods of the thermal pulse, compare with three kinds different heat stability in catalyst of it is the approximate to calculate and publish 3 kinds catalyst hot to last living speed equation. The materialization performance of forerunner's body of catalyst determines the appearance to signify with BET, TPR, XRD, TG-DTA, TEM and intensity. Flow littly in succession with fixed bed and add hydrogen turn into ring carry on laboratory appraise by own the response catalysis performance in catalyst s of alkenes with benzeneSecond, we has observed that the catalyst forms the impact on base catalyst performance of load type of nickel, Have prepared 8 pieces of catalyst, has observed the performance of the catalyst through threr kinds of ways in experiment : (l)The hydrogen benzene is to 3.1:1,3.5: l,The active temperature of response of catalyst,( 2) to act as temperature of reacting as 160癈, 220 癈, The hydrogen benzene is to 3.1:1,3. The LSHV range of catalyst of 3.5:1,( 3) observing heat stability of the catalyst through thermal pulse experiment.To improve the intensity of catalyst, we used the ultrafine particle NiO/TiOi-SiOi catalysts which were prepared by Sol-Gel method and two different adhesives: SiO2 and Ni2+-SiO2 adhesive. By wring the raw materials we had the catalysts extrusion molding. We used BET,FT-IR,XRD,TPR techniques to investigate the compression strength, the BET and the pore structure of catalysts by changing some factors such as the glutinousness and concentration of adhesive ,the ageing time and temperature and so on. The results showed that : the properties of adhesive and the concentration of adhesive have relatively great influence on the BET and pore structure of catalysts.Under the suitable condition, not only the compression strength of catalysts is relatively high,but also NiO particles of the supported ultrafine Ni catalysts disperse uniformly in the catalysts and their diameters arrange from 1.1 nm to 3.3nm.On the basis of research of the lab scale shaping process conditions of the catalyst, 10kg NiO/TiO2-SiO2 catalyst powder that used for industrial experiment was prepared by sol-gel method with the tetraethyl silicate N butyltitanate and nickel nitrate. Adhesive A was used for extrusion. The physical and chemical properties of the catalyst precursors were investigated by BE. XRD . TG-DTA . TEM and intensity test.The results show that, with the increase of the Adhesive content, the intensity of catalyst increases. XRD show NiO/SiO2-TiO2 has a new phases when the content of adhesive is 13%wt. The content of adhesive has little effect to the activity of catalyst. The results showed that these catalysts had good reaction activity and good cyclohexane selectivity in the Benzene hydrogenation reaction, the benzene conversion and cyclohexane selectivity kept 100% and 99.0% at 0.80Mpa> LVSH=1.0h"1 > and the ratio of benzene: H2=3.3:lThe pilot scales of catalyst appraise and laboratory lab scale appraise result result close very much, The catalyst is in PH2=1.0MPa , LHSV=2.0h'1, 220, the ratio of benzene and hydrogen is 3.3:1.benzene conversion ratio 100%, the own alkane alternative 99 of the ring . 92%, demonstrate excellent performance , one that is with 0510 nickel ba...