Study On Catalytic Hydrogenation Of Aromatics In Mild Conditions

With the continuous growth of national economy, the number of vehicles increases rapidly. The vehicle exhaust has become one of the main sources of Particulate Matter 2.5, thus the importance of treating vehicle exhaust is more and more prominent. The key requirements of specifications which are related to the fuel are the contents of sulfur and alkenes and aromatics. Especially the serious haze pollution in China from 2012 to 2016 makes the production of clean fuel extremely urgent.With regard to the shortages of traditional production process of clean fuel, this thesis suggested hydrodearomatization of feed oil in mild condition to produce clean fuel with Pd/C and Raney Ni as catalysts. The Pd/C was prepared using impregnation method and was characterized by SEM, TEM, XRD, XRF, EDX as well as N2 adsorption/desorption measurements. As a model compound, toluene was hydrogenated to investigate the performance of catalysts.The results of experiments using Raney Ni showed that the activity of aromatics hydrogenation was increased with temperature, and the conversion of toluene exhibited a tendency of growth but at low rate. Besides, the selectivity to methylcyclohexane decreased as a whole.The results of experiments using Pd/C showed that Pd/C could catalyze hydrogenation of toluene in mild condition and its activity was superior to Raney Ni. After investigating the effect of reaction temperature, pressure, ratio of solution to oil, Pd loading on toluene hydrogenation, the research indicated that under the proper condition of 1 MPa pressure,1.5 h reaction time,5% Pd loading and oil/catalyst ratio of 1:3, toluene hydrogenation achieved a conversion of 14% and the selectivity to methylcylohexane was 100%.The results of tetralin hydrogenation using Pd/C showed that Pd/C could catalyze the reaction in mild condition and the activity of reaction increased with temperature. The conversion of tetralin was 4.1% after 6 h reaction at 333 K under 1 MPa, while that was 16.1% after 6 h at 393 K under 1 MPa.