Hydrodesulfurization Of Diesel By Using Metal Over Aluminium Oxide Support

Research on the hydrodesulfurization(HDS)has become an important subject of Environmental catalysis studies worldwide.Sulfur content in diesel fuel has been identified as a major contributor to air pollution by sulfur dioxide and particulate emissions from vehicles.Reducing the sulfur content of diesel fuels has been found to result in particulate matter reduction.Hence,environmental regulations have been introduced in many countries to drastically reduce the sulfur content.The global trend for sulfur content in diesel fuels is towards 10-15 ppm.The primary objective of the present study was to develop highly active and selective catalysts for HDS of Benzothiophene(BT)and Dibenzothiophene(DBT).Based on the objectives a variety of nano-catalysts such as CoMo(1)/y-Al2O3,CoMo(2)/?-Al2O3,CoMo(3)/?-Al2O3,CoMoPd/?-Al2O3 and CoMoPt/?-Al2O3 were prepared,characterized and tested in a contineouse gas phase fixed bed stainless reactor under variable conditions of temperatures and variabble types and ratio of supported metal oxides.The thesis will have a summarized description of the catalyst.It will also go through the used devices,HDS reaction procedures and experiments conditions.The first study was focusing on the effect of Co/Mo ratio in CoMo/Al2O3 catalysts on HDS of Benzothiophene(BT)and Dibenzothiophene(DBT).The second study was adding Noble metals as Pd and Pt show promising activities in sulfur removal and thus had been studied as promoters to traditional alumina-supported CoMo.The alumina was loaded to active components ions through an initial impregnation process.Dibenzothiophene(DBT)and Benzothiophene(BT)as model compound on HDS was tested in continuous flow gas phase fixed bed reactor at 350?,400? and 450?under 1 atm over CoMo and CoMo with Pd and Pt catalysts supported on alumina.Samples of the catalysts were characterized using BET surface area,Powder X-ray diffraction(XRD),thermogravimetric analysis(TGA),SEM and TEM techniques.Based on the results,the HDS reactions of BT were much higher than DBT for all experiments at 350?,400? and 450?.HDS reaction of BT and DBT was slightly higher with CoMo(3)catalyst than either CoMo(l)or CoMo(2).After adding Pd and Pt to CoMo(3),the reaction of BT and DBT would be higher than CoMo3.