Study On Desulfurization Adsorbent And Investigation On Desulfurization Effect Of FCC Gasoline

With the development of social and economic, gasoline consumption increases rapidly. Under constantly strengthening of environmental protection consciousness of human beings and increasingly stringent environmental regulations, implementation of more strict clean fuel standard and engine emission standard becomes an inevitable trend. To minimize the emission of harmful substance, governments around the world gradually permit a lower sulfur standard in the field of transportation fuels. This requires to start deep desulfurization research work. In this paper, desulfurization adsorbents NiO/ZnO-SiO2-Al2O3 were perpared by different methods to remove sulfide from FCC gasoline.The adsorbents perpared by co-precipitation and fractional precipitation method showed better desulfurization capacity. The highest desulfurization rate could reach 79.9%, the equilibrium adsorption amount was 7.40mg/g, and the sulfur content of refined oil was 37.93 mg/g. The appropriate content of nickel oxide and zinc oxide obtained in the fixed-fluid reactor was respectively 26.09% and 50.72%. The desulfurization rate can reach 84.4%.The sulfur content of refined oil was 28.08 mg/g, and its liquid yield was more than 90%.The highest desulfurization rate was 86.33% when the initial concentration of thiophene was 100mg/L. The highest equilibrium adsorption amount was 13.72mg/g when the initial concentration of thiophene was 1000mg/L. The experimental data fitted mathematical model of adsorption kinetics. Langmuir Equation of the corresponding adsorption isotherms were better fitted. The rate equation of desulfurization reactions obtained by the investigation of kinetics was lnk=-1619.04(1/T)+0.623, and the activation energy was 13.46kJ/mol.The optimized operating conditions in fixed-fluidized reactor were:hydrogen oil volume ratio of 150, temperature of 380℃, reaction pressure of 1.5Mpa and WHSV of 8.736h-1. In these conditions, the sulfur content of the refined oil was 11.58mg/g, and RON reduced to 93.85 from 95.21.Regeneration by air roasting and hydrogen reduction method could get better effect. After four times regeneratio, the sulfur content of refined oil decreased from 6.55mg/g to 4.70mg/g.