Experimental Research And Mathematical Simulation Of Adsorptive Desulfurization Onto Activated Carbon

This paper gave both experimental researches and mathematical simulation of adsorptive desulfurization onto styrene-based spherical activated carbon in diesel. The research used model diesel fuel, which includes three main organic compounds of real diesel fuel:aromatic compounds (Nathalene,Methylnahthalene), nitrogen compounds (Quinoline, Indole), organic sulfur compound (Dibenzothiophene) and used octane as solvent.Through single component(Nathalene,Methylnahthalene,Quinoline,Indole,Dibenzothio-phene) equilibrium and fixed bed adsorption, the adsorption capacity and mechanism of different compounds onto styrene-based spherical activated carbon were investigated, the results of adsorption capacity showed that Nathalene<Methylnahthalene<Quinoline<Indole<Dibenzothiophene, which could be explained by acid-base theory. Through binary component (Dibenzothiophene+Nathalene,Dibenzothiophene+Methylnahthalene,Dibenzothi-ophene+Quinoline,Dibenzothiophene+Indole) equilibrium and fixed bed adsorption, the influence of different compounds on dibenzothiophene adsorption onto styrene-based spherical activated carbon was studied, the results shows that nitrogen compounds had stronger influence, so reducing the amount of nitrogen compounds will benifit adsorptive desulfurization onto styrene-based spherical activated carbon.Mathematical simulation was used to investigate the adsorption process. In order to evaluate the rate control step of diffusion and the effect of each variable on adsorption, simulation of single component fixed bed adsorption was performed, the results revealed that adsorption was controlled by both internal and external diffusion, and isotherm and flow velocity had stronger effect on adsorption. Besides, binary component fixed bed adsorption was simulated, the model neglected internal diffusion showed a great agreement, and the ideal adsorbed solution theory model (IAST) was best binary component isotherm. With that model, binary fixed adsorption could be easily predicted by single component equilibrium experimental data.