Influence Of Aromatic And Nitrogen Compounds On Desulfurization Onto Activated Carbon

Sulfur compounds can convert to SOx during combustion in the diesel, wich pollute atmosphere. In recent year much attention has been paid to the removal of organic sulfur compounds in diesel fuel. Catalytic hydrodesulfurization(HDS) at high temperature (320-380℃), high pressure(3-7MPa) and a lot of hydrogen is currently a major process in petroleum refineries to reduce the sulfur in diesel. It is not appropriate to removing refractory sulfur compounds largely existing in current commercial diesel, particularly dibenzothiophene (DBTS) and 4,6-demethyldibenzothiophene (4,6-DMDBT). Therefore, it is stronger necessary to find a new approach for efficiently removing DBTS of diesel.The influence of aromatic compounds(Methylnahthalene,Nahthalene) and nitrogen (quinoline,indole)compounds on dibenzothiophene onto Styrene-based spherical activated carbon (ACStyrene) in the diesel was investigated in order to study the reason that adsorption of dibenzothiophene was different between mode fuel and real fuel. DBT adsorption isotherm was determined by static adsorption method under different concentrations of aromatic and nitrogen compounds. The isotherm data of DBT was modeled by the Langmuir isotherm equation.The results revealed that adsorption equilibrium capacity of DBT decreased with the increase of concentration of aromatic and nitrogen compounds under the same equilibrium concentration. The influence on DBT onto activated carbon for nitrogen compounds are stronger than compounds (MNA is stronger than NA and indole is stronger than quinoline). The parameters of the Langmuir isotherm KL decreased as the concentration of aromatic compounds increased, However saturated adsorption capacity qm was basically unchanged.The composite materials between the resin-based spherical activated carbon (ACstyrene) and polyvinyl alcohol (PVA) adsorpted DBT and MNA, which was studied by adsorption equilibrium and dynamic adsorption in the single solute (DBT/octane, MNA/n-octane) and multi-solute solution (DBT, MNA/octane). The results show that the amount of equilibrium adsorption of DBT, MNA reduced about 3% in the initial concentration of 10μmol/g, but adsorption capacity of DBT over ACstyrene and ACstyrene/PVA were lower 14.5%,16.8%, respectively in two solutes than single solute solution. while the adsorption capacity of 1MNA were down by 63.8%,66.0%.