Preparationof Hierarchical Porouszeolite Adsorbentsfor Desulfurization Of Organic Sulfur Compounds Form Model Fuel

Sulfur oxides in emission exhaust gas from vehicles can cause haze and affect human health,the adsorption desulfurization of fuel can improve the quality of oil products and reduce environmental pollution.The adsorption desulfurization technology is an efficient method to remove thiophene organic sulfide in fuel.Molecular sieve has been widely employed for adsorption desulfurization but microporous zeolites have diffusion limitations on organic sulfide,such as TP,BT and 4,6-DMDBT.To decrease the diffusion limitations of the microporous zeolites we used the alkaline treatment,acid treatment and acid-alkaline sequential treatment to obtain hierarchical zeolites of ZSM-5,NaY and NaX.In addition,we prepared Ce-MOF adsorbents.Adsorbents were applied to adsorption desulfurization of model gasoline,and the residual sulfur content in gasoline was determined by UV-vis absorption spectroscopy method.The research contents and results can conclude the following points:1.The original ZSM-5 microporous zeolites were by alkaline treatment?AT?to obtain the hierarchical ZSM-5?ZSM-5-AT?.ZSM-5-AT-0.5 which treated by 0.5M sodium hydroxide showed the maximum specific surface area and mesoporous pore volume.Ce-ZSM-5-AT-0.5 showed the highest sulfur removal of 4,6-DMDBT?60%?.NaY-AT-M series have been prepared by the same method using original Y zeolites,the mesoporous surface area and the metal Ce and Ru loading increased,the adsorbents RuY-AT-0.5?90%?and CeY-AT-1.0?96%?showed the highest sulfur removal,respectively.2.NaY-DA-M obtained by H₄EDTA acid?DA?treatmentof NaY zeolites,and the acid treatment effect for pore structure and sulfur removal were investigated.Optimal concentration of H₄EDTA acid was 0.04M for NaY-DA-0.04,and the sulfur removal of BT and 4,6-DMDBT were 48%and 95%,respectively.NaY-CA-AT prepared by acid-alkaline sequential treatment of original NaY,the adsorbent AgY-CA?3.0?-AT0.1showedtheoptimaldesulfurizationresults.The AgX-CA?3.0?-AT0.1 prepared by the same conditions of original NaX zeolites showed the maximal sulfur capacity,the saturation sulfur capacities of BT and4,6-DMDBT were 2.32 and 4.81 mg-S/g,respectively.The sulfur removal was 85%even after four times adsorption-regeneration reaction.3.The Ce-MOF adsorbent prepared by solvent thermal method,and calcinated at 300°C and 500°C under nitrogen air,respectively.The pore distribution analysis showed that the sample appeared mesoporous.The Ce-MOF adsorbent had the best desulfurization effect,and the sulfur removal were TP?53.3%?,BT?64.5%?,4,6-DMDBT?70.8%?from model gasoline with low sulfur concentration?S=20ppm?.