Study On The Process Of Modified Solid Superacid For Oxidative Desulfurization Of Gasoline

The combustion of sulfur in oil products has caused great harm to the environment and human life.With the increase of the standard of motor gasoline introduced by countries all over the world,the limitation of sulfur content is becoming more and more strict.The total sulfur is required to be?10?g/g.Hydrogenation process was adopted by the refinery for gasoline desulfurization.However,the hydro-desulfurization has some problems,such as the poor effect on removal of sulfur compounds like thiophenes in gasoline,the decrease in octane number,and the large one-time investment.At present,researchers focus on catalytic oxidation and adsorption in non-hydrodesulfurization.SO₄^2-/M_xO_y and S₂O₈^2-/M_xO_y solid superacids show good catalytic activity in acid catalysis,they are promising solid superacids.Because oxidative desulfurization is also an acidcatalyzed reaction,so it is also feasible to use it as a catalyst in oxidative desulfurization.S₂O₈^2-/ZrO₂ solid superacid was synthesized by this introducing and studied on modification by introducing other transition metals.So S₂O₈^2-/ZrO₂-CuO and S₂O₈^2-/ZrO₂-CoO were synthesized.The catalysts were characterized by XRD,FT-IR,NH₃-TPD and BET,the results show that the tetragonal phase ZrO₂ content in S₂O₈^2-/ZrO₂-CoO is the highest,and the solid superacid acidity can be formed the most.The three characteristic superacids showed corresponding characteristic diffraction peaks at 900-1400cm^-1,among them,the characteristic peak of the catalyst S₂O₈^2-/ZrO₂-CoO was the sharpest,the specific surface area was the largest,and the acidity was the strongest.Three solid superacids were applied to the desulfurization of FCC gasoline and S₂O₈^2-/ZrO₂-CoO after cobalt modification showed better catalytic activity under the same reaction conditions,and when n?Zr?:n?Co?=2:1?C??NH₄?₂S₂O₈?=0.5mol/L,the catalyst is the best for gasoline desulfurization.The most catalytically active S₂O₈^2-/ZrO₂-CoO was applied to the desulfurization reaction of simulated oil?coker naphtha and FCCgasoline,and the effects of different process conditions on the desulfurization rate were investigated.The results show that the most suitable oxidation conditions for the removal of sulfide from simulated oil are:reaction temperature is 70?,the addition mass of S₂O₈^2-/ZrO₂-CoO is 0.02g/mL simulated oil,reaction time is 1.5 h V?simulated oil?:V?H₂O₂?=25:1,after the product is extracted by DMF with 1:1,the removal rate of BT can reach 90.56%;The most suitable oxidation conditions for coking gasoline are:reaction temperature is60?,S₂O₈^2-/ZrO₂-CoO added dosage 0.015g/mL coker naphtha,reaction time is 2 h,V?coker naphtha?:V?H₂O₂?=10:1 after the product was extracted by DMF at 1.2:1,the removal rate of sulfide in coking gasoline was about 71.31%;The most suitable oxidation conditions for FCC gasoline are:reaction temperature is 70?,S₂O₈^2-/ZrO₂-CoO addition mass 0.02g/mL FCC gasoline,reaction time is 1.5h,V?FCC gasoline?:V?H₂O₂?=7.5:1,after the product is extracted by DMF according to 1:1,the removal rate of sulfide in FCC gasoline can reach 85.34%.After the catalyst was repeatedly reacted for 4 times,the catalytic oxidative desulfurization activity remained at a high level,and the catalytic performance was relatively stable.