Green Catalytic Oxidative Desulfurization(ODS) Of Diesel

Ultra-deep desulfurization of fuel oils has become an environmentally urgent subject worldwide.Gasoline or diesel is considered the most used fuel for transportation,which is also main contribution to sulfur pollution resulting in the smog,acid rain and corrosion.ODS is involved in the oxidation of sulfur compounds to the corresponding sulfones and the removal of sulfones from diesel by extractionoradsorption.The oxidation of sulfur-containing compounds?BT,DBT,4,6-DMDBT?in model diesel was conducted in a novel oxidative system under mild conditions.In this system,the Anderson-type POM catalyst?C18H37?2N?CH3?2]3Co?OH?₆Mo₆O₁₈ was dissolved in ionic liquid [Bpy]BF4.Oxygen was used in this system as oxidant.The system demonstrated much higher recyclable than earlier report and the removal of DBT was almost 100%.The catalytic systems can be recycled five times withanunnoticeable decreaseinactivity.In addition,another work was about a novel Anderson-type polyoxometalate catalyst.The polyoxometalate {[?CH3?3N?CH2?2OH]2}[H0.2K0.2Na2.6?H2O?6][IMo6O24] was synthesized in a deep eutectic solvent?DES?and characterized by XRD,FT-IR,thermal analysis,electrochemical measurements and inductively-coupled plasma,atomic emission spectrometer?ICP-AES?.This hybrid polyoxometalate was used as a catalyst in ionic liquids?ILs?for desulfurization of model diesel.The catalyst?ChO?₂K_0.2Na_2.6IMo₆ in the extraction and catalytic oxidative desulfurization?ECODS?system,containing H2O2 and 1-octyl-3-methylimidazolium tetrafluoroborate?OmimBF4?,displayed so high activity that the removal of DBT can reach 100% at 60? in 60 min.Sulfur removal for S-compounds was in the following order: DBT > 4,6-DMDBT > BT.The desulfurization system shows so good stability that it can be recycled 20 times without noticeable decrease inactivity.Besides,the oxidation of dibenzothiophene?DBT?in model diesel catalyzed by an oxalate-based DES with a tetrabutyl ammonium chloride and oxalate acid with molar ratio of 1/2was studied.The oxalate-based DES was synthesized and characterized by IR,XRD,CV and EPR.The DES showed high activity both as a catalyst and the extractant.In order to get the ideal DES,some different kind quaternary ammonium cations were chosen as hydrogen-bond donor?HBD?while oxalic acid?OXA?was chosen as HBD.The oxalate-based DES displayed high activity that theremoval of DBTcanreach98% at 60? in 180 min.