Preparation Of Heteropoly Acid Based Poly Ionic Liquids And Their Application In Catalytic Oxidative Desulfurization Of Fuel Oil

The removal of thiophene compounds in fuel oil has been a challenge in the oil refining industry.Adsorption desulfurization,extractive desulfurization and catalytic oxidative desulfurization and other non-hydrodesulfurization technologies are effective alternatives and are worthy of further study.In this paper,two heteropoly acid based poly ionic liquids(HPW-PVP and V-PIL)were prepared by reaction of PVP and PVIM with a heteropoly acid,and their applicability in catalytic oxidation desulfurization were explored.Firstly,a novel polymerized ionic liquid(HPW-PVP)was synthesized by neutralization of polyvinyl pyridine(PVP)with phosphotungstic acid(HPW).X-ray powder diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR),scanning electron microscopy(SEM)and other analytical methods were used to analyze its morphology and structure.The HPW-PVP is found to be porous materials with amorphous structure.A new extraction-catalytic oxidation desulfurization(ECODS)system was constructed by using HPW-PVP as catalyst,H2O2 as oxidant,and EG as extractant,whereby DBT and BT in the model oil can be completely removed under the the following conditions:80 0C,nH2O2:ns = 20,mHPw-PVP:mOIL= 10 wt%,and mEG:mOIL?20%under stirring for 2 h.And the desulfurization efficiency did not decrease significantly after 5 consecutive uses.The used extractant and catalyst can be separated and regenerated easily.The present ECODS process also applicable to real diesel with 78%sulfur removal in one run.Second,a V-PIL catalyst was prepared by crosslinking reaction of peroxyvanadic acid and polyvinylimidazole(PVIM),and its morphology and structure were analyzed using XRD,FT-IR,SEM,N2 adsorption-desorption,and X-ray energy dispersive X-ray spectroscopy(EDX).A one-step ACODS process was established by using V-PIL as catalyst,CHP as oxidant being insitu formed via cumene oxidation by oxygen.Its desulfurization performance was tested for DBT model oil at varying conditions.The results show that the one-step ACODS desulfurization process is not satisfactory,and the desulfurization performance has little change at varying conditions.This is because CHP is not formed efficiently at present conditions.In addition,two new catalytic oxidation desulfurization systems with oxygen as oxidant were investigated,one is the metal-bromide catalytic oxidation system and the other is the radical initiator catalyzed oxidation system.The experimental results show that these two systems have no obvious desulfurization effect,which indicats that the oxidation mechanism of thiophenic sulfurs and alkylsubsituted aromatics is different.