Phosphotungstate-based Catalysts:Their Preparation And Catalytic Oxidation Performance For Thiophenic Sulfurs Of Fuel Oil

In order to cope with the increasingly strict environmental standards,removing sulfur compounds in fuel oil and achieving deep desulfurization,we need to develop a non-HDS technology with mild operating conditions and high desulfurization rate to assist the HDS.Therefor,two phosphotungstic-based catalysts were prepared for catalytic oxidative desulfurization of fuel oils.First,[C16MIM]3PWO was prepared,which is an amphiphilic heteropolyacid catalyst with special nanostructure.It was characterized by contact angle,XRD and EDS.We studied the influence of temperature,time,oxidant content and catalyst content of[C16MIM]3PWO on desulfurization of model oil with H2O2 as oxidant.The optimum reaction conditions were determined as follows:catalyst amount 1%w.r.t oil,n(H2O2)/n(S)=4,40?,whereby DBT and 4,6-DMDBT in model oil can completely removed within 40 min.And the desulfurization rate remains unchanged after 5 recycled uses without any treatment for the catalyst.Moreover,the present methos is also viable for real diesel oil.For the pre-treated commercial diesel oil,98.0%of desulfurization rate can be achieved.Second,a highly crosslinked polyionic liquid type catalyst of PVP-PWO was prepared by neutralization reaction of phosphotungstic acid and polyvinypyridine,and its constituent and structure was characterized by FT-IR,XRD and SEM,respectively.PVP-PWP is a porous particle with a diameter of about 20 ?m.Toward the regeneration of the glycerol extractant for the extractive desulfurization process,the oxidative of DBT in glycerol was studied.By using PVP-PWO as the catalyst and ozone as the oxidant,99.3%of DBT in glycerol can be oxidized in 80 min under the following conditions,air flow rate 500 mL/min,catalyst usage 1%w.r.t solution,and 115?.At last,t)he oxidative desulfurization performance of some advanced oxidation technologies was explored,including photocatalytic oxidation and catalyzed ozone oxidation.For this,some catalysts were prepared,such as g-C3N4,TiO2,MnO2,phosphotungstic acid and their modified derivatives.However,no satisfactory oxidative desulfurization result was achieved,but it is still of reference significance for further study of advanced oxidation technology in deep desulfurization.