Research On Catalytic Oxidative Fuel Oil Desulfurization Using Phosphotungstic Acid Alkyl Betaine

With more and more stringent environmental regulations, Removing the sulfur hasbecame a serious problem in the field of fuel oil and petrochemical industry. Compared withhydrogenation desulfurization, oxidative desulfurization has a better removal effect onremoval of benzothiophene sulfide, and it has a mild process conditions, do not consumehydrogen and other characteristics. But oxidative desulfurization reaction system is composedof two immiscible oil phase composition, it exists the small interface reaction, the massinterphase transfer resistance, oxidants contact with sulfides more difficult and other defects.Therefore, in order to achieve the best effect of desulfurization, it is critical to select asuitabale catalyst. Phase transfer catalyst can increase the degree of contact of two phases,improve the mass transfer rate and promote the oxidation reaction due to its amphiphilicstructure as hydrophile and hydrophobe groups.In the paper, with hydrogen peroxide as the oxidant, phosphotungstic acid alkyl betaineas phase transfer catalyst used in the oxidative desulfurization. First of all, BT/petroleumether model oil is catalyzed and oxidated for desulfuration in the emulsion system. Select thebest performance of the phase transfer catalyst, and using it for hydrogasoline, catalyticcracking gasoline and refined gasoline catalytic oxidative-extraction desulfurization. The trialinvestigated the conditions of the technology in the catalytic oxidation process includeamount of catalyst, the amount of hydrogen peroxide, reaction time,the emulsion mixingspeed and the oxidation reaction temperature for the effect on oil desulfurization rate. It alsodiscussed extraction of operating conditions include extractant type, amount of extractant andextraction times on the yield of gasoline and the desulfurization rate, and then the bestconditions of desulfurization process were determined.Phase transfer catalyst Phase on the properties of model oil catalytic oxidationdesulfurization results indicate: the catalytic which selected phsphotungstic acid C18alkylbetaine had better effect than phsphotungstic acid C16alkyl betaine and phsphotungstic acidC14alkyl betaine. The preparation of catalyst temperature of40℃, metal Cu modifiedphosphotungstic acid C18alkyl betaine as the best of the phase transfer catalys The molarratio of t metal Cu with phosphotungstic acid was0.02:1, the desulfurization rate is thehighest. The best process conditions of three kinds of actual gasoline catalytic oxidationextraction desulfurization is: under the conditions of the amount of catalyst0.003, Oxygensulfur ratio(molar ratio) is as11:1, reaction time10minutes, the emulsion mixing speed 2500r/min,the reaction time and standing time ratio of2:1, the reaction temperature of30℃,and using volume fraction of90%1,4-butyrolactone aqueous solution as extractant, theextractant and gasoline volume ratio of1, hydrogasoline desulfurization rate is94.06%,catalytic cracking gasoline desulfurization rate is92.31%and refined gasoline desulfurizationrate is90.12%.