催化裂化汽油光化学氧化脱硫

以水为萃取剂、空气中的O2为氧化剂、500W高压汞灯为紫外光光源,研究了催化裂化(FCC)汽油光化学氧化反应的机理和氧化产物,考察了反应条件对FCC汽油脱硫率的影响。实验结果表明,FCC汽油中的极性含硫化合物首先部分溶于水相中,然后在水相中被氧化。在空气通入量为150mL/min、水与FCC汽油的体积比为1.0的条件下,反应5h后FCC汽油脱硫率达40.6%,加入0.45g4A分子筛作为O2的吸附剂后FCC汽油脱硫率提高到70.2%。FCC汽油的光化学氧化反应为一级动力学反应,加入4A分子筛时的反应速率常数为0.217 4h-1,半衰期为3.18h。FCC汽油光化学氧化反应的主要产物为亚砜和砜,并进一步生成CO2、草酸、SO24-等。

Photochemical Oxidative Desulfurization of Fluidized Catalytic Cracking Gasoline

Photochemical oxidation of fluidized catalytic cracking(FCC)gasoline in oil-water system was studied with O2 in air as oxidant and a 500W high pressure mercury lamp as UV-light source.In oxidation,polar sulfocompounds in FCC gasoline firstly move into water phase and then are oxidized at normal pressure and temperature.Sulfocompounds can be oxidized into sulfone and sulfoxide,and then into oxalic acid,SO2-4 and CO2.Under appropriate conditions:air flux 150mL/min,V(H2O) ∶V(FCC gasoline) 1.0 and reaction time 5h,desulfurization rate of FCC gasoline can reach 40.6%.By adding 4A molecular sieve into reaction system,acted as an adsorbent for O2,desulfurization rate can further mount to 70.2%.Under such conditions,the photochemical oxidation of FCC gasoline is first order reaction with reaction rate constant of 0.217 4h-1 and half-life of 3.18h.