Preparation And Modification Of PVB Pervaporation Membrane For Gasoline Desulfurization

As the desulfurization of oil products has received more and more attention,compared with the traditional desulfurization process,pervaporation is also becoming more and more popular as a new membrane separation technology.However,due to the limitations of membrane materials,industrialization has not yet been achieved.Therefore,the development of high-performance membrane materials is imminent.In this paper,a series of researches have been carried out to simulate the desulfurization behavior of gasoline in membrane materials,crosslinking of membrane materials and modification of doping.Firstly,the desulfurization behavior of five-component gasoline in three kinds of membrane materials and the microscopic diffusion mechanism of gasoline molecules in the polymer were simulated by molecular dynamics method.The best choice of membrane material is polyvinyl butyral（PVB）.Second,PVB membrane with three crosslinkers of borax,boric acid and maleic anhydride was prepared.The effect of different cross-linking agents on the desulfurization performance was investigated.A self-made polyvinyl fluoride（PVDF）film was used as a base membrane to prepare PVB flat membranes and sulfur content in gasoline is 300 ppm The properties of crosslinked films were characterized by infrared,X-ray diffraction,scanning electron microscopy and atomic force microscopy.The experimental results show that after crosslinking,the sulfur enrichment factor of PVB membrane increases from 3.20 to 5.02,and the permeation flux is lower.In order to increase the permeation flux of the crosslinked membrane,the PVB crosslinked membrane was doped with SiO₂ hybrid modification.Nano-SiO₂ was surface-treated with a coupling agent and a series of PVB/nano-SiO₂ hybrid membranes with different mass fractions were prepared by blending.Infrared,X-ray diffraction,scanning electron microscopy,and atomic force microscopy were used to characterize the microscopic properties of the hybrid membrane,and the desulfurization performance of the gasoline was tested.The experimental results show that the permeation flux increases from0.60 kg/m²/h to 1.50 kg/m²/h after the hybrid modification.