Preparation And Performance Study Of Polystyrene Fiber Membrane For Flue Gas Desulfurization

Sulfur dioxide(SO₂)was common and one of the most harmful atmospheric pollutants.Flue gas desulfurization technology had attracted the attention of scientists and enterprises.The traditional flue gas desulfurization technology had some disadvantages such as low efficiency,high cost and easy to cause secondary pollution.The membrane contactor-based flue gas desulfurization technology had a broad application prospect due to the characteristics of small floor area,modularization and flexibility.However,There were some common problems that need to be solved for the existing membrane contactor,such as the membrane contactor was easy to be wetted by absorbent solution,which led to the decrease of desulfurization efficiency and made the membrane contactor unable to operate stably for a long time.In this paper,polystyrene(PS)with low surface energy was used as the main material of membrane contactor.The electrostatic spinning method,which was easy to control the precision of membrane pores and the microstructure of fiber membranes,was used to prepare PS nanofiber membranes.The effects of mixed solvent ratio,polymer concentration and binder content on PS nanofiber membranes and the stability of PS nanofiber membranes were investigated.The main research contents and conclusions are as follows:1.Preparation and desulfurization characteristics of PS nanofiber membranes were investigated.Polystyrene with good hydrophobicity was used as the main material of membrane contactor.PS nanofiber membranes were prepared by electrostatic spinning on porous polypropylene(PP)membranes.The effects of mixed solvent ratio and polymer concentration on PS nanofiber membranes were investigated.The results showed that the PS fiber membranes were prepared with DMF/NMP ratio of 80/20.The diameter,pore roughness and critical pervious pressure of PS fiber membranes were respectively 0.89?m,3.221?m and 0.6 bar.The desulfurization experiment showed that the desulfurization performance of hydrophobic PS nanofiber membranes was better than that of PP membranes.After 5 h desulfurization experiment,the SO₂absorption flux of hydrophobic PS nanofiber membranes were stable at 7.2×10^-4?7.6×10^-4 mol·m^-2·s^-1.This confirms that its stability had improved significantly.2.Preparation and desulfurization of polyvinyl butaldehyde(PVB)/PS nanofiber membranes were investigated.PVB was introduced to improve the adhesion between PS nanofiber membranes and PP nanofiber membranes,and PVB/PS nanofiber membranes were prepared.The structure and performance of PVB/PS nanofiber membrane were characterized by water contact Angle test,Gas-liquid aperture instrument,True color confocal microscope,SEM and other instruments.The influence of PVB content on the hydrophobic and desulfurization properties of PS nanofiber membranes were investigated.The results showed that when the PVB/PS ratio was 5/5,the average pore size of the nanofiber membranes was 1.09?m and the critical percolation pressure was up to 0.31 bar.After 7 h desulfurization experiment,the absorption flux f PVB/PS fiber membrane decreased by 10?12%.With the increase of PVB content,the adhesion between PP membranes and PS nanofiber membranes was enhanced,and the stability of PVB/PS nanofiber membranes was improved.