Experimental Study On The Influence Factors Of Polypropylene Hollow Fiber Membrane Aeration Oxidation Of Ammonium Sulfite

Ammonia desulfurization technology is an effective method for controlling SO2 pollution.People often use open-type aeration system oxidate ammonium sulfite solution of ammonia desulfurization by-product in the industry.There are some problems in this open-type aeration system,include the larger energy consumption,the larger space occupied and the absorption of SO2 again escape,etc.,but the membrane aeration process can avoid these problems.In this paper,the experimental apparatus of membrane aeration oxidation ammonium sulfite was designed and assembled by using the self-made polypropylene hollow fiber membrane contactor as the core,and the PP hollow fiber membrane was characterized by means of SEM and DSC.The effects of initial concentration of ammonium sulfite,gas-liquid ratio,liquid-phase flow rate,gas to liquid phase pressure difference,liquid-phase temperature,high-concentration ammonium sulfate and membrane contactor packing density on the oxidation rate of ammonium sulfite were studied.And the optimum oxidation conditions were obtained.On the basis of experimental research,the relationship between total mass transfer coefficient and air flow rate,liquid flow rate,gas-liquid pressure difference and liquid temperature is discussed by using the dual-mode theory.The influence of various factors on the oxidation efficiency of membrane aeration oxidation of ammonium sulfite was studied theoretically,And provide experimental data and theoretical basis for the application and popularization of membrane aeration oxidation ammonium sulfite.Representation of PP hollow fiber membrane:the microporous structure of the surface of the membrane is clearly visible in the image of PP hollow fiber membrane,microfibers are also found between the wafers.which increase the material's toughness;the completely melt temperature of PP hollow fiber membrane is 167?.The experimental results of membrane aeration compared with the open-type aeration show that:the membrane aeration oxidation of ammonium sulfite could be more efficient and there is no a lot of bubble phenomenon during the reaction,effectively avoid the problems of SO2 escape,etc.The experimental results of study on the influence factors of membrane aeration oxidation of ammonium sulfite show that:when in a solution the initial concentration of ammonium sulfite was O.lmol/L,the gas-liquid ratio was 3:1,the liquid phase flow rate was 5L/min,the gas to liquid phase pressure difference was 0.015MPa,and the liquid phase temperature was 50?,after 1h the oxidation rate of ammonium sulfite was 98.94%.The results of the research of membrane aeration oxidation ammonium sulfite mass transfer process show that:when in a solution the initial concentration of ammonium sulfite was 0.1 mol/L,the gas-liquid ratio was 3:1,the liquid phase flow rate was 5 L/min,the gas to liquid phase pressure difference was 0.015 MPa,and the liquid phase temperature was 50?,after lh the total mass transfer coefficient was 1.017×10-3 m/s.In summary,membrane aeration process for ammonium sulfite oxidation is both efficient and energy-saving,but also to prevent the SO2 re-escape,The feasibility of membrane aeration process for ammonium sulfite oxidation was preliminarily confirmed.