Study On Absorption Performances And Simulation Of Extracting Bromine From Brine With Gas Filled Membrane

Bromine is one of the important chemical raw materials, the industrialized bromine production methods are both distillation and air blowing, which are limited for huge energy input high, high bromine concentration in brine, absorption tower flooding and back-mixing. Membrane absorption perforamnces and transfer intensification of extracting bromine from brine with gas filled membrane were studied in this work.Membrane absorption performances of extracting bromine from aqueous bromine solution with polyvinylidene fluoride (PVDF) hydrophobic hollow fiber membrane were studied, and factors which affected aqueous bromine solution membrane absorption performances were analyzed in this study. The process of aqueous bromine solution membrane absorption was determined to be a first-order reaction kinetic, and membrane absorption performances of concentration polarization in the membrane absorption were discussed.Regression orthogonal experiment was adopted to develop the regression equation of membrane absorption of aqueous bromine solution, through which mass transfer performances under other different hydromechanics conditions could be predicted, and significant factors of aqueous bromine solution membrane absorption was determined.When feed temperature was50℃, feed flow rate was22.24cm/s, feed concentration was220mg/L, stripping flow rate was2L/h and stripping concentration was0.01mol/L, aqueous bromine solution membrane absorption flux6.17×103kg/(m2-h) was obtained.Transfer process of aqueous bromine solution membrane absorption process for PVDF hollow fiber membrane was discussied, and the mechanism was determined to be Knudsen diffusion model, the mathematical model was established at the same time, the simulated results had shown a good accordance with the experimental.The effects of inorganic ions on aqueous bromine solution membrane absorption performances results showed that:the fluid viscosity increased with the increasing of and diffusion coefficient decreased with the exit of salt in brine, so membrane absorption flux lower than that of without salts. The aqueous bromine solution membrane absorption flux was from0.49×10-3kg/(m2-h) to0.29×10-3kg/(m2-h) when NaCl concentration in brine was from0.01N to2N accordingly.Membrane absorption performances of extracting bromine from low and higher concentration brine were simulated in our work. Simulated results had not shown a good accordence with the experimental, which need the further study still.