Study On The Characteristics Of Mass Transfer In BPM Packed Electrodialysis Bed

The influencing factors of water splitting and the mass transfer process characteristic in the process of the bipolar membrane packed electrodialysis bed are discussed. It provides the theory bases for the technology of ion exchange resin electricity regeneration and the recycling of the sour and alkali waste liquid.The two-chamber electrodialysis and the three-chamber electrodialysis with bipolar membrane are composed in different films arrangement, by the analysis of experiments, the best applied voltage of the three-chamber electrodialysis with bipolar membrane is 60 V. When the the salt cell varies with a concentration of 1.5%-2.2% , the current efficiency are maximal and two circulating periods can respectively make the pH value of acid liquors and alkali liquors to be 2.43 and 11.60, the current efficiency may amount to 55%. The current efficiency of the three-chamber electrodialysis with bipolar membrane is higher, the production of sour alkali is more quicker, and the advantage in the aspect of the mass transfer process is obvious. Comparing with the two-chamber electrodialysis with bipolar membrane.The experiment of water splitting (the salt solution) takes the three-chamber electrodialysis with bipolar membrane as the object of study, the result of the experiment indicates that in the process of the bipolar membrane packed electrodialysis bed, as the effective conduction method, ion filling up resin accelerates the removing speed of the ion and greatly boosts the reaction of the water splitting. When the applied voltage is 50 V and the salt-cell varies with a concentration of 0.21-0.27mol / L, it can respectively makes the pH value of acid liquors and alkali liquors to be 2.50 and 11.52, the current efficiency could amount to 88%; the advantage in the aspect of energy consumption is obvious. According to the result of the experiment, the I-V and the pH-I characteristic curve of the bipolar membrane packed electrodialysis bed is observed. Making use of static regeneration ion exchange resin that be installed with the implement of the three-chamber bipolar membrane packed electrodialysis bed. When the regeneration voltage is 60 V and the regeneration time reaches to 60 mins, the regeneration effect of the device approaches to the chemistry regeneration effect and the experiment demonstrates that the technology is feasible. Finally, on the theory base of the mass transfer process of the electrodialysis and the bipolar membrane, fundamental equation of the mass transfer in the bipolar membrane packed electrodialysis bed is obtained, and simplification of model which shows the trend of the concentrationchanges in the alkali-cell is deduced.