Effects of Anolyte on Membrane Electrolysis Regeneration of Sodium Alkali Solution

Wet sodium alkali solution flue gas desulfurization technology has been widely applied in coal-fired power plants all over the world due to its high efficiency and reliability,but the problems of liquid waste disposal and sulfur dioxide-enriched absorption solution regeneration come along.This paper reports the membrane technique applied in the sulfur dioxide-enriched absorption solution regeneration process.The effects of anolyte such as dilute sulphuric acid and water solution on the regeneration process of sodium alkali solution have been systematically investigated in this paper,using a two-chamber electrolytic cell with an anion exchange membrane of A201.The results indicate that anolyte’s properties and concentration have an important influence on the membrane electrolysis process.To dilute sulphuric acid anolyte,currents will easily occur due to the better conductivity of sulphuric acid.Furthermore,the higher the initial concentration of sulphuric acid is,the better the efficiency of the recycling of sulphuric acid in anode chamber is and the higher the energy efficiency in the recycle of sodium alkali solution is.On the other hand,based on the effects of current density or energy consumption on the regeneration efficiency of sodium alkali solution,water solution anolyte will be better in terms of saving energy and improving the regeneration efficiency,compared with dilute sulphuric acid anolyte.The optimum energy consumption for membrane electrolysis is 690,kW.h/t(NaHSO3) when anolyte is water solution.