Oxidation Experiments Of Basic Aluminum Sulfate Reaction With Sulfur Dioxide

The basic aluminum sulfate desorption desulphurization method is a kind of deoxidation technique that the SO₂ can be recycled and the desulfurization solute can be reused,SO₃^2-oxidation in desulfurization process is one of the key technologies which restrict the application of law.For controlling SO₃^2-oxidation in desulfurization process can address for improving the recovery of SO₂ desorption and simplifying desulfurization-desorption process and etc.In this paper,the relationship between alkalinity,aluminum content,pH,dissolved oxygen and other related parameters in the preparation of basic aluminum sulfate solution was investigated;effect of oxidation reaction on SO₃^2-concentration and desorption rate in the process of absorption and desorption of SO₂ in basic aluminum sulfate solution;analyze the inhibition effect of adding antioxidant ascorbic acid on the SO₃^2-and the desorption rate in basic aluminum sulfate solution.The result shows that in the preparation of basic aluminum sulfate solution,the alkalinity is proportional to the stirring time;preparation of basic aluminum sulfate solution,the greater the alkalinity,the greater the pH and dissolved oxygen,the greater the amount of aluminum,the smaller the pH and dissolved oxygen.During the SO₂ absorption test,the initial dissolved oxygen in the solution is the cause of SO₃^2-oxidation,different parameter solution of the initial dissolved oxygen is different.When the amount of SO₂ absorption is different,the concentration of SO₃^2-in solution increased with the increase of SO₂ absorption,and the approximate multiple growth.When the amount of SO₂ absorbed simultaneously,the concentration of SO₃^2-in solution decreases with the increase of alkalinity,and increases with the increase of aluminum content.During the SO₂ desorption test,regardless of the change of SO₂ absorption or desorption temperature,the desorption rate was closely related to the concentration of SO₃^2-in the desulfurization rich liquid,the initial dissolved oxygen in the solution and the air in the system are the cause of SO₃^2-oxidation.Besides,using the method of adding antioxidant ascorbic acid in basic aluminum sulfate solution,in the process of absorption and desorption of SO₂,the inhibitory effect of SO₃^2-oxidizing into SO₄^2-would be nice and the desorption rate would also be increased.Therefore,the addition of inhibiting oxidant in the desulfurization solution is an effective method to reduce the amount of oxidation of basic aluminium sulfate solution SO₃^2-oxidizing into SO₄^2-and increase the desorption rate of SO₂.In engineering practice,except for the desulfurization solution of adding antioxidant ascorbic acid,we can also using the method of reducing the oxygen content in the flue gas,the gas-liquid reaction time and the gas-liquid contact area to suppress the oxidative side reation.