Study On Simultaneous Removal Of SO₂ And NO_x By Combination Of Ozone Oxidation And Ammonia Solution In Packed Tower

Simultaneous removal of SO₂ and NO_X by combination of ozone oxidation and ammonia solution is a promising technology.The removal of SO₂ and NO_X in packed tower,oxidation of?NH₄?₂SO₃ and mass transfer process of SO₂ in packed tower were investigated in this paper.Firstly,the experiment on simultaneous removal of NOx and SO₂ in packed tower was carried out.The results show that the denitrification efficiency greatly increases by adding ozone.To a certain degree,the denitrification efficiency also increases with rising ammonia mass fraction;the optimum operating condition is that:the O₃/NO mole ratio is 1.0,ammonia mass fraction is 0.15%,liquid-gas ratio is 40L·m^-3.When the SO₂ and NO inlet mass concentration are respective 5120 and 600mg·m^-3,the average desulfurization and denitrification efficiency can respectively retain 100%and 88.1%in the optimum operating condition.Secondly,the experiment on the oxidation of?NH₄?₂SO₃ in stirred reactor was investigated.The results show that oxidation ratio of?NH₄?₂SO₃ increases as air flow rate,oxygen content and?NH₄?₂SO₃ temperature increases.Among them,the effect of air flow rate on the oxidation ratio of?NH₄?₂SO₃ is more remarkable.When the pH of solution increases from 5 to 7,oxidation ratio of?NH₄?₂SO₃ decreases.By studying the kinetics of oxidation of?NH₄?₂SO₃,the reaction order of?NH₄?₂SO₃ and O₂ are respective 0.4975 and 0.7105,the activation energy of reaction is 34.05 kJ/mol.Finally,the mass transfer process of SO₂-NH₃-H₂O system in the packed tower was investigated.The results show that gas phase volume mass transfer coefficient?K_ga?gradually increases as the gas flow rate and the spray density of absorbing liquid.And the effect of the gas flow rate on the K_ga is more remarkable.As ammonia mass fraction increases and the SO₂ inlet concentration decreases,the K_ga increases gradually.In the experimental system,the K_ga is that:K_g a?28?0.1726G⁰.843.843 L^0.116.Through validation of the experimental data,this correlation equation has a certain reliability.