Abstract: Aqueous ammonia has potential to capture the large amounts of SO₂ and CO₂ in coal-fired flue gas.The study in this area, however, is very limited.The reaction of SO₂ with aqueous ammonia is much faster than that of CO₂, so SO₂ in the flue gas may have impact on capture of CO₂.A series of experimental tests were conducted in a wetted wall column system, and the impact of SO₂ concentration and SO₂ loading on CO₂ flux and coefficient of mass transfer using aqueous ammonia［1%—7%（mass)］was analyzed at various absorption temperatures(20—80℃)and CO₂ concentrations［5%—20%（vol)］.The results show that when SO₂ concentration increases from 0 to 11428 mg·m^-3, CO₂ mass transfer flux and coefficient decrease to one half of the original values.When SO₂ loading［0.1—0.4 mol SO₂·（mol NH₃)^-1］increases, CO₂ mass transfer flux and coefficient also have significant reduction.Higher ammonia concentration and absorption temperature can effectively improve CO₂ mass transfer flux and coefficient, and relatively reduce the impact of SO₂ on CO₂ mass transfer.CO₂ mass transfer flux increases when its concentration increases, and its mass transfer coefficient decreases.

Key words: CO₂ capture, aqueous ammonia, mass transfer, CO₂, SO₂

摘要： 利用湿壁塔实验台对燃煤烟气中SO₂对氨水溶液［1%～7%(质量）］吸收CO₂的影响进行了实验研究，具体分析了不同反应温度（20～80℃）和CO₂体积分数（5%～20%）条件下，CO₂传质通量及传质系数随SO₂浓度和SO₂负载量的变化规律。结果表明， SO₂浓度由0增至11428 mg·m^-3，CO₂传质通量及传质系数均有一半左右降幅，而SO₂负载量［0.1～0.4 mol SO₂·（mol NH₃）^-1］的增加，同样导致CO₂传质通量及传质系数明显减小。氨水浓度及反应温度增加可有效提高CO₂传质通量和传质系数，相对降低SO₂对CO₂传质的影响。CO₂浓度的增加可明显提高其传质通量，但是CO₂的传质系数有所降低。

关键词: 烟气脱碳, 氨法脱碳, 传质, CO₂, SO₂