关键词: 烟气脱碳, 氨法脱碳, 传质, CO₂, SO₂

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