Abstract:

SO₂ in the flue gas has high recovery value. In the process of adsorption purification of flue gas, condensation method can be applied to purify SO₂ in the desorbed gas into high-purity liquid product. In this paper, an experimental study on the recovery of SO₂ with condensation method was carried out by using the SO₂-rich desorbed gas as the feed gas with the concentration of 7%—12% in Handan Steel sintering machine desulfurization process. The effects of process parameters such as the SO₂ concentration of the feed gas, condensation pressure and temperature on the recovery rate and the SO₂ concentration in the exhaust gas from the outlet of the condenser were investigated. The results show that the recovery rate increases with increasing SO₂ concentration in the source gas and condensation pressure, and decreasing condensation temperature. The SO₂ concentration in the exhaust gas is a -1 power function of the pressure, and decreases exponentially as condensation temperature decreasing. The highest possible inlet SO₂ concentration should be used as the design basis for the condenser. In practice, the reasonable upper limit of pressure should be determined in conjunction with the expected recovery rate, and the strategy of reducing condensation temperature at low-pressure level for increasing the SO₂ recovery rate should be adopted. The research results can provide reference for the resource utilization of SO₂ in the process of flue gas adsorption and desulfurization.

Key words: SO₂ utilization, condensation, recovery, separation, saturated vapor pressure

摘要：

烟气中SO₂具有高回收价值，在吸附法净化烟气过程中，可采用冷凝法对解吸气中SO₂提纯为高纯度液态产品。基于邯钢烧结机烟气活性炭吸附脱硫工艺中的富硫解吸气，进行了冷凝法回收SO₂的实验研究。重点考察了SO₂气源浓度、压力和冷凝温度等工艺参数对回收率和冷凝排出气SO₂浓度的影响。结果显示，回收率随气源浓度、压力的升高和冷凝温度的减小而升高；排出气SO₂浓度是压力的-1次幂函数，并随冷凝温度的降低而呈指数型函数降低；设计冷凝器时要以可能出现的最高浓度为设计依据，实际生产时应结合预期回收率确定合理的压力上限，尽量采用以低压策略为基础降低温度的措施提升回收率。研究结果可为烟气吸附脱硫过程中SO₂的资源化提供参考。

关键词: SO₂资源化, 凝结, 回收, 分离, 饱和蒸气压