Abstract:

A membrane aeration-absorption combined flue gas desulfurization process was investigated using polypropylene hollow fiber dual-layer membrane contactor. The influences of flue gas flow rate, seawater flow rate, seawater pH and aeration flow rate on SO₂ absorption were investigated. The results show that higher desulfurization efficiency and mass transfer performance are achieved in the novel membrane aeration-absorption process, in which SO₂ absorption rate increases by 12.4% comparing to normal one. The flue gas flow rate increases induce to SO₂ absorption rate decreases, while total mass transfer coefficient increases first and then decreases. Increasing of seawater flow rate, seawater pH and aeration rate result in SO₂ absorption rate and total mass transfer coefficient increase. Aeration with higher seawater pH presents better absorption effect. Higher seawater pH and bigger aeration rate lead to larger absorbed flux. The characterization of SEM and contact angle show that the hollow fiber membrane still has high hydrophobic properties and usability after one month, which shows a good application prospects of polypropylene (PP) hollow fiber membranes.

Key words: absorption, membranes aeration, membrane contactor, desulphurization, polypropylene hollow fiber membrane, seawater

摘要：

利用聚丙烯中空纤维双层曝气式膜接触器，对膜曝气-膜吸收耦合式海水烟气脱硫过程开展实验研究，考察了烟气流量、海水流量、海水pH以及曝气量等因素对烟气脱硫参数的影响。结果表明，曝气式膜吸收过程具有更高的脱硫效率和传质性能，相较于非曝气过程，SO₂吸收率可提高12.4%。提高烟气流量，使SO₂吸收率降低，总传质系数先增大再减小；提高吸收剂流量、pH和曝气量，SO₂吸收率和总传质系数均会提高，海水pH较高条件下加入曝气更能有效加强吸收效果；烟气中SO₂的吸收通量均随海水pH和曝气量的增加而增加。扫描电镜及接触角测量显示在使用一个月后的膜丝仍具有较高的疏水性能和使用性能。

关键词: 吸收, 膜曝气, 膜接触器, 烟气脱硫, 中空纤维膜, 海水