电渗析法分离烟气氨法脱硫浆液中的Cl^-

Removal of Chloride from Ammonia-based Flue Gas Desulfurization Slurry by Electrodialysis

为解决烟道气氨法脱硫浆液中Cl^-的不断积累会导致装备严重腐蚀并影响硫铵结晶的问题,对异相离子交换膜堆为核心的电渗析器装置分离硫铵模拟浆液中Cl^-进行研究,探究工艺参数和浆液性质对分离效果的影响。结果表明,利用电渗析技术可将Cl^-进行有效分离,优化工作电压为20 V、浓、淡室的循环体积流量均为300 L/h;而pH对Cl^-分离效果影响较小。在电渗析过程中,Cl^-会优先于SO_4^(2-)从淡室迁移至浓室,但随着硫铵浓度的增大实现Cl^-完全迁移的时间会延长,当电渗析设备运行60 min时可达到对Cl^-较好的分离效果。电渗析装置对于分离烟道气氨法脱硫浆液中的Cl^-具有良好的应用前景。

To solve the problem of the accumulation of Cl in ammonia-based flue gas desulfurization slurry which leads to severe corrosion of equipment and affects the crystallization of the ammonia sulphate byproduct, this paper aims at the separation ofCl＂ fTom desulfurization slurry using electrodialysis with heterogeneous ion-exchange membrane, and the influence of operation parameters and the property of the slurry on the separation efficiency was studied. Results indicated that considerable separation of Cl was achieved by electrodialysis, and the optimized process condition was obtained as voltage of 20 V, influent and effluent volume flow rate of 300 L/h respectively, while the influence of pH on the process was negligible. During the process, the migration of CI was mitigated with increasing content of （NH4）2SO4 in slurry in spite of the preferential mobility of Cl-. The complete separation of CI from the ammonia-based flue gas desulfurization slurry was accomplished within 60 min under the optimal condition. That electrodialysis has tremendous application potential in the separation of Cl- from ammonia-based desulfurization slurry.