Dechlorination of coal-fired flue gas is a novel approach for realizing zero discharge of desulfurization wastewater. The core principle is to convert the HCl in the flue gas into chloride salt, which will migrate into the fly ash. Pilot-scale experiments were conducted to research the migration and agglomeration of chlorine in actual coal-fired flue gas in a power plant. The results indicate that the HCl removal efficiency in flue gas can rise to 70% at a Na/Cl molar ratio of 7.58 when using NaOH solution with clean water or a ratio of 8.93 when using NaOH solution with desulfurization wastewater. XPS shows that the characteristic peak of chloride in the dechlorinated ash is much more pronounced than that in the original ash. The content of inorganic chloride increases significantly with increasing Na/Cl or the utilization of desulfurization wastewater. SEM–EDS indicates that the various salts agglomerated on the fly ash surface notably increase after dechlorination. The contents of Na, Ca, Mg, Fe and S in the ash increase remarkably, especially with desulfurization wastewater. The chloride salts generated by flue gas dechlorination and the pollutants in the desulfurization wastewater are effectively agglomerated with the fly ash.

燃煤烟气脱氯是实现脱硫废水零排放的新途径。其核心原理是将烟气中的HCl转化为氯盐，然后迁移到飞灰中。开展了中试，研究了某电厂燃煤烟气中氯的迁移和团聚。结果表明，当Na/Cl摩尔比为7.58时，使用NaOH溶液与清水混合或使用NaOH溶液与脱硫废水的比例为8.93时，烟气中HCl的去除效率可提高至70%。XPS 表明，脱氯灰分中氯化物的特征峰比原灰分明显。无机氯化物的含量随着Na/Cl的增加或脱硫废水利用率的增加而显着增加。SEM-EDS 表明，在脱氯后，聚集在飞灰表面的各种盐分显着增加。灰分中Na、Ca、Mg、Fe、S的含量显着增加，尤其是脱硫废水。烟气脱氯产生的氯化物和脱硫废水中的污染物与飞灰有效团聚。