采用水合浸渍法制备Mn-Ce高铁灰脱硫剂，并将其用于脱除模拟烟气中的SO2，系统研究了金属组分在脱硫中的作用，以及脱硫温度和脱硫气氛对Mn-Ce/5FACa脱除SO2性能的影响。结果表明：在300 ℃模拟烟气（5%O2、500 mg/m3 SO2、167 mg/m3 NO和N2平衡气）中，Mn-Ce/5FACa对SO2具有较好的脱除性能，穿透时间和硫容分别为241 min和 108.45 mg/g。Mn-Ce/5FACa脱除SO2是吸附脱除和化学反应共同作用的结果，其中吸附脱除占比为30%，化学反应占比为70%。吸附反应动力学结果揭示化学吸附在Mn-Ce/5FACa吸附脱除SO2过程中起主导作用，吸附反应动力学遵循准二级动力学方程模型；添加Mn、Ce提升了Mn-Ce/5FACa的储氧能力和氧化还原能力，在与高铁灰联合作用下，利于形成K2 FeO4和MnAl2 O5，K2 FeO4中的Fe（VI）为Mn-Ce/5FACa表面提供氧化位点，促进SO2发生氧化反应。其中，化学吸附主要受脱硫温度的影响，Mn-Ce/5FACa对SO2的脱除能力随脱硫温度的升高先增强后减弱；O2在脱硫的化学反应过程中起关键作用，脱硫剂中的K2 FeO4等金属氧化物的氧化能力与O2含量有关;NO对Mn-Ce/5FACa与SO2的化学反应起促进作用，且脱硫能力随NO浓度增加而增加。

Mn-Ce high-content iron ash desulfurizer was prepared by hydration impregnation method and used to remove SO2 from the simulated flue gas. The role of metal components in desulfurization,and the effects of desulfurization temperature and atmosphere on the SO2 removal performance were systematically studied. The results show that Mn-Ce/5FACa has good SO2 removal performance at 300 ℃ in the simulated flue gas (5% O2,500 mg/m3 SO2,167 mg/m3 NO and N2 balance),with the breakthrough time of 241 min and sulfur capacity of 108.45 mg/g. The SO2 removal by Mn-Ce/5FACa is the result of the combined effect of adsorption removal and chemical reaction with proportion of 30% and 70%,respectively. The results of adsorption kinetics reveal that chemisorption plays a main role in the adsorption removal of SO2 by adsorption of Mn-Ce/5FACa,and the kinetics of adsorption reaction follows the quasi-second-order kinetic equation model. The addition of Mn and Ce improves the oxygen storage and redox ability of Mn-Ce/5FACa. The combined action of Mn，Ce and high-content iron ash is conducive to the formation of K2FeO4 and MnAl2O5. Fe(VI) in K2 FeO4 provides oxidation sites in the surface of Mn-Ce/5FACa and promotes the oxidation reaction of SO2. The chemisorption is mainly affected by the desulfurization tempera[JP2]ture,and the desulfurization capacity of Mn-Ce/5FACa for SO2 increases firstly and then decreases with the increasing temperature. O2 plays a key role in the chemical reaction desulfurization,and the oxidation ability of K2 FeO4 is affected by the content of O2. NO may promote the chemical reaction between Mn-Ce/5FACa and SO2,and the desulfurization ability increases with the increase of NO concentration.

0 引言

1 试验

2 结果与分析

   2.1 Mn-Ce/5FACa脱除SO2试验结果

   2.2 吸附动力学

   2.3 脱硫剂Mn-Ce/5FACa表征分析

   2.4 脱硫温度对Mn-Ce/5FACa脱除SO2性能的影响

   2.5 O2体积分数对Mn-Ce/5FACa脱除SO2性能的影响

   2.6 SO2质量浓度对Mn-Ce/5FACa脱除SO2性能的影响

   2.7 NO质量浓度对Mn-Ce/5FACa脱除SO2性能的影响

   2.8 水蒸气对Mn-Ce/5FACa脱除SO2性能的影响

3 结论