凹凸棒石粘土湿法脱除氮氧化物的研究

【作者】 马睿明；

【导师】 钟秦；

【作者基本信息】 南京理工大学 ， 环境工程， 2007， 硕士

【摘要】 通过建立模拟烟气脱硝实验装置，对凹凸棒石粘土浆液脱除NO_x工艺进行了研究。在模拟烟气流量0.3L／min、初始NO浓度300×10^-6、O₂浓度8％、凹凸棒石粘土加入量20％、pH值9.5及温度20℃的最佳工艺条件下，NO_x脱除效率可达43.5％。分别在无氧条件下和有氧条件下，分析了了脱硝反应前后气、液相的组成。结果表明，NO和O₂由气相进入液相后吸附在凹凸棒石粘土上，吸附态的氧将吸附态的NO氧化为易溶于水的NO₂，随后与NaOH反应生成盐，使NO得以脱除。用稀土对凹凸棒石粘土进行了改性实验研究。通过热重-差热分析、扫描电镜、红外光谱和X射线衍射等检测手段，对改性后的凹凸棒石粘土结构进行了表征分析。实验结果表明，负载铈的最佳煅烧温度为500℃，稀土铈氧化物的加入使得凹凸棒石载体表面结构较松散且具有更多的活性氧空位，改善了催化剂的活性和稳定性。通过对脱硝的工艺研究，在铈最佳负载量为5％的条件下，改性凹凸棒石粘土吸收剂NO_x脱除效率为59.57％。更多还原

【Abstract】 Experiment from establishing the simulated flue gas removal system, investigated thefactors during the purification process. The results show that the optimal formulas of theabsorbent solution are as follows: Under the optimal experimental conditions, which thesimulated nitrogen oxides waste gases flow rate is 0.3L/min and the nitrogen oxideconcentration is about 300×10^-6（oxygen 8％）, Attapulgite clay 20％, pH value 9.5 （NaOHabout 1％）, temperature 20℃. The waste gas removal efficiency has 43.5％.Experiments were used to test the constituents of the simulated nitrogen oxides waste gasesand liquid phases after absorbtion, under the aerobic and anaerobic conditions respectively.The result shows that nitrogen oxide and oxygen from gas phase shift into liquid, and theoxygen can adsorb on the attapulgite clay, which have strong oxidation capability. It can letnitrogen oxide oxidate into nitrogen dioxide to remove nitrogen oxide.Works had also been made on the rare earth modification of the attapulgite. Using modernmonitoring such as TG-DTA found the optimal temperature of modification was 500℃.And using SEM, FT-IR and XRD analyzed the structure of the rare earth modifiedattapulgite. From the results of the experiment, the doping rare earth in catalyst providedmore active oxygen sets, and also improved the catalytic activity and stability of catalyst.The optimal doping factor of the rare earth modification in attapulgite is m （Rare earth）: m（Attapulgite clay） 5％, which the removal efficiency of nitrogen oxides is 59.57％.更多还原