Lou Jie-Chung, Hung Chang-Mao, Yang Sheng-Fu
Institute of Environmental Engineering, National Sun Yat-Sen University, Kao-hsiung, Taiwan.
J Air Waste Manag Assoc. 2004 Jan;54(1):68-76. doi: 10.1080/10473289.2004.10470881.
This work considers the oxidation of ammonia (NH3) by selective catalytic oxidation (SCO) over a copper (Cu)-cerium (Ce) composite catalyst at temperatures between 150 and 400 degrees C. A Cu-Ce composite catalyst was prepared by coprecipitation of copper nitrate and cerium nitrate at various molar concentrations. This study also considers how the concentration of influent NH3 (500-1000 ppm), the space velocity (72,000-110,000 hr(-1)), the relative humidity (12-18%) and the concentration of oxygen (4-20%) affect the operational stability and the capacity for removing NH3. The effects of the O2 and NH3 content of the carrier gas on the catalyst's reaction rate also are considered. The experimental results show that the extent of conversion of NH3 by SCO in the presence of the Cu-Ce composite catalyst was a function of the molar ratio. The NH3 was removed by oxidation in the absence of Cu-Ce composite catalyst, and approximately 99.2% NH3 reduction was achieved during catalytic oxidation over the Cu-Ce (6:4, molar/molar) catalyst at 400 degrees C with an O2 content of 4%. Moreover, the effect of the initial concentration and reaction temperature on the removal of NH3 in the gaseous phase was also monitored at a gas hourly space velocity of less than 92,000 hr(-1).
本研究考察了在150至400摄氏度之间，氨（NH₃）在铜（Cu）-铈（Ce）复合催化剂上通过选择性催化氧化（SCO）进行的氧化反应。通过在不同摩尔浓度下共沉淀硝酸铜和硝酸铈制备了Cu-Ce复合催化剂。本研究还考虑了进水NH₃浓度（500 - 1000 ppm）、空速（72,000 - 110,000 hr⁻¹）、相对湿度（12 - 18%）和氧气浓度（4 - 20%）如何影响运行稳定性和NH₃去除能力。还考虑了载气中O₂和NH₃含量对催化剂反应速率的影响。实验结果表明，在Cu-Ce复合催化剂存在下，SCO对NH₃的转化程度是摩尔比的函数。在没有Cu-Ce复合催化剂的情况下，NH₃通过氧化被去除，在400摄氏度、O₂含量为4%的条件下，在Cu-Ce（6:4，摩尔/摩尔）催化剂上进行催化氧化时，NH₃的还原率约为99.2%。此外，在气体时空速小于92,000 hr⁻¹的条件下，还监测了初始浓度和反应温度对气相中NH₃去除的影响。
