Zhang Mengze, Zhu Xiao, Zhang Liqiang, Li Yang, Li Jun, Xia Xiao, Ma Chunyuan, Dong Yong
National Engineering Laboratory for Reducing Emissions from Coal Combustion, Engineering Research Center of Environmental Thermal Technology of Ministry of Education, Shandong Key Laboratory of Energy Carbon Reduction and Resource Utilization, School of Energy and Power Engineering, Shandong University, Jinan, Shandong 250061, China.
Xi'an Thermal Power Research Institute Co., Ltd, Xi'an 710054, China.
ACS Omega. 2021 May 12;6(20):13484-13495. doi: 10.1021/acsomega.1c01722. eCollection 2021 May 25.
Denitration (De-NO ) over activated cokes (ACs) for sintering flue gas needs intensification. Gaseous reactions in a gas mixture containing NO, NO, and NH, with the effect of O concentration and moisture, were taken into consideration in the study of NO conversion over ACs. Experimental studies on NO conversion with and without NH over ACs were conducted using a fixed-bed reactor at 100 °C. The results demonstrated that moisture significantly affected NO removal over ACs, especially the NO conversion. Under dry conditions, a disproportionation reaction of NO over ACs dominated NO conversion with no NH, whereas apparent fast selective catalytic reduction (SCR) over the ACs was observed in the presence of NH. Regardless of the presence of absence of NH in wet mixtures, NO adsorption on ACs via the disproportionation route dominated the NO conversion. Increasing the NO/NO ratio in the simulated flue gas enhanced the NO conversion rate over ACs. -C(ONO) deposition on ACs generated by the disproportionation route inhibited NO conversion with time. O oxidation was found to be efficient in increasing the NO/NO ratio and intensifying the NO conversion compared with commercially direct NH-SCR over ACs. Increasing the temperature and decreasing the gas hourly space velocity can promote NO conversion over ACs after O oxidation. NO oxidized with O coupled with NH spray and continuous regeneration of ACs is a potential method for removing NO from sintering flue gas.
用于烧结烟气的活性焦（ACs）上的脱硝（De-NO ）需要强化。在研究ACs上的NO 转化时，考虑了含有NO、NO和NH的气体混合物中的气相反应以及O浓度和水分的影响。在100℃下使用固定床反应器对ACs上有无NH时的NO 转化进行了实验研究。结果表明，水分对ACs上的NO 脱除有显著影响，尤其是对NO转化。在干燥条件下，ACs上NO的歧化反应主导了无NH时的NO 转化，而在有NH存在时观察到ACs上明显的快速选择性催化还原（SCR）。无论湿混合物中有无NH，通过歧化途径在ACs上的NO吸附主导了NO 转化。提高模拟烟气中的NO/NO比可提高ACs上的NO 转化率。通过歧化途径在ACs上生成的-C(ONO)沉积物随时间抑制NO 转化。与ACs上的商业直接NH-SCR相比，发现O氧化在提高NO/NO比和强化NO 转化方面是有效的。O氧化后提高温度和降低气体时空速可促进ACs上的NO 转化。用O氧化NO并结合NH喷射和ACs的连续再生是一种从烧结烟气中去除NO 的潜在方法。
