高砷煤SCR脱硝催化剂中毒失活研究

某电厂燃用霍林河高砷煤种，以该电厂选择性催化还原（SCR）脱硝蜂窝式催化剂为研究对象，对其在不同运行时间下的脱硝活性进行了中试检测评价，并采用X射线荧光光谱仪、氮气吸附脱附仪、压汞仪、全自动化学吸附仪等对其成分和微观特性进行了检测分析。研究结果表明，砷在催化剂表面和微孔内的沉积造成其微观比表面积和孔结构发生变化，降低了催化剂表面酸量和氧化还原特性，致使催化剂活性异常劣化，机组运行1 000 h 时的催化剂脱硝活性仅为新催化剂脱硝活性的69%。为提高催化剂的使用寿命，提出了燃用高砷煤时减缓催化剂砷中毒的催化剂寿命管理建议。

Deactivation of Honeycomb SCR Catalysts in High-Arsenic Coal-Fired Power Plant

In this paper, the arsenic deactivation of honeycomb Selective Catalytic Reaction (SCR) catalysts in Huolinhe coal-fired power plant were studied. The denitrification activity of catalyst were tested and assessed at different time points of its life cycle. In addition, by utilizing X-ray fluorescence spectrometer, N₂ adsorption-desorption, mercury porosimetry and automatic chemisorption analyzer (NH₃-TPD and H₂-TPR), the chemical compositions and physicochemical properties of the catalysts were explored and analyzed. As it is shown from the results, the deposition of arsenic in the surface and micro pores of the catalysts led to the decrease of specific surface area and acidity of the catalyst, which was the major reason for the poisoning of the catalyst. Bench-scale catalyst test results show that the activity of catalysts dropped down to 69% of the new catalysts after only about 1 000 hours service, suggesting a very fast deactivation process compared to normal catalyst. To extend the catalyst lifetime, certain procedures for catalyst lifetime managements were proposed to slow down the arsenic poisoning process in the coal-fired power plant fueled with high-arsenic coal.