Enhancement of the denitrification efficiency over low‐rank activated coke by doping with transition metal oxides

Abstract

Low-rank activated coke (AC) is widely used for industrial flue gas purification due to its multipollutant cooperative removal capability. To enhance the denitrification capacity of AC for the selective catalytic reduction (SCR) of NO with NH 3 , several transition metal (Fe, Mn, Ce, V) oxides were uniformly loaded into AC by solvent impregnation. Compared to untreated AC, modified AC showed excellent denitrification efficiency above 90%. N 2 adsorptiondesorption and Raman spectroscopy techniques were used to characterize the pore size distribution and crystal structure of AC samples. The introduction of transition metal oxides had little effect on the pore structure of AC but increased the nitrogen-containing functional groups, which facilitated NO removal. Moreover, x-ray photoelectron spectroscopy (XPS) was used to analyze the valence changes of metal elements before and after denitrification.After the reaction, the content increase of the low-valence metal oxides indicated that the transition metal oxides were involved in the reaction of NO with NH 3 . High-valence metal oxides oxidized NO to NO 2 , which reacts more easily with NH 3 , thereby increasing the denitrification efficiency. Importantly, in the presence of SO 2 , modified AC still presented high denitrification performance.This transition metal oxides doping method can effectively improve the ability of low-rank AC to remove NO in multi-contaminant flue gas. K E Y W O R D Sactivated coke, denitrification, flue gas, SCR, transition metal oxides

Study on the Effects of Fe Doping on C‐ZFe Catalyst for Catalytic Removal of NO from the Low‐Temperature Flue Gas

“…At 125–135 °C, the NO X conversion increased about 4 times. At present, the widely used vanadium‐titanium catalyst has an active temperature window of 300–400 °C [30] . Therefore, it was considered that 125–135 °C was an appropriate temperature range for C‐ZFe.…”

Low temperature selective catalytic reduction of nitric oxide with an activated carbon-supported zero-valent iron catalyst

“…The use of transition metals as the catalysts has been documented in some literature. 10,27,28 In addition, activated carbon as a structural carrier provided a suitable porous loading structure for iron. The denitrication process was mainly determined by the reducibility of activated carbon and the catalysis of elemental iron.…”

Effect of pre-oxidation process on V2O5/AC catalyst for the selective catalytic reduction of NOx with NH3

“…Studies have shown that it is superior to TiO 2 and SiO 2 in terms of resistance to ammonium sulfate, activated carbon, or coke as a carrier (Han et al 2018). Compared with the activated carbon, activated coke (AC) has the characteristics of low cost and high mechanical strength (Ye et al 2020). AC has a large specific surface area, abundant surface functional groups, and strong adsorption capacity, which had been successfully applied to SO 2 and Hg capture and NO x purification of flue gas in the steel industry (Liu and Liu 2013, Ye et al 2020.…”

“…Compared with the activated carbon, activated coke (AC) has the characteristics of low cost and high mechanical strength (Ye et al 2020). AC has a large specific surface area, abundant surface functional groups, and strong adsorption capacity, which had been successfully applied to SO 2 and Hg capture and NO x purification of flue gas in the steel industry (Liu and Liu 2013, Ye et al 2020. Pure AC shows a low catalytic activity; thus, the method of introducing new active components (such as MnO x , CuO, or V 2 O 5 ) is used to enhance its denitration activity (Marban et al 2004;Boyano et al (Sun et al 2009;Wang et al 2014).…”