NO removal by reducing agents and additives in the selective non-catalytic reduction (SNCR) process

Catalysis for NOx abatement

“…Further, the reaction also needs sufficient reaction time in that temperature window and need to be sufficiently mixed to avoid ammonia slip [216]. It has been reported that injection of some additives together with the reducing agents in SNCR processes can lower and widen the optimum reaction temperature window for NO x reduction [217]. Though selective non-catalytic reduction can achieve the same efficiency of about 90 % as SCR without a catalyst, practical constraints of temperature, time, and mixing often lead to worse results in practice.…”

NOx reduction using amine reclaimer wastes (ARW) generated in post combustion CO2 capture

“…Oxidation of CO in the presence of water vapor increases the net OH radical concentration (reactions (12)-(14)). As several experimental and kinetic modeling studies have shown (Brouwer and Heap, 1996;Bae et al, 2006;Javed et al, 2008;Klippenstein et al, 2011), this could shift the optimum SNCR temperature towards lower values by replenishing the radical pool. However, combustibles formed during the degradation of ARW will not serve to lower the temperature window beyond the range shown in the experiments of the present work.…”

Effect of mixing on NO removal in the selective noncatalytic reduction reaction process

“…[3][4][5][6] These investigations revealed that the maximum removal effi ciency of NOx in pilot-scale facilities ranged between 50% and 70%, 6,7 while laboratory studies indicated that NOx reduction could be achieved at over 90% under optimum conditions. 4,5 The performance of the SNCR process is infl uenced by several parameters, including (i) the fl ue gas temperature within the reducing agent injection zone, 8 (ii) the oxygen content in the fl ue gas, 9 (iii) additives, 10 (iv) the NH 3 /NOx molar ratio, 11 (v) the residence time of the fl ue gas, 12 (vi) the initial NOx concentration, 9,12 (vii) the water content of the fl ue gas, 8 and (viii) the mixing conditions. 13,14 Since the study of Lyon, 3 there have been many investigations on the effect of parameters on the performance of SNCR in laboratory-, pilot-, and full-scale plants, but these have mostly focused on the kinetic parameters.…”