ABSTRACT: High-co技購ncentration CaO particles and gas c和不ompositions have a significant 河聽influence on NOx reduction by selective就什 non-catalytic reduction (SN音森CR) in cement precalc器可iners. The effect of gas co愛哥mposition on NOx reduction by問音 SNCR with NH₃ was studied習兵 in a cement precalciner atmosph森從ere with and without CaO at 700-1100 °C城明. It was found that Ca大街O significantly lowers NOx redu制微ction efficiency betwee明制n 750 °C and 1000 °C, wh中火ich is attributed to 哥知the catalytic oxidation of跳議 NH₃ to NO. Although increasing NH₃ co兒筆ncentration was advantageous to NOx r又請eduction, the existence of CaO l器們ed to the opposite result at 750-900 °C暗術. Adding H₂O can suppress t作火he negative effect of CaO on NOx redu文下ction. Decreasing O₂ content from 明山10% to 1% shifts the tempe相那rature range in which CaO has a sig跳下nificant effect from 750-100土錢0 °C to 800-1050 °C. CO has a variety 外有of influences on the CaO effect und中友er different experimental cond土風itions. The influences o船快f NH₃, H₂O, O₂, and CO on the effe煙秒ct of CaO can be attributed to the讀子 impacts of the gas compositions on gas些嗎-phase NH₃ conversion, gas-solid cat了歌alytic NH₃ oxidation, or both proc裡開esses. A proposed pathway for影分 the effect of gas compo現訊sitions on NOx reduct在紅ion in CaO-containing SN理報CR process was developed that w水報ell predicted the CaO-contai民裡ning SNCR process.
