Characteristics of selective non-catalytic reduction of NO x with solid polymer denitration agent

doi:10.16085/j.issn.1000-6613.2022-1997

Abstract

Abstract:

The denitration efficiency, influencing factors and reaction mechanism of selective non-catalytic reduction of NO _x with solid polymer denitration agent (PNCR) were explored in a fluidized bed reactor. The results showed that the denitration using solid denitration agent was mainly a non-catalytic reduction reaction. As temperature increased from 850℃ to 1150℃, the denitration efficiency increased with temperature, with the highest denitration efficiency of 97% at 950℃, and then the denitration efficiency decreased due to the high-temperature oxidation. The reaction did not need the oxygen and the denitration efficiency gradually decreased as the oxygen concentration increased. Steam addition could weaken the oxidation of denitration agent by O₂ and delay the high-temperature oxidation reaction. In the thermal decomposition of solid denitration agent, O element mainly escaped in the form of CO₂. And N and C elements were converted into active free radicals such as NH, CH₂ and CN. CH₂ and CN could react and thus consumed the strong oxidizing groups (e.g., O₂, O and OH) in the furnace, and inhibit the formation of NO, which might further accelerate the reduction reaction of NH and other free radicals with NO to achieve high denitration efficiency. The research results could provide theoretical support and technical reference for the applications of polymer denitration technology.

Key words: polymer non-catalytic reduction (PNCR), selectivity, polymers, reduction, denitration efficiency

摘要：

在流化床反应器中研究了固体高分子脱硝剂选择性非催化还原（PNCR）脱硝效率、影响因素及反应机理。结果表明，固体脱硝剂炉内发生非催化还原反应，在850～1150℃范围内，随着温度升高，脱硝效率逐步增加，在950℃达到最佳（97%左右），之后脱硝剂主要受高温氧化反应的影响，脱硝效率下降。氧气不利于脱硝反应，随着氧气的增加，脱硝效率逐渐降低；水蒸气加入能减弱O₂的氧化作用，延迟脱硝剂的高温氧化反应。固体脱硝剂热分解过程的O元素主要以CO₂形式析出，N和C元素生成NH、CH₂和CN等自由基，CH₂和CN则通过与O₂、O和OH反应而消耗炉内强氧化性基团，抑制NO的生成，加快NH等自由基与NO还原反应而实现高效脱硝。该研究结果为高分子脱硝技术的应用提供了理论支撑和技术参考。

关键词: 高分子非催化还原, 选择性, 聚合物, 还原, 脱硝效率

CLC Number:

X701

ZHU Chuanqiang, RU Jinbo, SUN Tingting, XIE Xingwang, LI Changming, GAO Shiqiu. Characteristics of selective non-catalytic reduction of NO _x with solid polymer denitration agent[J]. Chemical Industry and Engineering Progress, 2023, 42(9): 4939-4946.

朱传强, 茹晋波, 孙亭亭, 谢兴旺, 李长明, 高士秋. 固体高分子脱硝剂选择性非催化还原NO _x 特性[J]. 化工进展, 2023, 42(9): 4939-4946.

Figures/Tables 7

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