复杂组分调质煤粉再燃中焦和气体产物还原NOx的竞争机制

再燃是降低燃煤锅炉NOx排放的有效手段。传统煤粉再燃使用空气作为输送再燃煤粉介质，由于空气中氧消耗大量煤粉，严重制约再燃降低NOx效果。申请者提出采用燃气或者煤的气化气调质再燃煤粉品质工艺，有望大幅度提高煤粉再燃还原NOx效果。本项目针对不同反应气氛、反应温度下进行煤焦和气体组分活化实验，定量分析反应气氛对煤焦中含氮含氧复合物及其物理结构演化和气体产物组分变化的影响，获得活化过程中产物演化特性；对活化产物进行两相还原NOx实验，获得活化过程对NOx还原影响的宏观规律；综合研究再燃煤粉调质活化和NOx还原反应，并与各子反应过程对比分析，获得煤焦和气体产物多组分在再燃还原NOx过程中的竞争机制和主要反应路径，并以同相异相反应动力学数据为依据，建立和完善煤粉在复杂组分下调质活化产物再燃还原NOx宏观动力学模型。本项目将为丰富燃料N转化反应机理，进一步促进再燃技术中NOx减排提供基础理论支撑。

Reburning is an effective means to reduce NOx emission from coal-fired boilers. Traditional pulverized coal reburning uses air as the medium to transport reburn pulverized coal. Oxygen in the air consumes a large amount of pulverized coal, which seriously restricts the effect of reburning to reduce NO. The applicant proposes the process of gas or coal gasification gas conditioned reburning to improve the quality of pulverized coal, which is expected to greatly improve the effect of pulverized coal reburning to reduce NOx. In this project, the activation experiments of coal char and gas components are carried out under different reaction atmosphere and temperature. The effects of reaction atmosphere on the evolution of nitrogen-containing oxygen-containing complexes and their physical structures in coal char and gas product components are quantitatively analyzed, and the evolution characteristics of products during activation are obtained. The macro rule of activation process on the reduction of NOx can be obtained by two-phase reduction of NOx. By synthetically studying the conditioning and activation of reburning pulverized coal and the reduction of NOx, and comparing with each sub-reaction process, the competitive mechanism and main reaction path of coal char and gas products in the process of NOx reduction by reburning can be obtained. Based on the kinetics data of homogeneous and heterogeneous reactions, a macro-kinetics model of NOx reduction by reburning of modified activated products of pulverized coal in complex components will be established and perfected. This project will provide basic theoretical support for enriching the mechanism of fuel N conversion reaction and further promoting NOx emission reduction in reburning technology.