CO2/H2O对富氧燃烧条件下煤/煤焦表面结构及NO反应过程调控机理研究

This project studies on the co-effect of CO2/ H2O on the structural features of the coal/char particle during coal pyrolysis, combustion and NO formation ubder oxy-fuel combustion conditions. The distribution parameters of pores on the coal/char particle surface are measured by SEM, atmosphere adsorption/desorption and NMR. The physical structures of the coal/char particle are correspondingly analyzed and identified. The chemical functional-groups and skeletal carbon structures on the coal/char surface are analyzed by FT-IR/Raman, as well as XPS and XRD under the different stages of coal pyrolysis and combustion process. The chemical structures of the coal/char particle are further quantitatively/semi-quantitatively evaluated and the coal/char particle structural features at the different stages of oxy-fuel combustion can be revealed. Meanwhile, detailed studies on the reaction kinetics of coal/char combustion and NO reactions during oxy-fuel combustion are performed in this project. The co-effect of CO2/H2O and their gasifications on the coal/char structural features, combustion characteristics and NO formation in oxy-fuel combustion process with different controlled conditions can be deeply revealed. Finally, the correlation mechanism models among the coal/char structural features, combustion characteristics and NO formation in oxy-fuel combustion would be set up. The accomplishment of this project will provide the fundamental understanding of the mechanism of coal combustion and NO formation in oxy-fuel combustion.

本课题针对CO2/H2O共同作用对富氧燃烧条件下典型煤种在热解、燃烧及NO反应过程中煤/煤焦表面物理化学结构的影响规律，利用扫描电镜、气体吸附/脱附、核磁共振等方法精确测定煤/煤焦孔隙分布等结构特征参数，实现煤/煤焦颗粒表面物理结构的定量表征；同时采用FT-IR/Raman结合XPS、XRD等先进测量手段测定不同热解、燃烧阶段煤/煤焦表面化学官能团及碳骨骼结构特征，实现煤/煤焦颗粒表面化学结构半定量/定量描述；深刻揭示富氧燃烧条件下不同反应阶段煤/煤焦表面物理化学结构瞬态分布特征。通过对富氧燃烧条件下煤/煤焦及NO反应动力学的系统研究及相关分析，获得CO2/H2O及其气化反应在不同控制条件下对富氧燃烧过程中煤/煤焦表面物理化学结构、燃烧特性及NO反应特性的调控机理；进而建立煤/煤焦表面物理化学结构参数与燃烧特性及NO反应特性的关联模型，有效阐释富氧燃烧条件下煤粉燃烧及NO反应过程本质机理。

本项目针对CO2/H2O对富氧燃烧条件下煤/煤焦表面物理化学结构、反应性以及NO生成特性调控机理这一基础科学问题，利用扫描电镜、气体吸附/脱附等方法精确测定了煤/煤焦孔隙分布等结构特征参数，实现了煤/煤焦颗粒表面物理结构的定量表征；同时采用Raman、FT-IR、XPS等测量手段测定了不同热解、燃烧阶段煤/煤焦表面化学官能团及碳骨骼结构特征，实现了煤/煤焦颗粒表面化学结构半定量描述；深刻揭示了富氧燃烧条件下不同反应阶段煤/煤焦表面结构瞬态分布特征。通过对富氧燃烧条件下煤/煤焦及NO反应动力学的系统研究及相关分析，获得了CO2/H2O及其气化反应对富氧燃烧过程中煤/煤焦表面物理化学结构、燃烧特性及NO生成特性的调控机理；通过系统研究表征煤/煤焦表面结构的拉曼光谱特征参数，最终建立了不同燃烧条件下煤/煤焦表面结构特征参数与燃烧特性的关联模型，有效阐释了富氧燃烧条件下煤粉燃烧及NO反应过程本质机理。