煤粉机械力化学改性及O2/CO2燃烧的基础研究

The fragmenting process of superfine pulverized coal is not only a simple mechanical and physical process but also a complicated physical chemistry process. Mechanochemistry modification of pulverized coal will occur in the presence of severe mechanical force. Due to the mechanochemistry modification, better fluidity and reactivity, lower contamination emission characteristic, higher burnout rate and better combustion process will be obtained. A combination of mechanochemistry modification and conventional pulverized coal O2/CO2 combustion possesses many advantages, for instance, increasing the CO2 concentration in the flue gas, reducing the separation and capture cost, improving the combustion characteristic, reducing the contamination emissions, improving the burnout rate and raising the desulfurization efficiency. This novel combustion technology makes up for the deficiency of conventional O2/CO2 combustion. Test research and theoretical analysis will be carried out to systematically investigate the mechanochemistry modification and O2/CO2 combustion process. The object of this work is (i) to analyzes the surface chemistry and micro structure of superfine pulverized coal to evaluate the change regularity and mechanism (ii) to delve into the NOx formation and removal mechanism from the heterogeneous reaction point of view, which is aided by the foregoing change regularity and mechanism (iii) to get the combustion characteristics and regularities of mechanochemistry modification coal O2/CO2 combustion. On this basis, a integral combustion theory and technology system on mechanochemistry modification coal O2/CO2 combustion can be established.

煤粉超细化过程不只是简单的机械物理过程，而是一种复杂的物理化学过程。在剧烈的机械力作用下，煤粉会发生机械力化学改性，使煤粉在燃烧过程中具有更好的反应性、流动性、低污染排放性和更高的燃尽性，燃烧过程得以完善。将煤粉的机械力化学改性应用于常规煤粉O2/ CO2燃烧过程，不仅能提高烟气中CO2浓度减少分离和捕集成本，同时具有良好的燃烧特性、低NOx排放特性和高的燃烧与脱硫效率，从而克服常规煤粉O2/ CO2燃烧技术存在的不足。本课题采用试验研究与理论分析相结合的研究方法，对煤粉机械力化学改性及O2/ CO2燃烧过程进行深入系统的研究。旨在揭示改性煤粉表面化学与微观结构的变化规律与机理；揭示基于机械力化学改性煤粉颗粒表面化学与微观结构的NOx生成与脱除异相反应分子机理；获得机械力化学改性煤粉O2/CO2燃烧特性与规律。在此基础上建立机械力化学改性煤粉O2/CO2燃烧理论与技术体系。

煤的燃烧是一个非常复杂的物理化学过程，它首先是从煤表面开始的并通过表面不断深入煤颗粒内部。煤的表面物理和化学特性对煤的燃烧具有很大的影响，因此对其进行系统的研究具有十分重要的意义。本项目通过采用现代分析仪器和自建试验台架对煤粉在O2/CO2气氛中燃烧过程及煤粉和煤焦表面化学与微观结构进行深入系统的研究，揭示了煤粉表面化学与微观结构及其对燃烧过程影响的机理与机制，并将试验结果与量子化学模拟相结合对化学反应机理进行计算和分析，揭示了基于煤粉表面化学与微观结构的氮氧化物生成与脱除的异相分子机理，为完善煤粉在O2/CO2气氛中燃烧理论提供资料和参考。本项研究对于推动煤粉燃烧过程的详细机理的研究意义重大，能极大的深化和丰富煤粉在O2/CO2气氛中燃烧这一新兴的CO2减排技术的理论体系。