摘要
在全球能源危机和环境污染日益严重的背景下,如何高效、绿色提高煤炭的利用率已成为我国亟待解决的重要问题.通过在煤炭中添加金属氧化物,能够有效地提升燃烧速率,但这类催化剂与煤的接触面积过小,导致其利用率较低.本文研究了金属离子催化剂(主要组成为碱土金属和过渡金属,简称催化剂)在煤燃烧过程中的高效助燃机制.运用热重分析、热重-质谱联用、热重-红外联用及原位X射线光电子能谱分析等多种实验方法,探究了催化剂在煤燃烧过程中的化学成分变化、煤样热解机理以及催化剂对煤燃烧特性的影响.数据结果显示,加入催化剂后,各类煤的着火温度降低,最大失重速率和最大反应速率提高,煤样活化能下降,且CO和CH4等气体产量增加.研究表明该催化剂在煤的燃烧热解过程中发挥了显著的催化助燃作用:在脱气阶段,催化剂中的金属离子通过和煤结构中的极性基团发生配位作用,促进水分和挥发分的脱气,降低了煤燃烧的着火点;在燃烧过程中,金属离子促进了氧气的传递,降低了燃烧反应的能垒,显著提升了燃烧速率,从而促进了煤的氧化燃烧;在焦炭燃烧过程中,过渡金属催化了碳的缩聚反应,产生氢气,并促进了碳碳键的裂解,进一步增强了煤燃烧过程中的热值.本研究为提升煤炭燃烧效率提供了理论依据,优化催化剂使用可减少有害物质排放,助力改善空气质量和应对全球气候变化.
Against the backdrop of the global energy crisis and the increasingly severe environmental pollution,how to efficiently and greenly improve the utilization rate of coal has become an important issue that urgently needs to be addressed in China.Adding metal oxides to coal can effectively increase the combustion rate.However,the contact area between this type of catalyst and coal is too small,resulting in low utilization efficiency.This paper studies the efficient combustion-promoting mechanism of metal ion catalysts(mainly composed of alkaline earth metals and transition metals,hereinafter referred to as catalysts)during the coal combustion process.Multiple experimental methods such as thermogravimetric analysis,thermogravimetry-mass spectrometry,thermogravimetry-infrared spectrometry,and in-situ X-ray photoelectron spectroscopy are used to explore the changes in chemical composition of the catalyst during coal combustion,the pyrolysis mechanism of coal samples,and the influence of the catalyst on the combustion characteristics of coal.The data results show that after adding the catalyst,the ignition temperature of various types of coal decreases,the maximum weight loss rate and the maximum reaction rate increase,the activation energy of coal samples decreases,and the yields of gases such as CO and CH4 increase.The research shows that the catalyst plays a significant combustion-promoting role in the combustion and pyrolysis of coal:during the degassing stage,the metal ions in the catalyst coordinate with the polar groups in the coal structure,promoting the degassing of moisture and volatile matter and reducing the ignition point of coal combustion;during the combustion process,the metal ions promote the transfer of oxygen,reduce the energy barrier of the combustion reaction,and significantly increase the combustion rate,thus promoting the oxidative combustion of coal;during the coke combustion process,transition metals catalyze the polycondensation reaction of carbon,generate hydrogen,and promote the cleavage of carbon-carbon bonds,further enhancing the calorific value during the coal combustion process.This research provides a theoretical basis for improving the combustion efficiency of coal.Optimizing the use of catalysts can reduce the emission of harmful substances and contribute to improving air quality and addressing global climate change.
作者
陈苗
刘叠
袁培俊
陈阳
CHEN Miao;LIU Die;YUAN Peijun;CHEN Yang(Jiangxi Ying nan yuan Environmental Energy Co.,Ltd,Pingxiang,337000,China;Central South University,Changsha,410083,China)
出处
《环境化学》
北大核心
2025年第6期2254-2267,共14页
Environmental Chemistry
基金
国家自然科学基金(22476215)资助.
关键词
金属离子催化剂
煤燃烧
助燃机制
燃烧特性
Metal ion catalyst
coal combustion
combustion-promoting mechanism
combustion characteristics
