煤气化细渣及其分离后富碳组分的气化反应性

Gasification reactivity of coal gasification fine slag and its separatedcarbon-rich residues

随着气流床煤气化技术在我国煤化工产业的广泛应用,煤气化后生成的气化细渣排放量逐年增加,目前气化细渣的资源化利用已成为煤化工固废治理的难题之一。选取不同碳含量的气化细渣及其分离后富碳组分为研究对象,解析了其组成、孔隙结构和微观形貌等结构参数,基于热重分析仪探究了其在CO_(2)气氛下的气化反应性,并采用等转化率法分析了气化反应动力学,揭示了煤气化细渣及其富碳组分结构特性与其气化反应性的内在关联。结果表明:孔隙结构是影响气化细渣及其富碳组分气化反应性的关键因素,孔结构发达的样品具有更高的气化反应性。随气化过程升温速率升高,气化细渣及其富碳组分的气化反应区间均向高温偏移。此外,具有相对较高固定碳含量的气化细渣、富碳组分气化反应活化能随转化率升高而降低,而样品本身高灰分气化细渣、富碳组分的气化反应活化能随转化率的增大而升高。研究结果为气化细渣及其分离后富碳组分的资源化利用提供理论指导。

With the widely application of entrained-flow coal gasification technology in China′s coal chemical industry,the production of coal gasification fine slag is increasing year by year.At present,the resource utilization of gasification fine slag has become one of the difficult problems in the treatment of solid waste in coal chemical industry.In this paper,gasification fine slag with different carbon contents and its separated carbon-rich residues were selected as the research objects.The structural parameters such as composition,pore structure and microstructure were analyzed.The gasification reactivity of coal gasification fine slag under CO 2 atmosphere was investigated based on thermogravimetric analyzer.The gasification reaction kinetics was analyzed by iso-conversional method,and the internal relationship between the structural characteristics of coal gasification fine slags and its carbon-rich residues and their gasification reactivity was revealed.The results show that the pore structure is the key factor affecting the gasification reactivity of gasification fine slag and its separated carbon-rich residues,and the samples with developed pore structure have higher gasification reactivity.With the increase of heating rate in gasification process,the gasification reaction range of gasification fine slag and its carbon-rich residues shiftes to high temperature.In addition,the gasification reaction activation energy of gasification fine slag and carbon-rich residues with relatively high fixed carbon content decreases with the increase of conversion rate,while the gasification reaction activation energy of gasification fine slag and carbon-rich residues with high ash content of the sample itself increases with the increase of conversion rate.The research results provide theoretical guidance for the resource utilization of gasification fine slag and its separated carbon-rich residues.