气煤活性组分对高硫煤热解硫分的调控作用研究

Effect of gas coal active components on sulfur regulation during high sulfur coal pyrolysis

在热转化过程中对硫分变迁行为进行定向调控从而改变硫分在热解产物中的分布,将是解决高硫煤配煤炼焦所面临难题的有效途径。通过对气固相的分析探讨从而研究气煤活性组分对硫分的调控机制,以期为气煤(QM)和高硫煤配煤炼焦提供理论基础。根据国标方法将气煤进行浮沉实验,得到4个分选组分QM-D1(<1.30 g/cm^(3))、QM-D2(1.30 g/cm^(3)~1.35 g/cm^(3))、QM-D3(1.35 g/cm^(3)~1.40 g/cm^(3))、QM-D4(1.40 g/cm^(3)~1.50 g/cm^(3)),对其煤质特性、煤岩组成以及在高硫煤配煤热解过程中硫分的调控行为进行研究,并与原煤进行对比分析。结果表明:气煤不同分选组分的煤质特性存在显著差异,随着密度的增加,煤样的芳构化程度增加,烷烃类气体的释放温度向高温区移动;脂肪结构丰富的活性组分主要富集在低密度组分(QM-D1)中,惰性组分集中在高密度组分(QM-D4)中;在煤共热解过程中用QM-D1代替QM时可降低焦中硫含量,究其原因是煤中活性组分产生的氢自由基会稳定硫自由基并形成气体释放。

In the thermal conversion process,it’s an effective way to solve the problem faced during coal blending coking of high-sulfur coal by the directional regulation of sulfur transformation behavior to change the sulfur distribution in pyrolysis products.Through the analysis of the gas and solid phase,the regulation mechanism of the active components in gas coal on sulfur was studied.It is expected to provide a theoretical basis for the coal blending coking of gas coal and high sulfur coal.According to the national standard method,the gas coal(QM)was subjected to the flotation experiment,and four fractions,QM-D1(<1.30 g/cm^(3)),QM-D2(1.30 g/cm^(3)~1.35 g/cm^(3)),QM-D3(1.35 g/cm^(3)~1.40 g/cm^(3))and QM-D4(1.40 g/cm^(3)~1.50 g/cm^(3))were obtained.The coal quality characteristics,petrographic constituent of both raw coal and different fractions were studied.Their effect on the sulfur regulation during the blending coking of high-sulfur coal was investigated as well.Compared with the raw gas coal,the characteristics of different active fractions derived from gas coal are significantly different.As the density increases,the degree of aromatization of coal samples increases and the release temperature of alkanes tends to move to higher temperature zones.The active components with abundant aliphatic structures are mainly enriched in the low-density fraction(QM-D1),the inert components are concentrated in the high-density fraction(QM-D4).In the process of coal co-pyrolysis,the sulfur content in coke can be reduced when QM-D1 is used to replace QM.The reason is that the hydrogen radicals produced by the active components in gas coal will stabilize the sulfur radicals and form gas to release.