矿物质对高碱煤显微组分热解特性的影响

doi:10.16085/j.issn.1000-6613.2018-2465

摘要/Abstract

摘要：

利用固定床热解炉和热重分析仪研究了沙尔湖煤显微组分的热解特性和产物产率，考察了酸洗处理对热解产物和动力学参数的影响。结果表明：经浮沉实验发现镜质组富集于S2（密度为1.4～1.5g/cm³浮选煤样）中，惰质组富集于S3（密度为>1.5g/cm³浮选煤样）中，其中S3所含硅铝酸盐类矿物显著高于S2。且碱及碱土金属（alkali and alkaline earth metals, AAEM）多以可溶性形式存在，经酸洗处理后剩余矿物质主要为石英、高岭土及硅酸盐类。在选用不同煤样进行热解特性分析发现，碱及碱土金属的存在会抑制热解主反应阶段的挥发分释放，而在二次脱气阶段，AAEM矿物质则会提高挥发分的释放速率。且在热解实验中发现，AAEM在热解中会充当煤大分子结构的交联点，降低热解焦油产率。对比不同显微组分发现，惰质组热稳定性更强，镜质组中烷烃侧链较多，芳香度较小，更易受热断裂。采用Doyle积分法确定了沙尔湖煤热解反应的动力学参数。

关键词: 沙尔湖煤, 酸洗, 热解, 傅里叶红外光谱, 动力学参数

Abstract:

The fixed bed furnace and thermogravimetric analyzer were used to investigate the pyrolysis characteristics and products distribution of maceral in Shaerhu coal. Furthermore, the influence of acid washing treatment on pyrolysis products and kinetics of Shaerhu coal was also discussed. The vitrinite was enriched in S2 (the densities ranging from 1.4—1.5g/cm³) and the inertinite was enriched in S3 (the densities ranging from >1.5g/cm³) with the floatation experiments. The content of silicate minerals in S3 was more than that in S2. And AAEM (alkali and alkaline earth metals) was existed in soluble form. The results showed that the acid washing of coal could remove most of the minerals, and the residual minerals were mainly quartz, kaolinite and silicate. The release rate of volatiles during the pyrolysis stage was inhibited, while during the secondary degassing stage it was raised in the presence of alkali and alkaline earth metals (AAEM). The release rate of volatiles during the main pyrolysis stage and final weight loss reduced. In this case, the decreasing yield of tar lied in the fact that AAEM was regarded as the cross-linking point for coal macromolecules in pyrolysis. Compared with different macerals, the thermal stability of inertinite group was stronger. The vitrinite group had more alkane side chains, less aromaticity and more susceptible to thermal fracture. The kinetic parameters of coal pyrolysis were obtained by the processing method with Doyle integration.

Key words: Shaerhu coal, acid-washing, pyrolysis, Fourier transform infrared spectroscopy, kinetic

中图分类号:

TQ530.2

李首毅,林雄超,鲁倍倍,王永刚,张登跃,周云辉. 矿物质对高碱煤显微组分热解特性的影响[J]. 化工进展, 2019, 38(08): 3650-3657.

Shouyi LI,Xiongchao LIN,Beibei LU,Yonggang WANG,Dengyue ZHANG,Yunhui ZHOU. Effects of minerals on pyrolysis characteristics of maceralin high-alkali coal[J]. Chemical Industry and Engineering Progress, 2019, 38(08): 3650-3657.

图/表 13

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样品	工业分析/%				元素分析/%
样品	M_ar	V_d	A_d	FC_d	C_daf	H_daf	N_daf	S_td,daf	O_daf
S2	5.35	37.25	6.16	56.59	73.72	5.28	1.01	0.26	19.73
S3	4.64	26.12	22.84	51.04	74.16	4.96	1.09	0.25	19.54
S2-S	3.64	39.79	2.39	57.82	73.02	4.19	0.84	0.21	21.74
S3-S	3.69	30.25	11.11	58.64	76.84	3.29	0.85	0.20	18.82

样品	工业分析/%				元素分析/%
样品	M_ar	V_d	A_d	FC_d	C_daf	H_daf	N_daf	S_td,daf	O_daf
S2	5.35	37.25	6.16	56.59	73.72	5.28	1.01	0.26	19.73
S3	4.64	26.12	22.84	51.04	74.16	4.96	1.09	0.25	19.54
S2-S	3.64	39.79	2.39	57.82	73.02	4.19	0.84	0.21	21.74
S3-S	3.69	30.25	11.11	58.64	76.84	3.29	0.85	0.20	18.82

样品	S2质量分数/%	S3质量分数/%
镜质组（去矿物质基）	60.85	37.26
惰质组（去矿物质基）	39.15	62.74

样品	S2质量分数/%	S3质量分数/%
镜质组（去矿物质基）	60.85	37.26
惰质组（去矿物质基）	39.15	62.74

样品	SiO₂	Al₂O₃	Fe₂O₃	CaO	K₂O	Na₂O	MgO	SO₃	TiO₂	MnO
S2	18.89	14.94	10.32	40.49	0.01	0.92	6.83	4.09	1.57	0.15
S3	40.14	19.75	12.84	20.11	0.28	1.78	1.89	0.96	1.24	0.28