Effect of sodium carboxylate on pyrolysis of Zhundong coal (H-form coal)

doi:10.11949/j.issn.0438-1157.20160847

Abstract

Abstract:

A Na⁺-exchanged coal (Na-form coal) containing sodium carboxylate, was prepared by ion exchange of an acid-washed Zhunong coal (H-form coal). A H-form-1 coal, prepared from the acid-washing of Na-form coal, was set as a blank. Pyrolysis of the two samples was performed in a fixed-bed reactor. The portable infrared gas analyzer, FTIR and thermogravimetric analyzer were employed to investigate the composition and yields of volatiles, the decomposed components, the variation of functional groups and the char reactivity. It shows that, in presence of sodium carboxylate the production rates of volatiles and release of CH₄, C₂H₄ and C₂H₆ were inhibited when temperature was above 600℃, while the production of CO was promoted at temperature above 800℃. Besides, the tar yield is remarkably inhibited at 700℃. The char reactivity was significantly improved due to sodium carboxylate especially at 700℃. The presence of sodium carboxylate in coal greatly affects the variation of functional groups during the pyrolysis.

Key words: Zhundong coal, ion exchange, pyrolysis, reaction, reactivity

摘要：

将酸洗后的准东煤（H-form coal）进行离子交换得到含羧酸钠的离子交换煤（Na-form coal），再次酸洗脱钠得到的二次酸洗煤（H-form-1 coal）作为对照试样，在固定床反应器上进行热解。借助便携式气体分析仪、热重分析仪和红外光谱仪研究总挥发分和焦油产率、热解气体组分、焦炭反应活性以及焦炭官能团的变化。研究表明：温度高于600℃时，羧酸钠会减小挥发分产率，抑制CH₄、C₂H₄、C₂H₆气体的产生，高于800℃时促进了CO的生成；羧酸钠抑制了焦油的生成且在700℃时抑制作用最为明显；羧酸钠显著提高了焦炭的反应活性，700℃时效果更为明显。羧酸钠的存在对热解过程中煤焦官能团有显著影响。

关键词: 准东煤, 离子交换, 热解, 反应, 活性

CLC Number:

TQ523.3

LIU Hui, ZHAO Deng, JIANG Leixiao, XU Lianfei, YAN Yonghong, WU Dongyang, GAO Jihui, WU Shaohua. Effect of sodium carboxylate on pyrolysis of Zhundong coal (H-form coal)[J]. CIESC Journal, 2016, 67(11): 4795-4801.

刘辉, 赵登, 姜雷霄, 许连飞, 闫永宏, 吴东阳, 高继慧, 吴少华. 羧酸钠对准东煤热解过程的影响[J]. 化工学报, 2016, 67(11): 4795-4801.

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