Effects of temperature gradient and product flow on distribution of pyrolysis products of Xianfeng lignite

doi:10.11949/j.issn.0438-1157.20171345

Abstract

Abstract:

The processes of coal pyrolysis and secondary reactions were separated by using two-stage fixed bed reactor to simulate the product flow and the interactions among reaction particles for coal pyrolysis in the traditional indirect heating reactor and indirect heating reactor with internals, and to investigate the effects of different temperature char on the distribution and quality of pyrolysis products of Xianfeng lignite. The results showed that the drastic secondary reactions occurred when tar flowed through the 500-900℃ char layer, the yield of pyrolysis gas increased, the tar yield and atomic H/C ratio were lower than those of blank control experiment, and the quality of oil decreased. Under the action of 100-400℃ char layer, the slight secondary reaction of the tar occurred, the yield of pyrolysis gas increased slightly, the tar yield had a little decrease, the atomic H/C ratio was higher than that of blank control, and the oil quality increased. The results verified the conclusion that the tar with indirect heating reactor with internals produced higher yield and better quality.

Key words: coal pyrolysis, temperature, char, secondary reactions

摘要：

通过两段固定床反应器分离了煤热解和二次反应过程，模拟了传统外热式固定床反应器和外热式内构件固定床反应器内挥发性热解产物流动与固相反应颗粒间的相互作用，研究了不同温度的半焦对先锋褐煤热解产物分布和品质的影响。结果表明：当半焦的温度在500～900℃时，焦油发生剧烈的二次反应，热解气收率增加，焦油收率大幅下降，H/C同时大量降低且均低于空白样，油品质下降；在100～400℃半焦作用下，焦油发生轻微的二次反应，热解气收率略微增加，焦油收率缓慢下降，但H/C均高于空白样，油品质提升。该结果验证内构件外热式固定床反应器热解产生的焦油具有更高的收率及品质。

关键词: 煤热解, 温度, 半焦, 二次反应

CLC Number:

TQ530.2

ZHOU Guojiang, LIU Zhutao, ZHAN Jinhui, LAI Dengguo, LIU Xiaoxing. Effects of temperature gradient and product flow on distribution of pyrolysis products of Xianfeng lignite[J]. CIESC Journal, 2018, 69(6): 2672-2680.

周国江, 刘竹涛, 战金辉, 赖登国, 刘晓星. 温度梯度与产物流动对先锋褐煤热解产物分布的影响[J]. 化工学报, 2018, 69(6): 2672-2680.

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