半焦基固体热载体法神东煤热解产物分布的试验研究

Experimental study of flash pyrolysis product yield of Shendong long-flame coal with solid heat carrier

  • 摘要: 以自建的固体热载体煤热解实验平台为基础,以神东长焰煤为原料,神东长焰煤的热解半焦作为热载体,研究煤样分布器的转动机制(不同的混合效果)与煤的热解产物的分布及其变化规律,研究结果表明:反应器内部温度场的均匀性会显著影响热解产物产率,即针对无搅拌混合(搅拌0圈),转动搅拌桨后热解气体积明显增大,且析出速率明显加快;但是随着热解时间的进一步延长,最终的热解气体积基本一致;与此同时,搅拌桨转动圈数从1.5圈增大到10圈时,热解气体积略有增大,但增大幅度较小。在此基础上进一步将其与格金低温干馏实验数据进行比较,确定神东长焰煤粒径013 mm的固体热载体的热解时间为30 min,为千吨级的工业示范的反应器设计提供设计依据。

     

    Abstract: Flash pyrolysis of coal produces tar, char, and a range of low molecular weight gases in various proportions and amounts depending on the pyrolysis conditions (temperature, pressure, heating rate) and the coal being pyrolyzed.Experimental data were collected on a solid heat carrier coal pyrolysis experiment test platform which included a unique agitated reactor to improve both heat and mass transfer.The raw material was Shendong long-flame coal with its semi-coke being used as solid hear carrier.The yield variation of coal pyrolysis under different agitation conditions (different mixing effect from the coal sample distributor) was investigated.Resultsindicate that the uniformity of the temperature field during reaction strongly affects the yield of pyrolysis products.Pyrolysis gas generation rate significantly increases when agitator is turned on compared to the conditions without agitation.However, once approaching to the end of pyrolysis, the final volumes of pyrolysis gas product are basically the same under different conditions. The agitation speed also slightly accelerates the gas product generation rate, not significantly though.By comparing the agitated flash pyrolysis data with Gray-King's pyrolysis data for Shendong coal, it is found that the pyrolysis time using solid heat carrier is about 30 minutes for particles with a diameter range of 0-13 mm.All the data and findings in this study provide a design basis for an industrial demonstration kiloton reactor.

     

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