胜利褐煤温和气化焦油催化重整研究
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摘要
本研究采用两段式石英流化床反应器进行褐煤气化实验，采用四种不同方法制得的半焦催化剂（未活化半焦、水蒸气活化半焦、氨水活化半焦、氨气活化半焦），将气化产生的焦油在半焦催化剂的作用下进行原位重整，并采用冷态溶剂吸收的方式收集未能发生重整的焦油组分。并通过色谱-质谱联用仪检测焦油成分及相对含量、通过气相色谱检测气体成分及相对含量。在与气化实验相同的条件下，进行了褐煤热解实验研究水蒸气对焦油的重整作用，研究了温度、升温速率、催化剂及气氛对焦油和气体的产率、组成的影响。同时通过多种方法对使用前后的半焦催化剂进行了表征，研究并提出半焦催化重整焦油的作用机理。结果表明，半焦催化剂对焦油的重整具有显著的促进作用。在使用氨气活化半焦催化剂时，胜利褐煤900℃气化的焦油产率为0.45%，用GC-MS测试焦油组分仅测出微量的菲，无其它组分测出。与相同条件下不使用催化剂的情况相比，焦油产率下降了88.72%，气体产率增加了5.16%，气体中的有效气体含量从82.90%增加到83.83%。
Coal chars were employed to catalyze the in-situ tar reforming reactions during the pyrolysisand gasification of Shengli brown coal in a two-stage quartz reactor at different temperatures. Fourdifferent chars (inactivated char, steam activated char, ammonia water activated char and ammoniagas activated char) as catalysts were prepared. The tar derived from the gasification of Shenglibrown coal under different conditions was collected by cold solvent. In order to clarify the role ofsteam playing in the tar reduction with and without catalysts, pyrolysis at the same conditionswere always carried out for the purpose of comparison. The effect of temperature, heating rate,steam and catalysts on the yield and composition of tar and gas product were investigated under awide range of experimental conditions. Wherein, the compositions of coal tar were characterizedby GC-MS and the composition of gas were tested by GC. Several kinds of techniques were usedto characterize the char catalysts before and after use to provide the mechanism of tar reformingby char catalyst. It was found that char catalysts showed obvious effect on the tar derived from thepyrolysis/gasification of Shengli brown coal. Ammonia gas activated char showed the mostobvious effect on the reforming of gasification coal tar, and a yield decrease of88.72%in thegasification under900℃was achieved comparing with the same condition that no catalyst wasutilized. No compound was detected except trace phenanthrene. The gas product yield wasincreased by5.16%and the content of H2+CO grew from82.90%to83.83%.
Coal chars were employed to catalyze the in-situ tar reforming reactions during the pyrolysisand gasification of Shengli brown coal in a two-stage quartz reactor at different temperatures. Fourdifferent chars (inactivated char, steam activated char, ammonia water activated char and ammoniagas activated char) as catalysts were prepared. The tar derived from the gasification of Shenglibrown coal under different conditions was collected by cold solvent. In order to clarify the role ofsteam playing in the tar reduction with and without catalysts, pyrolysis at the same conditionswere always carried out for the purpose of comparison. The effect of temperature, heating rate,steam and catalysts on the yield and composition of tar and gas product were investigated under awide range of experimental conditions. Wherein, the compositions of coal tar were characterizedby GC-MS and the composition of gas were tested by GC. Several kinds of techniques were usedto characterize the char catalysts before and after use to provide the mechanism of tar reformingby char catalyst. It was found that char catalysts showed obvious effect on the tar derived from thepyrolysis/gasification of Shengli brown coal. Ammonia gas activated char showed the mostobvious effect on the reforming of gasification coal tar, and a yield decrease of88.72%in thegasification under900℃was achieved comparing with the same condition that no catalyst wasutilized. No compound was detected except trace phenanthrene. The gas product yield wasincreased by5.16%and the content of H2+CO grew from82.90%to83.83%.
引文
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