Simple pyrolysis experiments for the preliminary assessment of biomass feedstocks and low-cost tar cracking catalysts for downdraft gasification applications
Simple pyrolysis experiments for the preliminary assessment of biomass feedstocks and low-cost tar cracking catalysts for downdraft gasification applications
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DOI：
10.1016/j.biombioe.2017.10.048
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发表时间：
2018
影响因子：
6
通讯作者：
Matthew E Boot-Handford;E. Virmond;Nicholas H. Florin;R. Kandiyoti;P. Fennell
中科院分区：
文献类型：
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作者：
Matthew E Boot-Handford;E. Virmond;Nicholas H. Florin;R. Kandiyoti;P. Fennell
采用实验室规模的两级固定床反应器在773 K下研究了山毛榉木、巴西稻壳（BRH）和泰国稻壳（TRH）以及纺织废水处理残渣（TIR）的热解行为。随着灰分含量的增加，焦炭产率增加，挥发分产率下降。TRH释放的焦油比BRH少40%，这是由于泰国物种的钾含量高得多。TRH焦在空气中在773 K的燃烧反应性是相似的BW焦和几乎两倍的BRH和TIR焦的反应性。BW和TRH焦具有较大的大孔体积，表明焦燃烧主要通过大孔孔网络的生长和延伸发生。在1173 K时，煤焦与CO2的气化反应性呈现不同的变化趋势。结果表明，半焦中的Ca和Mg含量对半焦与CO2的气化反应具有更重要的催化作用。此外，还研究了高温（973-1173 K）和含煅烧石灰石或白云石的砂床对山毛榉热解挥发性产物的影响。焦油产量下降后，暴露于高温和煅烧石灰石或白云石。焦油裂解有利于CO的生成，在1173 K时CO产率为22 ~ 23wt%。煅烧白云石在裂解焦油方面比煅烧石灰石稍微更有效，在1173 K下消除了98重量%的焦油。
The pyrolysis behaviour of beech wood, two rice husk variants from Brazil (BRH) and Thailand (TRH) and a solid waste water treatment residue from textile manufacture (TIR) were investigated using a lab-scale, 2-stage fixed-bed reactor at 773 K. Char yields increased and volatile yields decreased with increasing ash content. The TRH released 40% less tar than the BRH which was attributed to the substantially higher potassium content of the Thai species. The combustion reactivity of the TRH char in air at 773 K was similar to the BW char and almost double the reactivity of the BRH and TIR chars. The BW and TRH chars had a greater volume of macropores indicating that char combustion occurs predominantly through the growth and extension of the macroporous pore network. A different trend was observed for the char gasification reactivity with CO2at 1173 K. The Ca and Mg content of the chars were found to have a more important catalytic role in the char gasification reactions with CO2.The effect of exposing volatile products from beech wood pyrolysis to elevated temperatures (973–1173 K) and sand beds containing calcined limestone or dolomite in a simulated downdraft gasification environment was also investigated. Tar yields decreased after exposure to elevated temperature and calcined limestone or dolomite. Tar cracking favoured the production of CO. CO yields were between 22 and 23 wt% at 1173 K. Calcined dolomite was slightly more effective at cracking tar than calcined limestone, eliminating 98 wt% of the tar at 1173 K.