CO_2气氛下煤/生物质混合热解过程氮转化特性实验

Experimental study on transformation characteristics of nitrogen during coal/biomass co-pyrolysis in CO_2 atmosphere

本文在卧式管式炉实验装置上进行了平凉煤、麦秆及其混合物料分别在CO_2和Ar气氛下700～900℃范围内的热解特性实验研究,获得CO_2气氛对热解过程氮元素迁移的影响以及煤/生物质混合热解过程中氮元素转化特性。实验发现:在高温时,CO_2气氛可使燃料发生气化反应,促进燃料中的氮元素析出进入挥发分中,降低半焦氮含量,并提高2种燃料的NH3及N2产率和麦秆的HCN产率;煤/生物质混合热解过程发生了协同作用,降低了HCN和NH3的产率,并提高了N2在700℃的产率。

Pyrolysis experiments o f Pingliang coal, wheat straw and their blends were carried out in a tube furnace in CO2 and A r atmosphere at 700-900°C , to investigate the nitrogen transformation characteristics during coal-biomass co-pyrolysis in CO2 atmosphere. The results show that, at high temperatures, gasification occurs in CO2 atmosphere, which promotes the nitrogen release from the fuel and enter the volatile matters, which reduces the nitrogen content in char, so the NH3 and N2 yield o f Pingliang coal and wheat straw as well as the HCN yield o f wheat straw rises. Interactions which occur in co-pyrolysis suppress the HCN and NH3 yield but promote production o f N2 at 700 °C .