半焦制备条件对其还原NO反应性的影响

Effect of preparation conditions on gasification reactivity of char with NO

在石英固定床反应器上研究了龙口褐煤半焦制备条件与其还原NO反应性的关系 .研究结果表明 ,制备半焦的温度越高、停留时间越长 ,半焦的反应性越低 ;制备时升温速率对龙口煤半焦反应性的影响不大 ;预氧化增大了半焦的比表面积并在半焦的表面上形成新的活性位而促进半焦还原NO ;酸洗脱除矿物质使半焦的反应性显著降低 。

Coal chars were prepared at various conditions including pyrolysis temperatures, heating rates, residence time, pre oxidation and acid washing. The gasification activities of the resulting chars with NO were determined in a quartz fixed bed reactor at atmospheric pressure. The results showed that the higher the pyrolysis temperatures, the lower the reactivities of the chars. The reactivities of the chars decreased with increasing soaking time. The effect of heating rates was negligible on this coal chars due to the non thermoplastic property of the coal. Pre oxidation significantly improved the activity of char while acid washing remarkably decreased the activity of char, which implied the catalytic effect of mineral matter in the coal on NO char reaction.