基于赤铁矿的生物质化学链燃烧过程中氮氧化物的释放特性

在单批次进料固定床上,基于赤铁矿载氧体,研究了还原反应阶段反应温度和水蒸气量对谷壳的氮氧化物释放特性的影响。研究表明,碳转化率随反应温度升高而增加,但随水蒸气量呈先增加后下降,并在水蒸气量为1.0 g/min时达到最大值。在实验条件下,还原阶段未检测到NO₂。随着反应温度由750 ℃升高到900 ℃,NO的生成率增加,而N₂O的生成率先增加后降低,在850 ℃时达到最大值。水蒸气量由0.5 g/min升高到2.0 g/min,N₂O和NO的生成率均增加,且NO增加速率高于N₂O。在反应后的载氧体中,检测到KAlSi₃O₈存在,表明载氧体与生物质中的K元素发生反应。

NOx release in chemical looping combustion of biomass based on hematite

Nitrogen emission during chemical looping combustion (CLC) of rice husk based on hematite in a batch fixed bed reactor was studied. Different variables affecting the process, such as reduction temperature and steam content, were tested. The results show that higher reduction temperature results in a higher carbon conversion which reaches the highest value when the steam flow is 1.0 g/min. Furthermore, there are no NO₂ detected at all experiments. The rise of reduction temperature from 750 to 900 ℃ could contribute to the rise of NO, whereas the concentration of N₂O reaches the highest value at 850 ℃. Both N₂O and NO increase remarkably with the increase of steam flow. Nevertheless, the increasing rate of NO is faster than that of N₂O. Besides, KAlSi₃O₈ is detectable in the reduced oxygen carrier, attributing to the reaction of K in biomass with hematite.