麦秆热解过程中氮迁移特性的试验研究

在氩气气氛下，利用热重-傅里叶红外光谱联用技术研究麦秆热解过程中含氮气体NH3、HCN、NO及HNCO等的析出及分布特性。揭示生物质挥发分中含氮化合物的主要存在形态和转化率。结果表明：热解条件影响生物质燃料氮的析出分布。升温速率提高，NH3及HCN的析出总量减少，但NO及HNCO的析出总量呈增加趋势；麦秆粒径增加，热解产生的含氮气体的析出量减小。NH3所占份额增加明显，HCN/NH3质量比减小。粒径越小，HNCO及NO在含氮气体中所占份额越大；热解终温升高，NH3及HCN的析出量增加，HNCO及NO的析出量减小。低温热解，残留在焦中的氮含量较高。

Experimental Research on Formation Behavior of Fuel-nitrogen During Wheat Straw Pyrolysis

The release behavior of nitrogen-containing gases such as NH3, HCN, NO and HNCO during wheat straw pyrolysis were examined with a thermogravimetric analyzer(TGA) coupled with a Fourier transform infrared (FTIR) spectrometer in argon atmosphere. Distribution and selectivity of nitrogen compounds from biomass volatile matters were revealed. The results show that experimental conditions have great effects on the distribution of fuel-nitrogen during pyrolysis. Heating rate increases, the yields of NH3 and HCN decrease, while which of HNCO and NO increase. Increase in particle size leads to less release of nitrogen-containing gases. Meanwhile, the share of NH3 in nitrogen-containing gases increases obviously, and the HCN/NH3 mass ratio decreases. Decrease in particle size leads to bigger share of HNCO and NO. The yields of NH3 and HCN increase with the final pyrolysis temperature, nevertheless which of HNCO and NO decrease. At lower temperature, the share of the nitrogen residual in the char is higher.